Selenium (Se), a nutritionally essential trace element with known antioxidant potential, protects the brain from oxidative damage in various models of neurodegeneration. Intracerebroventricular-streptozotocin (ICV-STZ) in rats causes impairment of brain glucose and energy metabolism along with oxida
tive damage and cholinergic dysfunction, and provides a relevant model for sporadic dementia of Alzheimer's type (SDAT). The present study demonstrates the therapeutic efficacy of Se on cognitive deficits and oxidative damage in ICV-STZ in rats. Male Wistar rats were pre-treated with sodium selenite, a salt of Se (0.1 mg/kg; body weight) for 7 days and then were injected bilaterally with ICV-STZ (3 mg/kg), while sham rats received the same volume of vehicle. After two ICV-STZ infusions, rats were tested for memory deficits in passive avoidance and Morris water maze (MWM) tests and then were sacrificed for biochemical and histopathological assays. ICV-STZ-infused rats showed significant loss in learning and memory ability, which were significantly improved by Se supplementation. A significant increase in thio-barbituric acid reactive species (TBARS), protein carbonyl (PC) and a significant decrease in reduced glutathione (GSH), antioxidant enzymes (glutathione peroxidase [GPx] and glutathione reductase [GR]) and adenosine triphosphate (ATP) in the hippocampus and cerebral cortex and choline acetyltransferase (ChAT) in hippocampus were observed in ICV-STZ rats. Se supplementation significantly ameliorated all alterations induced by ICV-STZ in rats. Our study reveals that Se, as a powerful antioxidant, prevents cognitive deficits, oxidative damage and morphological changes in the ICV-STZ rats. Thus, it may have a therapeutic value for the treatment of SDAT.
The pneumococcal conjugate vaccine (CV), although highly immunogenic in infants and young children, does not consistently demonstrate an advantage over the pneumococcal polysaccharide vaccine (PPV) in older adults. To further elucidate the adult immune response to CV, we compared its response to PPV
on a molecular level using a severe combined immunodeficient (SCID) mouse model. This model allowed us to analyze a single individual's response to two different forms of antigen and define differences in gene usage elicited by these vaccines. We reconstituted SCID mice with human lymphocytes derived from an unimmunized donor; the mice were divided into two groups and immunized with either the PPV or CV. Our results demonstrate significant differences in variable gene usage in SCID mice immunized with PPV versus CV and suggest that the nature of the immunizing agent has a significant impact on gene usage and therefore influences antibody function and vaccine efficacy.
Shriner D, etal., BMC Med Genet. 2015 Nov 5;16:103. doi: 10.1186/s12881-015-0249-z.
BACKGROUND: Hyperuricemia and associated cardio-metabolic disorders are more prevalent in African Americans than in European Americans. We used genome-wide admixture mapping and association testing to identify loci with ancestry effects on serum uric acid levels. METHODS: We analyzed 1,976 African
Americans from Washington, D.C, including 1,322 individuals from 328 pedigrees and 654 unrelated individuals, enrolled in the Howard University Family Study. We performed admixture mapping and genome-wide association testing using ~800 k autosomal single-nucleotide polymorphisms (SNPs). We performed fine mapping by dense genotyping. We assessed functionality by a combination of bioinformatic annotation, reporter gene assays, and gel shift experiments. We also analyzed 12,641 individuals enrolled in the National Health and Nutrition Examination Survey. RESULTS: We detected a genome-wide significant locus on chromosome 11p15.4 at which serum uric acid levels increased with increasing African ancestry, independent of kidney function. Fine-mapping identified two independent signals in the beta-globin locus. The ancestral allele at SNP rs2855126, located upstream of the hemoglobin, gamma A gene HBG1, was associated with increased serum uric acid levels and higher expression of a reporter gene relative to the derived allele. Hyperuricemia was associated with increased risk of hypertension in 3,767 African Americans (Odds Ratio = 2.48, p = 2.71 x 10(-19)). CONCLUSIONS: Given that increased expression of gamma-globin leads to increased levels of fetal hemoglobin which confers protection against malaria, we hypothesize that evolution in Africa of protection against malaria may have occurred at the cost of increased serum uric acid levels, contributing to the high rates of hyperuricemia and associated cardio-metabolic disorders observed in African Americans.
We describe two unreported types of congenital disorders of glycosylation (CDG) which are caused by mutations in different isoforms of the catalytic subunit of the oligosaccharyltransferase (OST). Each isoform is encoded by a different gene (STT3A or STT3B), resides in a different OST complex and ha
s distinct donor and acceptor substrate specificities with partially overlapping functions in N-glycosylation. The two cases from unrelated consanguineous families both show neurologic abnormalities, hypotonia, intellectual disability, failure to thrive and feeding problems. A homozygous mutation (c.1877T > C) in STT3A causes a p.Val626Ala change and a homozygous intronic mutation (c.1539 + 20G > T) in STT3B causes the other disorder. Both mutations impair glycosylation of a GFP biomarker and are rescued with the corresponding cDNA. Glycosylation of STT3A- and STT3B-specific acceptors is decreased in fibroblasts carrying the corresponding mutated gene and expression of the STT3A (p.Val626Ala) allele in STT3A-deficient HeLa cells does not rescue glycosylation. No additional cases were found in our collection or in reviewing various databases. The STT3A mutation significantly impairs glycosylation of the biomarker transferrin, but the STT3B mutation only slightly affects its glycosylation. Additional cases of STT3B-CDG may be missed by transferrin analysis and will require exome or genome sequencing.
Shridhar V, etal., Oncogene. 1996 May 2;12(9):1931-9.
We have identified a gene, called ARP for Arginine-rich protein, in human chromosomal band 3p21. It is approximately 600 Kb telomeric to the ACY1 locus (Miller et al., 1989) and encodes a previously unidentified 234 amino acid long, highly basic protein. This gene is highly conserved at the DNA and
RNA level. It is found in all species including hamster, rat, mouse, bovine and yeast. We have detected a point mutation (ATG50 to AGG) or deletion of ATG50 in 10 of 21 sporadic renal cell carcinomas. The mutable region is in an imperfect trinucleotide repeat in the coding region which is non-polymorphic among 50 normal individuals examined. The point mutation (ATG50 to AGG) or deletion of codon 50 removes a methionine and increases the stretch of arginines encoded by the AGG repeats in the ARP gene.
Shrestha A, etal., J Cell Physiol. 2016 Feb;231(2):357-69. doi: 10.1002/jcp.25080.
Adiponectin predominantly secreted from adipose tissue has exhibited potent anti-proliferative properties in cancer cells via modulating cell cycle and apoptosis. FoxO3A, a Forkhead box O member of the transcription factor, plays a critical role in modulating expression of genes involved in cell dea
th and/or survival. In this study, we investigated the role of FoxO3A signaling in anti-cancer activities of adiponectin. Herein, we have shown that treatment with globular adiponectin (gAcrp) increases p27 but decreases cyclinD1 expression in human hepatoma (HepG2) and breast (MCF-7) cancer cells. Gene ablation of FoxO3A prevented gAcrp-induced increase in p27 and decreased in cyclin D1 expression, and further ameliorated cell cycle arrest by gAcrp, indicating a critical role of FoxO3A in gAcrp-induced cell cycle arrest of cancer cells. Moreover, treatment with gAcrp also induced caspase-3/7 activation and increased Fas ligand (FasL) expression in both HepG2 and MCF-7 cells. Transfection with FoxO3A siRNA inhibited gAcrp-induced caspase-3/7 activation and FasL expression, suggesting that FoxO3A signaling also plays an important role in gAcrp-induced apoptosis of cancer cells. We also found that gene silencing of AMPK prevented gAcrp-induced nuclear translocation of FoxO3A in HepG2 and MCF-7 cells. In addition, suppression of AMPK also blocked gAcrp-induced cell cycle arrest and further attenuated gAcrp-induced caspase-3/7 activation, indicating that AMPK signaling plays a pivotal role in both gAcrp-induced cell cycle arrest and apoptosis via acting as an upstream signaling of FoxO3A. Taken together, our findings demonstrated that AMPK/FoxO3A axis plays a cardinal role in anti-proliferative effect of adiponectin in cancer cells.
Shrestha S, etal., Life Sci Alliance. 2022 Feb 18;5(5):e202201369. doi: 10.26508/lsa.202201369. Print 2022 May.
Lymphangioleiomyomatosis (LAM) is a rare progressive disease, characterized by mutations in the tuberous sclerosis complex genes (TSC1 or TSC2) and hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1). Here, we report that E26 transformation-specific (ETS) variant transcription fact
or 2 (ETV2) is a critical regulator of Tsc2-deficient cell survival. ETV2 nuclear localization in Tsc2-deficient cells is mTORC1-independent and is enhanced by spleen tyrosine kinase (Syk) inhibition. In the nucleus, ETV2 transcriptionally regulates poly(ADP-ribose) polymerase 1 binding protein (PARPBP) mRNA and protein expression, partially reversing the observed down-regulation of PARPBP expression induced by mTORC1 blockade during treatment with both Syk and mTORC1 inhibitors. In addition, silencing Etv2 or Parpbp in Tsc2-deficient cells induced ER stress and increased cell death in vitro and in vivo. We also found ETV2 expression in human cells with loss of heterozygosity for TSC2, lending support to the translational relevance of our findings. In conclusion, we report a novel ETV2 signaling axis unique to Syk inhibition that promotes a cytocidal response in Tsc2-deficient cells and therefore maybe a potential alternative therapeutic target in LAM.
microRNA-142 (miR-142) is an important regulator of many biological processes and associated signaling pathways during embryonic development, homeostasis and disease. The miR-142 hairpin gives rise to the "guide strand" miR-142-3p and the sister "passenger" strand miR-142-5p. miR-142-3p has been sh
own to play critical, non-redundant functions in the development of the hematopoietic lineage. We have recently reported that miR-142-3p is critical for the control of Wnt signaling in the mesenchyme of the developing lung. miR-142-5p has been proposed to control adaptive growth in cardiomyocytes postnatally and its increase is associated with extensive apoptosis and cardiac dysfunction in a murine heart failure model. Using homologous recombination, we now report the generation and validation of miR-142-null mice. miR-142-null mice show a significant decrease in th expression levels of both the 3p and 5p isoforms. The expression of Bzrap1, a gene immediately flanking miR-142 is not altered while the expression of a long non-coding RNA embedded within the miR-142 gene is decreased. miR-142-null newborn pups appear normal and are normally represented indicating absence of embryonic lethality. At embryonic day 18.5, miR-142-null lungs display increased Wnt signaling associated with the up-regulation of Apc and p300, two previously reported targets of miR-142-3p and -5p, respectively. Adult miR-142-null animals display impaired hematopoietic lineage formation identical to previously reported miR-142 gene trap knockdown mice. We report, for the first time, the homologous recombination-based miR-142-null mice that will be useful for the scientific community working on the diverse biological functions of miR-142.
Shrestha RL and Draviam VM, Curr Biol. 2013 Aug 19;23(16):1514-26. doi: 10.1016/j.cub.2013.06.040. Epub 2013 Jul 25.
BACKGROUND: Proper attachment of chromosomes to microtubules is crucial for the accurate segregation of chromosomes. Human chromosomes attach initially to lateral walls of microtubules. Subsequently, attachments to lateral walls disappear and attachments to microtubule ends (end-on attachments) pred
ominate. While it is known in yeasts that lateral to end-on conversion of attachments occurs through a multistep process, equivalent conversion steps in humans remain unknown. RESULTS: By developing a high-resolution imaging assay to visualize intermediary steps of the lateral to end-on conversion process, we show that the mechanisms that bring a laterally bound chromosome and its microtubule end closer to each other are indispensable for proper end-on attachment because laterally attached chromosomes seldom detach. We show that end-on conversion requires (1) the plus-end-directed motor CENP-E to tether the lateral kinetochore onto microtubule walls and (2) the microtubule depolymerizer MCAK to release laterally attached microtubules after a partial end-on attachment is formed. CONCLUSIONS: By uncovering a CENP-E mediated wall-tethering event and a MCAK-mediated wall-removing event, we establish that human chromosome-microtubule attachment is achieved through a set of deterministic sequential events rather than stochastic direct capture of microtubule ends.
Subcutaneous injection of endothelin-1 (ET-1) into the glabrous skin of the rat's hind paw is known to produce impulses in nociceptors and acute nocifensive behavioral responses, such as hind paw flinching, and to sensitize the skin to mechanical and thermal stimulation. In this report, we show that
in contrast to the responses in glabrous skin, ET-1 injected subcutaneously into rat hairy skin causes transient antinociception. Concentrations of 1 to 50 microM ET-1 (in 0.05 mL) depress the local nocifensive response to noxious tactile probing at the injection site with von Frey filaments for 30 to 180 minutes; distant injections have no effect at this site, showing that the response is local. Selective inhibition of ET(A) but not of ET(B) receptors inhibits this antinociception, as does coinjection with nimodipine (40 muM), a blocker of L-type Ca(2+) channels. Local subcutaneous injection of epinephrine (45 microM) also causes antinociception through alpha-1 adrenoreceptors, but such receptors are not involved in the ET-1-induced effect. Both epinephrine and ET-1, at antinociceptive concentrations, reduce blood flow in the skin; the effect from ET-1 is largely prevented by subcutaneous nimodipine. These data suggest that ET-1-induced antinociception in the hairy skin of the rat involves cutaneous vasoconstriction, presumably through neural ischemia, resulting in conduction block. PERSPECTIVE: The pain-inducing effects of ET-1 have been well documented in glabrous skin of the rat, a frequently used test site. The opposite behavioral effect, antinociception, occurs from ET-1 in hairy skin and is correlated with a reduction in blood flow. Vasoactive effects are important in assessing mechanisms of peripherally acting agents.
Shridhar V, etal., Oncogene. 1997 May 8;14(18):2213-6.
The ARP gene encodes a highly conserved arginine-rich protein from chromosomal band 3p21.1. At the cytogenetic level this region is frequently deleted in a variety of different solid tumors, although not in pancreatic cancer. We have reported the presence of a specific mutation (ATG50-->AGG) or dele
tion of codon 50 of the ARP gene in different tumor types (Shridhar et al., 1996, 1996a). In the present study, we have observed mutations involving codon 50 in 11 of 37 pancreatic tumors. The frequency of codon 50 mutation is roughly the same in pancreatic tumors as in the other types of tumors previously examined. In addition, we have detected mutations at codon 51 in multiple PCR subclones in two other pancreatic tumors. Mutations in the ARP gene are thus commonly observed in pancreatic cancer, as well as many other cancers.
Shridhar R, etal., Cancer Res. 1996 Dec 15;56(24):5576-8.
Arginine-rich protein (ARP) is a highly conserved gene that maps to human chromosomal band 3p21.1. This gene contains an imperfect trinucleotide repeat which encodes a string of arginines. We previously detected a specific mutation (ATG50-->AGG) within this region of the gene in 10 of 21 sporadic re
nal cell carcinomas. Here, we report the detection of the same mutation in 5 of 21 squamous cell carcinomas of the head and neck, 1 of 2 small cell lung cancer cell lines, 6 of 18 non-small cell lung carcinomas, 9 of 22 breast tumors, and 5 of 13 prostate tumors. This mutation was seen in several early stage tumors and may thus be an early event in tumorigenesis. We also detected a mutation at codon 53 of this gene in both primary and metastatic tumors from one patient. Other nucleotide changes were observed in a few PCR subclones, but their frequency was the same in both tumor and control samples, suggesting that many of these changes were PCR or subcloning artifacts rather than mutations in the tumor cells themselves.
Shrestha E, etal., J Biol Chem. 2016 May 20;291(21):11172-84. doi: 10.1074/jbc.M116.726729. Epub 2016 Mar 29.
Liver X receptors (LXR) are oxysterol-activated nuclear receptors that play a central role in reverse cholesterol transport through up-regulation of ATP-binding cassette transporters (ABCA1 and ABCG1) that mediate cellular cholesterol efflux. Mouse models of atherosclerosis exhibit reduced atheroscl
erosis and enhanced regression of established plaques upon LXR activation. However, the coregulatory factors that affect LXR-dependent gene activation in macrophages remain to be elucidated. To identify novel regulators of LXR that modulate its activity, we used affinity purification and mass spectrometry to analyze nuclear LXRa complexes and identified poly(ADP-ribose) polymerase-1 (PARP-1) as an LXR-associated factor. In fact, PARP-1 interacted with both LXRa and LXRß. Both depletion of PARP-1 and inhibition of PARP-1 activity augmented LXR ligand-induced ABCA1 expression in the RAW 264.7 macrophage line and primary bone marrow-derived macrophages but did not affect LXR-dependent expression of other target genes, ABCG1 and SREBP-1c. Chromatin immunoprecipitation experiments confirmed PARP-1 recruitment at the LXR response element in the promoter of the ABCA1 gene. Further, we demonstrated that LXR is poly(ADP-ribosyl)ated by PARP-1, a potential mechanism by which PARP-1 influences LXR function. Importantly, the PARP inhibitor 3-aminobenzamide enhanced macrophage ABCA1-mediated cholesterol efflux to the lipid-poor apolipoprotein AI. These findings shed light on the important role of PARP-1 on LXR-regulated lipid homeostasis. Understanding the interplay between PARP-1 and LXR may provide insights into developing novel therapeutics for treating atherosclerosis.
BACKGROUND: Preterm infants with bronchopulmonary dysplasia (BPD) have lifelong increased risk of respiratory morbidities associated with environmental pathogen exposure and underlying mechanisms are poorly understood. The resident immune cells of the lung play vital roles in host defense
. However, the effect of perinatal events associated with BPD on pulmonary-specific immune cells is not well understood. METHODS: We used a double-hit model of BPD induced by prenatal chorioamnionitis followed by postnatal hyperoxia, and performed a global transcriptome analysis of all resident pulmonary immune cells. RESULTS: We show significant up-regulation of genes involved in chemokine-mediated signaling and immune cell chemotaxis, and down-regulation of genes involved in multiple T lymphocyte functions. Multiple genes involved in T cell receptor signaling are downregulated and Cd8a gene expression remains downregulated at 2 months of age in spite of recovery in normoxia for 6 weeks. Furthermore, the proportion of CD8a+CD3+ pulmonary immune cells is decreased. CONCLUSIONS: Our study has highlighted that perinatal lung inflammation in a double-hit model of BPD results in short- and long-term dysregulation of genes associated with the pulmonary T cell receptor signaling pathway, which may contribute to increased environmental pathogen-associated respiratory morbidities seen in children and adults with BPD. IMPACT: In a translationally relevant double-hit model of BPD induced by chorioamnionitis and postnatal hyperoxia, we identified pulmonary immune cell-specific transcriptomic changes and showed that T cell receptor signaling genes are downregulated in short term and long term. This is the first comprehensive report delineating transcriptomic changes in resident immune cells of the lung in a translationally relevant double-hit model of BPD. Our study identifies novel resident pulmonary immune cell-specific targets for potential therapeutic modulation to improve short- and long-term respiratory health of preterm infants with BPD.
Shriberg LD, etal., J Speech Lang Hear Res. 2006 Jun;49(3):500-25.
PURPOSE: The primary goal of this case study was to describe the speech, prosody, and voice characteristics of a mother and daughter with a breakpoint in a balanced 7;13 chromosomal translocation that disrupted the transcription gene, FOXP2 (cf. J. B. Tomblin et al., 2005). As with affected members
of the widely cited KE family, whose communicative disorders have been associated with a point mutation in the FOXP2 gene, both mother and daughter had cognitive, language, and speech challenges. A 2nd goal of the study was to illustrate in detail, the types of speech, prosody, and voice metrics that can contribute to phenotype sharpening in speech-genetics research. METHOD: A speech, prosody, and voice assessment protocol was administered twice within a 4-month period. Analyses were aided by comparing profiles from the present speakers (the TB family) with those from 2 groups of adult speakers: 7 speakers with acquired (with one exception) spastic or spastic-flaccid dysarthria and 14 speakers with acquired apraxia of speech. RESULTS: The descriptive and inferential statistical findings for 13 speech, prosody, and voice variable supported the conclusion that both mother and daughter had spastic dysarthria, an apraxia of speech, and residual developmental distortion errors. CONCLUSION: These findings are consistent with, but also extend, the reported communicative disorders in affected members of the KE family. A companion article (K. J. Ballard, L. D. Shriberg, J. R. Duffy, & J. B. Tomblin, 2006) reports information from the orofacial and speech motor control measures administered to the same family; reports on neuropsychological and neuroimaging findings are in preparation.
Shrivastava S, etal., Mol Cancer Ther. 2016 Mar;15(3):471-9. doi: 10.1158/1535-7163.MCT-15-0581. Epub 2015 Dec 30.
Although radical cystectomy surgery is the standard-of-care for muscle-invasive bladder cancer, it entails complete removal of the bladder and surrounding organs which leads to substantial loss in the quality-of-life of patients. Radiotherapy, which spares the bladder, would be a more appropriate tr
eatment modality if we can utilize molecular markers to select patients with better response to radiation. In this study, we investigate a protein called high mobility group box protein 1 (HMGB1) as a predictive marker for radiotherapy response in bladder cancer. Our in vitro results indicate a positive correlation between higher levels of HMGB1 protein and resistance to radiation in various cell lines. Upon HMGB1 protein knockdown, highly significant (>1.5-fold) sensitization to radiotherapy was achieved. We saw that loss of HMGB1 was associated with at least two times higher (P < 0.001) DNA damage in cell lines postradiation. Our results also depicted that autophagy was inhibited more than 3-fold (P < 0.001) upon HMGB1 knockdown, implicating its role in autophagy as another cause of bladder cancer radioresistance. Further validation was done in vivo by conducting mouse tumor xenograft experiments, where HMGB1 knockdown tumors showed a significantly better (P < 0.001) response to radiotherapy and decreased autophagy (shown by P62 staining) as compared with controls. The cumulative findings of our in vitro and in vivo studies highlight the significance of HMGB1 as a radiation response marker as well as its utility in radiosensitization of bladder cancer.
Scoggan KA, etal., J Lipid Res 2003 May;44(5):911-6. Epub 2003 Mar 1.
Sitosterolemia is an autosomal recessive disorder caused by mutations in the ABCG5 or ABCG8 half-transporter genes. These mutations disrupt the mechanism that distinguishes between absorbed sterols and is most prominently characterized by hyperabsorption and impaired biliary elimination of dietary p
lant sterols. Sitosterolemia patients retain 15-20% of dietary plant sterols, whereas normal individuals absorb less than 1-5%. Normotensive Wistar Kyoto inbred (WKY inbred), spontaneously hypertensive rat (SHR), and stroke-prone spontaneously hypertensive rat (SHRSP) strains also display increased absorption and decreased elimination of dietary plant sterols. To determine if the genes responsible for sitosterolemia in humans are also responsible for phytosterolemia in rats, we sequenced the Abcg5 and Abcg8 genes in WKY inbred, SHR, and SHRSP rat strains. All three strains possessed a homozygous guanine-to-thymine transversion in exon 12 of the Abcg5 gene that results in the substitution of a conserved glycine residue for a cysteine amino acid in the extracellular loop between the fifth and sixth membrane-spanning domains of the ATP binding cassette half-transporter, sterolin-1. The identification of this naturally occurring mutation confirms that these rat strains are important animal models of sitosterolemia in which to study the mechanisms of sterol trafficking.
Kloting I, etal., Biochem Biophys Res Commun 2001 May 4;283(2):399-405.
Diabetes in BB rats share many common features with human type 1 diabetes. One of them is the complex and polygenic nature of disease. Analysis of cross hybrids of diabetic BB/OK rats and rats of different diabetes-resistant strains has demonstrated that beside the MHC genes, Iddm1 and the lymphopen
ia, Iddm2, additional non-MHC genes are involved in diabetes development. To study the importance of the non-MHC genes, Iddm4 and Iddm3, two congenic BB.SHR rat strains were generated by recombining a segment of the SHR chromosome 6 (Iddm4; termed BB.6S; 15cM) or chromosome 18 (Iddm3; termed BB.18S; 24cM) into the BB/OK background by serial backcrossing and marker-aided selection. The characterization of both congenic strains demonstrates a drastic reduction of diabetes frequency in comparison to the BB/OK strain (86% vs 14% and 34%). It is supposed that diabetes protective genes of SHR must be located on both chromosomal segments and that these suppress the action of the essential and most important genes of diabetes development in the BB/OK rat, Iddm1, and Iddm2.
Eckart RE, etal., J Interv Cardiol. 2004 Feb;17(1):27-31.
BACKGROUND: Extracellular matrix remodeling is a component of coronary artery disease (CAD). Matrix metalloproteinases (MMPs) are enzymes involved in extracellular matrix degradation. The extrapolation of the role MMPs play in the clinical setting of acute coronary syndromes has not yet been defined
. METHODS: Samples from 100 subjects undergoing cardiac catheterization were analyzed for serum levels of MMP-1, MMP-2, and MMP-9. These markers were assessed before, immediately after, and 24 hours after cardiac catheterization. Relationships among MMP levels, baseline characteristics, angiography findings and clinical course were assessed. RESULTS: Comparing subjects with myocardial infarction versus those without, baseline MMP-1 levels were not different at baseline but increased during the hospital stay, MMP-2 levels were higher at baseline and throughout the monitoring period and MMP-9 levels lower and decreased over time. MMP-1 was higher 24 hours after catheterization in subjects undergoing revascularization. Subjects undergoing percutaneous revascularization had higher MMP-9 levels following revascularization than those subjects undergoing angiography without angioplasty. CONCLUSIONS: Serial monitoring of MMPs indicates a differential subtype response to myocardial infarction and percutaneous revascularization. Results of this study indicate that MMP subtypes may play differing roles in the manifestation of acute coronary syndromes and response to revascularization.
Agapova TIu, etal., Mol Gen Mikrobiol Virusol. 2008;(3):28-32.
Semax is a synthetic peptide, which consists of the N-terminal adrenocorticotropic hormone fragment (4-7) (ACTH4-7) and C-terminal Pro-Gly-Pro peptide. Semax promotes neuron survival in hypoxia, increases selective attention and memory storage. It was shown that this synthetic peptide exerted a numb
er of gene expressions, especially brain derived neurotrophic factor gene (Bdnf) and nerve growth factor gene (Ngf). Temporary dynamics of Bdnf and Ngf ex- pression in rat hippocampus and frontal cortex under Semax action (50 mg/kg, single intranasal administration) was studied in this work. It was shown that the studied gene expression levels changed significantly both in the hippocampus and the frontal cortex tissues 20 minutes after the peptide preparation application. The expression levels decreased in the hippocampus and increased in the frontal cortex. Forty minutes after Semax administration both gene expression levels returned to the level typical of control tissues. After that they increased significantly by 90 minutes after experiment start. Bdnf and Ngf expression levels decreased up to the control levels by 8 hours after medicine applying maximum gene expression levels were attained. Thus, Semax administration results in rapid, long-term, and specific activation of Bdnf and Ngf expression changes in different rat brain departments.
Vivante A, etal., J Am Soc Nephrol. 2017 Aug;28(8):2364-2376. doi: 10.1681/ASN.2016060694. Epub 2017 Apr 5.
Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of CKD in the first three decades of life. However, for most patients with CAKUT, the causative mutation remains unknown. We identified a kindred with an autosomal dominant form of CAKUT. By whole-exome sequencing
, we identified a heterozygous truncating mutation (c.279delG, p.Trp93fs*) of the nuclear receptor interacting protein 1 gene (NRIP1) in all seven affected members. NRIP1 encodes a nuclear receptor transcriptional cofactor that directly interacts with the retinoic acid receptors (RARs) to modulate retinoic acid transcriptional activity. Unlike wild-type NRIP1, the altered NRIP1 protein did not translocate to the nucleus, did not interact with RARα, and failed to inhibit retinoic acid-dependent transcriptional activity upon expression in HEK293 cells. Notably, we also showed that treatment with retinoic acid enhanced NRIP1 binding to RARα RNA in situ hybridization confirmed Nrip1 expression in the developing urogenital system of the mouse. In explant cultures of embryonic kidney rudiments, retinoic acid stimulated Nrip1 expression, whereas a pan-RAR antagonist strongly reduced it. Furthermore, mice heterozygous for a null allele of Nrip1 showed a CAKUT-spectrum phenotype. Finally, expression and knockdown experiments in Xenopus laevis confirmed an evolutionarily conserved role for NRIP1 in renal development. These data indicate that dominant NRIP1 mutations can cause CAKUT by interference with retinoic acid transcriptional signaling, shedding light on the well documented association between abnormal vitamin A levels and renal malformations in humans, and suggest a possible gene-environment pathomechanism in this disease.
Rao J, etal., J Clin Invest. 2017 Dec 1;127(12):4257-4269. doi: 10.1172/JCI94138. Epub 2017 Oct 23.
Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of chronic kidney disease. Here, we identified recessive mutations in the gene encoding the actin-binding protein advillin (AVIL) in 3 unrelated families with SRNS. While all AVIL mutations resulted in a marked loss of its actin-bundlin
g ability, truncation of AVIL also disrupted colocalization with F-actin, thereby leading to impaired actin binding and severing. Additionally, AVIL colocalized and interacted with the phospholipase enzyme PLCE1 and with the ARP2/3 actin-modulating complex. Knockdown of AVIL in human podocytes reduced actin stress fibers at the cell periphery, prevented recruitment of PLCE1 to the ARP3-rich lamellipodia, blocked EGF-induced generation of diacylglycerol (DAG) by PLCE1, and attenuated the podocyte migration rate (PMR). These effects were reversed by overexpression of WT AVIL but not by overexpression of any of the 3 patient-derived AVIL mutants. The PMR was increased by overexpression of WT Avil or PLCE1, or by EGF stimulation; however, this increased PMR was ameliorated by inhibition of the ARP2/3 complex, indicating that ARP-dependent lamellipodia formation occurs downstream of AVIL and PLCE1 function. Together, these results delineate a comprehensive pathogenic axis of SRNS that integrates loss of AVIL function with alterations in the action of PLCE1, an established SRNS protein.
Congenital anomalies of the kidney and urinary tract (CAKUT) represent the most common cause of chronic kidney failure in children. Despite growing knowledge of the genetic causes of CAKUT, the majority of cases remain etiologically unsolved. Genetic alterations in roundabout guidance receptor 1 (RO
BO1) have been associated with neuronal and cardiac developmental defects in living individuals. Although Slit-Robo signaling is pivotal for kidney development, diagnostic ROBO1 variants have not been reported in viable CAKUT to date. By next-generation-sequencing methods, we identified six unrelated individuals and two non-viable fetuses with biallelic truncating or combined missense and truncating variants in ROBO1. Kidney and genitourinary manifestation included unilateral or bilateral kidney agenesis, vesicoureteral junction obstruction, vesicoureteral reflux, posterior urethral valve, genital malformation, and increased kidney echogenicity. Further clinical characteristics were remarkably heterogeneous, including neurodevelopmental defects, intellectual impairment, cerebral malformations, eye anomalies, and cardiac defects. By in silico analysis, we determined the functional significance of identified missense variants and observed absence of kidney ROBO1 expression in both human and murine mutant tissues. While its expression in multiple tissues may explain heterogeneous organ involvement, variability of the kidney disease suggests gene dosage effects due to a combination of null alleles with mild hypomorphic alleles. Thus, comprehensive genetic analysis in CAKUT should include ROBO1 as a new cause of recessively inherited disease. Hence, in patients with already established ROBO1-associated cardiac or neuronal disorders, screening for kidney involvement is indicated.
Mann N, etal., Am J Hum Genet. 2019 Dec 5;105(6):1286-1293. doi: 10.1016/j.ajhg.2019.10.004. Epub 2019 Nov 7.
Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of chronic kidney disease in the first three decades of life, and in utero obstruction to urine flow is a frequent cause of secondary upper urinary tract malformations. Here, using whole-exome sequencing, we ident
ified three different biallelic mutations in CHRNA3, which encodes the α3 subunit of the nicotinic acetylcholine receptor, in five affected individuals from three unrelated families with functional lower urinary tract obstruction and secondary CAKUT. Four individuals from two families have additional dysautonomic features, including impaired pupillary light reflexes. Functional studies in vitro demonstrated that the mutant nicotinic acetylcholine receptors were unable to generate current following stimulation with acetylcholine. Moreover, the truncating mutations p.Thr337Asnfs∗81 and p.Ser340∗ led to impaired plasma membrane localization of CHRNA3. Although the importance of acetylcholine signaling in normal bladder function has been recognized, we demonstrate for the first time that mutations in CHRNA3 can cause bladder dysfunction, urinary tract malformations, and dysautonomia. These data point to a pathophysiologic sequence by which monogenic mutations in genes that regulate bladder innervation may secondarily cause CAKUT.
Schneider R, etal., Am J Hum Genet. 2020 Dec 3;107(6):1113-1128. doi: 10.1016/j.ajhg.2020.11.008. Epub 2020 Nov 23.
The discovery of >60 monogenic causes of nephrotic syndrome (NS) has revealed a central role for the actin regulators RhoA/Rac1/Cdc42 and their effectors, including the formin INF2. By whole-exome sequencing (WES), we here discovered bi-allelic variants in the formin DAAM2 in four unrelated families
with steroid-resistant NS. We show that DAAM2 localizes to the cytoplasm in podocytes and in kidney sections. Further, the variants impair DAAM2-dependent actin remodeling processes: wild-type DAAM2 cDNA, but not cDNA representing missense variants found in individuals with NS, rescued reduced podocyte migration rate (PMR) and restored reduced filopodia formation in shRNA-induced DAAM2-knockdown podocytes. Filopodia restoration was also induced by the formin-activating molecule IMM-01. DAAM2 also co-localizes and co-immunoprecipitates with INF2, which is intriguing since variants in both formins cause NS. Using in vitro bulk and TIRF microscopy assays, we find that DAAM2 variants alter actin assembly activities of the formin. In a Xenopus daam2-CRISPR knockout model, we demonstrate actin dysregulation in vivo and glomerular maldevelopment that is rescued by WT-DAAM2 mRNA. We conclude that DAAM2 variants are a likely cause of monogenic human SRNS due to actin dysregulation in podocytes. Further, we provide evidence that DAAM2-associated SRNS may be amenable to treatment using actin regulating compounds.
Braun DA, etal., Nephrol Dial Transplant. 2019 Mar 1;34(3):485-493. doi: 10.1093/ndt/gfy028.
BACKGROUND: Nephrotic syndrome (NS), a chronic kidney disease, is characterized by significant loss of protein in the urine causing hypoalbuminemia and edema. In general, ∼15% of childhood-onset cases do not respond to steroid therapy and are classified as steroid-resistant NS (SRNS). In
∼30% of cases with SRNS, a causative mutation can be detected in one of 44 monogenic SRNS genes. The gene LAMA5 encodes laminin-α5, an essential component of the glomerular basement membrane. Mice with a hypomorphic mutation in the orthologous gene Lama5 develop proteinuria and hematuria. METHODS: To identify additional monogenic causes of NS, we performed whole exome sequencing in 300 families with pediatric NS. In consanguineous families we applied homozygosity mapping to identify genomic candidate loci for the underlying recessive mutation. RESULTS: In three families, in whom mutations in known NS genes were excluded, but in whom a recessive, monogenic cause of NS was strongly suspected based on pedigree information, we identified homozygous variants of unknown significance (VUS) in the gene LAMA5. While all affected individuals had nonsyndromic NS with an early onset of disease, their clinical outcome and response to immunosuppressive therapy differed notably. CONCLUSION: We here identify recessive VUS in the gene LAMA5 in patients with partially treatment-responsive NS. More data will be needed to determine the impact of these VUS in disease management. However, familial occurrence of disease, data from genetic mapping and a mouse model that recapitulates the NS phenotypes suggest that these genetic variants may be inherited factors that contribute to the development of NS in pediatric patients.
Braun DA, etal., Nat Genet. 2017 Oct;49(10):1529-1538. doi: 10.1038/ng.3933. Epub 2017 Aug 14.
Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS
complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.
Steroid-resistant nephrotic syndrome is a frequent cause of chronic kidney disease almost inevitably progressing to end-stage renal disease. More than 58 monogenic causes of SRNS have been discovered and majority of known steroid-resistant nephrotic syndrome causing genes are predominantly expressed
in glomerular podocytes, placing them at the center of disease pathogenesis. Herein, we describe two unrelated families with steroid-resistant nephrotic syndrome with homozygous mutations in the KIRREL1 gene. One mutation showed high frequency in the European population (minor allele frequency 0.0011) and this patient achieved complete remission following treatment, but later progressed to chronic kidney disease. We found that mutant KIRREL1 proteins failed to localize to the podocyte cell membrane, indicating defective trafficking and impaired podocytes function. Thus, the KIRREL1 gene product has an important role in modulating the integrity of the slit diaphragm and maintaining glomerular filtration function.
Braun DA, etal., J Clin Invest. 2018 Oct 1;128(10):4313-4328. doi: 10.1172/JCI98688. Epub 2018 Sep 4.
Steroid-resistant nephrotic syndrome (SRNS) almost invariably progresses to end-stage renal disease. Although more than 50 monogenic causes of SRNS have been described, a large proportion of SRNS remains unexplained. Recently, it was discovered that mutations of NUP93 and NUP205, encoding 2 proteins
of the inner ring subunit of the nuclear pore complex (NPC), cause SRNS. Here, we describe mutations in genes encoding 4 components of the outer rings of the NPC, namely NUP107, NUP85, NUP133, and NUP160, in 13 families with SRNS. Using coimmunoprecipitation experiments, we showed that certain pathogenic alleles weakened the interaction between neighboring NPC subunits. We demonstrated that morpholino knockdown of nup107, nup85, or nup133 in Xenopus disrupted glomerulogenesis. Re-expression of WT mRNA, but not of mRNA reflecting mutations from SRNS patients, mitigated this phenotype. We furthermore found that CRISPR/Cas9 knockout of NUP107, NUP85, or NUP133 in podocytes activated Cdc42, an important effector of SRNS pathogenesis. CRISPR/Cas9 knockout of nup107 or nup85 in zebrafish caused developmental anomalies and early lethality. In contrast, an in-frame mutation of nup107 did not affect survival, thus mimicking the allelic effects seen in humans. In conclusion, we discovered here that mutations in 4 genes encoding components of the outer ring subunits of the NPC cause SRNS and thereby provide further evidence that specific hypomorphic mutations in these essential genes cause a distinct, organ-specific phenotype.
Braun DA, etal., Nat Genet. 2016 Apr;48(4):457-65. doi: 10.1038/ng.3512. Epub 2016 Feb 15.
Nucleoporins are essential components of the nuclear pore complex (NPC). Only a few diseases have been attributed to NPC dysfunction. Steroid-resistant nephrotic syndrome (SRNS), a frequent cause of chronic kidney disease, is caused by dysfunction of glomerular podocytes. Here we identify in eight f
amilies with SRNS mutations in NUP93, its interaction partner NUP205 or XPO5 (encoding exportin 5) as hitherto unrecognized monogenic causes of SRNS. NUP93 mutations caused disrupted NPC assembly. NUP93 knockdown reduced the presence of NUP205 in the NPC, and, reciprocally, a NUP205 alteration abrogated NUP93 interaction. We demonstrate that NUP93 and exportin 5 interact with the signaling protein SMAD4 and that NUP93 mutations abrogated interaction with SMAD4. Notably, NUP93 mutations interfered with BMP7-induced SMAD transcriptional reporter activity. We hereby demonstrate that mutations of NUP genes cause a distinct renal disease and identify aberrant SMAD signaling as a new disease mechanism of SRNS, opening a potential new avenue for treatment.
Gee HY, etal., Am J Hum Genet. 2016 Jun 2;98(6):1228-34. doi: 10.1016/j.ajhg.2016.03.026. Epub 2016 May 19.
Nephrolithiasis, a condition in which urinary supersaturation leads to stone formation in the urinary system, affects about 5%-10% of individuals worldwide at some point in their lifetime and results in significant medical costs and morbidity. To date, mutations in more than 30 genes have been descr
ibed as being associated with nephrolithiasis, and these mutations explain about 15% of kidney stone cases, suggesting that additional nephrolithiasis-associated genes remain to be discovered. To identify additional genes whose mutations are linked to nephrolithiasis, we performed targeted next-generation sequencing of 18 hypothesized candidate genes in 348 unrelated individuals with kidney stones. We detected biallelic mutations in SLC26A1 (solute carrier family 26 member 1) in two unrelated individuals with calcium oxalate kidney stones. We show by immunofluorescence, immunoblotting, and glycosylation analysis that the variant protein mimicking p.Thr185Met has defects in protein folding or trafficking. In addition, by measuring anion exchange activity of SLC26A1, we demonstrate that all the identified mutations in SLC26A1 result in decreased transporter activity. Our data identify SLC26A1 mutations as causing a recessive Mendelian form of nephrolithiasis.
Vivante A, etal., Am J Hum Genet. 2015 Aug 6;97(2):291-301. doi: 10.1016/j.ajhg.2015.07.001. Epub 2015 Jul 30.
Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of chronic kidney disease in the first three decades of life. Identification of single-gene mutations that cause CAKUT permits the first insights into related disease mechanisms. However, for most cases the under
lying defect remains elusive. We identified a kindred with an autosomal-dominant form of CAKUT with predominant ureteropelvic junction obstruction. By whole exome sequencing, we identified a heterozygous truncating mutation (c.1010delG) of T-Box transcription factor 18 (TBX18) in seven affected members of the large kindred. A screen of additional families with CAKUT identified three families harboring two heterozygous TBX18 mutations (c.1570C>T and c.487A>G). TBX18 is essential for developmental specification of the ureteric mesenchyme and ureteric smooth muscle cells. We found that all three TBX18 altered proteins still dimerized with the wild-type protein but had prolonged protein half life and exhibited reduced transcriptional repression activity compared to wild-type TBX18. The p.Lys163Glu substitution altered an amino acid residue critical for TBX18-DNA interaction, resulting in impaired TBX18-DNA binding. These data indicate that dominant-negative TBX18 mutations cause human CAKUT by interference with TBX18 transcriptional repression, thus implicating ureter smooth muscle cell development in the pathogenesis of human CAKUT.
Braun DA, etal., Am J Med Genet A. 2018 Nov;176(11):2460-2465. doi: 10.1002/ajmg.a.40489. Epub 2018 Aug 6.
Galloway-Mowat syndrome (GAMOS) is a phenotypically heterogeneous disorder characterized by neurodevelopmental defects combined with renal-glomerular disease, manifesting with proteinuria. To identify additional monogenic disease causes, we here performed whole exome sequencing (WES), linkage analys
is, and homozygosity mapping in three affected siblings of an Indian family with GAMOS. Applying established criteria for variant filtering, we identify a novel homozygous splice site mutation in the gene WDR4 as the likely disease-causing mutation in this family. In line with previous reports, we observe growth deficiency, microcephaly, developmental delay, and intellectual disability as phenotypic features resulting from WDR4 mutations. However, the newly identified allele additionally gives rise to proteinuria and nephrotic syndrome, a phenotype that was never reported in patients with WDR4 mutations. Our data thus expand the phenotypic spectrum of WDR4 mutations by demonstrating that, depending on the specific mutated allele, a renal phenotype may be present. This finding suggests that GAMOS may occupy a phenotypic spectrum with other microcephalic diseases. Furthermore, WDR4 is an additional example of a gene that encodes a tRNA modifying enzyme and gives rise to GAMOS, if mutated. Our findings thereby support the recent observation that, like neurons, podocytes of the renal glomerulus are particularly vulnerable to cellular defects resulting from altered tRNA modifications.
Connaughton DM, etal., Am J Hum Genet. 2020 Oct 1;107(4):727-742. doi: 10.1016/j.ajhg.2020.08.013. Epub 2020 Sep 4.
Congenital anomalies of the kidney and urinary tract (CAKUT) constitute one of the most frequent birth defects and represent the most common cause of chronic kidney disease in the first three decades of life. Despite the discovery of dozens of monogenic causes of CAKUT, most pathogenic pathways rema
in elusive. We performed whole-exome sequencing (WES) in 551 individuals with CAKUT and identified a heterozygous de novo stop-gain variant in ZMYM2 in two different families with CAKUT. Through collaboration, we identified in total 14 different heterozygous loss-of-function mutations in ZMYM2 in 15 unrelated families. Most mutations occurred de novo, indicating possible interference with reproductive function. Human disease features are replicated in X. tropicalis larvae with morpholino knockdowns, in which expression of truncated ZMYM2 proteins, based on individual mutations, failed to rescue renal and craniofacial defects. Moreover, heterozygous Zmym2-deficient mice recapitulated features of CAKUT with high penetrance. The ZMYM2 protein is a component of a transcriptional corepressor complex recently linked to the silencing of developmentally regulated endogenous retrovirus elements. Using protein-protein interaction assays, we show that ZMYM2 interacts with additional epigenetic silencing complexes, as well as confirming that it binds to FOXP1, a transcription factor that has also been linked to CAKUT. In summary, our findings establish that loss-of-function mutations of ZMYM2, and potentially that of other proteins in its interactome, as causes of human CAKUT, offering new routes for studying the pathogenesis of the disorder.
PURPOSE: Nephrolithiasis (NL) affects 1 in 11 individuals worldwide, leading to significant patient morbidity. NL is associated with nephrocalcinosis (NC), a risk factor for chronic kidney disease. Causative genetic variants are detected in 11% to 28% of NL and/or NC, suggesting that addi
tional NL/NC-associated genetic loci await discovery. Therefore, we employed genomic approaches to discover novel genetic forms of NL/NC. METHODS: Exome sequencing and directed sequencing of the OXGR1 locus were performed in a worldwide NL/NC cohort. Putatively deleterious, rare OXGR1 variants were functionally characterized. RESULTS: Exome sequencing revealed a heterozygous OXGR1 missense variant (c.371T>G, p.L124R) cosegregating with calcium oxalate NL and/or NC disease in an autosomal dominant inheritance pattern within a multigenerational family with 5 affected individuals. OXGR1 encodes 2-oxoglutarate (α-ketoglutarate [AKG]) receptor 1 in the distal nephron. In response to its ligand AKG, OXGR1 stimulates the chloride-bicarbonate exchanger, pendrin, which also regulates transepithelial calcium transport in cortical connecting tubules. Strong amino acid conservation in orthologs and paralogs, severe in silico prediction scores, and extreme rarity in exome population databases suggested that the variant was deleterious. Interrogation of the OXGR1 locus in 1107 additional NL/NC families identified 5 additional deleterious dominant variants in 5 families with calcium oxalate NL/NC. Rare, potentially deleterious OXGR1 variants were enriched in patients with NL/NC compared with Exome Aggregation Consortium controls (χ2 = 7.117, P = .0076). Wild-type OXGR1-expressing Xenopus oocytes exhibited AKG-responsive Ca2+ uptake. Of 5 NL/NC-associated missense variants, 5 revealed impaired AKG-dependent Ca2+ uptake, demonstrating loss of function. CONCLUSION: Rare, dominant loss-of-function OXGR1 variants are associated with recurrent calcium oxalate NL/NC disease.
Nephrotic syndrome (NS) is a leading cause of chronic kidney disease. We found recessive NOS1AP variants in two families with early-onset NS by exome sequencing. Overexpression of wild-type (WT) NOS1AP, but not cDNA constructs bearing patient variants, increased active CDC42 and promoted filopodia a
nd podosome formation. Pharmacologic inhibition of CDC42 or its effectors, formin proteins, reduced NOS1AP-induced filopodia formation. NOS1AP knockdown reduced podocyte migration rate (PMR), which was rescued by overexpression of WT Nos1ap but not by constructs bearing patient variants. PMR in NOS1AP knockdown podocytes was also rescued by constitutively active CDC42Q61L or the formin DIAPH3 Modeling a NOS1AP patient variant in knock-in human kidney organoids revealed malformed glomeruli with increased apoptosis. Nos1apEx3-/Ex3- mice recapitulated the human phenotype, exhibiting proteinuria, foot process effacement, and glomerulosclerosis. These findings demonstrate that recessive NOS1AP variants impair CDC42/DIAPH-dependent actin remodeling, cause aberrant organoid glomerulogenesis, and lead to a glomerulopathy in humans and mice.
Subramanian S, etal., AJNR Am J Neuroradiol. 2022 Jan;43(1):146-150. doi: 10.3174/ajnr.A7364. Epub 2021 Dec 2.
BACKGROUND AND PURPOSE: Pathogenic variants in the ACTA2 gene cause a distinctive arterial phenotype that has recently been described to be associated with brain malformation. Our objective was to further characterize gyral abnormalities in patients with ACTA2 pathogenic variants as per t
he 2020 consensus recommendations for the definition and classification of malformations of cortical development. MATERIALS AND METHODS: We performed a retrospective, multicentric review of patients with proved ACTA2 pathogenic variants, searching for the presence of malformations of cortical development. A consensus read was performed for all patients, and the type and location of cortical malformation were noted in each. The presence of the typical ACTA2 arterial phenotype as well as demographic and relevant clinical data was obtained. RESULTS: We included 13 patients with ACTA2 pathogenic variants (Arg179His mutation, n = 11, and Arg179Cys mutation, n = 2). Ninety-two percent (12/13) of patients had peri-Sylvian dysgyria, 77% (10/13) had frontal dysgyria, and 15% (2/13) had generalized dysgyria. The peri-Sylvian location was involved in all patients with dysgyria (12/12). All patients with dysgyria had a characteristic arterial phenotype described in ACTA2 pathogenic variants. One patient did not have dysgyria or the characteristic arterial phenotype. CONCLUSIONS: Dysgyria is common in patients with ACTA2 pathogenic variants, with a peri-Sylvian and frontal predominance, and was seen in all our patients who also had the typical ACTA2 arterial phenotype.
Korkmaz E, etal., J Am Soc Nephrol. 2016 Jan;27(1):63-8. doi: 10.1681/ASN.2014121240. Epub 2015 May 12.
Hereditary defects of coenzyme Q10 biosynthesis cause steroid-resistant nephrotic syndrome (SRNS) as part of multiorgan involvement but may also contribute to isolated SRNS. Here, we report 26 patients from 12 families with recessive mutations in ADCK4. Mutation detection rate was 1.9% among 534 con
secutively screened cases. Patients with ADCK4 mutations showed a largely renal-limited phenotype, with three subjects exhibiting occasional seizures, one subject exhibiting mild mental retardation, and one subject exhibiting retinitis pigmentosa. ADCK4 nephropathy presented during adolescence (median age, 14.1 years) with nephrotic-range proteinuria in 44% of patients and advanced CKD in 46% of patients at time of diagnosis. Renal biopsy specimens uniformly showed FSGS. Whereas 47% and 36% of patients with mutations in WT1 and NPHS2, respectively, progressed to ESRD before 10 years of age, ESRD occurred almost exclusively in the second decade of life in ADCK4 nephropathy. However, CKD progressed much faster during adolescence in ADCK4 than in WT1 and NPHS2 nephropathy, resulting in similar cumulative ESRD rates (>85% for each disorder) in the third decade of life. In conclusion, ADCK4-related glomerulopathy is an important novel differential diagnosis in adolescents with SRNS/FSGS and/or CKD of unknown origin.
The Kv4.2 transient voltage-dependent potassium current contributes to the morphology of the cardiac action potential as well as to neuronal excitability and firing frequency. Here we report profound effects of the Kv4.2 C terminus on the surface expression and activation gating properties of Kv4.2
that are modulated by the direct interaction between KChIP2, an auxiliary regulatory subunit, and the C terminus of Kv4.2. We show that increasingly large truncations of the C terminus of rat Kv4.2 (wild type) cause a progressive decrease of Kv4.2 current along with a shift in voltage-dependent activation that is closely correlated with negative charge deletion. Co-expression of more limited Kv4.2 C-terminal truncation mutants (T588 and T528) with KChIP2 results in a doubling of Kv4.2 protein expression and up to an 8-fold increase in Kv4.2 current amplitude. Pulsechase experiments show that co-expression with KChIP2 slows Kv4.2 wild type degradation 8-fold. Co-expression of KChIP2 with an intermediate-length C-terminal truncation mutant (T474) shifts Kv4.2 activation voltage dependence and enhances expression of Kv4.2 current. The largest truncation mutants (T417 and DeltaC) show an intracellular localization with no measurable currents and no response to KChIP2 co-expression. Co-immunoprecipitation and competitive glutathione S-transferase-binding assays indicate a direct interaction between KChIP2 and the Kv4.2 C terminus with a relative binding affinity comparable with that of the N terminus. Overall, these results suggest that the C-terminal domain of Kv4.2 plays a critical role in voltage-dependent activation and functional expression that is mediated by direct interaction between the Kv4.2 C terminus and KChIP2.
Zaun HC, etal., J Biol Chem. 2008 May 2;283(18):12456-67. doi: 10.1074/jbc.M800267200. Epub 2008 Mar 5.
Calcineurin B homologous protein (CHP) 1 and 2 are Ca(2+)-binding proteins that modulate several cellular processes, including cytoplasmic pH by positively regulating plasma membrane-type Na(+)/H(+) exchangers (NHEs). Recently another CHP-related protein, termed tescalcin or CHP3, was also shown to
interact with the ubiquitous NHE1 isoform, but seemingly suppressed its activity. However, the precise physical and functional nature of this association was not examined in detail. In this study, biochemical and cellular studies were undertaken to further delineate this relationship. Glutathione S-transferase-NHE1 fusion protein pulldown assays revealed that full-length CHP3 binds directly to the proximal juxtamembrane C-terminal region (amino acids 505-571) of rat NHE1 in the same region that binds CHP1 and CHP2. The interaction was further validated by coimmunoprecipitation and coimmunolocalization experiments using full-length CHP3 and wild-type NHE1 in transfected Chinese hamster ovary AP-1 cells. Simultaneous mutation of four hydrophobic residues within this region ((530)FLDHLL(535)) to either Ala, Gln, or Arg (FL-A, FL-Q, or FL-R) abrogated this interaction both in vitro and in intact cells. The NHE1 mutants were sorted properly to the cell surface but showed markedly reduced (FL-A) or minimal (FL-R and FL-Q) activity. Interestingly, and contrary to an earlier finding, ectopic coexpression of CHP3 up-regulated the cell surface activity of wild-type NHE1. This stimulation was not observed with the CHP3 binding-defective mutants. Mechanistically, overexpression of CHP3 did not alter the H(+) sensitivity of wild-type NHE1 but rather promoted its biosynthetic maturation and half-life at the cell surface, thereby increasing the steady-state abundance of functional NHE1 protein.
Poly[adenosine diphosphate (ADP)-ribose] polymerases (PARPs) are a family of enzymes that modulate diverse biological processes through covalent transfer of ADP-ribose from the oxidized form of nicotinamide adenine dinucleotide (NAD(+)) onto substrate proteins. Here we report a robust NAD(+) analog-
sensitive approach for PARPs, which allows PARP-specific ADP-ribosylation of substrates that is suitable for subsequent copper-catalyzed azide-alkyne cycloaddition reactions. Using this approach, we mapped hundreds of sites of ADP-ribosylation for PARPs 1, 2, and 3 across the proteome, as well as thousands of PARP-1-mediated ADP-ribosylation sites across the genome. We found that PARP-1 ADP-ribosylates and inhibits negative elongation factor (NELF), a protein complex that regulates promoter-proximal pausing by RNA polymerase II (Pol II). Depletion or inhibition of PARP-1 or mutation of the ADP-ribosylation sites on NELF-E promotes Pol II pausing, providing a clear functional link between PARP-1, ADP-ribosylation, and NELF. This analog-sensitive approach should be broadly applicable across the PARP family and has the potential to illuminate the ADP-ribosylated proteome and the molecular mechanisms used by individual PARPs to mediate their responses to cellular signals.
Wilk JB, etal., Am J Respir Crit Care Med. 2012 Oct 1;186(7):622-32. doi: 10.1164/rccm.201202-0366OC. Epub 2012 Jul 26.
RATIONALE: Genome-wide association studies (GWAS) have identified loci influencing lung function, but fewer genes influencing chronic obstructive pulmonary disease (COPD) are known. OBJECTIVES: Perform meta-analyses of GWAS for airflow obstruction, a key pathophysiologic characteristic of COPD asses
sed by spirometry, in population-based cohorts examining all participants, ever smokers, never smokers, asthma-free participants, and more severe cases. METHODS: Fifteen cohorts were studied for discovery (3,368 affected; 29,507 unaffected), and a population-based family study and a meta-analysis of case-control studies were used for replication and regional follow-up (3,837 cases; 4,479 control subjects). Airflow obstruction was defined as FEV(1) and its ratio to FVC (FEV(1)/FVC) both less than their respective lower limits of normal as determined by published reference equations. MEASUREMENTS AND MAIN RESULTS: The discovery meta-analyses identified one region on chromosome 15q25.1 meeting genome-wide significance in ever smokers that includes AGPHD1, IREB2, and CHRNA5/CHRNA3 genes. The region was also modestly associated among never smokers. Gene expression studies confirmed the presence of CHRNA5/3 in lung, airway smooth muscle, and bronchial epithelial cells. A single-nucleotide polymorphism in HTR4, a gene previously related to FEV(1)/FVC, achieved genome-wide statistical significance in combined meta-analysis. Top single-nucleotide polymorphisms in ADAM19, RARB, PPAP2B, and ADAMTS19 were nominally replicated in the COPD meta-analysis. CONCLUSIONS: These results suggest an important role for the CHRNA5/3 region as a genetic risk factor for airflow obstruction that may be independent of smoking and implicate the HTR4 gene in the etiology of airflow obstruction.
Reversible acetylation of lysine residues within a protein is considered a biologically relevant modification that rivals phosphorylation ( Kouzarides, T. (2000) EMBO J. 19, 1176-1179 ). The enzymes responsible for such protein modification are called histone acetyltransferases (HATs) and deacetylas
es (HDACs). A role of protein phosphorylation in regulating muscle contraction is well established ( Solaro, R. J., Moir, A. J., and Perry, S. V. (1976) Nature 262, 615-617 ). Here we show that reversible protein acetylation carried out by HATs and HDACs also plays a role in regulating the myofilament contractile activity. We found that a Class II HDAC, HDAC4, and an HAT, PCAF, associate with cardiac myofilaments. Primary cultures of cardiomyocytes as well as mouse heart sections examined by immunohistochemical and electron microscopic analyses revealed that both HDAC4 and PCAF associate with the Z-disc and I- and A-bands of cardiac sarcomeres. Increased acetylation of sarcomeric proteins by HDAC inhibition (using class I and II HDAC inhibitors or anti-HDAC4 antibody) enhanced the myofilament calcium sensitivity. We identified the Z-disc-associated protein, MLP, a sensor of cardiac mechanical stretch, as an acetylated target of PCAF and HDAC4. We also show that trichostatin-A, a class I and II HDAC inhibitor, increases myofilament calcium sensitivity of wild-type, but not of MLP knock-out mice, thus demonstrating a role of MLP in acetylation-dependent increased contractile activity of myofilaments. These studies provide the first evidence that HATs and HDACs play a role in regulation of muscle contraction.
Mohan S, etal., Asian Pac J Cancer Prev. 2009 Apr-Jun;10(2):295-8.
The renal cell carcinoma (RCC) is a rare condition, accounting for only 3% of all adult malignancies although constituting 90% of kidney cancers. The tumor is immunogenic and the host immune system may modulate the clinical course of the disease. It has been reported that genetic polymorphisms in th
e interleukin-4-receptor alpha gene are associated with risk and prognosis in RCCs. The present study is aimed at analyzing the presence and significance of the interleukin-4-receptor alpha Ile50Val and Gln576Arg polymorphisms in a group of RCC patients from South India. PCR-RFLP analysis was performed on genomic DNA isolated from blood samples and the genotypes deduced. A significant association was found between the IL4 R alpha Val/Val genotype and increased risk of RCC (OR: 3.45, CI: 1.15-10.38, P: 0.04). The Val/Val genotype was also found to be significantly associated with increased risk in individuals below 54 years (OR: 5.79, CI: 1.33-25.07 P: 0.03) of age and in females (OR: 7.47, CI: 1.4-39.84, P: 0.03). However, no significant association was observed with the Gln576Arg polymorphism. Stratified analysis based on the genotypes and the stage of tumor revealed no significant association. Thus, the present study indicates that IL4Ralpha could be a candidate gene for assessing the risk of RCC.
Chen C, etal., Cancer Cell. 2014 May 12;25(5):652-65. doi: 10.1016/j.ccr.2014.03.016. Epub 2014 May 1.
Recurring deletions of chromosome 7 and 7q [-7/del(7q)] occur in myelodysplastic syndromes and acute myeloid leukemia (AML) and are associated with poor prognosis. However, the identity of functionally relevant tumor suppressors on 7q remains unclear. Using RNAi and CRISPR/Cas9 approaches, we show
that an approximately 50% reduction in gene dosage of the mixed lineage leukemia 3 (MLL3) gene, located on 7q36.1, cooperates with other events occurring in -7/del(7q) AMLs to promote leukemogenesis. Mll3 suppression impairs the differentiation of HSPC. Interestingly, Mll3-suppressed leukemias, like human -7/del(7q) AMLs, are refractory to conventional chemotherapy but sensitive to the BET inhibitor JQ1. Thus, our mouse model functionally validates MLL3 as a haploinsufficient 7q tumor suppressor and suggests a therapeutic option for this aggressive disease.
Javle M, etal., Hum Pathol. 2014 Apr;45(4):701-8. doi: 10.1016/j.humpath.2013.11.001. Epub 2013 Nov 12.
Gallbladder cancer is relatively uncommon, with a high incidence in certain geographic locations, including Latin America, East and South Asia, and Eastern Europe. Molecular characterization of this disease has been limited, and targeted therapy options for advanced disease remain an open area of in
vestigation. In the present study, surgical pathology obtained from resected gallbladder cancer cases (n = 72) was examined for the presence of targetable, somatic mutations. All cases were formalin fixed and paraffin embedded (FFPE). Two approaches were used: (a) mass spectroscopy-based profiling for 159 point ("hot spot") mutations in 33 genes commonly involved in solid tumors and (b) next-generation sequencing (NGS) platform that examined the complete coding sequence of in 182 cancer-related genes. Fifty-seven cases were analyzed for hot spot mutations; and 15, for NGS. Fourteen hot spot mutations were identified in 9 cases. Of these, KRAS mutation was significantly associated with poor survival on multivariate analysis. Other targetable mutations included PIK3CA (n = 2) and ALK (n = 1). On NGS, 26 mutations were noted in 15 cases. TP53 and PI3 kinase pathway (STK11, RICTOR, TSC2) mutations were common. One case had FGF10 amplification, whereas another had FGF3-TACC gene fusion, not previously described in gallbladder cancer. In conclusion, somatic mutation profiling using archival FFPE samples from gallbladder cancer is feasible. NGS, in particular, may be a useful platform for identifying novel mutations for targeted therapy.
BACKGROUND: Cholangiocarcinoma (CCA) is clinically heterogeneous; intra and extrahepatic CCA have diverse clinical presentations. Next generation sequencing (NGS) technology may identify the genetic differences between these entities and identify molecular subgroups for targeted therapeut
ics. METHODS: We describe successful NGS-based testing of 75 CCA patients along with the prognostic and therapeutic implications of findings. Mutation profiling was performed using either a) NGS panel of hotspot regions in 46 cancer-related genes using a 318-chip on Ion PGM Sequencer or b) Illumina HiSeq 2000 sequencing platform for 3,769 exons of 236 cancer-related genes plus 47 introns from 19 genes to an average depth of 1000X. Clinical data was abstracted and correlated with clinical outcome. Patients with targetable mutations were referred to appropriate clinical trials. RESULTS: There were significant differences between intrahepatic (n = 55) and extrahepatic CCA (n = 20) in regard to the nature and frequency of the genetic aberrations (GAs). IDH1 and DNA repair gene alterations occurred more frequently in intrahepatic CCA, while ERBB2 GAs occurred in the extrahepatic group. Commonly occurring GAs in intrahepatic CCA were TP53 (35%), KRAS (24%), ARID1A (20%), IDH1 (18%), MCL1 (16%) and PBRM1 (11%). Most frequent GAs in extrahepatic CCA (n = 20) were TP53 (45%), KRAS (40%), ERBB2 (25%), SMAD4 (25%), FBXW7 (15%) and CDKN2A (15%). In intrahepatic CCA, KRAS, TP53 or MAPK/mTOR GAs were significantly associated with a worse prognosis while FGFR GAs correlated with a relatively indolent disease course. IDH1 GAs did not have any prognostic significance. GAs in the chromatin modulating genes, BAP1 and PBRM1 were associated with bone metastases and worse survival in extrahepatic CCA. Radiologic responses and clinical benefit was noted with EGFR, FGFR, C-met, B-RAF and MEK inhibitors. CONCLUSION: There are significant genetic differences between intra and extrahepatic CCA. NGS can potentially identify disease subsets with distinct prognostic and therapeutic implications.
Ahn DH, etal., Cancer. 2016 Dec 1;122(23):3657-3666. doi: 10.1002/cncr.30247. Epub 2016 Aug 6.
BACKGROUND: Biliary tract cancers (BTCs) are uncommon and are associated with a dismal prognosis. Combinations of gemcitabine and platinum chemotherapy (gemcitabine and platinum-based therapy [GP]) form the standard approach for treating advanced BTC. To characterize the spectrum of mutat
Baroudi G, etal., Circ Res. 2001 Jun 22;88(12):E78-83.
The SCN5A gene encodes the alpha subunit of the human heart sodium channel (hH1), which plays a critical role in cardiac excitability. Mutations of SCN5A underlie Brugada syndrome, an inherited disorder that leads to ventricular fibrillation and sudden death. This study describes changes in cellula
r localization and functional expression of hH1 in a naturally occurring SCN5A mutation (R1432G) reported for Brugada syndrome. Using patch-clamp experiments, we show that there is an abolition of functional hH1 expression in R1432G mutants expressed in human tsA201 cells but not in Xenopus oocytes. In tsA201 cells, a conservative positively charged mutant, R1432K, produced sodium currents with normal gating properties, whereas other mutations at this site abolished functional sodium channel expression. Immunofluorescent staining and confocal microscopy showed that the wild-type alpha subunit expressed in tsA201 cells was localized to the cell surface, whereas the R1432G mutant was colocalized with calnexin within the endoplasmic reticulum. The beta(1) subunit was also localized to the cell surface in the presence of the alpha subunit; however, in its absence, the beta(1) subunit was restricted to a perinuclear localization. These results demonstrate that the disruption of SCN5A cell-surface localization is one mechanism that can account for the loss of functional sodium channels in Brugada syndrome. The full text of this article is available at http://www.circresaha.org.
PURPOSE: To assess the frequency and clinical features of childhood-onset intractable epilepsy caused by the most common mutations in the POLG gene, which encodes the catalytic subunit of mitochondrial DNA polymerase gamma. METHODS: Children presenting with nonsyndromic intractable epilepsy of unkn
own etiology but without documented liver dysfunction at presentation were eligible for this prospective, population-based study. Blood samples were analyzed for the three most common POLG mutations. If any of the three tested mutations were found, all the exons and the exon-intron boundaries of the POLG gene were sequenced. In addition, we retrospectively reviewed the notes of patients presenting with intractable epilepsy in which we had found POLG mutations. All available clinical data were collected by questionnaire and by reviewing the medical records. KEY FINDINGS: We analyzed 213 blood DNA samples from patients fulfilling the inclusion criteria of the prospective study. Among these, five patients (2.3%) were found with one of the three common POLG mutations as homozygous or compound heterozygous states. In addition, three patients were retrospectively identified. Seven of the eight patients had either raised cerebrospinal fluid (CSF) lactate (n = 3) or brain magnetic resonance imaging (MRI) changes (n = 4) at presentation with intractable epilepsy. Three patients later developed liver dysfunction, progressing to fatal liver failure in two without previous treatment with sodium valproate (VPA). Furthermore, it is worth mentioning that one patient presented first with an autism spectrum disorder before seizures emerged. SIGNIFICANCE: Mutations in POLG are an important cause of early and juvenile onset nonsyndromic intractable epilepsy with highly variable associated manifestations including autistic features. This study emphasizes that genetic testing for POLG mutations in patients with nonsyndromic intractable epilepsies is very important for clinical diagnostics, genetic counseling, and treatment decisions because of the increased risk for VPA-induced liver failure in patients with POLG mutations. We recommend POLG gene testing for patients with intractable seizures and at least one elevated CSF lactate or suggestive brain MRI changes (predominantly abnormal T2 -weighted thalamic signal) with or without status epilepticus, epilepsia partialis continua, or liver manifestations typical for Alpers disease, especially when the disease course is progressive.
Fahien LA, etal., J Biol Chem. 1985 May 25;260(10):6069-79.
Citrate, malate, and high levels of ATP dissociate the mitochondrial aspartate aminotransferase-glutamate dehydrogenase complex and have an inhibitory effect on the latter enzyme. These effects are opposed by Mg2+, leucine, Mg2+ plus ATP, and carbamyl phosphate synthase-I. In addition, Mg2+ directly
facilitates formation of a complex between glutamate dehydrogenase and the aminotransferase and displaces the aminotransferase from the inner mitochondrial membrane which could enable it to interact with glutamate dehydrogenase in the matrix. Zn2+ also favors an aminotransferase-glutamate dehydrogenase complex. It, however, is a potent inhibitor of and has a high affinity for glutamate dehydrogenase. Leucine, however, enhances binding of Mg2+ and decreases binding of and the effect of Zn2+ on the enzyme. Thus, since both metal ions enhance enzyme-enzyme interaction and Zn2+ is a more potent inhibitor, the addition of leucine in the presence of both metal ions results in activation of glutamate dehydrogenase without disruption of the enzyme-enzyme complex. Furthermore, the combination of leucine plus Mg2+ produces slightly more activation than leucine alone. These results indicate that leucine, carbamyl phosphate synthase-I, and its substrate and cofactor, ATP and Mg2+, operate synergistically to facilitate glutamate dehydrogenase activity and interaction between this enzyme and the aminotransferase. Alternatively, Krebs cycle intermediates, such as citrate and malate, have opposing effects.
Cui X, etal., Toxicol Pathol. 2004 Jan-Feb;32(1):64-72.
Although arsenic exposure causes liver disease and/or hepatoma, little is known about molecular mechanisms of arsenic-induced liver toxicity or carcinogenesis. We investigated the effects of arsenic on expression of cancer-related genes in a rat liver following subchronic exposure to sodium arsenate
(1, 10, 100 ppm in drinking water), by using real-time quantitative RT-PCR and immunohistochemical analyses. Arsenic accumulated in the rat liver dose-dependently and caused hepatic histopathological changes, such as disruption of hepatic cords, sinusoidal dilation, and fatty infiltration. A 1-month exposure to arsenic significantly increased hepatic mRNA levels of cyclin D1 (10 ppm), ILK (1 ppm), and p27(Kip1) (10 ppm), whereas it reduced mRNA levels of PTEN (1 ppm) and beta-catenin (100 ppm). In contrast, a 4-month arsenic exposure showed increased mRNA expression of cyclin D1 (100 ppm), ILK (1 ppm), and p27(Kip1) (1 and 10 ppm), and decreased expression of both PTEN and beta-catenin at all 3 doses. An immunohistochemical study revealed that each protein expression accords closely with each gene expression of mRNA level. In conclusion, subchronic exposure to inorganic arsenate caused pathological changes and altered expression of cyclin D1, p27(Kip1), ILK, PTEN, and beta-catenin in the liver. This implies that arsenic liver toxicity involves disturbances of some cancer-related molecules.
Poojary SS, etal., J Cancer Res Ther. 2017 Apr-Jun;13(2):235-239. doi: 10.4103/0973-1482.184512.
BACKGROUND: Telomeres, which are bound with shelterin protein complex, play an important role in maintaining genomic stability and its dysfunction may lead to carcinogenesis. Here, we aimed to analyze whether shelterin complex gene expression and telomere length variation, play any role i
n gallbladder carcinogenesis. METHODS: Telomere length analysis was carried out by monochrome multiplex qPCR, whereas expression analysis of shelterin genes was carried out using RT-qPCR. Statistical analysis was carried out using SigmaPlot 11 software. RESULTS: We found significantly reduced telomere length in tumor tissues, and this reduction was seen in both, tumors with or without gallstones in comparison to adjacent non tumor and gallstone (chronic calculous cholecystitis: Inflamed) tissues. Inflamed tissues showed increased telomere length as compared to both adjacent non tumor and tumor tissues. Expression analysis of five shelterin genes showed significant downregulation of TERF1, POT1, and TINF2 genes in inflamed tissues as compared to non tumor and tumor tissues. POT1 was also found to be significantly upregulated in tumor tissues and specifically in tumor tissues with gallstones compared to inflamed tissues. CONCLUSION: This study, thus, suggests that, gallstone does not affect telomere length and even after having increased telomere length, decreased expression of some shelterin genes in inflamed tissue might cause telomeres to cap improperly, possibly leading to telomere dysfunction and further, gallbladder carcinogenesis. Also, increased expression of POT1 in tumor tissues with gallstones could act as a diagnostic marker in patients with gallstones.
Ahmad F, etal., PLoS One. 2008 Jul 9;3(7):e2642. doi: 10.1371/journal.pone.0002642.
BACKGROUND: Hypertrophic (HCM) and dilated (DCM) cardiomyopathies result from sarcomeric protein mutations, including cardiac troponin T (cTnT, TNNT2). We determined whether TNNT2 mutations cause cardiomyopathies by altering cTnT function or quantity; whether the severity of DCM is related to the ra
tio of mutant to wildtype cTnT; whether Ca(2+) desensitization occurs in DCM; and whether absence of cTnT impairs early embryonic cardiogenesis. METHODS AND FINDINGS: We ablated Tnnt2 to produce heterozygous Tnnt2(+/-) mice, and crossbreeding produced homozygous null Tnnt2(-/-) embryos. We also generated transgenic mice overexpressing wildtype (TG(WT)) or DCM mutant (TG(K210Delta)) Tnnt2. Crossbreeding produced mice lacking one allele of Tnnt2, but carrying wildtype (Tnnt2(+/-)/TG(WT)) or mutant (Tnnt2(+/-)/TG(K210Delta)) transgenes. Tnnt2(+/-) mice relative to wildtype had significantly reduced transcript (0.82+/-0.06[SD] vs. 1.00+/-0.12 arbitrary units; p = 0.025), but not protein (1.01+/-0.20 vs. 1.00+/-0.13 arbitrary units; p = 0.44). Tnnt2(+/-) mice had normal hearts (histology, mass, left ventricular end diastolic diameter [LVEDD], fractional shortening [FS]). Moreover, whereas Tnnt2(+/-)/TG(K210Delta) mice had severe DCM, TG(K210Delta) mice had only mild DCM (FS 18+/-4 vs. 29+/-7%; p<0.01). The difference in severity of DCM may be attributable to a greater ratio of mutant to wildtype Tnnt2 transcript in Tnnt2(+/-)/TG(K210Delta) relative to TG(K210Delta) mice (2.42+/-0.08, p = 0.03). Tnnt2(+/-)/TG(K210Delta) muscle showed Ca(2+) desensitization (pCa(50) = 5.34+/-0.08 vs. 5.58+/-0.03 at sarcomere length 1.9 microm, p<0.01), but no difference in maximum force generation. Day 9.5 Tnnt2(-/-) embryos had normally looped hearts, but thin ventricular walls, large pericardial effusions, noncontractile hearts, and severely disorganized sarcomeres. CONCLUSIONS: Absence of one Tnnt2 allele leads to a mild deficit in transcript but not protein, leading to a normal cardiac phenotype. DCM results from abnormal function of a mutant protein, which is associated with myocyte Ca(2+) desensitization. The severity of DCM depends on the ratio of mutant to wildtype Tnnt2 transcript. cTnT is essential for sarcomere formation, but normal embryonic heart looping occurs without contractile activity.
Sonnenblick A, etal., Clin Transl Oncol. 2012 Mar;14(3):232-6. doi: 10.1007/s12094-012-0789-z.
BACKGROUND: Although lymph node-positive breast cancers are associated with poorer prognosis, individual patients may have different clinical outcomes. Signal transducer and activator of transcription 3 (STAT3) is a point of convergence for numerous oncogenic signalling pathways. The goal of this st
udy was to determine the prognostic value of phosphorylated (tyrosine705)-STAT3 in node-positive breast cancer patients. METHODS: Immunohistochemical analysis of Phospho- STAT3 was performed on a tissue microarray of breast cancer specimens. The expression pattern of Phospho-STAT3 was correlated with survival outcome, and clinical and pathological parameters. RESULTS: Out of 125 interpretable tumours, positive Phospho- STAT3 nuclear expression was seen in 35 (28%) of tumours. There was no significant relationship between Phospho-STAT3 expression and clinical-pathological parameters including age, hormonal receptor status, grade and tumour size. Interestingly positive tumours had a significantly improved disease-free survival at 5 years (p=0.035). Additionally, positive Phospho-STAT3 nuclear expression was correlated with significantly improved survival at both 5 years (p=0.023) and 10 years (p=0.026). Finally, in multivariate analyses Phospho-STAT3 was found to be an independent prognostic marker of overall survival in node-positive breast cancer patients. CONCLUSION: These findings support the role of Phospho- STAT3 as an important independent prognostic marker in node-positive breast cancer patients.
Transient receptor potential melastatin 7 (TRPM7) is a bifunctional protein comprising a magnesium (Mg(2+))/cation channel and a kinase domain. We previously demonstrated that vasoactive agents regulate vascular TRPM7. Whether TRPM7 plays a role in the pathophysiology of hypertension and associated
cardiovascular dysfunction is unknown. We studied TRPM7 kinase-deficient mice (TRPM7Deltakinase; heterozygous for TRPM7 kinase) and wild-type (WT) mice infused with angiotensin II (Ang II; 400 ng/kg per minute, 4 weeks). TRPM7 kinase expression was lower in heart and aorta from TRPM7Deltakinase versus WT mice, effects that were further reduced by Ang II infusion. Plasma Mg(2+) was lower in TRPM7Deltakinase versus WT mice in basal and stimulated conditions. Ang II increased blood pressure in both strains with exaggerated responses in TRPM7Deltakinase versus WT groups (P<0.05). Acetylcholine-induced vasorelaxation was reduced in Ang II-infused TRPM7Deltakinase mice, an effect associated with Akt and endothelial nitric oxide synthase downregulation. Vascular cell adhesion molecule-1 expression was increased in Ang II-infused TRPM7 kinase-deficient mice. TRPM7 kinase targets, calpain, and annexin-1, were activated by Ang II in WT but not in TRPM7Deltakinase mice. Echocardiographic and histopathologic analysis demonstrated cardiac hypertrophy and left ventricular dysfunction in Ang II-treated groups. In TRPM7 kinase-deficient mice, Ang II-induced cardiac functional and structural effects were amplified compared with WT counterparts. Our data demonstrate that in TRPM7Deltakinase mice, Ang II-induced hypertension is exaggerated, cardiac remodeling and left ventricular dysfunction are amplified, and endothelial function is impaired. These processes are associated with hypomagnesemia, blunted TRPM7 kinase expression/signaling, endothelial nitric oxide synthase downregulation, and proinflammatory vascular responses. Our findings identify TRPM7 kinase as a novel player in Ang II-induced hypertension and associated vascular and target organ damage.
Wang H, etal., Proc Natl Acad Sci U S A. 2006 Sep 5;103(36):13463-7. doi: 10.1073/pnas.0603676103. Epub 2006 Aug 28.
Prematurity is more prevalent in African Americans than in European Americans. We investigated the contribution of a functional SNP in the promoter of the SERPINH1 gene, enriched among those of African ancestry, to preterm premature rupture of membranes (PPROM), the leading identifiable cause of pre
term birth. SERPINH1 encodes heat-shock protein 47, a chaperone essential for collagen synthesis. The SERPINH1 -656 minor T allele had a greater frequency in African populations and African Americans than in European Americans (7.4% [corrected] vs. 4.1%). The -656 T allele displayed significantly reduced promoter activity compared to the major -656 C allele in amnion fibroblasts, which lay down the fibrillar collagen that gives tensile strength to the amnion. An initial case-control study demonstrated that the -656 T allele is significantly more frequent in African-American neonates (P < 0.0009) born from pregnancies complicated by PPROM compared with controls (odds ratio of 3.22, 95% confidence interval 1.50, 7.22). There was no significant difference in ancestry among cases and controls using a dihybrid model based on 29 ancestry-informative markers. Adjusting the results of the case-control study for admixture still yielded a statistically significant association between the -656 T allele and PPROM (P < 0.002). A follow-up case-control study gave similar results. The combined case-control findings showed a highly significant (P < 0.0000045) association between the -656 T allele and PPROM. The SERPINH1 -656 T allele is the first example of an ancestry-informative marker associated with preterm birth in African Americans.
Stargardt disease (STGD, also known as fundus flavimaculatus; FFM) is an autosomal recessive retinal disorder characterized by a juvenile-onset macular dystrophy, alterations of the peripheral retina, and subretinal deposition of lipofuscin-like material. A gene encoding an ATP-binding cassette (ABC
) transporter was mapped to the 2-cM (centiMorgan) interval at 1p13-p21 previously shown by linkage analysis to harbour the STGD gene. This gene, ABCR, is expressed exclusively and at high levels in the retina, in rod but not cone photoreceptors, as detected by in situ hybridization. Mutational analysis of ABCR in STGD families revealed a total of 19 different mutations including homozygous mutations in two families with consanguineous parentage. These data indicate that ABCR is the causal gene of STGD/FFM.
Mayfield DK, etal., Biochem Biophys Res Commun. 2001 Sep 21;287(2):568-73.
The murine Agouti-Related Protein (mAGRP) is upregulated in obese and diabetic mice and can stimulate hyperphagia when overexpressed in transgenic models. Here we report upstream nucleotide sequences of the human hAGRP gene with putative recognition sites for transcription factors including a site f
or the STAT transactivators. A polymorphism (-38C-->T) was identified in the promoter region and the C/C genotype had significantly higher promoter activity and affinity for transcription factors as tested in periphery- and hypothalamus-derived cell lines. The polymorphic site could affect the expression levels of hAGRP and the high expressing C/C genotype was significantly associated with high BMI and type 2 diabetes in Africans.
PURPOSES: We determined whether a small molecule inhibitor of apoptosis signal-regulating kinase 1 (ASK1-i) could reduce myocardial infarct size in a rat ischemia/reperfusion model. METHODS AND RESULTS: Sprague-Dawley rats were randomized to 3 groups: ASK1-i infusion (n = 16), vehicle infusion (n =
16), or ischemic preconditioning (IPC; n = 15). Infusion of ASK1-i (10 mg/kg, iv) or vehicle commenced 45 minutes before myocardial ischemia. IPC consisted of 3 cycles of 3 minutes of coronary occlusion followed by 5 minutes of reperfusion immediately before index myocardial ischemia, which consisted of 30-minute left coronary occlusion followed by 180 minutes of reperfusion. Pathologic analysis revealed no significant difference in the ischemic risk size among the 3 groups. ASK1-I and IPC significantly reduced myocardial infarct size (27.7% +/- 3.3%, 16.5% +/- 3.4%, and 41.5% +/- 4.8% in the ASK1-i group, the IPC group, and the vehicle group, respectively; P = 0.0002) and apoptosis (the percentage of apoptotic nuclei averaged 11.6% +/- 1.0%, 10.2% +/- 1.7%, and 17.7% +/- 2.0% in the ASK1-i group, IPC group, and vehicle group, respectively, P = 0.0055). CONCLUSIONS: A small molecule inhibitor of ASK1 was shown for the first time to reduce apoptosis and myocardial infarct size in a rat model of ischemia/reperfusion.
Rapid conduction in myelinated axons depends on the generation of specialized subcellular domains to which different sets of ion channels are localized. Here, we describe the identification of Caspr2, a mammalian homolog of Drosophila Neurexin IV (Nrx-IV), and show that this neurexin-like protein a
nd the closely related molecule Caspr/Paranodin demarcate distinct subdomains in myelinated axons. While contactin-associated protein (Caspr) is present at the paranodal junctions, Caspr2 is precisely colocalized with Shaker-like K+ channels in the juxtaparanodal region. We further show that Caspr2 specifically associates with Kv1.1, Kv1.2, and their Kvbeta2 subunit. This association involves the C-terminal sequence of Caspr2, which contains a putative PDZ binding site. These results suggest a role for Caspr family members in the local differentiation of the axon into distinct functional subdomains.
Lee CM, etal., Gynecol Oncol. 2005 Nov;99(2):415-21. Epub 2005 Sep 12.
OBJECTIVE: To investigate prognostic significance of and correlations between HER1 (EGFR), HER2 (c-erb-B2), HER3 (c-erb-B3), HER4 (c-erb-B4), and phosphorylated Akt (P-Akt) in patients treated with radiation for cervical carcinoma. METHODS: Fifty-five patients with stages I-IVA cervical carcinoma we
re treated with definitive radiotherapy. Tumor expression of each biomarker was quantitatively scored by an automated immunohistochemical imaging system. Parametric correlations were performed between biomarkers. Univariate and multivariate analysis was performed with disease-free survival (DFS) and overall survival (OS) as primary endpoints. RESULTS: Correlations were observed between expression of HER2 and HER4 (P = 0.003), and HER3 and HER4 (P = 0.004). Decreased HER2, HER4, and P-Akt expressions were significant for diminished DFS on univariate analysis (P = 0.04, P = 0.008, and P = 0.02, respectively). Increased EGFR, and diminished HER2, HER4, and P-Akt expression were significant or showed trends toward significance for diminished OS on univariate analysis (P = 0.07, P = 0.008, P = 0.09, and P = 0.08, respectively). After controlling for pretreatment factors, multivariate analysis revealed HER2 associated with improved OS (P = 0.05). CONCLUSIONS: These data emphasize that significant correlations exist between the differential expression of various HER family receptors. Multivariate analysis revealed only increased HER2 expression associated with improved OS after controlling for pretreatment clinical factors. These data emphasize the importance of continued basic and translational research on the HER family of receptors in cervical carcinoma.
Action potential conduction velocity increases dramatically during early development as axons become myelinated. Integral to this process is the clustering of voltage-gated Na(+) (Nav) channels at regularly spaced gaps in the myelin sheath called nodes of Ranvier. We show here that some aspects of
peripheral node of Ranvier formation are distinct from node formation in the CNS. For example, at CNS nodes, Nav1.2 channels are detected first, but are then replaced by Nav1.6. Similarly, during remyelination in the CNS, Nav1.2 channels are detected at newly forming nodes. By contrast, the earliest Nav-channel clusters detected during developmental myelination in the PNS have Nav1.6. Further, during PNS remyelination, Nav1.6 is detected at new nodes. Finally, we show that accumulation of the cell adhesion molecule neurofascin always precedes Nav channel clustering in the PNS. In most cases axonal neurofascin (NF-186) accumulates first, but occasionally paranodal neurofascin is detected first. We suggest there is heterogeneity in the events leading to Nav channel clustering, indicating that multiple mechanisms might contribute to node of Ranvier formation in the PNS.
Rummel S, etal., Breast Cancer Res Treat. 2013 Jan;137(1):119-25. doi: 10.1007/s10549-012-2348-2. Epub 2012 Nov 29.
Triple-negative breast cancer (TNBC) is characterized by aggressive behavior and poor prognosis. While >50 % of patients with inherited BRCA1 mutations have TNBC, the prevalence of BRCA1 mutations in patients with TNBC remains unclear. Deciphering the relationship between BRCA1 and TNBC is critical
to understanding the etiology of TNBC, leading to improved patient counseling and treatment. All female patients with TNBC enrolled in the Clinical Breast Care Project were identified. Genomic DNA was isolated from blood and the exonic regions of the BRCA1 gene were amplified and sequenced. Sequence data was analyzed and mutations identified using Sequencher 4.10.1. Of the 190 women with TNBC, genomic DNA was available for 182. Seventy percent of patients were considered high-risk for having a BRCA1 mutation based on the National Comprehensive Cancer Network criteria. Clinically relevant mutations were detected in 16 (9 %) patients ranging in age from 26 to 69 years at diagnosis. Six of these patients were diagnosed >50 years. The C61G mutation was found in three Caucasian women diagnosed >40 years, while six African-American women had mutations, including the 943ins10 West African founder mutation. Upon conclusion, causative BRCA1 mutations were detected in 9 % of TNBC patients, including patients without significant family histories and/or diagnosed at a later age. The mutation frequency in patients <60 years was 11.2-18.3 % in those patients with significant risk factors and 4.6 % in those without, while in patients >60 years, the mutation frequency was 3.5-7.7 % in patients with risk factors, 2.3 % in those without. Thus, evaluation of additional risk factors in both patients younger and older than 60 years should improve the identification of TNBC patients benefiting from genetic testing of BRCA1.
Gastrin-releasing peptide (GRP), a member of the bombesin family of peptides, has been shown to have mitogenic activity in small cell lung carcinoma (SCLC), and to be produced by SCLC in an autocrine fashion. In this report, we demonstrate that both GRP and another member of the bombesin family of
peptides, neuromedin B (NMB), are also autocrine growth factors for non-small cell lung carcinoma (NSCLC). Using the reverse transcription-polymerase chain reaction (RT-PCR), we have detected mRNA for the neuromedin B receptor (NMBR) in all 14 of the NSCLC cell lines examined. GRP receptor (GRPR) mRNA was also expressed in the majority of NSCLC cell lines (nine of 14). By immunoblotting using SDS-PAGE gradient gels fixed in trichloroacetic acid, GRP and NMB were found in fractions of culture medium that had been purified by high pressure liquid chromatography (HPLC) from NSCLC cell lines. NMB was detected in the conditioned medium of seven of nine cell lines and GRP in seven of nine cell lines; both peptides were produced in six cell lines. In four of the cell lines where both peptides were produced, the relative amount of NMB secreted into the medium was 7-15 times that of GRP; in the other two cases, the relative amounts of GRP and NMB were equivalent. Cultured human bronchial epithelial (HBE) cells expressed the GRPR and NMBR but did not produce either peptide. A subline of A549 cells that was adapted to grow in serum-free and growth factor-free conditions, termed A549-R(0), secreted both bombesin-like peptides (BLPs) into the culture medium. Using either a colony-forming assay or a BrDU incorporation assay, both NMB and GRP were found to be mitogens for three NSCLC cell lines that express mRNA for BLP receptors and secrete BLPs, regardless of which peptide and/or receptor subtype was detected. The monoclonal antibody 2A11, which preferentially recognizes GRP, was able to block the in vitro proliferative response to GRP in the BrDU incorporation assay, and partially blocked the response to NMB. The 2A11 antibody could only partially block the in vivo growth of cell lines that showed proliferative responses to BLPs. 2A11 antibody was more effective against the 239T cell line, which secreted a low amount of GRP into the medium (0.6 nM), compared to the 201T cell line, which secreted a higher amount of both GRP and NMB (4.2 nM and 36.6 nM, respectively). These results suggest that both NMB and GRP are autocrine growth factors for NSCLC, but that the production of NMB and expression of the NMBR may be more prominent than the production of GRP and expression of the GRP receptor. If BLP ligand-receptor systems are to be targeted therapeutically in NSCLC, it will be necessary to inhibit both NMB and GRP.
Owens JM, etal., Arch Otolaryngol Head Neck Surg. 2008 Aug;134(8):825-31.
OBJECTIVE: To evaluate the expression of cyclooxygenase (COX) and lipoxygenase (LO) enzymes in the sinonasal mucosa of patients with cystic fibrosis (CF). DESIGN: Immunohistochemical staining of archived tissue. PARTICIPANTS: Specimens from 9 patients with CF were analyzed; control specimens were ob
tained from 4 patients without a history of CF or rhinosinusitis. INTERVENTIONS: Expression of the enzymes COX-1, COX-2, 5-LO, 12-LO, and 15-LO was evaluated with the use of immunohistochemical techniques in archived sinonasal mucosal tissue from patients with CF. These results were compared with those of the control group. RESULTS: We noted the characteristic staining patterns of epithelium and submucosal glands for each enzyme. Statistically significant (P < .05) differences between control and CF specimens were noted in the staining intensity of columnar epithelium for COX-2 (cytoplasm) and 12-LO (cytoplasm and nucleus) and of submucosal glands for COX-2 (cytoplasm) and 12-LO (cytoplasm). No significant differences were noted for the staining intensity of COX-1, 5-LO, or 15-LO between the groups. CONCLUSIONS: Significant differences in sinonasal mucosal expression of COX-2 and 12-LO enzymes exist between patients with CF and controls. This suggests a difference in arachidonic acid metabolism between these 2 groups.
Katsanis N, etal., Clin Genet. 2001 Jun;59(6):424-9.
Fundus albipunctatus (FA; OMIM 136880) is a rare form of apparently stationary night blindness characterized by the presence of myriad symmetrical round white dots in the fundus with a greater concentration in the midperiphery. A distantly similar but distinct clinical entity, retinitis punctata alb
escens (RPA), is also characterized by aggregation of irregular white flecks but is progressive and evolves to generalized atrophy of the retina. We studied 4 consanguineous kindreds diagnosed with FA from Saudi Arabia. Given the substantial phenotypic variation and overlap between different flecked retinal dystrophies, we evaluated all known genes associated with such conditions by both genetic analysis and direct sequencing. In one kindred, KKESH-099, we identified a homozygous R150Q alteration in RLBP1, the gene encoding the cellular retinaldehyde binding protein, associated previously with both recessive retinitis pigmentosa (arRP) and RPA. Examination of several patients aged 3-20 years over a 9-year period presented no evidence for either RP or RPA. In contrast, clinical examination of individuals with the same mutation in their fourth and fifth decade revealed signs consistent with RPA. The data suggest that the R150Q mutation in RLBP1 may result in RPA with slow progression. More importantly, younger individuals diagnosed with the milder disorder FA thought to be stationary may evolve to a more devastating and progressive phenotype.
Glucose levels 2 h after an oral glucose challenge are a clinical measure of glucose tolerance used in the diagnosis of type 2 diabetes. We report a meta-analysis of nine genome-wide association studies (n = 15,234 nondiabetic individuals) and a follow-up of 29 independent loci (n = 6,958-30,620). W
e identify variants at the GIPR locus associated with 2-h glucose level (rs10423928, beta (s.e.m.) = 0.09 (0.01) mmol/l per A allele, P = 2.0 x 10(-15)). The GIPR A-allele carriers also showed decreased insulin secretion (n = 22,492; insulinogenic index, P = 1.0 x 10(-17); ratio of insulin to glucose area under the curve, P = 1.3 x 10(-16)) and diminished incretin effect (n = 804; P = 4.3 x 10(-4)). We also identified variants at ADCY5 (rs2877716, P = 4.2 x 10(-16)), VPS13C (rs17271305, P = 4.1 x 10(-8)), GCKR (rs1260326, P = 7.1 x 10(-11)) and TCF7L2 (rs7903146, P = 4.2 x 10(-10)) associated with 2-h glucose. Of the three newly implicated loci (GIPR, ADCY5 and VPS13C), only ADCY5 was found to be associated with type 2 diabetes in collaborating studies (n = 35,869 cases, 89,798 controls, OR = 1.12, 95% CI 1.09-1.15, P = 4.8 x 10(-18)).
The metabolic syndrome (MetS) is a constellation of metabolic disorders that increase the risk of developing several diseases including type 2 diabetes and cardiovascular diseases. Although genome-wide association studies (GWAS) have successfully identified variants associated with individual traits
comprising MetS, the genetic basis and pathophysiological mechanisms underlying the clustering of these traits remain unclear. We conducted GWAS of MetS in 1427 Africans from Ghana and Nigeria followed by replication testing and meta-analysis in another continental African sample from Kenya. Further replication testing was performed in an African American sample from the Atherosclerosis Risk in Communities (ARIC) study. We found two African-ancestry specific variants that were significantly associated with MetS: SNP rs73989312[A] near CA10 that conferred increased risk (P=3.86 x 10(-8), OR=6.80) and SNP rs77244975[C] in CTNNA3 that conferred protection against MetS (P=1.63 x 10(-8), OR=0.15). Given the exclusive expression of CA10 in the brain, our CA10 finding strengthens previously reported link between brain function and MetS. We also identified two variants that are not African specific: rs76822696[A] near RALYL associated with increased MetS risk (P=7.37 x 10(-9), OR=1.59) and rs7964157[T] near KSR2 associated with reduced MetS risk (P=4.52 x 10(-8), Pmeta=7.82 x 10(-9), OR=0.53). The KSR2 locus displayed pleiotropic associations with triglyceride and measures of blood pressure. Rare KSR2 mutations have been reported to be associated with early onset obesity and insulin resistance. Finally, we replicated the LPL and CETP loci previously found to be associated with MetS in Europeans. These findings provide novel insights into the genetics of MetS in Africans and demonstrate the utility of conducting trans-ethnic disease gene mapping studies for testing the cosmopolitan significance of GWAS signals of cardio-metabolic traits.
Lewis RA, etal., Am J Hum Genet. 1999 Feb;64(2):422-34.
Mutation scanning and direct DNA sequencing of all 50 exons of ABCR were completed for 150 families segregating recessive Stargardt disease (STGD1). ABCR variations were identified in 173 (57%) disease chromosomes, the majority of which represent missense amino acid substitutions. These ABCR varian
ts were not found in 220 unaffected control individuals (440 chromosomes) but do cosegregate with the disease in these families with STGD1, and many occur in conserved functional domains. Missense amino acid substitutions located in the amino terminal one-third of the protein appear to be associated with earlier onset of the disease and may represent misfolding alleles. The two most common mutant alleles, G1961E and A1038V, each identified in 16 of 173 disease chromosomes, composed 18.5% of mutations identified. G1961E has been associated previously, at a statistically significant level in the heterozygous state, with age-related macular degeneration (AMD). Clinical evaluation of these 150 families with STGD1 revealed a high frequency of AMD in first- and second-degree relatives. These findings support the hypothesis that compound heterozygous ABCR mutations are responsible for STGD1 and that some heterozygous ABCR mutations may enhance susceptibility to AMD.
Liu Y, etal., J Invest Dermatol. 2016 Feb;136(2):378-86. doi: 10.1016/j.jid.2015.10.067. Epub 2015 Nov 24.
GORAB is a golgin that localizes predominantly at the Golgi apparatus and physically interacts with small guanosine triphosphatases. GORAB is ubiquitously expressed in mammalian tissues, including the skin. However, the biological function of this golgin in skin is unknown. Here, we report that dis
rupting the expression of the Gorab gene in mice results in hair follicle morphogenesis defects that were characterized by impaired follicular keratinocyte differentiation. This hair follicle phenotype was associated with markedly suppressed hedgehog (Hh) signaling pathway in dermal condensates in vivo. Gorab-deficient dermal mesenchymal cells also displayed a significantly reduced capability to respond to Hh pathway activation in vitro. Furthermore, we found that the formation of the primary cilium, a cellular organelle that is essential for the Hh pathway, was impaired in mutant dermal condensate cells, suggesting that Gorab may be required for the Hh pathway through facilitating the formation of primary cilia. Thus, data obtained from this study provided insight into the biological functions of Gorab during embryonic morphogenesis of the skin in which Hh signaling and primary cilia exert important functions.
Krishnaveni D, etal., Indian J Cancer. 2015 Apr-Jun;52(2):251-4. doi: 10.4103/0019-509X.175806.
BACKGROUND: Gastric cancer (GC) is the third most common cancer in India and is mediated by multiple genetic, epigenetic and environmental risk factors. A single nucleotide polymorphism rs3025058 at -1171 of the stromelysin-1 (matrix metalloproteinase [MMP]-3) promoter is resulting due to insertion/
deletion of adenine thought to have an impact on increasing the risk for tumor formation. AIM: This study is aimed to understand the role of stromelysin-1 rs3025058 (-1171, 5A/6A) promoter polymorphism in the etiology of GC in Indian population. MATERIALS AND METHODS: Genomic DNA was isolated from blood samples of the GC patients and controls. The genotyping of stromelysin-1 rs3025058 (-1171, 5A/6A) promoter polymorphism was carried out by amplification refractory mutation system-polymerase chain reaction method followed by agarose gel electrophoresis. RESULTS: The frequency of 5A/5A, 5A/6A, and 6A/6A genotypes in GC patients were 7.69%, 76.92%, and 15.38%, while in controls were 5.31%, 86.73%, and 7.96%, respectively. There was a significant difference in the distribution of 5A/6A genotype in patients compared to the controls (P < 0.05). CONCLUSION: This study showed an increased frequency of heterozygotes for stromelysin-1 rs3025058 and thought to be involved in the etiology of GC.
Evensen NA, etal., Oncotarget. 2015 Aug 21;6(24):20723-39.
Hypoxic stress drives cancer progression by causing a transcriptional reprogramming. Recently, KIAA1199 was discovered to be a cell-migration inducing protein (renamed CEMIP) that is upregulated in human cancers. However, the mechanism of induction of CEMIP in cancer was hitherto unknown. Here we d
emonstrate that hypoxia induces CEMIP expression leading to enhanced cell migration. Immunohistochemistry of human colon cancer tissues revealed that CEMIP is upregulated in cancer cells located at the invasive front or in the submucosa. CEMIP localization inversely correlated with E-cadherin expression, which is characteristic of the epithelial-to-mesenchymal transition. Mechanistically, hypoxia-inducible-factor-2alpha (HIF-2alpha), but not HIF-1alpha binds directly to the hypoxia response element within the CEMIP promoter region resulting in increased CEMIP expression. Functional characterization reveals that CEMIP is a downstream effector of HIF-2alpha-mediated cell migration. Expression of CEMIP was demonstrated to negatively correlate with the expression of Jarid1A, a histone demethylase that removes methyl groups from H3K4me3 (an activation marker for transcription), resulting in altered gene repression. Low oxygen tension inhibits the function of Jarid1A, leading to increased presence of H3K4me3 within the CEMIP promoter. These results provide insight into the upregulation of CEMIP within cancer and can lead to novel treatment strategies targeting this cancer cell migration-promoting gene.
Bastos MF, etal., FASEB J. 2018 Aug;32(8):4470-4481. doi: 10.1096/fj.201700844R. Epub 2018 Mar 20.
Cerebral malaria (CM) is a multifactorial syndrome involving an exacerbated proinflammatory status, endothelial cell activation, coagulopathy, hypoxia, and accumulation of leukocytes and parasites in the brain microvasculature. Despite significant improvements in malaria control, 15% of mortality is
still observed in CM cases, and 25% of survivors develop neurologic sequelae for life-even after appropriate antimalarial therapy. A treatment that ameliorates CM clinical signs, resulting in complete healing, is urgently needed. Previously, we showed a hyperbaric oxygen (HBO)-protective effect against experimental CM. Here, we provide molecular evidence that HBO targets brain endothelial cells by decreasing their activation and inhibits parasite and leukocyte accumulation, thus improving cerebral microcirculatory blood flow. HBO treatment increased the expression of aryl hydrocarbon receptor over hypoxia-inducible factor 1-α (HIF-1α), an oxygen-sensitive cytosolic receptor, along with decreased indoleamine 2,3-dioxygenase 1 expression and kynurenine levels. Moreover, ablation of HIF-1α expression in endothelial cells in mice conferred protection against CM and improved survival. We propose that HBO should be pursued as an adjunctive therapy in CM patients to prolong survival and diminish deleterious proinflammatory reaction. Furthermore, our data support the use of HBO in therapeutic strategies to improve outcomes of non-CM disorders affecting the brain.-Bastos, M. F., Kayano, A. C. A. V., Silva-Filho, J. L., Dos-Santos, J. C. K., Judice, C., Blanco, Y. C., Shryock, N., Sercundes, M. K., Ortolan, L. S., Francelin, C., Leite, J. A., Oliveira, R., Elias, R. M., Câmara, N. O. S., Lopes, S. C. P., Albrecht, L., Farias, A. S., Vicente, C. P., Werneck, C. C., Giorgio, S., Verinaud, L., Epiphanio, S., Marinho, C. R. F., Lalwani, P., Amino, R., Aliberti, J., Costa, F. T. M. Inhibition of hypoxia-associated response and kynurenine production in response to hyperbaric oxygen as mechanisms involved in protection against experimental cerebral malaria.
Lindemans CA, etal., Nature. 2015 Dec 24;528(7583):560-4. doi: 10.1038/nature16460. Epub 2015 Dec 9.
Epithelial regeneration is critical for barrier maintenance and organ function after intestinal injury. The intestinal stem cell (ISC) niche provides Wnt, Notch and epidermal growth factor (EGF) signals supporting Lgr5(+) crypt base columnar ISCs for normal epithelial maintenance. However, little i
s known about the regulation of the ISC compartment after tissue damage. Using ex vivo organoid cultures, here we show that innate lymphoid cells (ILCs), potent producers of interleukin-22 (IL-22) after intestinal injury, increase the growth of mouse small intestine organoids in an IL-22-dependent fashion. Recombinant IL-22 directly targeted ISCs, augmenting the growth of both mouse and human intestinal organoids, increasing proliferation and promoting ISC expansion. IL-22 induced STAT3 phosphorylation in Lgr5(+) ISCs, and STAT3 was crucial for both organoid formation and IL-22-mediated regeneration. Treatment with IL-22 in vivo after mouse allogeneic bone marrow transplantation enhanced the recovery of ISCs, increased epithelial regeneration and reduced intestinal pathology and mortality from graft-versus-host disease. ATOH1-deficient organoid culture demonstrated that IL-22 induced epithelial regeneration independently of the Paneth cell niche. Our findings reveal a fundamental mechanism by which the immune system is able to support the intestinal epithelium, activating ISCs to promote regeneration.
In myelinated axons, K+ channels are concealed under the myelin sheath in the juxtaparanodal region, where they are associated with Caspr2, a member of the neurexin superfamily. Deletion of Caspr2 in mice by gene targeting revealed that it is required to maintain K+ channels at this location. Furth
ermore, we show that the localization of Caspr2 and clustering of K+ channels at the juxtaparanodal region depends on the presence of TAG-1, an immunoglobulin-like cell adhesion molecule that binds Caspr2. These results demonstrate that Caspr2 and TAG-1 form a scaffold that is necessary to maintain K+ channels at the juxtaparanodal region, suggesting that axon-glia interactions mediated by these proteins allow myelinating glial cells to organize ion channels in the underlying axonal membrane.
Yatsenko AN, etal., Hum Genet. 2001 Apr;108(4):346-55.
Based on recent studies of the photoreceptor-specific ABC transporter gene ABCR (ABCA4) in Stargardt disease (STGD1) and other retinal dystrophies, we and others have developed a model in which the severity of retinal disease correlates inversely with residual ABCR activity. This model predicts that
patients with late-onset STGDI may retain partial ABCR activity attributable to mild missense alleles. To test this hypothesis, we used late-onset STGDI patients (onset: > or =35 years) to provide an in vivo functional analysis of various combinations of mutant alleles. We sequenced directly the entire coding region of ABCR and detected mutations in 33/50 (66%) disease chromosomes, but surprisingly, 11/33 (33%) were truncating alleles. Importantly, all 22 missense mutations were located outside the known functional domains of ABCR (ATP-binding or transmembrane), whereas in our general cohort of STGDI subjects, alterations occurred with equal frequency across the entire protein. We suggest that these missense mutations in regions of unknown function are milder alleles and more susceptible to modifier effects. Thus, we have corroborated a prediction from the model of ABCR pathogenicity that (1) one mutant ABCR allele is always missense in late-onset STGD1 patients, and (2) the age-of-onset is correlated with the amount of ABCR activity of this allele. In addition, we report three new pseudodominant families that now comprise eight of 178 outbred STGD1 families and suggest a carrier frequency of STGD1-associated ABCR mutations of about 4.5% (approximately 1/22).
Zhang T, etal., Int J Cardiol. 2011 Mar 3;147(2):239-45. doi: 10.1016/j.ijcard.2009.08.047. Epub 2009 Sep 17.
OBJECTIVE: Mutations in the cardiac sodium channel gene SCN5A cause long QT syndrome (LQTS). We previously generated an LQTS mouse model (TG-NS) that overexpresses the LQTS mutation N1325S in SCN5A. The TG-NS mice manifested the clinical features of LQTS including spontaneous VT, syncope and sudden
death. However, the long-term prognosis of LQTS on the structure of the heart has not been investigated in this or any other LQTS models and human patients. METHODS AND RESULTS: Impaired systolic function and reduced left ventricular fractional shortening were detected by echocardiography, morphological and histological examination in two lines of adult mutant transgenic mice. Histological and TUNEL analyses of heart sections revealed fibrosis lesions and increased apoptosis in an age-dependent manner. Cardiomyocyte apoptosis was associated with the increased activation of caspases 3 and 9 in TG-NS hearts. Western blot analysis showed a significantly increased expression of the key Ca(2+) handling proteins L-type Ca(2+) channel, RYR2 and NCX in TG-NS hearts. Increased apoptosis and an altered expression of Ca(2+) handling proteins could be detected as early as 3months of age when echocardiography showed little or no alterations in TG-NS mice. CONCLUSIONS: Our findings revealed for the first time that the LQTS mutation N1325S in SCN5A causes cardiac fibrosis and contractile dysfunction in mice, possibly through cellular mechanisms involving aberrant cardiomyocyte apoptosis. Therefore, we provide the experimental evidence supporting the notion that some LQTS patients have an increased risk of structural and functional cardiac damage in a prolonged disease course.
Age-related macular degeneration (AMD) is the leading cause of severe central visual impairment among the elderly and is associated both with environmental factors such as smoking and with genetic factors. Here, 167 unrelated AMD patients were screened for alterations in ABCR, a gene that encodes a
retinal rod photoreceptor protein and is defective in Stargardt disease, a common hereditary form of macular dystrophy. Thirteen different AMD-associated alterations, both deletions and amino acid substitutions, were found in one allele of ABCR in 26 patients (16%). Identification of ABCR alterations will permit presymptomatic testing of high-risk individuals and may lead to earlier diagnosis of AMD and to new strategies for prevention and therapy.
Hedstrom KL, etal., J Cell Biol. 2007 Aug 27;178(5):875-86. doi: 10.1083/jcb.200705119. Epub 2007 Aug 20.
Action potential initiation and propagation requires clustered Na(+) (voltage-gated Na(+) [Nav]) channels at axon initial segments (AIS) and nodes of Ranvier. In addition to ion channels, these domains are characterized by cell adhesion molecules (CAMs; neurofascin-186 [NF-186] and neuron glia-relat
ed CAM [NrCAM]), cytoskeletal proteins (ankyrinG and betaIV spectrin), and the extracellular chondroitin-sulfate proteoglycan brevican. Schwann cells initiate peripheral nervous system node formation by clustering NF-186, which then recruits ankyrinG and Nav channels. However, AIS assembly of this protein complex does not require glial contact. To determine the AIS assembly mechanism, we silenced expression of AIS proteins by RNA interference. AnkyrinG knockdown prevented AIS localization of all other AIS proteins. Loss of NF-186, NrCAM, Nav channels, or betaIV spectrin did not affect other neuronal AIS proteins. However, loss of NF-186 blocked assembly of the brevican-based AIS extracellular matrix, and NF-186 overexpression caused somatodendritic brevican clustering. Thus, NF-186 assembles and links the specialized brevican-containing AIS extracellular matrix to the intracellular cytoskeleton.
Gao L, etal., Am J Respir Cell Mol Biol. 2006 Apr;34(4):487-95. Epub 2006 Jan 6.
The genetic basis of acute lung injury (ALI) is poorly understood. The myosin light chain kinase (MYLK) gene encodes the nonmuscle myosin light chain kinase isoform, a multifunctional protein involved in the inflammatory response (apoptosis, vascular permeability, leukocyte diapedesis). To examine M
YLK as a novel candidate gene in sepsis-associated ALI, we sequenced exons, exon-intron boundaries, and 2 kb of 5' UTR of the MYLK, which revealed 51 single-nucleotide polymorphisms (SNPs). Potential association of 28 MYLK SNPs with sepsis-associated ALI were evaluated in a case-control sample of 288 European American subjects (EAs) with sepsis alone, subjects with sepsis-associated ALI, or healthy control subjects, and a sample population of 158 African American subjects (AAs) with sepsis and ALI. Significant single locus associations in EAs were observed between four MYLK SNPs and the sepsis phenotype (P<0.001), with an additional SNP associated with the ALI phenotype (P=0.03). A significant association of a single SNP (identical to the SNP identified in EAs) was observed in AAs with sepsis (P=0.002) and with ALI (P=0.01). Three sepsis risk-conferring haplotypes in EAs were defined downstream of start codon of smooth muscle MYLK isoform, a region containing putative regulatory elements (P<0.001). In contrast, multiple haplotypic analyses revealed an ALI-specific, risk-conferring haplotype at 5' of the MYLK gene in both European and African Americans and an additional 3' region haplotype only in African Americans. These data strongly implicate MYLK genetic variants to confer increased risk of sepsis and sepsis-associated ALI.
Bateman NW, etal., Cancer. 2017 Oct 15;123(20):4004-4012. doi: 10.1002/cncr.30813. Epub 2017 Jun 27.
BACKGROUND: The objective of this study was to identify molecular alterations associated with disease outcomes for white and black patients with endometrioid endometrial cancer (EEC). METHODS: EEC samples from black (n = 17) and white patients (n = 13) were analyzed by proteomic
Jones JM, etal., Neurobiol Dis. 2016 May;89:36-45. doi: 10.1016/j.nbd.2016.01.018. Epub 2016 Jan 22.
Mutations of the neuronal sodium channel gene SCN8A are associated with lethal movement disorders in the mouse and with human epileptic encephalopathy. We describe a spontaneous mouse mutation, Scn8a(9J), that is associated with a chronic movement disorder with early onset tremor and adult onset dys
tonia. Scn8a(9J) homozygotes have a shortened lifespan, with only 50% of mutants surviving beyond 6months of age. The 3bp in-frame deletion removes 1 of the 3 adjacent isoleucine residues in transmembrane segment DIVS6 of Nav1.6 (p.Ile1750del). The altered helical orientation of the transmembrane segment displaces pore-lining amino acids with important roles in channel activation and inactivation. The predicted impact on channel activity was confirmed by analysis of cerebellar Purkinje neurons from mutant mice, which lack spontaneous and induced repetitive firing. In a heterologous expression system, the activity of the mutant channel was below the threshold for detection. Observations of decreased nerve conduction velocity and impaired behavior in an open field are also consistent with reduced activity of Nav1.6. The Nav1.6Delta1750 protein is only partially glycosylated. The abundance of mutant Nav1.6 is reduced at nodes of Ranvier and is not detectable at the axon initial segment. Despite a severe reduction in channel activity, the lifespan and motor function of Scn8a(9J/9J) mice are significantly better than null mutants lacking channel protein. The clinical phenotype of this severe hypomorphic mutant expands the spectrum of Scn8a disease to include a recessively inherited, chronic and progressive movement disorder.
Perry ST, etal., PLoS Pathog. 2011 Feb;7(2):e1001297. doi: 10.1371/journal.ppat.1001297. Epub 2011 Feb 17.
Dengue virus (DENV) is a mosquito-borne flavivirus, and symptoms of infection range from asymptomatic to the severe dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). High viral loads correlate with disease severity, and both type I & II interferons (IFNs) are crucial for controlling viral re
plication. We have previously reported that signal transducer and activator of transcription (STAT) 1-deficient mice are resistant to DENV-induced disease, but little is known about this STAT1-independent mechanism of protection. To determine the molecular basis of the STAT1-independent pathway, mice lacking STAT1, STAT2, or both STAT1 and STAT2 were infected with a virulent mouse-adapted strain of DENV2. In the first 72 hours of infection, the single-deficient mice lacking STAT1 or STAT2 possessed 50-100 fold higher levels of viral RNA than wild type mice in the serum, spleen, and other visceral tissues, but remained resistant to DENV-induced death. In contrast, the double-deficient mice exhibited the early death phenotype previously observed in type I and II IFN receptor knockout mice (AG129), indicating that STAT2 is the mediator of the STAT1-independent host defense mechanism. Further studies demonstrated that this STAT2-dependent STAT1-independent mechanism requires the type I IFN receptor, and contributes to the autocrine amplification of type I IFN expression. Examination of gene expression in the spleen and bone marrow-derived macrophages following DENV infection revealed STAT2-dependent pathways can induce the transcription of a subset of interferon stimulated genes even in the absence of STAT1. Collectively, these results help elucidate the nature of the poorly understood STAT1-independent host defense mechanism against viruses by identifying a functional type I IFN/STAT2 signaling pathway following DENV infection in vivo.
Cleveland HH, etal., Dev Psychopathol. 2015 Feb;27(1):51-67. doi: 10.1017/S0954579414001291.
Data drawn from the in-home subsample of the PROSPER intervention dissemination trial were used to investigate the moderation of intervention effects on underage alcohol use by maternal involvement and candidate genes. The primary gene examined was dopamine receptor D4 (DRD4). Variation in this gene
and maternal involvement were hypothesized to moderate the influence of intervention status on alcohol use. The PROSPER data used were drawn from 28 communities randomly assigned to intervention or comparison conditions. Participating youth were assessed in five in-home interviews from sixth to ninth grades. A main effect of sixth-grade pretest maternal involvement on ninth-grade alcohol use was found. Neither intervention status nor DRD4 variation was unconditionally linked to ninth-grade drinking. However, moderation analyses revealed a significant three-way interaction among DRD4 status, maternal involvement, and intervention condition. Follow-up analyses revealed that prevention reduced drinking risk, but only for youth with at least one DRD4 seven-repeat allele who reported average or greater pretest levels of maternal involvement. To determine if this conditional pattern was limited to the DRD4 gene, we repeated analyses using the serotonin transporter linked polymorphic region site near the serotonin transporter gene. The results for this supplemental analysis revealed a significant three-way interaction similar but not identical to that found for DRD4.
1. Adipocyte A(1)-adenosine receptors (A(1) AdoR) tonically inhibit adenylyl cyclase and lipolysis. Three potential explanations for tonic activity of A(1)AdoR of rat epididymal adipocytes were investigated: high affinity of adenosine for the receptor, efficient coupling of receptor activation to re
sponse, and spontaneous activity of the receptor in the absence of agonist. 2. The affinity of adenosine for the adipocyte A(1)AdoR was determined as 4.6 microM by analysis of effects of an irreversible receptor antagonist on agonist concentration-response relationships. In contrast, the potency of adenosine to decrease cyclic AMP in isolated adipocytes was 1.4 nM. 3. Occupancy by agonist of the A(1)AdoR was efficiently coupled to functional response (decrease of adipocyte cyclic AMP content). Activation by adenosine of less than 1% of A(1)AdoRs caused a near-maximal decrease of cyclic AMP in adipocytes. Thus the receptor reserve for adenosine to decrease cyclic AMP content of adipocytes was greater than 99%. 4. Affinities and receptor reserves for other A(1)AdoR agonists were determined. Agonists appeared to differ more in their affinity for the receptor than in their intrinsic efficacy to activate it. 5. A(1)AdoRs were inactive in the absence of agonist. 6. It is concluded that adipocyte A(1)AdoR are tonically activated by endogenous adenosine at nanomolar concentrations. The expression of a high density of A(1)AdoR that are efficiently coupled to a functional response enables the adipocyte to respond with high sensitivity to the low-affinity agonist, adenosine. Adipocytes may be a model for cells whose functions are tonically modulated by adenosine present in the interstitium of well-oxygenated tissues.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic with millions of human infections. One limitation to the evaluation of potential therapies and vaccines to inhibit SARS-CoV-2 infection and ameliorate disease is the lack of susceptible small animals in large numbers.
Commercially available laboratory strains of mice are not readily infected by SARS-CoV-2 because of species-specific differences in their angiotensin-converting enzyme 2 (ACE2) receptors. Here, we transduced replication-defective adenoviruses encoding human ACE2 via intranasal administration into BALB/c mice and established receptor expression in lung tissues. hACE2-transduced mice were productively infected with SARS-CoV-2, and this resulted in high viral titers in the lung, lung pathology, and weight loss. Passive transfer of a neutralizing monoclonal antibody reduced viral burden in the lung and mitigated inflammation and weight loss. The development of an accessible mouse model of SARS-CoV-2 infection and pathogenesis will expedite the testing and deployment of therapeutics and vaccines.
Eising E, etal., Mol Psychiatry. 2019 Jul;24(7):1065-1078. doi: 10.1038/s41380-018-0020-x. Epub 2018 Feb 20.
Genetic investigations of people with impaired development of spoken language provide windows into key aspects of human biology. Over 15 years after FOXP2 was identified, most speech and language impairments remain unexplained at the molecular level. We sequenced whole genomes of nineteen unrelated
individuals diagnosed with childhood apraxia of speech, a rare disorder enriched for causative mutations of large effect. Where DNA was available from unaffected parents, we discovered de novo mutations, implicating genes, including CHD3, SETD1A and WDR5. In other probands, we identified novel loss-of-function variants affecting KAT6A, SETBP1, ZFHX4, TNRC6B and MKL2, regulatory genes with links to neurodevelopment. Several of the new candidates interact with each other or with known speech-related genes. Moreover, they show significant clustering within a single co-expression module of genes highly expressed during early human brain development. This study highlights gene regulatory pathways in the developing brain that may contribute to acquisition of proficient speech.
Huntoon KM, etal., Mol Immunol. 2013 Oct;55(3-4):345-54. doi: 10.1016/j.molimm.2013.03.008. Epub 2013 Mar 30.
Haptoglobin (Hp), an acute phase reactant and major hemoglobin-binding protein, has a unique role in host immunity. Previously, we demonstrated that Hp-deficient C57BL/6J mice exhibit stunted development of mature T- and B-cells resulting in markedly lower levels of antigen-specific IgG. The current
study identified leukocyte-derived pro-Hp as a relevant mediator of an optimal immune response. Reconstitution of Hp-/- mice with Hp+/+ bone marrow restored normal immune response to ovalbumin. Furthermore, transplanting a mixture of bone marrow-derived from B-cell-deficient and Hp-deficient mice into Rag1-/-/Hp+/+ recipients resulted in mice with a defective immune response similar to Hp-/- mice. This suggests that Hp generated by the B-cell compartment, rather than by the liver, is functionally contributing to a normal immune response. Leukocytes isolated from the spleen express Hp and release a non-proteolytically processed pro-Hp that uniquely differed from liver-derived Hp by not binding to hemoglobin. While addition of purified plasma Hp to cultured B-cells did not alter responses, pro-Hp isolated from splenocytes enhanced cellular proliferation and production of IgG. Collectively, the comparison of wild-type and Hp-deficient mice suggests a novel regulatory activity for lymphocyte-derived Hp, including Hp produced by B-cells themselves, that supports in vivo survival and functional differentiation of the B-cells to ensure an optimal immune response.
Barry J, etal., J Cell Sci. 2013 May 1;126(Pt 9):2027-41. doi: 10.1242/jcs.122234. Epub 2013 Mar 13.
The conventional kinesin motor transports many different cargos to specific locations in neurons. How cargos regulate motor function remains unclear. Here we focus on KIF5, the heavy chain of conventional kinesin, and report that the Kv3 (Shaw) voltage-gated K(+) channel, the only known tetrameric K
IF5-binding protein, clusters and activates KIF5 motors during axonal transport. Endogenous KIF5 often forms clusters along axons, suggesting a potential role of KIF5-binding proteins. Our biochemical assays reveal that the high-affinity multimeric binding between the Kv3.1 T1 domain and KIF5B requires three basic residues in the KIF5B tail. Kv3.1 T1 competes with the motor domain and microtubules, but not with kinesin light chain 1 (KLC1), for binding to the KIF5B tail. Live-cell imaging assays show that four KIF5-binding proteins, Kv3.1, KLC1 and two synaptic proteins SNAP25 and VAMP2, differ in how they regulate KIF5B distribution. Only Kv3.1 markedly increases the frequency and number of KIF5B-YFP anterograde puncta. Deletion of Kv3.1 channels reduces KIF5 clusters in mouse cerebellar neurons. Therefore, clustering and activation of KIF5 motors by Kv3 regulate the motor number in carrier vesicles containing the channel proteins, contributing not only to the specificity of Kv3 channel transport, but also to the cargo-mediated regulation of motor function.
Park H, etal., J Cell Biol. 2015 Nov 9;211(3):619-37. doi: 10.1083/jcb.201503113.
The phosphoinositide 3-kinase-Akt signaling pathway is essential to many biological processes, including cell proliferation, survival, metabolism, and angiogenesis, under pathophysiological conditions. Although 3-phosphoinositide-dependent kinase 1 (PDK1) is a primary activator of Akt at the plasma
membrane, the optimal activation mechanism remains unclear. We report that adhesion molecule with IgG-like domain 2 (AMIGO2) is a novel scaffold protein that regulates PDK1 membrane localization and Akt activation. Loss of AMIGO2 in endothelial cells (ECs) led to apoptosis and inhibition of angiogenesis with Akt inactivation. Amino acid residues 465-474 in AMIGO2 directly bind to the PDK1 pleckstrin homology domain. A synthetic peptide containing the AMIGO2 465-474 residues abrogated the AMIGO2-PDK1 interaction and Akt activation. Moreover, it effectively suppressed pathological angiogenesis in murine tumor and oxygen-induced retinopathy models. These results demonstrate that AMIGO2 is an important regulator of the PDK1-Akt pathway in ECs and suggest that interference of the PDK1-AMIGO2 interaction might be a novel pharmaceutical target for designing an Akt pathway inhibitor.
Wachman EM, etal., Am J Addict. 2017 Jan;26(1):42-49. doi: 10.1111/ajad.12483. Epub 2016 Dec 16.
BACKGROUND AND OBJECTIVES: There is significant variability in severity of neonatal abstinence syndrome (NAS) due to in utero opioid exposure. Our previous study identified single nucleotide polymorphisms (SNPs) in the prepronociceptin (PNOC) and catechol-O-methyltransferase (COMT) genes
that were associated with differences in NAS outcomes. This study looks at the same SNPs in PNOC and COMT in an independent cohort in an attempt to replicate previous findings. METHODS: For the replication cohort, full-term opioid-exposed newborns and their mothers (n = 113 pairs) were studied. A DNA sample was obtained and genotyped for five SNPs in the PNOC and COMT genes. The association of each SNP with NAS outcomes (length of hospitalization, need for pharmacologic treatment, and total opioid days) was evaluated, with an experiment-wise significance level set at α < .003 and point-wise level of α < .05. SNP associations in a combined cohort of n = 199 pairs (replication cohort plus 86 pairs previously reported), were also examined. RESULTS: In the replication cohort, mothers with the COMT rs4680 G allele had infants with a reduced risk for treatment with two medications for NAS (adjusted OR = .5, p = .04), meeting point-wise significance. In the combined cohort, infants with the PNOC rs4732636 A allele had a reduced need for medication treatment (adjusted OR 2.0, p = .04); mothers with the PNOC rs351776 A allele had infants who were treated more often with two medications (adjusted OR 2.3, p = .004) with longer hospitalization by 3.3 days (p = .01). Mothers with the COMT rs740603 A allele had infants who were less often treated with any medication (adjusted OR .5, p = .02). Though all SNP associations all met point wise and clinical significance, they did not meet the experiment-wise significance threshold. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: We found differences in NAS outcomes depending on PNOC and COMT SNP genotype. This has important implications for identifying infants at risk for severe NAS who could benefit from tailored treatment regimens. Further testing in a larger sample is warranted. This has important implications for prenatal prediction and personalized treatment regimens for infants with NAS. (Am J Addict 2017;26:42-49).
Regulatory T (Treg) cells respond to immune and inflammatory signals to mediate immunosuppression, but how the functional integrity of Treg cells is maintained under activating environments is unclear. Here we show that autophagy is active in Treg cells and supports their lineage stability and survi
val fitness. Treg cell-specific deletion of Atg7 or Atg5, two essential genes in autophagy, leads to loss of Treg cells, greater tumor resistance and development of inflammatory disorders. Atg7-deficient Treg cells show increased apoptosis and readily lose expression of the transcription factor Foxp3, especially after activation. Mechanistically, autophagy deficiency upregulates metabolic regulators mTORC1 and c-Myc and glycolysis, which contribute to defective Treg function. Therefore, autophagy couples environmental signals and metabolic homeostasis to protect lineage and survival integrity of Treg cells in activating contexts.
Chromatin remodeling is of crucial importance during brain development. Pathogenic alterations of several chromatin remodeling ATPases have been implicated in neurodevelopmental disorders. We describe an index case with a de novo missense mutation in CHD3, identified during whole genome sequencing o
f a cohort of children with rare speech disorders. To gain a comprehensive view of features associated with disruption of this gene, we use a genotype-driven approach, collecting and characterizing 35 individuals with de novo CHD3 mutations and overlapping phenotypes. Most mutations cluster within the ATPase/helicase domain of the encoded protein. Modeling their impact on the three-dimensional structure demonstrates disturbance of critical binding and interaction motifs. Experimental assays with six of the identified mutations show that a subset directly affects ATPase activity, and all but one yield alterations in chromatin remodeling. We implicate de novo CHD3 mutations in a syndrome characterized by intellectual disability, macrocephaly, and impaired speech and language.
Zhang J, etal., Cancer Res 2004 Oct 1;64(19):6957-64.
The contribution of pericellular proteolysis to tumor progression is well documented. To better understand protease biology and facilitate clinical translation, specific proteolytic systems need to be better defined. In particular, the precise role of endogenous protease inhibitors still needs to be
deciphered. We reported previously that cystatin M, a potent endogenous inhibitor of lysosomal cysteine proteases, significantly suppressed in vitro cell proliferation, migration, and Matrigel invasion. Here, we show that scid mice orthotopically implanted with breast cancer cells expressing cystatin M show significantly delayed primary tumor growth and lower metastatic burden in the lungs and liver when compared with mice implanted with mock controls. The incidence of metastasis, however, appeared to be unaltered between the cystatin M group and the control group. Experimental metastasis assays suggest that cystatin M suppressed tumor cell proliferation at the secondary site. By using laser capture microdissection and quantitative reverse transcription-polymerase chain reaction, we found consistent expression of cystatin M in normal human breast epithelial cells, whereas expression was decreased by 86% in invasive ductal carcinoma (IDC) cells of stage I to IV patients. Complete loss of expression of cystatin M was observed in two of three IDCs from stage IV patients. Immunohistochemical studies confirmed that expression of cystatin M in IDCs was partially or completely lost. We propose cystatin M as a novel candidate tumor suppressor gene for breast cancer.
Carotid intima-media thickness (cIMT) is a subclinical measure of atherosclerosis with mounting evidence that higher cIMT confers an increased risk of cardiovascular disease. The ryanodine receptor 3 gene (RYR3) has previously been linked to increased cIMT; however, the causal variants have not yet
been localized. Therefore, we sequenced 339,480 bp encompassing 104 exons and 2 kb flanking region of the RYR3 gene in 96 HIV-positive white men from the extremes of the distribution of common cIMT from the Fat Redistribution and Metabolic Changes in HIV infection study (FRAM). We identified 2710 confirmed variants (2414 single-nucleotide polymorphisms (SNPs) and 296 insertion/deletions (indels)), with a mean count of 736 SNPs (ranging from 528 to 1032) and 170 indels (ranging from 128 to 214) distributed in each individual. There were 39 variants in the exons and 15 of these were non-synonymous, of which with only 4 were common variants and the remaining 11 were rare variants, one was a novel SNP. We confirmed that the common variant rs2229116 was significantly associated with cIMT in this design (P<7.9 x 10(-9)), and observed seven other significantly associated SNPs (P<10(-8)). These variants including the private non-synonymous SNPs need to be followed up in a larger sample size and also tested with clinical atherosclerotic outcomes.
Ata H, etal., PLoS One. 2012;7(6):e39009. doi: 10.1371/journal.pone.0039009. Epub 2012 Jun 14.
BACKGROUND: Adult mammalian cardiac myocytes are generally assumed to be terminally differentiated; nonetheless, a small fraction of cardiac myocytes have been shown to replicate during ventricular remodeling. However, the expression of Replication Factor C (RFC; RFC140/40/38/37/36) and D
NA polymerase δ (Pol δ) proteins, which are required for DNA synthesis and cell proliferation, in the adult normal and hypertrophied hearts has been rarely studied. METHODS: We performed qRT-PCR and Western blot analysis to determine the levels of RFC and Pol δ message and proteins in the adult normal cardiac myocytes and cardiac fibroblasts, as well as in adult normal and pulmonary arterial hypertension induced right ventricular hypertrophied hearts. Immunohistochemical analyses were performed to determine the localization of the re-expressed DNA replication and cell cycle proteins in adult normal (control) and hypertrophied right ventricle. We determined right ventricular cardiac myocyte polyploidy and chromosomal missegregation/aneuploidy using Fluorescent in situ hybridization (FISH) for rat chromosome 12. RESULTS: RFC40-mRNA and protein was undetectable, whereas Pol δ message was detectable in the cardiac myocytes isolated from control adult hearts. Although RFC40 and Pol δ message and protein significantly increased in hypertrophied hearts as compared to the control hearts; however, this increase was marginal as compared to the fetal hearts. Immunohistochemical analyses revealed that in addition to RFC40, proliferative and mitotic markers such as cyclin A, phospho-Aurora A/B/C kinase and phospho-histone 3 were also re-expressed/up-regulated simultaneously in the cardiac myocytes. Interestingly, FISH analyses demonstrated cardiac myocytes polyploidy and chromosomal missegregation/aneuploidy in these hearts. Knock-down of endogenous RFC40 caused chromosomal missegregation/aneuploidy and decrease in the rat neonatal cardiac myocyte numbers. CONCLUSION: Our novel findings suggest that transcription of RFC40 is suppressed in the normal adult cardiac myocytes and its insufficient re-expression may be responsible for causing chromosomal missegregation/aneuploidy and in cardiac myocytes during right ventricular hypertrophy.
BACKGROUND: To evaluate the impact of the duration of chronic inflammation on gene expression in skeletal muscle biopsies (MBx) from untreated children with juvenile dermatomyositis (JDM) and identify genes and biological processes associated with the disease progression, expression profiling data f
rom 16 girls with active symptoms of JDM greater than or equal to 2 months were compared with 3 girls with active symptoms less than 2 months. RESULTS: Seventy-nine genes were differentially expressed between the groups with long or short duration of untreated disease. Genes involved in immune responses and vasculature remodelling were expressed at a higher level in muscle biopsies from children with greater or equal to 2 months of symptoms, while genes involved in stress responses and protein turnover were expressed at a lower level. Among the 79 genes, expression of 9 genes showed a significant linear regression relationship with the duration of untreated disease. Five differentially expressed genes--HLA-DQA1, smooth muscle myosin heavy chain, clusterin, plexin D1 and tenomodulin--were verified by quantitative RT-PCR. The chronic inflammation of longer disease duration was also associated with increased DC-LAMP+ and BDCA2+ mature dendritic cells, identified by immunohistochemistry. CONCLUSION: We conclude that chronic inflammation alters the gene expression patterns in muscle of untreated children with JDM. Symptoms lasting greater or equal to 2 months were associated with dendritic cell maturation and anti-angiogenic vascular remodelling, directly contributing to disease pathophysiology.
Bueno AN, etal., Biochemistry. 2015 Oct 6;54(39):6038-51. doi: 10.1021/acs.biochem.5b00631.
The endosome-associated deubiquitinase (DUB) AMSH is a member of the JAMM family of zinc-dependent metallo isopeptidases with high selectivity for Lys63-linked polyubiquitin chains, which play a key role in endosomal-lysosomal sorting of activated cell surface receptors. The catalytic domain of the
enzyme features a flexible flap near the active site that opens and closes during its catalytic cycle. Structural analysis of its homologues, AMSH-LP (AMSH-like protein) and the fission yeast counterpart, Sst2, suggests that a conserved Phe residue in the flap may be critical for substrate binding and/or catalysis. To gain insight into the contribution of this flap in substrate recognition and catalysis, we generated mutants of Sst2 and characterized them using a combination of enzyme kinetics, X-ray crystallography, molecular dynamics simulations, and isothermal titration calorimetry (ITC). Our analysis shows that the Phe residue in the flap contributes key interactions during the rate-limiting step but not to substrate binding, since mutants of Phe403 exhibit a defect only in kcat but not in KM. Moreover, ITC studies show Phe403 mutants have similar KD for ubiquitin compared to the wild-type enzyme. The X-ray structures of both Phe403Ala and the Phe403Trp, in both the free and ubiquitin bound form, reveal no appreciable structural change that might impair substrate or alter product binding. We observed that the side chain of the Trp residue is oriented identically with respect to the isopeptide moiety of the substrate as the Phe residue in the wild-type enzyme, so the loss of activity seen in this mutant cannot be explained by the absence of a group with the ability to provide van der Waals interactions that facilitate the hyrdolysis of the Lys63-linked diubiquitin. Molecular dynamics simulations indicate that the flap in the Trp mutant is quite flexible, allowing almost free rotation of the indole side chain. Therefore, it is possible that these different dynamic properties of the flap in the Trp mutant, compared to the wild-type enzyme, manifest as a defect in interactions that facilitate the rate-limiting step. Consistent with this notion, the Trp mutant was able to cleave Lys48-linked and Lys11-linked diubiquitin better than the wild-type enzyme, indicating altered mobility and hence reduced selectivity.
Al Alam D, etal., Development. 2015 Dec 1;142(23):4139-50. doi: 10.1242/dev.109173. Epub 2015 Oct 28.
Lipid-containing alveolar interstitial fibroblasts (lipofibroblasts) are increasingly recognized as an important component of the epithelial stem cell niche in the rodent lung. Although lipofibroblasts were initially believed merely to assist type 2 alveolar epithelial cells in surfactant production
during neonatal life, recent evidence suggests that these cells are indispensable for survival and growth of epithelial stem cells during adulthood. Despite increasing interest in lipofibroblast biology, little is known about their cellular origin or the molecular pathways controlling their formation during embryonic development. Here, we show that a population of lipid-droplet-containing stromal cells emerges in the developing mouse lung between E15.5 and E16.5. This is accompanied by significant upregulation, in the lung mesenchyme, of peroxisome proliferator-activated receptor gamma (master switch of lipogenesis), adipose differentiation-related protein (marker of mature lipofibroblasts) and fibroblast growth factor 10 (previously shown to identify a subpopulation of lipofibroblast progenitors). We also demonstrate that although only a subpopulation of total embryonic lipofibroblasts derives from Fgf10(+) progenitor cells, in vivo knockdown of Fgfr2b ligand activity and reduction in Fgf10 expression lead to global reduction in the expression levels of lipofibroblast markers at E18.5. Constitutive Fgfr1b knockouts and mutants with conditional partial inactivation of Fgfr2b in the lung mesenchyme reveal the involvement of both receptors in lipofibroblast formation and suggest a possible compensation between the two receptors. We also provide data from human fetal lungs to demonstrate the relevance of our discoveries to humans. Our results reveal an essential role for Fgf10 signaling in the formation of lipofibroblasts during late lung development.
Mullany SA, etal., Clin Cancer Res. 2011 Feb 1;17(3):427-36. doi: 10.1158/1078-0432.CCR-09-3069. Epub 2010 Nov 23.
PURPOSE: The purpose of this study was to determine if loss of serine protease HtrA1 in endometrial cancer will promote the invasive potential of EC cell lines. EXPERIMENTAL DESIGN: Western blot analysis and immunohistochemistry methods were used to determine HtrA1 expression in
EC cell lines and primary tumors, respectively. Migration, invasion assays and in vivo xenograft experiment were performed to compare the extent of metastasis between HtrA1 expressing and HtrA1 knocked down clones. RESULTS: Western blot analysis of HtrA1 in 13 EC cell lines revealed complete loss of HtrA1 expression in all seven papillary serous EC cell lines. Downregulation of HtrA1 in Hec1A and Hec1B cell lines resulted in a three- to fourfold increase in the invasive potential. Exogenous expression of HtrA1 in Ark1 and Ark2 cells resulted in three- to fourfold decrease in both invasive and migration potential of these cells. There was an increased rate of metastasis to the lungs associated with HtrA1 downregulation in Hec1B cells compared to control cells with endogenous HtrA1 expression. Enhanced expression of HtrA1 in Ark2 cells resulted in significantly less tumor nodules metastasizing to the lungs compared to parental or protease deficient (SA mutant) Ark2 cells. Immunohistochemical analysis showed 57% (105/184) of primary EC tumors had low HtrA1 expression. The association of low HtrA1 expression with high-grade endometrioid tumors was statistically significant (P = 0.016). CONCLUSIONS: Collectively, these data indicate loss of HtrA1 may contribute to the aggressiveness and metastatic ability of endometrial tumors.
Li YQ, etal., J Clin Invest. 2016 Jan;126(1):40-9. doi: 10.1172/JCI76348. Epub 2015 Nov 23.
Activation of brain melanocortin 4 receptors (MC4Rs) leads to reduced food intake, increased energy expenditure, increased insulin sensitivity, and reduced linear growth. MC4R effects on energy expenditure and glucose metabolism are primarily mediated by the G protein Gsalpha in brain regions outsi
de of the paraventricular nucleus of the hypothalamus (PVN). However, the G protein(s) that is involved in MC4R-mediated suppression of food intake and linear growth, which are believed to be regulated primarily though action in the PVN, is unknown. Here, we show that PVN-specific loss of Gqalpha and G11alpha, which stimulate PLC, leads to severe hyperphagic obesity, increased linear growth, and inactivation of the hypothalamic-pituitary-adrenal axis, without affecting energy expenditure or glucose metabolism. Moreover, we demonstrate that the ability of an MC4R agonist delivered to PVN to inhibit food intake is lost in mice lacking Gq/11alpha in the PVN but not in animals deficient for Gsalpha. The blood pressure response to the same MC4R agonist was only lost in animals lacking Gsalpha specifically in the PVN. Together, our results exemplify how different physiological effects of GPCRs may be mediated by different G proteins and identify a pathway for appetite regulation that could be selectively targeted by Gq/11alpha-biased MC4R agonists as a potential treatment for obesity.
Li YQ, etal., Proc Natl Acad Sci U S A. 2016 Jan 12;113(2):446-51. doi: 10.1073/pnas.1517142113. Epub 2015 Dec 28.
Gsalpha, the G protein that transduces receptor-stimulated cAMP generation, mediates sympathetic nervous system stimulation of brown adipose tissue (BAT) thermogenesis and browning of white adipose tissue (WAT), which are both potential targets for treating obesity, as well as lipolysis. We generate
d a mouse line with Gsalpha deficiency in mature BAT and WAT adipocytes (Ad-GsKO). Ad-GsKO mice had impaired BAT function, absent browning of WAT, and reduced lipolysis, and were therefore cold-intolerant. Despite the presence of these abnormalities, Ad-GsKO mice maintained normal energy balance on both standard and high-fat diets, associated with decreases in both lipolysis and lipid synthesis. In addition, Ad-GsKO mice maintained at thermoneutrality on a standard diet also had normal energy balance. Ad-GsKO mice had improved insulin sensitivity and glucose metabolism, possibly secondary to the effects of reduced lipolysis and lower circulating fatty acid binding protein 4 levels. Gsalpha signaling in adipose tissues may therefore affect whole-body glucose metabolism in the absence of an effect on body weight.
AIMS: HtrA1 is a member of the HtrA (high-temperature requirement factor A) family of serine proteases. HtrA1 plays a protective role in various malignancies due to its tumour suppressive properties. The aim of this study was to determine HtrA1 expression as a predictor of chemoresponse i
n patients with advanced gastric cancer. METHODS AND RESULTS: HtrA1 expression was determined by immunohistochemistry on specimens of primary gastric cancer from 80 patients treated consecutively with cisplatin-based combination chemotherapy. Response to chemotherapy was assessed according to Response Evaluation Criteria in Solid Tumours (RECIST) criteria. Our population consisted of males/females [51/29; median age 64 years (range 32-82)]. A complete or partial response was observed in 71.4% [95% confidence interval (CI) 54.7-88.2], 66.7% (95% CI 47.8-85.5) and 28.6% (95 CI 11.8-45.3) of tumours showing high, medium and low HtrA1 expression, respectively. A statistically significant association between HtrA1 expression and the clinical response was observed (P = 0.002). The median overall survival for patients with high/medium expression was 17 months compared to 9.5 months for patients with low HtrA1 expression (P = 0.037). CONCLUSIONS: Identification of HtrA1 in gastric cancer prior to chemotherapy indicates that levels of HtrA1 could be used to predict response to platinum-based combination therapies. Further assessment of HtrA1 expression is highly warranted in large, prospective studies.
Davis DA, etal., PLoS Pathog. 2015 Jul 28;11(7):e1005064. doi: 10.1371/journal.ppat.1005064. eCollection 2015 Jul.
Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8, is the causative agent of three hyperproliferative disorders: Kaposi's sarcoma, primary effusion lymphoma (PEL) and multicentric Castleman's disease. During viral latency a small subset of viral genes are produced, in
cluding KSHV latency-associated nuclear antigen (LANA), which help the virus thwart cellular defense responses. We found that exposure of KSHV-infected cells to oxidative stress, or other inducers of apoptosis and caspase activation, led to processing of LANA and that this processing could be inhibited with the pan-caspase inhibitor Z-VAD-FMK. Using sequence, peptide, and mutational analysis, two caspase cleavage sites within LANA were identified: a site for caspase-3 type caspases at the N-terminus and a site for caspase-1 and-3 type caspases at the C-terminus. Using LANA expression plasmids, we demonstrated that mutation of these cleavage sites prevents caspase-1 and caspase-3 processing of LANA. This indicates that these are the principal sites that are susceptible to caspase cleavage. Using peptides spanning the identified LANA cleavage sites, we show that caspase activity can be inhibited in vitro and that a cell-permeable peptide spanning the C-terminal cleavage site could inhibit cleavage of poly (ADP-ribose) polymerase and increase viability in cells undergoing etoposide-induced apoptosis. The C-terminal peptide of LANA also inhibited interleukin-1 beta (IL-1beta) production from lipopolysaccharide-treated THP-1 cells by more than 50%. Furthermore, mutation of the two cleavage sites in LANA led to a significant increase in IL-1beta production in transfected THP-1 cells; this provides evidence that these sites function to blunt the inflammasome, which is known to be activated in latently infected PEL cells. These results suggest that specific caspase cleavage sites in KSHV LANA function to blunt apoptosis as well as interfere with the caspase-1-mediated inflammasome, thus thwarting key cellular defense mechanisms.
Despite limited genomic diversity, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has shown a wide range of clinical manifestations in different patient populations. The mechanisms behind these host differences are still unclear. Here, we examined host response gene expression across i
nfection status, viral load, age, and sex among shotgun RNA sequencing profiles of nasopharyngeal (NP) swabs from 430 individuals with PCR-confirmed SARS-CoV-2 and 54 negative controls. SARS-CoV-2 induced a strong antiviral response with up-regulation of antiviral factors such as OAS1-3 and IFIT1-3 and T helper type 1 (Th1) chemokines CXCL9/10/11, as well as a reduction in transcription of ribosomal proteins. SARS-CoV-2 culture in human airway epithelial (HAE) cultures replicated the in vivo antiviral host response 7 days post infection, with no induction of interferon-stimulated genes after 3 days. Patient-matched longitudinal specimens (mean elapsed time = 6.3 days) demonstrated reduction in interferon-induced transcription, recovery of transcription of ribosomal proteins, and initiation of wound healing and humoral immune responses. Expression of interferon-responsive genes, including ACE2, increased as a function of viral load, while transcripts for B cell-specific proteins and neutrophil chemokines were elevated in patients with lower viral load. Older individuals had reduced expression of the Th1 chemokines CXCL9/10/11 and their cognate receptor CXCR3, as well as CD8A and granzyme B, suggesting deficiencies in trafficking and/or function of cytotoxic T cells and natural killer (NK) cells. Relative to females, males had reduced B cell-specific and NK cell-specific transcripts and an increase in inhibitors of nuclear factor kappa-B (NF-κB) signaling, possibly inappropriately throttling antiviral responses. Collectively, our data demonstrate that host responses to SARS-CoV-2 are dependent on viral load and infection time course, with observed differences due to age and sex that may contribute to disease severity.
BACKGROUND & AIMS: Dual oxidase 2 (DUOX2), a hydrogen-peroxide generator at the apical membrane of gastrointestinal epithelia, is up-regulated in patients with inflammatory bowel disease (IBD) before the onset of inflammation, but little is known about its effects. We investigated the role of DUOX2
in maintaining mucosal immune homeostasis in mice. METHODS: We analyzed the regulation of DUOX2 in intestinal tissues of germ-free vs conventional mice, mice given antibiotics or colonized with only segmented filamentous bacteria, mice associated with human microbiota, and mice with deficiencies in interleukin (IL) 23 and IL22 signaling. We performed 16S ribosomal RNA gene quantitative polymerase chain reaction of intestinal mucosa and mesenteric lymph nodes of Duoxa(-/-) mice that lack functional DUOX enzymes. Genes differentially expressed in Duoxa(-/-) mice compared with co-housed wild-type littermates were correlated with gene expression changes in early-stage IBD using gene set enrichment analysis. RESULTS: Colonization of mice with segmented filamentous bacteria up-regulated intestinal expression of DUOX2. DUOX2 regulated redox signaling within mucosa-associated microbes and restricted bacterial access to lymphatic tissues of the mice, thereby reducing microbiota-induced immune responses. Induction of Duox2 transcription by microbial colonization did not require the mucosal cytokines IL17 or IL22, although IL22 increased expression of Duox2. Dysbiotic, but not healthy human microbiota, activated a DUOX2 response in recipient germ-free mice that corresponded to abnormal colonization of the mucosa with distinct populations of microbes. In Duoxa(-/-) mice, abnormalities in ileal mucosal gene expression at homeostasis recapitulated those in patients with mucosal dysbiosis. CONCLUSIONS: DUOX2 regulates interactions between the intestinal microbiota and the mucosa to maintain immune homeostasis in mice. Mucosal dysbiosis leads to increased expression of DUOX2, which might be a marker of perturbed mucosal homeostasis in patients with early-stage IBD.
UNLABELLED: Upon activation of Toll-like and RIG-I-like receptor signaling pathways, the transcription factor IRF5 translocates to the nucleus and induces antiviral immune programs. The recent discovery of a homozygous mutation in the immunoregulatory gene guanine exchange factor dedicato
r of cytokinesis 2 (Dock2mu/mu) in several Irf5-/- mouse colonies has complicated interpretation of immune functions previously ascribed to IRF5. To define the antiviral functions of IRF5 in vivo, we infected backcrossed Irf5-/-×Dock2wt/wt mice (here called Irf5-/- mice) and independently generated CMV-Cre Irf5fl/fl mice with West Nile virus (WNV), a pathogenic neurotropic flavivirus. Compared to congenic wild-type animals, Irf5-/- and CMV-Cre Irf5fl/fl mice were more vulnerable to WNV infection, and this phenotype was associated with increased infection in peripheral organs, which resulted in higher virus titers in the central nervous system. The loss of IRF5, however, was associated with only small differences in the type I interferon response systemically and in the draining lymph node during WNV infection. Instead, lower levels of several other proinflammatory cytokines and chemokines, as well as fewer and less activated immune cells, were detected in the draining lymph node 2 days after WNV infection. WNV-specific antibody responses in Irf5-/- mice also were blunted in the context of live or inactivated virus infection and this was associated with fewer antigen-specific memory B cells and long-lived plasma cells. Our results with Irf5-/- mice establish a key role for IRF5 in shaping the early innate immune response in the draining lymph node, which impacts the spread of virus infection, optimal B cell immunity, and disease pathogenesis. IMPORTANCE: Although the roles of IRF3 and IRF7 in orchestrating innate and adaptive immunity after viral infection are established, the function of the related transcription factor IRF5 remains less certain. Prior studies in Irf5-/- mice reported conflicting results as to the contribution of IRF5 in regulating type I interferon and adaptive immune responses. The lack of clarity may stem from a recently discovered homozygous loss-of-function mutation of the immunoregulatory gene Dock2 in several colonies of Irf5-/- mice. Here, using a mouse model with a deficiency in IRF5 and wild-type Dock2 alleles, we investigated how IRF5 modulates West Nile virus (WNV) pathogenesis and host immune responses. Our in vivo studies indicate that IRF5 has a key role in shaping the early proinflammatory cytokine response in the draining lymph node, which impacts immunity and control of WNV infection.
Kawakami M, etal., Int J Oncol. 1999 Oct;15(4):715-20.
Ovarian cancer is one of the leading causes of mortality unique to women. Deletions within chromosome 6q are the most frequent events in high-grade invasive epithelial ovarian cancer (IEOC). While previous reports seem to indicate that there is loss of 16q sequences in IOEC, only a very small number
of markers (single marker in two different reports) were used. In order to more precisely define the regions of deletions on 16q, we first analyzed LOH with 13 polymorphic markers on 16q in 10 benign, 3 low-grade and 21 high-grade invasive ovarian cancer samples. There was no loss with any of the markers with the benign ovarian samples and loss of one marker in one of three low-grade tumors. In contrast, 14 of 21 (67%) high-grade invasive ovarian tumors showed loss of one or more markers. Detailed deletion mapping revealed three distinct commonly deleted regions on this chromosomal arm: 10/21 (48%) of high-grade tumors showed loss at 16q23.1-23.2 (D16S518, D16S3049 and D16S3029). The second region of loss at 16q23.3-16q24.1 (D16S3144, D16S504, HSD17B2 and D16S507) was observed in 11/21 (52%) of the tumors. The highest frequency of loss was seen at 16q24.2-16q24.3 (D16S422, D16S402 and D16S520) in 12/21 (57%) of tumors. The genomic map of CDH13 indicates that the marker D16S422 that was lost in 5 of these 12 tumors is part of this gene. Three of these 5 tumors showed very low levels of CDH13 expression. Three tumors with LOH of other markers in this region also showed lower levels of CDH13 expression. Analysis of the methylation status of CDH13 in tumors with low levels of expression with methylation-specific PCR revealed that four of six (67%) tumors had methylation of one of the CDH13 alleles. These results suggest that a combination of hyper-methylation and deletion cause the inactivation of CDH13 in ovarian tumors.
The immune co-inhibitory receptors lymphocyte activation gene-3 (LAG3) and programmed cell death 1 (PD1) synergistically contribute to autoimmunity and tumor evasion. Here we demonstrate how they collaborate and interact to regulate T cell function. We first show that LAG3 and PD1 are co-expressed
on both OVA-specific and non-specific T cells infiltrating murine ovarian tumors. Dual antibody blockade or genetic knockout of LAG3 and PD1 significantly enhanced T effector function and delayed tumor growth. LAG3 and PD1 co-localized in activated CD8+ T cells in vitro at the trans-Golgi vesicles, early/recycling endosomal compartments, lysosomes, and microtubule organizing center. Importantly, LAG3 and PD1 cluster with pLck at the immunological synapse. Reciprocal immunoprecipitation of T cell extracts revealed physical interaction between LAG3 and PD1. Mutational analyses indicate that the cytoplasmic domain of LAG3 is not absolutely required for its association with PD1, while the ITIM and ITSM of PD1 are necessary for its association with LAG3. Finally, LAG3 protein also associates with the Src-homology-2 domain-containing phosphatases (SHP1/2) which are known to be recruited by PD1 during T cell signaling. Our data indicate that the association of LAG3 with PD1 contributes to their rapid trafficking to the immunological synapse, leading to a synergistic inhibitory effect on T cell signaling.
PURPOSE: The aims of this study were (a) to locate the breakpoints of a balanced translocation (7;13) within a mother (B) and daughter (T); (b) to describe the language and cognitive skills of B and T; and (c) to compare this profile with affected family members of the KE family who have a mutation
within FOXP2. METHOD: The breakpoint locations for T and B were identified by use of fluorescent in situ hybridization analysis followed by DNA sequencing using long-range polymer chain reaction amplification methods. The cognitive and language characteristics were obtained via the use of standardized tests of intelligence, receptive and expressive vocabulary and sentence use, and a spontaneous language sample. RESULTS: The translocation breakpoints in T and B were found in FOXP2 on chromosome 7 and in RFC3 on chromosome 13. T and B's pattern of relative strengths and weaknesses across their cognitive and language performance was found to be similar to descriptions of the affected KE family members. CONCLUSIONS: Prior reports of individuals with chromosomal rearrangements of FOXP2 have emphasized their speech impairment. This study provides additional evidence that language-in particular, grammar-is likely to be influenced by abnormalities of FOXP2 function.
High cholesterol and diabetes are major risk factors for atherosclerosis. Regression of atherosclerosis is mediated in part by the Liver X Receptor (LXR) through the induction of genes involved in cholesterol transport and efflux. In the context of diabetes, regression of atherosclerosis is impaired
. We proposed that changes in glucose levels modulate LXR-dependent gene expression. Using a mouse macrophage cell line (RAW 264.7) and primary bone marrow derived macrophages (BMDMs) cultured in normal or diabetes relevant high glucose conditions we found that high glucose inhibits the LXR-dependent expression of ATP-binding cassette transporter A1 (ABCA1), but not ABCG1. To probe for this mechanism, we surveyed the expression of a host of chromatin-modifying enzymes and found that Protein Arginine Methyltransferase 2 (PRMT2) was reduced in high compared to normal glucose conditions. Importantly, ABCA1 expression and ABCA1-mediated cholesterol efflux were reduced in Prmt2-/- compared to wild type BMDMs. Monocytes from diabetic mice also showed decreased expression of Prmt2 compared to non-diabetic counterparts. Thus, PRMT2 represents a glucose-sensitive factor that plays a role in LXR-mediated ABCA1-dependent cholesterol efflux and lends insight to the presence of increased atherosclerosis in diabetic patients.
Cao S, etal., Sci Rep. 2017 May 25;7(1):2417. doi: 10.1038/s41598-017-02679-z.
The NLRP3 inflammasome is activated in the early period following subarachnoid hemorrhage(SAH), resulting in inflammatory responses. Recent studies have shown that activation of NLRP3 inflammasome is suppressed by autophagy, but the potential mechanism is unclear. In this study, we examined whether
mitophagy was involved in the beneficial effect of melatonin and its relationship with NLRP3 inflammasome activation after SAH. In total, 130 adult-male SD rats were randomly divided into four groups: sham group, SAH¿+¿vehicle group, SAH¿+¿melatonin group, and SAH¿+¿3-methyladenine (3-MA)¿+¿melatonin group. Brain samples were used for brain water content analysis, ROS assay, Western blot, immunohistochemistry and transmission electron microscopy. The results showed that melatonin treatment markedly increased the expression of both autophagy markers(LC3-II/LC3-I and Atg 5), and mitophagy markers(Parkin and PINK-1) following SAH induction. Additionally, melatonin treatment attenuated pathological changes in mitochondria and reduced ROS generation, which are closely related to NLRP3 inflammasome activation. Consequently, melatonin-mediated upregulation of proteins associated with mitophagy inhibited NLRP3 inflammasome activation and significantly reduced pro-inflammatory cytokine levels after SAH. Conversely, 3-MA, an autophagy inhibitor, reversed these beneficial effects of melatonin on mitophagy and the NLRP3 inflammasome. These results suggest that mitophagy-associated NLRP3 inflammasome inhibition by melatonin is neuroprotective against early brain injury post-SAH in rats.
Alloreactive donor T cells are the driving force in the induction of graft-versus-host disease (GVHD), yet little is known about T cell metabolism in response to alloantigens after hematopoietic cell transplantation (HCT). Here, we have demonstrated that donor T cells undergo metabolic reprograming
after allogeneic HCT. Specifically, we employed a murine allogeneic BM transplant model and determined that T cells switch from fatty acid beta-oxidation (FAO) and pyruvate oxidation via the tricarboxylic (TCA) cycle to aerobic glycolysis, thereby increasing dependence upon glutaminolysis and the pentose phosphate pathway. Glycolysis was required for optimal function of alloantigen-activated T cells and induction of GVHD, as inhibition of glycolysis by targeting mTORC1 or 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) ameliorated GVHD mortality and morbidity. Together, our results indicate that donor T cells use glycolysis as the predominant metabolic process after allogeneic HCT and suggest that glycolysis has potential as a therapeutic target for the control of GVHD.
Del Pino Sans J, etal., Neuroscience. 2015 Sep 10;303:312-22. doi: 10.1016/j.neuroscience.2015.07.008. Epub 2015 Jul 9.
Sexually dimorphic neural structures regulate numerous gender-specific functions including luteinizing hormone (LH) release patterns. The female cyclic surge pattern of release is controlled by the anteroventral periventricular nucleus (AVPV), a preoptic area (POA) region that is significantly smal
ler in males. The prevailing hypothesis used to explain these differences in structure and function is that a "default" feminine AVPV is defeminized by exposure to estradiol (E2), a metabolite of testosterone (T) produced by the perinatal testes. E2 exposure then culminates in apoptosis in the male AVPV, but the upstream pathways are poorly understood. To address this issue, we compared AVPV transcriptomes of postnatal day 2 (PND2) males and females with those of females treated with E2 or vehicle. Only six of 89 sex-specific genes were also regulated by E2 in the PND2 AVPV and E2 regulated over 280 genes not found to be sex-specific. Of targets that changed similarly in males and E2-treated females, the gene encoding CUG triplet repeat, RNA-binding protein 2 (Cugbp2), a proapoptotic protein, showed the highest fold-changes. Quantitative polymerase chain reaction (QPCR) studies confirmed higher mRNA levels in PND2 male and E2-treated female AVPVs wherein E2 induces apoptosis. POA mapping studies detected Cugbp2 mRNA in the AVPV and in the sexually dimorphic nucleus of the POA (SDN-POA); however, sex differences and E2 effects occurred only in the AVPV. Combined with evidence that Cugbp2 regulates splicing and translation of mRNAs linked to sexual differentiation, we propose that this gene mediates E2-dependent effects on AVPV defeminization.
Hess CW, etal., Neurology. 2007 Feb 13;68(7):522-4.
Although myoclonus and dystonia are the hallmarks of myoclonus-dystonia (M-D), psychiatric features, particularly obsessive-compulsive disorder and alcohol dependence, have been reported in three families linked to chromosome 7q21. As the epsilon sarcoglycan (SGCE) gene for M-D was subsequently iden
tified, we evaluated the relationship between psychiatric features and SGCE mutations in these original and two additional families and confirm that OCD and alcohol dependence are associated with manifesting mutated SGCE.
Mutations in the human LMNA gene cause muscular dystrophy by mechanisms that are incompletely understood. The LMNA gene encodes A-type lamins, intermediate filaments that form a network underlying the inner nuclear membrane, providing structural support for the nucleus and organizing the genome. To
better understand the pathogenesis caused by mutant lamins, we performed a structural and functional analysis on LMNA missense mutations identified in muscular dystrophy patients. These mutations perturb the tertiary structure of the conserved A-type lamin Ig-fold domain. To identify the effects of these structural perturbations on lamin function, we modeled these mutations in Drosophila Lamin C and expressed the mutant lamins in muscle. We found that the structural perturbations had minimal dominant effects on nuclear stiffness, suggesting that the muscle pathology was not accompanied by major structural disruption of the peripheral nuclear lamina. However, subtle alterations in the lamina network and subnuclear reorganization of lamins remain possible. Affected muscles had cytoplasmic aggregation of lamins and additional nuclear envelope proteins. Transcription profiling revealed upregulation of many Nrf2 target genes. Nrf2 is normally sequestered in the cytoplasm by Keap-1. Under oxidative stress Nrf2 dissociates from Keap-1, translocates into the nucleus, and activates gene expression. Unexpectedly, biochemical analyses revealed high levels of reducing agents, indicative of reductive stress. The accumulation of cytoplasmic lamin aggregates correlated with elevated levels of the autophagy adaptor p62/SQSTM1, which also binds Keap-1, abrogating Nrf2 cytoplasmic sequestration, allowing Nrf2 nuclear translocation and target gene activation. Elevated p62/SQSTM1 and nuclear enrichment of Nrf2 were identified in muscle biopsies from the corresponding muscular dystrophy patients, validating the disease relevance of our Drosophila model. Thus, novel connections were made between mutant lamins and the Nrf2 signaling pathway, suggesting new avenues of therapeutic intervention that include regulation of protein folding and metabolism, as well as maintenance of redox homoeostasis.
Although activated spinal cord glia contribute importantly to neuropathic pain, how nerve injury activates glia remains controversial. It has recently been proposed, on the basis of genetic approaches, that toll-like receptor 4 (TLR4) may be a key receptor for initiating microglial activation follow
ing L5 spinal nerve injury. The present studies extend this idea pharmacologically by showing that TLR4 is key for maintaining neuropathic pain following sciatic nerve chronic constriction injury (CCI). Established neuropathic pain was reversed by intrathecally delivered TLR4 receptor antagonists derived from lipopolysaccharide. Additionally, (+)-naltrexone, (+)-naloxone, and (-)-naloxone, which we show here to be TLR4 antagonists in vitro on both stably transfected HEK293-TLR4 and microglial cell lines, suppressed neuropathic pain with complete reversal upon chronic infusion. Immunohistochemical analyses of spinal cords following chronic infusion revealed suppression of CCI-induced microglial activation by (+)-naloxone and (-)-naloxone, paralleling reversal of neuropathic pain. Together, these CCI data support the conclusion that neuron-to-glia signaling through TLR4 is important not only for initiating neuropathic pain, as suggested previously, but also for maintaining established neuropathic pain. Furthermore, these studies suggest that the novel TLR4 antagonists (+)-naloxone and (-)-naloxone can each fully reverse established neuropathic pain upon multi-day administration. This finding with (+)-naloxone is of potential clinical relevance. This is because (+)-naloxone is an antagonist that is inactive at the (-)-opioid selective receptors on neurons that produce analgesia. Thus, these data suggest that (+)-opioid antagonists such as (+)-naloxone may be useful clinically to suppress glial activation, yet (-)-opioid agonists suppress pain.
PURPOSE: The goal of this study was to identify new candidate genes and genomic copy-number variations associated with a rare, severe, and persistent speech disorder termed childhood apraxia of speech. Childhood apraxia of speech is the speech disorder segregating with a mutation in FOXP2 in a multi
generational London pedigree widely studied for its role in the development of speech-language in humans. METHODS: A total of 24 participants who were suspected to have childhood apraxia of speech were assessed using a comprehensive protocol that samples speech in challenging contexts. All participants met clinical-research criteria for childhood apraxia of speech. Array comparative genomic hybridization analyses were completed using a customized 385K Nimblegen array (Roche Nimblegen, Madison, WI) with increased coverage of genes and regions previously associated with childhood apraxia of speech. RESULTS: A total of 16 copy-number variations with potential consequences for speech-language development were detected in 12 or half of the 24 participants. The copy-number variations occurred on 10 chromosomes, 3 of which had two to four candidate regions. Several participants were identified with copy-number variations in two to three regions. In addition, one participant had a heterozygous FOXP2 mutation and a copy-number variation on chromosome 2, and one participant had a 16p11.2 microdeletion and copy-number variations on chromosomes 13 and 14. CONCLUSION: Findings support the likelihood of heterogeneous genomic pathways associated with childhood apraxia of speech.
The host-encoded Perforin-2 (encoded by the macrophage-expressed gene 1, Mpeg1), which possesses a pore-forming MACPF domain, reduces the viability of bacterial pathogens that reside within membrane-bound compartments. Here, it is shown that Perforin-2 also restricts the proliferation of the intra
cytosolic pathogen Listeria monocytogenes Within a few hours of systemic infection, the massive proliferation of L. monocytogenes in Perforin-2(-/-)mice leads to a rapid appearance of acute disease symptoms. We go on to show in cultured Perforin-2(-/-)cells that the vacuole-to-cytosol transitioning of L. monocytogenesis greatly accelerated. Unexpectedly, we found that in Perforin-2(-/-)macrophages,Listeria-containing vacuoles quickly (= 15 min) acidify, and that this was coincident with greater virulence gene expression, likely accounting for the more rapid translocation of L. monocytogenes to its replicative niche in the cytosol. This hypothesis was supported by our finding that aL. monocytogenes strain expressing virulence factors at a constitutively high level replicated equally well in Perforin-2(+/+)and Perforin-2(-/-)macrophages. Our findings suggest that the protective role of Perforin-2 against listeriosis is based on it limiting the intracellular replication of the pathogen. This cellular activity of Perforin-2 may derive from it regulating the acidification of Listeria-containing vacuoles, thereby depriving the pathogen of favorable intracellular conditions that promote its virulence gene activity.
Rice GM, etal., Am J Med Genet A. 2012 Jan;158A(1):174-81. doi: 10.1002/ajmg.a.34354. Epub 2011 Nov 21.
Disruptions in FOXP2, a transcription factor, are the only known monogenic cause of speech and language impairment. We report on clinical findings for two new individuals with a submicroscopic deletion of FOXP2: a boy with severe apraxia of speech and his currently moderately affected mother. A 1.5
7 Mb deletion on chromosome 7q31 was detected by array comparative genomic hybridization (aCGH). In addition to FOXP2, the patients' deletion involves two other genes, MDFIC and PPP1R3A, neither of which has been associated with speech or language disorders. Thus, findings for these two family members provide informative phenotypic information on FOXP2 haploinsufficiency. Evaluation by a clinical geneticist indicated no major congenital anomalies or dysmorphic features. Evaluations by a clinical psychologist and occupational therapist indicated cognitive-linguistic processing and sensorimotor control deficits, but did not support a diagnosis of autism spectrum disorder. Evaluation by clinical and research speech pathologists confirmed that both patients' speech deficits met contemporary criteria for apraxia of speech. Notably, the patients were not able to laugh, cough, or sneeze spontaneously, replicating findings reported for two other FOXP2 cases and a potential diagnostic sign of nonsyndromic apraxia of speech. Speech severity findings for the boy were not consistent with the hypothesis that loss of maternal FOXP2 should be relatively benign. Better understanding of the behavioral phenotype of FOXP2 disruptions will aid identification of patients, toward an eventual understanding of the pathophysiology of syndromic and nonsyndromic apraxia of speech.
Mul JD, etal., PLoS One. 2013;8(3):e60214. doi: 10.1371/journal.pone.0060214. Epub 2013 Mar 26.
The orexigenic neuropeptide melanin-concentrating hormone (MCH), a product of Pmch, is an important mediator of energy homeostasis. Pmch-deficient rodents are lean and smaller, characterized by lower food intake, body-, and fat mass. Pmch is expressed in hypothalamic neurons that ultimately are comp
onents in the sympathetic nervous system (SNS) drive to white and interscapular brown adipose tissue (WAT, iBAT, respectively). MCH binds to MCH receptor 1 (MCH1R), which is present on adipocytes. Currently it is unknown if Pmch-ablation changes adipocyte differentiation or sympathetic adipose drive. Using Pmch-deficient and wild-type rats on a standard low-fat diet, we analyzed dorsal subcutaneous and perirenal WAT mass and adipocyte morphology (size and number) throughout development, and indices of sympathetic activation in WAT and iBAT during adulthood. Moreover, using an in vitro approach we investigated the ability of MCH to modulate 3T3-L1 adipocyte differentiation. Pmch-deficiency decreased dorsal subcutaneous and perirenal WAT mass by reducing adipocyte size, but not number. In line with this, in vitro 3T3-L1 adipocyte differentiation was unaffected by MCH. Finally, adult Pmch-deficient rats had lower norepinephrine turnover (an index of sympathetic adipose drive) in WAT and iBAT than wild-type rats. Collectively, our data indicate that MCH/MCH1R-pathway does not modify adipocyte differentiation, whereas Pmch-deficiency in laboratory rats lowers adiposity throughout development and sympathetic adipose drive during adulthood.
INTRODUCTION: Recent studies have shown that histones, the chief protein component of chromatin, are released into the extracellular space during sepsis, trauma, and ischemia-reperfusion injury, and act as major mediators of the death of an organism. This study was designed to elucidate the cellul
ar and molecular basis of histone-induced lethality and to assess the protective effects of recombinant thrombomodulin (rTM). rTM has been approved for the treatment of disseminated intravascular coagulation (DIC) in Japan, and is currently undergoing a phase III clinical trial in the United States. METHODS: Histone H3 levels in plasma of healthy volunteers and patients with sepsis and DIC were measured using enzyme-linked immunosorbent assay. Male C57BL/6 mice were injected intravenously with purified histones, and pathological examinations were performed. The protective effects of rTM against histone toxicity were analyzed both in vitro and in mice. RESULTS: Histone H3 was not detectable in plasma of healthy volunteers, but significant levels were observed in patients with sepsis and DIC. These levels were higher in non-survivors than in survivors. Extracellular histones triggered platelet aggregation, leading to thrombotic occlusion of pulmonary capillaries and subsequent right-sided heart failure in mice. These mice displayed symptoms of DIC, including thrombocytopenia, prolonged prothrombin time, decreased fibrinogen, fibrin deposition in capillaries, and bleeding. Platelet depletion protected mice from histone-induced death in the first 30 minutes, suggesting that vessel occlusion by platelet-rich thrombi might be responsible for death during the early phase. Furthermore, rTM bound to extracellular histones, suppressed histone-induced platelet aggregation, thrombotic occlusion of pulmonary capillaries, and dilatation of the right ventricle, and rescued mice from lethal thromboembolism. CONCLUSIONS: Extracellular histones cause massive thromboembolism associated with consumptive coagulopathy, which is diagnostically indistinguishable from DIC. rTM binds to histones and neutralizes the prothrombotic action of histones. This may contribute to the effectiveness of rTM against DIC.
Jiang Y, etal., Int J Clin Exp Pathol. 2015 Aug 1;8(8):9042-51. eCollection 2015.
Oral squamous cell carcinoma (OSCC) is one of the most lethal malignant tumors. The cadherin/catenin cell-cell adhesion complex plays a major role in cancer development and progression. p120-catenin (p120) is a cytoplasmic molecule closely associated with E-cadherin which activates phospholipase C-g
amma1 (PLC-gamma1). Our previous studies indicate that activation of PLC-gamma1 plays a critical role in epidermal growth factor (EGF)-induced migration and proliferation of squamous cell carcinoma (SCC) cells and phosphatidylinositol 3-kinase enhancer (PIKE) is highly expressed in SCC cells and mediates EGFR-dependent SCC cell proliferation. Our current study was to determine whether the expression of E-cadherin, p120, PLC-gamma1, and PIKE, is associated with OSCC. To address this issue, we assessed levels and localization of E-cadherin, p120, PLC-gamma1, and PIKE in specimen of 92 patients with OSCC by immunohistochemistry. The results showed that the expression of E-cadherin, and p120 negatively correlated with the tumor differentiation and the expression of PLC-gamma1 and PIKE positively correlated with the tumor differentiation. The expression of PLC-gamma1 and PIKE in OSCC stage T3 + T4 or in OSCC with lymph node metastasis was significantly higher than that in OSCC stage T1 + T2 or in OSCC without lymph node metastasis. The expression of p120 positively correlated with levels of E-cadherin but negatively correlated with levels of PLC-gamma1 and PIKE in OSCC. These data indicate that increased expression of PLC-gamma1 and PIKE and decreased expression of E-cadherin and p120 are associated with the aggressiveness of OSCC.
Respiratory syncytial virus (RSV) is the most common cause of infant hospitalizations and severe RSV infections are a significant risk factor for childhood asthma. The pathogenic mechanisms responsible for RSV induced immunopathophysiology remain elusive. Using an age-appropriate mouse model of RSV,
we show that IL-33 plays a critical role in the immunopathogenesis of severe RSV, which is associated with higher group 2 innate lymphoid cells (ILC2s) specifically in neonates. Infection with RSV induced rapid IL-33 expression and an increase in ILC2 numbers in the lungs of neonatal mice; this was not observed in adult mice. Blocking IL-33 with antibodies or using an IL-33 receptor knockout mouse during infection was sufficient to inhibit RSV immunopathogenesis (i.e., airway hyperresponsiveness, Th2 inflammation, eosinophilia, and mucus hyperproduction); whereas administration of IL-33 to adult mice during RSV infection was sufficient to induce RSV disease. Additionally, elevated IL-33 and IL-13 were observed in nasal aspirates from infants hospitalized with RSV; these cytokines declined during convalescence. In summary, IL-33 is necessary, either directly or indirectly, to induce ILC2s and the Th2 biased immunopathophysiology observed following neonatal RSV infection. This study provides a mechanism involving IL-33 and ILC2s in RSV mediated human asthma.
Resistance to chemotherapy presents a serious challenge in the successful treatment of various cancers and is mainly responsible for mortality associated with disseminated cancers. Here we show that expression of HtrA1, which is frequently downregulated in ovarian cancer, influences tumor response t
o chemotherapy by modulating chemotherapy-induced cytotoxicity. Downregulation of HtrA1 attenuated cisplatin- and paclitaxel-induced cytotoxicity, while forced expression of HtrA1 enhanced cisplatin- and paclitaxel-induced cytotoxicity. HtrA1 expression was upregulated by both cisplatin and paclitaxel treatment. This upregulation resulted in limited autoproteolysis and activation of HtrA1. Active HtrA1 induces cell death in a serine protease-dependent manner. The potential role of HtrA1 as a predictive factor of clinical response to chemotherapy was assessed in both ovarian and gastric cancer patients receiving cisplatin-based regimens. Patients with ovarian or gastric tumors expressing higher levels of HtrA1 showed a higher response rate compared with those with lower levels of HtrA1 expression. These findings uncover what we believe to be a novel pathway by which serine protease HtrA1 mediates paclitaxel- and cisplatin-induced cytotoxicity and suggest that loss of HtrA1 in ovarian and gastric cancers may contribute to in vivo chemoresistance.
Zhang X, etal., Oncotarget. 2014 Nov 30;5(22):11365-80.
FoxM1 is an oncogenic Forkhead transcription factor that is overexpressed in ovarian cancer. However, the mechanisms by which FoxM1 is deregulated in ovarian cancer and the extent to which FoxM1 can be targeted in ovarian cancer have not been reported previously. In this study, we showed that MDM2
inhibitor Nutlin-3 upregulated p53 protein and downregulated FoxM1 expression in several cancer cell lines with wild type TP53 but not in cell lines with mutant TP53. FoxM1 downregulation was partially blocked by cycloheximide or actinomycin D, and pulse-chase studies indicate Nutlin-3 enhances FoxM1 mRNA decay. Knockdown of p53 using shRNAs abrogated the FoxM1 downregulation by Nutlin-3, indicating a p53-dependent mechanism. FoxM1 inhibitor, thiostrepton, induces apoptosis in cancer cell lines and enhances sensitivity to cisplatin in these cells. Thiostrepton downregulates FoxM1 expression in several cancer cell lines and enhances sensitivity to carboplatin in vivo. Finally, FoxM1 expression is elevated in nearly all (48/49) ovarian tumors, indicating that thiostrepton target gene is highly expressed in ovarian cancer. In summary, the present study provides novel evidence that both amorphic and neomorphic mutations in TP53 contribute to FoxM1 overexpression and that FoxM1 may be targeted for therapeutic benefits in cancers.
BACKGROUND/AIMS: The slow healing process of tendon-to-bone junctions can be accelerated via implanted tendon-derived stem cells (TDSCs) with silenced transforming growth interacting factor 1 (TGIF1) gene. Tendon-to-bone insertion site is the special form of connective tissues derivatives of common
connective progenitors, where TGF-beta plays bidirectional effects (chondrogenic or fibrogenic) through different signaling pathways at different stages. A recent study revealed that TGF-beta directly induces the chondrogenic gene Sox9. However, TGIF1 represses the expression of the cartilage master Sox9 gene and changes its expression rate against the fibrogenesis gene Scleraxis (Scx). METHODS: TGIF1 siRNA was transduced or TGIF1 was over-expressed in tendon-derived stem cells. Following suprapinatus tendon repair, rats were either treated with transduced TDSCs or nontransduced TDSCs. Histologic examination and Western blot were performed in both groups. RESULTS: In this study, the silencing of TGIF1 significantly upregulated the chondrogenic genes and markers. Similarly, TGIF1 inhibited TDSC differentiation into cartilage via interactions with TGF-beta-activated Smad2 and suppressed the phosphorylation of Smad2. The area of fibrocartilage at the tendon-bone interface was significantly increased in the TGIF1 (-) group compared with the control and TGIF1-overexpressing groups in the early stages of the animal model. The interface between the tendon and bone showed a increase of new bone and fibrocartilage in the TGIF1 (-) group at 4 weeks. Fibrovascular scar tissue was observed in the TGIF1-overexpressing group and the fibrin glue only group. Low levels of fibrocartilage and fibrovascular scar tissue were found in the TDSCs group. CONCLUSION: Collectively, this study shows that the tendon-derived stem cell modified with TGIF1 gene silencing has promising effects on tendon-to-bone healing which can be further explored as a therapeutic tool in regenerative medicine.
Gays F, etal., J Immunol. 2000 May 15;164(10):5094-102.
As a potential means for facilitating studies of NK cell-related molecules, we examined the expression of these molecules on a range of mouse tumor cell lines. Of the lines we initially examined, only EL4 and RMA expressed such molecules, both lines expressing several members of the Ly49 and NKRP1
families. Unexpectedly, several of the NK-related molecules, together with certain other molecules including CD2, CD3, CD4, CD32, and CD44, were often expressed in a mosaic manner, even on freshly derived clones, indicating frequent switching in expression. In each case examined, switching was controlled at the mRNA level, with expression of CD3zeta determining expression of the entire CD3-TCR complex. Each of the variable molecules was expressed independently, with the exception that CD3 was restricted to cells that also expressed CD2. Treatment with drugs that affect DNA methylation and histone acetylation could augment the expression of at least some of the variable molecules. The striking phenotypic similarity between EL4 and RMA led us to examine the state of their TCRbeta genes. Both lines had identical rearrangements on both chromosomes, indicating that RMA is in fact a subline of EL4. Overall, these findings suggest that EL4 is an NK-T cell tumor that may have retained a genetic mechanism that permits the variable expression of a restricted group of molecules involved in recognition and signaling.
Traditional markers mammaglobin and GCDFP15 show good specificity but lack sensitivity and can be difficult to interpret in small tissue samples. We undertook a comparative study of the novel nuclear marker GATA3 (expression typically restricted to breast and urothelial carcinomas) and GCDFP15 and m
ammaglobin. We first compared quantitative mRNA expression levels of these 3 markers across a diverse set of over 6000 tumors and 500 normal samples from The Cancer Genome Atlas which showed dramatically higher GATA3 expression (>10-fold higher) in breast cancer as compared with GCDFP15 or mammaglobin (both P<2.2e-16), suggesting that GATA3 may represent a more sensitive marker of breast cancer than GCDFP15 or mammaglobin. We next examined protein expression by immunohistochemistry in 166 cases (including surgical and cytology specimens) of metastatic breast carcinoma and 54 cases with available matched primaries. One whole-slide section from each case was stained for monoclonal GATA3 (L50-823), monoclonal mammaglobin (31A5), and monoclonal GCDFP15 (EP1582Y). Staining intensity (0 to 3+) and extent (0% to 100%) were scored with an H-score calculated (range, 0 to 300). Sensitivities by varying H-score cutoffs for a positive result in metastatic breast carcinoma among GATA3/GCDFP15/mammaglobin, respectively, were as follows: any H-score=95%/65%/78%, H-score>50=93%/37%/47%, H-score>100=90%/25%/27%, H-score>150=86%/21%/19%, H-score>200=73%/18%/9%, H-score>250=66%/14%/6%. Significant staining differences by specimen type, tumor subtype/grade, or ER/PR/HER2 status were not identified. Significantly stronger correlation was observed between primary/metastatic GATA3 expression [Pearson's correlation=0.81 (0.68-0.89)] as compared with the primary/metastatic correlations of GCDFP15 [Pearson's correlation=0.57 (0.33-0.74)] and mammaglobin [Pearson's correlation=0.50 (0.24-0.70)] (both P<0.05). In conclusion, the novel marker GATA3 stains a significantly higher proportion of both primary and metastatic breast carcinomas than GCDFP15 or mammaglobin with stronger and more diffuse staining, helpful in cases with small tissue samples. The matched primary/metastatic expression of GATA3 is also more consistent. We propose that GATA3 be included among a panel of confirmatory markers for metastatic breast carcinoma.
Perivascular soft tissue tumors are relatively uncommon neoplasms of unclear lineage of differentiation, although most are presumed to originate from or differentiate to pericytes or a modified perivascular cell. Among these, glomus tumor, myopericytoma, and angioleiomyoma share a spectrum of histol
ogic findings and a perivascular growth pattern. In contrast, solitary fibrous tumor was once hypothesized to have pericytic differentiation--although little bona fide evidence of pericytic differentiation exists. Likewise the perivascular epithelioid cell tumor (PEComa) family shares a perivascular growth pattern, but with distinctive dual myoid-melanocytic differentiation. RGS5, regulator of G-protein signaling 5, is a novel pericyte antigen with increasing use in animal models. Here, we describe the immunohistochemical expression patterns of RGS5 across perivascular soft tissue tumors, including glomus tumor (n = 6), malignant glomus tumor (n = 4), myopericytoma (n = 3), angioleiomyoma (n = 9), myofibroma (n = 4), solitary fibrous tumor (n = 10), and PEComa (n = 19). Immunohistochemical staining and semi-quantification was performed, and compared to alphaSMA (smooth muscle actin) expression. Results showed that glomus tumor (including malignant glomus tumor), myopericytoma, and angioleiomyoma shared a similar diffuse immunoreactivity for RGS5 and alphaSMA across all tumors examined. In contrast, myofibroma, solitary fibrous tumor and PEComa showed predominantly focal to absent RGS5 immunoreactivity. These findings further support a common pericytic lineage of differentiation in glomus tumors, myopericytoma and angioleiomyoma. The pericyte marker RGS5 may be of future clinical utility for the evaluation of pericytic differentiation in soft tissue tumors.
Recent research progress indicates a close link between ghrelin, a natural ligand of GH secretagogues receptor (GHS-R), and both the metabolic balance and body composition. To clarify the involvement of ghrelin and GHS-R in the process of adipogenesis, we measured the expression of GHS-R and peroxis
ome proliferator-activated receptor gamma 2 (PPAR-gamma 2) mRNA in rat adipocytes using semiquantitative RT-PCR methods. The levels of GHS-R mRNA increased by up to 4-fold in adipose tissue from epididymal and parametrial regions as the rat aged from 4-20 wk and were significantly elevated during the differentiation of preadipocytes in vitro. Ghrelin (10(-8) M for 10 d) stimulated the activity of glycerol-3-phosphate dehydrogenase and the differentiation of rat preadipocytes in vitro. Ghrelin treatment also significantly increased the levels of PPAR-gamma 2 mRNA in primary cultured rat differentiated adipocytes. In addition, isoproterenol (10(-8) M, 40 min)-stimulated lipolysis was significantly reduced by simultaneous ghrelin treatment in a dose-dependent manner in vitro. In conclusion, the expression of GHS-R in rat adipocytes increases with the age and during adipogenesis. Ghrelin in vitro stimulates the differentiation of preadipocytes and antagonizes lipolysis. Ghrelin may therefore play an important role in the process of adipogenesis in rats.
Demidov ON, etal., Oncogene. 2007 Apr 12;26(17):2502-6. Epub 2006 Oct 2.
There is increasing evidence for the role of wild-type p53 induced phosphatase 1 (Wip1) phosphatase in the regulation of tumorigenesis. To evaluate Wip1 as a breast cancer oncogene, we generated a mouse strain with targeted expression of Wip1 to the breast epithelium. We found that these mice are p
rone to cancer when intercrossed with transgenics expressing the ErbB2 oncogene but not conditional knockouts for Brca2. This tumor-prone phenotype of Wip1 is fully eliminated through attenuation of proliferation by activating the MKK6/p38 mitogen-activated protein kinases (MAPK) cascade in mice bearing a constitutively active form of MKK6. We propose that Wip1 phosphatase operates within the MKK6/p38 MAPK signaling pathway to promote ErbB2-driven mammary gland tumorigenesis.
Baldi A, etal., Pharmacogenomics. 2008 Aug;9(8):1069-77. doi: 10.2217/14622416.9.8.1069.
AIMS: The objective of our study was to analyze the potential prognostic value of the expression of the serine protease HtrA1 and of EGFR in 70 malignant mesotheliomas. MATERIALS & METHODS: Immunohistochemistry was used to determine the expression of HtrA1 and EGFR. Univariate a
nd multivariate analyses were used to correlate expression of these molecular factors in combination with available clinicopathologic data to patient survival. RESULTS: A positive, statistically significant relationship has been recorded between HtrA1 expression level and survival (p < 0.0001). By contrast, a negative relationship has been identified between EGFR expression and survival (p = 0.02). Moreover, extension of the tumor (T) and involvement of lymph nodes (N) advanced status (p = 0.001 and 0.002, respectively), as well as the sarcomatoid histotype (p = 0.005), correlated significantly with poor survival. Finally, by a multivariate Cox regression analysis, the only immunohistochemical parameter that resulted to influence overall survival was HtrA1 (p = 0.0001). Interestingly, the prognostic value of HtrA1 expression was completely independent from EGFR expression (p < 0.0001). CONCLUSION: This is the first study of the relationship between HtrA1 expression and survival of mesothelioma patients. The data obtained strongly indicate the utilization of HtrA1 expression as a prognostic parameter for mesothelioma and suggest this serine protease as a possible molecular target for the treatment of malignant mesotheliomas.
The TAM receptors Tyro3, Axl and Mertk are receptor tyrosine kinases that dampen host innate immune responses following engagement with their ligands Gas6 and Protein S, which recognize phosphatidylserine on apoptotic cells. In a form of apoptotic mimicry, many enveloped viruses display phosphatidy
lserine on the outer leaflet of their membranes, enabling TAM receptor activation and downregulation of antiviral responses. Accordingly, we hypothesized that a deficiency of TAM receptors would enhance antiviral responses and protect against viral infection. Unexpectedly, mice lacking Mertk and/or Axl, but not Tyro3, exhibited greater vulnerability to infection with neuroinvasive West Nile and La Crosse encephalitis viruses. This phenotype was associated with increased blood-brain barrier permeability, which enhanced virus entry into and infection of the brain. Activation of Mertk synergized with interferon-beta to tighten cell junctions and prevent virus transit across brain microvascular endothelial cells. Because TAM receptors restrict pathogenesis of neuroinvasive viruses, these findings have implications for TAM antagonists that are currently in clinical development.
The t(8;21) rearrangement, which creates the AML1-ETO fusion protein, represents the most common chromosomal translocation in acute myeloid leukemia (AML). Clinical data suggest that CBL mutations are a frequent event in t(8;21) AML, but the role of CBL in AML1-ETO-induced leukemia has not been inv
estigated. In this study, we demonstrate that CBL mutations collaborate with AML1-ETO to expand human CD34+ cells both in vitro and in a xenograft model. CBL depletion by shRNA also promotes the growth of AML1-ETO cells, demonstrating the inhibitory function of endogenous CBL in t(8;21) AML. Mechanistically, loss of CBL function confers hyper-responsiveness to thrombopoietin and enhances STAT5/AKT/ERK/Src signaling in AML1-ETO cells. Interestingly, we found the protein tyrosine phosphatase UBASH3B/Sts-1, which is known to inhibit CBL function, is upregulated by AML1-ETO through transcriptional and miR-9-mediated regulation. UBASH3B/Sts-1 depletion induces an aberrant pattern of CBL phosphorylation and impairs proliferation in AML1-ETO cells. The growth inhibition caused by UBASH3B/Sts-1 depletion can be rescued by ectopic expression of CBL mutants, suggesting that UBASH3B/Sts-1 supports the growth of AML1-ETO cells partly through modulation of CBL function. Our study reveals a role of CBL in restricting myeloid proliferation of human AML1-ETO-induced leukemia, and identifies UBASH3B/Sts-1 as a potential target for pharmaceutical intervention.
The success of Mycobacterium tuberculosis (Mtb) as a pathogen rests upon its ability to grow intracellularly in macrophages. Interferon-gamma (IFN-gamma) is critical in host defense against Mtb and stimulates macrophage clearance of Mtb through an autophagy pathway. Here we show that the host protei
n ubiquilin 1 (UBQLN1) promotes IFN-gamma-mediated autophagic clearance of Mtb. Ubiquilin family members have previously been shown to recognize proteins that aggregate in neurodegenerative disorders. We find that UBQLN1 can interact with Mtb surface proteins and associates with the bacilli in vitro. In IFN-gamma activated macrophages, UBQLN1 co-localizes with Mtb and promotes the anti-mycobacterial activity of IFN-gamma. The association of UBQLN1 with Mtb depends upon the secreted bacterial protein, EsxA, which is involved in permeabilizing host phagosomes. In autophagy-deficient macrophages, UBQLN1 accumulates around Mtb, consistent with the idea that it marks bacilli that traffic through the autophagy pathway. Moreover, UBQLN1 promotes ubiquitin, p62, and LC3 accumulation around Mtb, acting independently of the E3 ligase parkin. In summary, we propose a model in which UBQLN1 recognizes Mtb and in turn recruits the autophagy machinery thereby promoting intracellular control of Mtb. Thus, polymorphisms in ubiquilins, which are known to influence susceptibility to neurodegenerative illnesses, might also play a role in host defense against Mtb.
Adiponectin and leptin, both produced from adipose tissue, cause cell cycle arrest and progression, respectively in cancer cells. Ubiquitin specific protease-2 (USP-2), a deubiquitinating enzyme, is known to impair proteasome-induced degradation of cyclin D1, a critical cell cycle regulator. Herein,
we investigated the effects of these adipokines on USP-2 expression and its potential role in the modulation of cell cycle. Treatment with globular adiponectin (gAcrp) decreased, whereas leptin increased USP-2 expression both in human hepatoma and breast cancer cells. In addition, overexpression or gene silencing of USP-2 affected cyclin D1 expression and cell cycle progression/arrest by adipokines. Adiponectin and leptin also modulated in vitro proteasomal activity, which was partially dependent on USP-2 expression. Taken together, our results reveal that modulation of USP-2 expression plays a crucial role in cell cycle regulation by adipokines. Thus, USP-2 would be a promising therapeutic target for the modulation of cancer cell growth by adipokines.
Retinal pigment epithelium-specific 65 kDa (RPE65)-associated Leber congenital amaurosis is an autosomal recessive disease that results in reduced visual acuity and night blindness beginning at birth. It is one of the few retinal degenerative disorders for which promising clinical gene transfer tria
ls are currently underway. However, the ability to enroll patients in a gene augmentation trial is dependent on the identification of 2 bona fide disease-causing mutations, and there are some patients with the phenotype of RPE65-associated disease who might benefit from gene transfer but are ineligible because 2 disease-causing genetic variations have not yet been identified. Some such patients have novel mutations in RPE65 for which pathogenicity is difficult to confirm. The goal of this study was to determine if an intronic mutation identified in a 2-year-old patient with presumed RPE65-associated disease was truly pathogenic and grounds for inclusion in a clinical gene augmentation trial. Sequencing of the RPE65 gene revealed 2 mutations: (1) a previously identified disease-causing exonic leucine-to-proline mutation (L408P) and (2) a novel single point mutation in intron 3 (IVS3-11) resulting in an A>G change. RT-PCR analysis using RNA extracted from control human donor eye-derived primary RPE, control iPSC-RPE cells, and proband iPSC-RPE cells revealed that the identified IVS3-11 variation caused a splicing defect that resulted in a frameshift and insertion of a premature stop codon. In this study, we demonstrate how patient-specific iPSCs can be used to confirm pathogenicity of unknown mutations, which can enable positive clinical outcomes.
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene but the association between mutation (genotype) and disease presentation (phenotype) is not straightforward. We have been investigating whether variants in the CFTR gene that alter splicing efficien
cy of exon 9 can affect the phenotype produced by a mutation. A missense mutation, R117H, which has been observed in three phenotypes, was found to occur on two chromosome backgrounds with intron 8 variants that have profoundly different effects upon splicing efficiency. A close association is shown between chromosome background of the R117H mutation and phenotype. These findings demonstrate that the genetic context in which a mutation occurs can play a significant role in determining the type of illness produced.
Hoopes RR Jr, etal., Am J Hum Genet. 2005 Feb;76(2):260-7. Epub 2004 Dec 30.
Dent disease is an X-linked renal proximal tubulopathy associated with mutations in the chloride channel gene CLCN5. Lowe syndrome, a multisystem disease characterized by renal tubulopathy, congenital cataracts, and mental retardation, is associated with mutations in the gene OCRL1, which encodes a
phosphatidylinositol 4,5-bisphosphate (PIP(2)) 5-phosphatase. Genetic heterogeneity has been suspected in Dent disease, but no other gene for Dent disease has been reported. We studied male probands in 13 families, all of whom met strict criteria for Dent disease but lacked mutations in CLCN5. Linkage analysis in the one large family localized the gene to a candidate region at Xq25-Xq27.1. Sequencing of candidate genes revealed a mutation in the OCRL1 gene. Of the 13 families studied, OCRL1 mutations were found in 5. PIP(2) 5-phosphatase activity was markedly reduced in skin fibroblasts cultured from the probands of these five families, and protein expression, measured by western blotting, was reduced or absent. Slit-lamp examinations performed in childhood or adulthood for all five probands showed normal results. Unlike patients with typical Lowe syndrome, none of these patients had metabolic acidosis. Three of the five probands had mild mental retardation, whereas two had no developmental delay or behavioral disturbance. These findings demonstrate that mutations in OCRL1 can occur with the isolated renal phenotype of Dent disease in patients lacking the cataracts, renal tubular acidosis, and neurological abnormalities that are characteristic of Lowe syndrome. This observation confirms genetic heterogeneity in Dent disease and demonstrates more-extensive phenotypic heterogeneity in Lowe syndrome than was previously appreciated. It establishes that the diagnostic criteria for disorders resulting from mutations in the Lowe syndrome gene OCRL1 need to be revised.
MacDonald ME, etal., Neurology 1999 Oct 12;53(6):1330-2.
Huntington's disease (HD) is attributed to a triplet CAG repeat mutation, and about half of the variation in onset age can be explained by the size of the repeat expansion. Recently, a TAA repeat polymorphism in close linkage to the kainate receptor, GluR6, was reported related to onset age in HD. W
e examined this polymorphism in 258 unrelated HD-affected persons (172 from a clinic sample and 86 from a postmortem series). This study confirms that the 155 allele is associated with younger onset age of HD and suggests that it is in linkage disequilibrium with a variant of the GluR6 gene or another gene in this region.
Stremenova Spegarova J, etal., Blood. 2020 Aug 27;136(9):1055-1066. doi: 10.1182/blood.2020005844.
Molecular dissection of inborn errors of immunity can help to elucidate the nonredundant functions of individual genes. We studied 3 children with an immune dysregulation syndrome of susceptibility to infection, lymphadenopathy, hepatosplenomegaly, developmental delay, autoimmunity, and lymphoma of
B-cell (n = 2) or T-cell (n = 1) origin. All 3 showed early autologous T-cell reconstitution following allogeneic hematopoietic stem cell transplantation. By whole-exome sequencing, we identified rare homozygous germline missense or nonsense variants in a known epigenetic regulator of gene expression: ten-eleven translocation methylcytosine dioxygenase 2 (TET2). Mutated TET2 protein was absent or enzymatically defective for 5-hydroxymethylating activity, resulting in whole-blood DNA hypermethylation. Circulating T cells showed an abnormal immunophenotype including expanded double-negative, but depleted follicular helper, T-cell compartments and impaired Fas-dependent apoptosis in 2 of 3 patients. Moreover, TET2-deficient B cells showed defective class-switch recombination. The hematopoietic potential of patient-derived induced pluripotent stem cells was skewed toward the myeloid lineage. These are the first reported cases of autosomal-recessive germline TET2 deficiency in humans, causing clinically significant immunodeficiency and an autoimmune lymphoproliferative syndrome with marked predisposition to lymphoma. This disease phenotype demonstrates the broad role of TET2 within the human immune system.
Lin WY, etal., Hum Mol Genet. 2015 Jan 1;24(1):285-98. doi: 10.1093/hmg/ddu431. Epub 2014 Aug 28.
Previous studies have suggested that polymorphisms in CASP8 on chromosome 2 are associated with breast cancer risk. To clarify the role of CASP8 in breast cancer susceptibility, we carried out dense genotyping of this region in the Breast Cancer Association Consortium (BCAC). Single-nucleotide polym
orphisms (SNPs) spanning a 1 Mb region around CASP8 were genotyped in 46 450 breast cancer cases and 42 600 controls of European origin from 41 studies participating in the BCAC as part of a custom genotyping array experiment (iCOGS). Missing genotypes and SNPs were imputed and, after quality exclusions, 501 typed and 1232 imputed SNPs were included in logistic regression models adjusting for study and ancestry principal components. The SNPs retained in the final model were investigated further in data from nine genome-wide association studies (GWAS) comprising in total 10 052 case and 12 575 control subjects. The most significant association signal observed in European subjects was for the imputed intronic SNP rs1830298 in ALS2CR12 (telomeric to CASP8), with per allele odds ratio and 95% confidence interval [OR (95% confidence interval, CI)] for the minor allele of 1.05 (1.03-1.07), P = 1 x 10(-5). Three additional independent signals from intronic SNPs were identified, in CASP8 (rs36043647), ALS2CR11 (rs59278883) and CFLAR (rs7558475). The association with rs1830298 was replicated in the imputed results from the combined GWAS (P = 3 x 10(-6)), yielding a combined OR (95% CI) of 1.06 (1.04-1.08), P = 1 x 10(-9). Analyses of gene expression associations in peripheral blood and normal breast tissue indicate that CASP8 might be the target gene, suggesting a mechanism involving apoptosis.
Helman A, etal., Nat Med. 2016 Apr;22(4):412-20. doi: 10.1038/nm.4054. Epub 2016 Mar 7.
Cellular senescence is thought to contribute to age-associated deterioration of tissue physiology. The senescence effector p16(Ink4a) is expressed in pancreatic beta cells during aging and limits their proliferative potential; however, its effects on beta cell function are poorly characterized. We
found that beta cell-specific activation of p16(Ink4a) in transgenic mice enhances glucose-stimulated insulin secretion (GSIS). In mice with diabetes, this leads to improved glucose homeostasis, providing an unexpected functional benefit. Expression of p16(Ink4a) in beta cells induces hallmarks of senescence--including cell enlargement, and greater glucose uptake and mitochondrial activity--which promote increased insulin secretion. GSIS increases during the normal aging of mice and is driven by elevated p16(Ink4a) activity. We found that islets from human adults contain p16(Ink4a)-expressing senescent beta cells and that senescence induced by p16(Ink4a) in a human beta cell line increases insulin secretion in a manner dependent, in part, on the activity of the mechanistic target of rapamycin (mTOR) and the peroxisome proliferator-activated receptor (PPAR)-gamma proteins. Our findings reveal a novel role for p16(Ink4a) and cellular senescence in promoting insulin secretion by beta cells and in regulating normal functional tissue maturation with age.
BACKGROUND: High mobility group box1 (HMGB1) and poly(ADP-ribose) polymerase1 (PARP1) proteins repair cellular DNA damage. Reduced expression of the corresponding genes can lead to an impaired DNA damage repair mechanism. Intracellular replication of hepatitis B virus (HBV) in such conditions can fa
vor the integration of viral DNA into host genome leading to the development of hepatocellular carcinoma (HCC). OBJECTIVE: This study was performed to assess the expression of HMGB1 and PARP1 mRNAs in conjunction with the estimation of HBV replication intermediate pregenomic RNA (PgRNA) in various phases of HBV infection. MATERIALS: Eighty eight patients and 26 voluntary blood donors as controls were included in the study. Patients were grouped in to acute (AHB; n = 15), inactive carriers (IC; n = 36), cirrhosis (Cirr; n = 25) and hepatocellular carcinoma (HCC; n = 12). Serum HBV DNA was quantified by real time polymerase chain reaction (PCR) assay. Expression of HMGB1, PARP1 and PgRNA were evaluated using peripheral blood mononuclear cells (PBMCs) derived RNA by reverse transcription PCR (RT-PCR) and densitometry. RESULTS: Significant reduction of HMGB1 and PARP1 gene expressions (P < 0.05) were observed in patients than controls with more explicit decline of PARP1 (P = 0.0002). Both genes were significantly downregulated (P < 0.001) in ICs than controls. In ICs, HMGB1 was significantly lowered than cirrhosis (P = 0.002) and HCC (P = 0.0006) while PARP1 declined significantly (P = 0.04) than HCC. Level of PgRNA was comparable in all the disease categories. CONCLUSION: In conclusion, our findings indicate impaired DNA damage repair mechanisms in HBV infected cells of ICs. This, along with low viral load but higher level of PgRNA in this group is suggestive of the diversion of HBV replication pathway that might facilitate viral DNA integration in to host genome. Intrusion of HBV PgRNA reverse transcription in early stage of infection might appear advantageous to thwart the development of HCC.
Baglia FA, etal., J Biol Chem. 2003 Jun 13;278(24):21744-50. Epub 2003 Jan 6.
Factor XI binds to activated platelets where it is efficiently activated by thrombin. The factor XI receptor is the platelet membrane glycoprotein (GP) Ib-IX-V complex (Baglia, F. A., Badellino, K. O., Li, C. Q., Lopez, J. A., and Walsh, P. N. (2002) J. Biol. Chem. 277, 1662-1668), a significant fra
ction of which exists within lipid rafts on stimulated platelets (Shrimpton, C. N., Borthakur, G., Larrucea, S., Cruz, M. A., Dong, J. F., and Lopez, J. A. (2002) J. Exp. Med. 196, 1057-1066). Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids implicated in localizing membrane ligands and in cellular signaling. We now show that factor XI was localized to lipid rafts in activated platelets ( approximately 8% of total bound) but not in resting platelets. Optimal binding of factor XI to membrane rafts required prothrombin (and Ca2+) or high molecular weight kininogen (and Zn2+), which are required for factor XI binding to platelets. An antibody to GPIb (SZ-2) that disrupts factor XI binding to the GPIb-IX-V complex also disrupted factor XI-raft association. The isolated recombinant Apple 3 domain of factor XI, which mediates factor XI binding to platelets, also completely displaces factor XI from membrane rafts. To investigate the physiological relevance of the factor XI-raft association, the structural integrity of lipid rafts was disrupted by cholesterol depletion utilizing methyl-beta-cyclodextrin. Cholesterol depletion completely prevented FXI binding to lipid rafts, and initial rates of factor XI activation by thrombin on activated platelets were inhibited >85%. We conclude that factor XI is localized to GPIb in membrane rafts and that this association is important for promoting the activation of factor XI by thrombin on the platelet surface.
Speir E, etal., J Cell Physiol. 1991 May;147(2):362-73.
The activity of acidic and basic fibroblast growth factor-like mitogens (aFGF, bFGF) extracted from cultured bovine aortic endothelial (BAEC) and rat aortic smooth muscle cells (SMC) was compared with that of freshly isolated cells from the same tissues. Extracts of subendothelial extracellular matr
ix (ECM) and cell lysates of cultured BAEC contained 4-fold more bFGF-like activity than the extracts of fresh cells. ECM and cell lysates of SMC yielded 10-fold more bFGF-like activity than the fresh cell lysates. We consistently find aFGF-like activity in both cell types. In the case of BAEC, cultured cells and ECM contained 3-fold more aFGF-like activity when compared with freshly isolated cells, whereas in cultured SMC, aFGF-like activity in cell and ECM extracts was 8-fold higher than in fresh cell extracts. The mitogens extracted from cell lysates and from the ECM are closely related to aFGF or bFGF by the criteria that they bind to heparin-sepharose and elute at 1.1 M (aFGF) or 1.5 M (bFGF) NaCl, have molecular weights of about 18,000, and react with anti-aFGF (1.1 M), or anti-bFGF (1.5 M) antibodies when analyzed by Western blots and by radioimmunoassay specific for aFGF and bFGF. This mitogenic activity is inhibited by neutralizing antibodies to aFGF and bFGF. In addition, the column fractions are potent mitogens for Balb/c 3T3 fibroblasts. Acidic and basic FGF-like mitogenic activity could also be extracted from the cell nuclei. The subcellular localization of both FGFs was visualized in both nuclei and cytoplasm with immunoperoxidase. Compared with primary SMC, secondary SMC had an increased capacity to bind 125IaFGF to high affinity receptors, while binding to freshly isolated BAEC and SMC was negligible. We conclude that FGFs are present at low levels in freshly isolated cells and that propagation in cell culture provides a stimulus for production of these mitogens.
Follicle stimulating hormone (FSH) plays a central role in growth and differentiation of ovarian follicles. A plethora of information exists on molecular aspects of FSH responses but little is known about the mechanisms involved in its cross-talk with insulin/IGF-1 pathways implicated in the coordin
ation of energy homeostasis in preovulatory granulosa cells (GCs). In this study, we hypothesized that FSH may regulate IRS-2 expression and thereby maintain the energy balance in GCs. We demonstrate here that FSH specifically increases IRS-2 expression in human and rat GCs. FSH-stimulated IRS-2 expression was inhibited by actinomycin D or cycloheximide. Furthermore, FSH decreases IRS-2 mRNA degradation indicating post-transcriptional stabilization. Herein, we demonstrate a role of cAMP pathway in the activation of IRS-2 expression by FSH. Scan and activity analysis of IRS-2 promoter demonstrated that FSH regulates IRS-2 expression through SP1 binding sites. FSH stimulates SP1 translocation into nucleus and its binding to IRS-2 promoter. These results are corroborated by the fact that siRNA mediated knockdown of IRS-2 decreased the FSH-stimulated PI3K activity, p-Akt levels, GLUT4 translocation and glucose uptake. However, FSH was not able to increase IRS-2 expression in GCs from PCOS women undergoing IVF. Interestingly, IRS-2 mRNA expression was downregulated in GCs from the PCOS rat model. Taken together, our findings establish that FSH induces IRS-2 expression and thereby activates PI3K, Akt and glucose uptake. Crucially, our data confirms a molecular defect in FSH action in PCOS GCs which may cause deceleration of metabolism and follicular growth leading to infertility. These results lend support for a therapeutic potential of IRS-2 in the management of PCOS.
Sahasrabuddhe NA, etal., Biochem Biophys Res Commun. 2014 Apr 18;446(4):863-9. doi: 10.1016/j.bbrc.2014.03.017. Epub 2014 Mar 20.
Gallbladder cancer is an uncommon but lethal malignancy with particularly high incidence in Chile, India, Japan and China. There is a paucity of unbiased large-scale studies investigating molecular basis of gallbladder cancer. To systematically identify differentially regulated proteins in gallbladd
er cancer, iTRAQ-based quantitative proteomics of gallbladder cancer was carried out using Fourier transform high resolution mass spectrometry. Of the 2575 proteins identified, proteins upregulated in gallbladder cancer included several lysosomal proteins such as prosaposin, cathepsin Z and cathepsin H. Downregulated proteins included serine protease HTRA1 and transgelin, which have been reported to be downregulated in several other cancers. Novel biomarker candidates including prosaposin and transgelin were validated to be upregulated and downregulated, respectively, in gallbladder cancer using tissue microarrays. Our study provides the first large scale proteomic characterization of gallbladder cancer which will serve as a resource for future discovery of biomarkers for gallbladder cancer.
Esposito I, etal., Hum Pathol. 2001 Nov;32(11):1174-83. doi: 10.1053/hupa.2001.28947.
Chronic pancreatitis (CP) is characterized by mononuclear inflammatory cell infiltration and replacement of the destroyed parenchyma by fibrous tissue. Recently, mast cells have been implicated in chronic inflammatory processes with fibrous tissue deposition. Therefore, the number and distribution o
f mast cells and their state of activation were evaluated in 12 normal specimens and in 46 specimens of CP with different causes (alcoholic, tropical, and idiopathic). Furthermore, the presence of stem cell factor (SCF), the main mast cell growth factor, and of its receptor, c-kit, was also assessed. In CP tissues, mast cells were localized both in the fibrotic areas and in the residual acinar parenchyma. The total number of mast cells was significantly higher in CP than in the normal pancreas (P < .0001) and correlated positively with the extent of fibrosis and the intensity of inflammation. Immunoglobulin E (IgE)-dependent mast cell activation was higher in CP than in the normal pancreas. No differences in mast cell number or IgE positivity were found among the 3 causes of CP. SCF-and c-kit immunoreactive mast cells were mostly localized in fibrous tissue and around regenerating ducts, which were also positive for c-kit but were negative for SCF. These results suggest that mast cells, activated by an IgE-dependent mechanism and/or by an SCF-c-kit autocrine loop, are a relevant component of the inflammatory infiltrate in CP, independent of the underlying cause. Their localization near degenerating acini and regenerating ducts might indicate that they play a crucial role in tissue destruction and remodeling in CP.
Gounaris E, etal., PLoS One. 2015 Mar 6;10(3):e0121402. doi: 10.1371/journal.pone.0121402. eCollection 2015.
PURPOSE: Leukotrienes and prostaglandins, products of arachidonic acid metabolism, sustain both systemic and lesion-localized inflammation. Tumor-associated Inflammation can also contribute to the pathogenesis of colon cancer. Patients with inflammatory bowel disease (IBD) have increased risk of dev
eloping colon cancer. The levels of 5-lipoxygenase (5-LO), the key enzyme for leukotrienes production, are increased in colon cancer specimens and colonic dysplastic lesions. Here we report that Zileuton, a specific 5-LO inhibitor, can prevent polyp formation by efficiently reducing the tumor-associated and systemic inflammation in APCDelta468 mice. EXPERIMENTAL DESIGN: In the current study, we inhibited 5-LO by dietary administration of Zileuton in the APCDelta468 mouse model of polyposis and analyzed the effect of in vivo 5-LO inhibition on tumor-associated and systemic inflammation. RESULTS: Zileuton-fed mice developed fewer polyps and displayed marked reduction in systemic and polyp-associated inflammation. Pro-inflammatory cytokines and pro-inflammatory innate and adaptive immunity cells were reduced both in the lesions and systemically. As part of tumor-associated inflammation Leukotriene B4 (LTB4), product of 5-LO activity, is increased focally in human dysplastic lesions. The 5-LO enzymatic activity was reduced in the serum of Zileuton treated polyposis mice. CONCLUSIONS: This study demonstrates that dietary administration of 5-LO specific inhibitor in the polyposis mouse model decreases polyp burden, and suggests that Zileuton may be a potential chemo-preventive agent in patients that are high-risk of developing colon cancer.
Repairing defective cardiac cells is important towards improving heart function. Due to the frequency and severity of ischemic heart disease, management of patients featuring this type of cardiac failure receives significant interest. Previously we discovered that Thymosin beta4 (TB4), a 43 amino-a
cid secreted actin sequestering peptide, is beneficial for myocardial cell survival and coronary re-growth after infarction in adult mammals. Considering the regenerative potential of full-length TB4 in the heart, and that minimal structural variations alter TB4's influence on actin assembly and cell movement, we investigated how various TB4 domains affect cardiac cell behavior and post-ischemic mammalian heart function. We synthesized 17 domain combinations of full-length TB4 and analyzed their impact on embryonic cardiac cells in vitro, and after cardiac infarction in vivo. We discovered the domains of TB4 affect cardiac cell behavior distinctly. We revealed TB4 specific C-terminal tetrapeptide, AGES, increases embryonic cardiac cell migration and myocyte beating in culture, and improves adult mammalian heart function following ischemia. Investigating the molecular background and mechanism we discovered systemic injection of AGES enhances early myocyte survival by activating Akt-mediated signaling mechanisms, increases coronary vessel growth and inhibits inflammation in mice and pigs. Biodistribution analyses revealed cardiomyocytes uptake AGES efficiently in vitro and in vivo projecting a potential independent clinical utilization for the tetrapeptide. Our comprehensive domain investigations also suggest, preservation and/or restoration of cardiomyocyte communication is a target of TB4 and AGES, and critical to improve post-ischemic heart function in pigs. In summary, we identified the C-terminal four amino-acid variable end of TB4 as the essential and responsible domain for the molecule's full benefits in the hypoxic heart. Additionally, we introduced AGES as a novel, systemically applicable drug candidate to aid cardiac infarction in adult mammals.
Dutta A, etal., Structure. 2012 Nov 7;20(11):1838-49. doi: 10.1016/j.str.2012.08.012. Epub 2012 Sep 6.
Ionotropic glutamate receptors (iGluRs) harbor two extracellular domains: the membrane-proximal ligand-binding domain (LBD) and the distal N-terminal domain (NTD). These are involved in signal sensing: the LBD binds L-glutamate, which activates the receptor channel. Ligand binding to the NTD modulat
es channel function in the NMDA receptor subfamily of iGluRs, which has not been observed for the AMPAR subfamily to date. Structural data suggest that AMPAR NTDs are packed into tight dimers and have lost their signaling potential. Here, we assess NTD dynamics from both subfamilies, using a variety of computational tools. We describe the conformational motions that underly NMDAR NTD allosteric signaling. Unexpectedly, AMPAR NTDs are capable of undergoing similar dynamics; although dimerization imposes restrictions, the two subfamilies sample similar, interconvertible conformational subspaces. Finally, we solve the crystal structure of AMPAR GluA4 NTD, and combined with molecular dynamics simulations, we characterize regions pivotal for an as-yet-unexplored dynamic spectrum of AMPAR NTDs.
Growing evidence has shown that developmental alcohol exposure induces central nervous system inflammation and microglia activation, which may contribute to long-term health conditions, such as fetal alcohol spectrum disorders. These studies sought to investigate whether neonatal alcohol exposure du
ring postnatal days (PND) 2-6 in rats (third trimester human equivalent) leads to long-term disruption of the neuroimmune response by microglia. Exposure to neonatal alcohol resulted in acute increases in activation and inflammatory gene expression in hypothalamic microglia including tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). Adults with neonatal alcohol pre-exposure (alcohol fed; AF) animals showed an exaggerated peripheral stress hormonal response to an immune challenge (lipopolysaccharides; LPS). In addition, there were significantly more microglia present in the hypothalamus of adult AF animals, and their hypothalamic microglia showed more cluster of differentiation molecule 11b (Cd11b) activation, TNF-α expression, and IL-6 expression in response to LPS. Interestingly, blocking microglia activation with minocycline treatment during PND 2-6 alcohol exposure ameliorated the hormonal and microglial hypersensitivity to LPS in AF adult animals. Investigation of possible epigenetic programming mechanisms by alcohol revealed neonatal alcohol decreased several repressive regulators of transcription in hypothalamic microglia, while concomitantly increasing histone H3 acetyl lysine 9 (H3K9ac) enrichment at TNF-α and IL-6 promoter regions. Importantly, adult hypothalamic microglia from AF animals showed enduring increases in H3K9ac enrichment of TNF-α and IL-6 promoters both at baseline and after LPS exposure, suggesting a possible epigenetic mechanism for the long-term immune disruption due to hypothalamic microglial priming.
Pneumonia is a severe infection that causes high morbidity and mortality rate worldwide. It is caused by Klebsiella pneumoniae, which generally causes upper respiratory tract infection. In case of such type of infection, levels of oxidant and antioxidant become imbalanced, which may contribute to lu
ng injury. The present study was planned to evaluate the status of oxidant and antioxidant enzyme activities in plasma and lung tissue of pneumonia-infected rats model. Animals were randomly distributed into 3 groups of 8 rats each: groups I (control, normal saline treated), II (infected group), and III (infected + treated group). The findings showed that there was significant increase (P < .001) in body temperature along with decreased body weight in the infected group as compared to the control group. Similarly, all the activities of antioxidant enzymes (superoxide dismutase [SOD], catalase) were significantly decreased along with increased malonaldialdehyde (MDA) levels in plasma and lung tissue of the infected group as compared to the control group. These enzyme activities along with MDA levels were improved and came back near to normal level after administration of cefepime plus amikacin (potentox) for 7 days in group III. These studies concluded that fixed-dose combination of potentox improved oxidant and antioxidant levels in pneumonia infection.
Exposure to high altitude results in hypobaric hypoxia which is considered as an acute physiological stress and often leads to high altitude maladies such as high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). The best way to prevent high altitude injuries is hypoxic preco
nditioning which has potential clinical usefulness and can be mimicked by cobalt chloride. Preconditioning with cobalt has been reported to provide protection in various tissues against ischemic injury. However, the effect of preconditioning with cobalt against high altitude induced pulmonary edema has not been investigated in vivo. Therefore, in the present study, rats pretreated with saline or cobalt (12.5mg/kg body weight) for 7days were exposed to hypobaric hypoxia of 9142m for 5h at 24 degrees C. Formation of pulmonary edema was assessed by measuring transvascular leakage of sodium fluorescein dye and lung water content. Total protein content, albumin content, vascular endothelial growth factor (VEGF) and cytokine levels were measured in bronchoalveolar lavage fluid. Expression of HO-1, MT, NF-kappaB DNA binding activity and lung tissue pathology were evaluated to determine the effect of preconditioning on HAPE. Hypobaric hypoxia induced increase in transvascular leakage of sodium fluorescein dye, lung water content, lavage total protein, albumin, VEGF levels, pro-inflammatory cytokine levels, tissue expression of cell adhesion molecules and NF-kappaB DNA binding activity were reduced significantly after hypoxic preconditioning with cobalt. Expression of anti-inflammatory protein HO-1, MT, TGF-beta and IL-6 were increased after hypoxic preconditioning. These data suggest that hypoxic preconditioning with cobalt has protective effect against HAPE.
Bhattacharya S, etal., Am J Pathol. 2016 Feb;186(2):242-7. doi: 10.1016/j.ajpath.2015.10.003.
Hepatocellular carcinoma (HCC) is one of the most aggressive cancers and is the third leading cause of all cancer-related death. Limited noninvasive biomarkers are available for HCC detection. Early detection is the key in improving the survival of HCC patients. In this study, we tested the hypothes
is that serum miRNAs can be used as a potential biomarker for HCC. Quantitative RT-PCR for miRNA analysis was performed using 70 serum samples. Receiver operating characteristic analysis was performed to measure the prognostic power of the miRNAs. The miRNA expression level was also measured from liver biopsy samples. Our study revealed that two miRNAs, miR-30e and miR-223, were expressed at significantly lower levels (P < 0.003) in the sera of HCC patients compared with healthy volunteers. Furthermore, expression of these miRNAs was compared between sera from chronic liver disease and sera from HCC patients. miR-30e and miR-223 expression was significantly lower in HCC sera compared with sera from chronic liver disease patients. Both miRNA expression levels were lower in HCC liver biopsy specimens compared with normal liver RNA. Taken together, our results suggested that serum miR-30e and miR-223 are useful biomarkers of HCC, irrespective of etiology, and deserve further study for their diagnostic value.
Porras P, etal., Nat Commun. 2020 Dec 1;11(1):6144. doi: 10.1038/s41467-020-19942-z.
The International Molecular Exchange (IMEx) Consortium provides scientists with a single body of experimentally verified protein interactions curated in rich contextual detail to an internationally agreed standard. In this update to the work of the IMEx Consortium, we discuss how this initiative has
been working in practice, how it has ensured database sustainability, and how it is meeting emerging annotation challenges through the introduction of new interactor types and data formats. Additionally, we provide examples of how IMEx data are being used by biomedical researchers and integrated in other bioinformatic tools and resources.
Hepatitis C virus (HCV)-induced chronic liver disease is one of the leading causes of hepatocellular carcinoma (HCC). The molecular events leading to HCC following chronic HCV infection remain poorly defined. MicroRNAs (miRNAs) have been implicated in the control of many biological processes, and th
eir deregulation is associated with different viral infections. In this study, we observed that HCV infection of hepatocytes transcriptionally downregulates miR-181c expression by modulating CCAAT/enhancer binding protein β (C/EBP-β). Reduced expression of the pri-miR-181c transcript was noted following HCV infection. In silico prediction suggests that homeobox A1 (HOXA1) is a direct target of miR-181c. HOXA1 is a member of the homeodomain-containing transcription factor family and possesses pivotal roles in normal growth, development, and differentiation of mammalian tissues. Our results demonstrated that HOXA1 expression is enhanced in HCV-infected hepatocytes. Exogenous expression of the miR-181c mimic inhibits HOXA1 and its downstream molecules STAT3 and STAT5, which are involved in cell growth regulation. Interestingly, overexpression of miR-181c inhibited HCV replication by direct binding with E1 and NS5A sequences. Furthermore, accumulation of HCV genotype 2a RNA with miR-181c was observed in an RNA-induced silencing complex in Huh7.5 cells. Our results provide new mechanistic insights into the role of miR-181c in HCV-hepatocyte interactions, and miR-181c may act as a target for therapeutic intervention. Importance: Chronic HCV infection is one of the major causes of end-stage liver disease, including hepatocellular carcinoma. An understanding of the molecular mechanisms of HCV-mediated hepatocyte growth promotion is necessary for therapeutic intervention against HCC. In this study, we have provided evidence of HCV-mediated transcriptional downregulation of miR-181c. HCV-infected liver biopsy specimens also displayed lower expression levels of miR-181c. We have further demonstrated that inhibition of miR-181c upregulates homeobox A1 (HOXA1), which is important for hepatocyte growth promotion. Exogenous expression of miR-181c inhibited HCV replication by directly binding with HCV E1 and NS5A sequences. Taken together, our results provided new mechanistic insights for an understanding of the role of miR-181c in HCV-hepatocyte interactions and revealed miR-181c as a potential target for therapeutic intervention.
Ebola virus disease (EVD) is associated with elevated cytokine levels, and hypercytokinemia is more pronounced in fatal cases. This type of hyperinflammatory state is reminiscent of 2 rheumatologic disorders known as macrophage activation syndrome and hemophagocytic lymphohistiocytosis, which are ch
aracterized by macrophage and T-cell activation. An evaluation of 2 cohorts of patients with EVD revealed that a marker of macrophage activation (sCD163) but not T-cell activation (sCD25) was associated with severe and fatal EVD. Furthermore, substantial immunoreactivity of host tissues to a CD163-specific antibody, predominantly in areas of extensive immunostaining for Ebola virus antigens, was observed in fatal cases. These data suggest that host macrophage activation contributes to EVD pathogenesis and that directed antiinflammatory therapies could be beneficial in the treatment of EVD.
Virgin and breeder, spontaneously hypertensive and stroke prone rats (SHR/SP) were observed from weaning until 130 +/- 10 days of age. Blood pressure rose rapidly, reaching 230--240 mm Hg. After the birth of the second litter of pups, male and female breeders be
gan to die suddenly, due to myocardial necrosis and congestive heart failure. At autopsy, the brains of virgin and breeder SHR/SP were swollen but were free of any pathologic changes. There were no significant alterations in the blood chemistry of virgin rats but breeder SHR/SP had super-normal enzyme levels, CPK, SGOT, SGPT and LDH, hyperglycemia, hyperlipidemia, and hypersecretion of corticosterone. Breeder SHR/SP developed PAN-like lesions of the mesenteric arcades and adrenal cortex along with severe fibrino-hyalin lesions of the testicular and ovarian arteries. It is suggested that alterations in hypothalamic-pituitary-adrenal function associated with the reproductive effort conditioned these SHR/SP to develop myocardial necrosis rather than stroke and the development of unusual hypertensive arteriopathy.
Shrestha Palikhe N, etal., PLoS One. 2015 Dec 14;10(12):e0144500. doi: 10.1371/journal.pone.0144500. eCollection 2015.
BACKGROUND: Protease-Activated Receptor-2 (PAR-2), a G protein coupled receptor activated by serine proteases, is widely expressed in humans and is involved in inflammation. PAR-2 activation in the airways plays an important role in the development of allergic airway inflammation. PAR-2 expression i
s known to be upregulated in the epithelium of asthmatic subjects, but its expression on immune and inflammatory cells in patients with asthma has not been studied. METHODS: We recruited 12 severe and 24 mild/moderate asthmatics from the University of Alberta Hospital Asthma Clinics and collected baseline demographic information, medication use and parameters of asthma severity. PAR-2 expression on blood inflammatory cells was analyzed by flow cytometry. RESULTS: Subjects with severe asthma had higher PAR-2 expression on CD14++CD16+ monocytes (intermediate monocytes) and also higher percentage of CD14++CD16+PAR-2+ monocytes (intermediate monocytes expressing PAR-2) in blood compared to subjects with mild/moderate asthma. Receiver operating characteristics (ROC) curve analysis showed that the percent of CD14++CD16+PAR-2+ in peripheral blood was able to discriminate between patients with severe and those with mild/moderate asthma with high sensitivity and specificity. In addition, among the whole populations, subjects with a history of asthma exacerbations over the last year had higher percent of CD14++CD16+ PAR-2+ cells in peripheral blood compared to subjects without exacerbations. CONCLUSIONS: PAR-2 expression is increased on CD14++CD16+ monocytes in the peripheral blood of subjects with severe asthma and may be a biomarker of asthma severity. Our data suggest that PAR-2 -mediated activation of CD14++CD16+ monocytes may play a role in the pathogenesis of severe asthma.
Aortae taken from spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats aged 4, 8 and 16 weeks were prepared as rings and used to measure the effects of five vasoconstrictors. The endothelium was removed in order to measure selectively the contractile res
ponses induced by potassium chloride (KCl), phenylephrine (PHE), angiotensin-II (Ang II), endothelin-1 (ET-1) and human urotensin-II (U-II). These responses were assumed to derive from the activation of specific receptors (namely alpha1, AT1, ETA and UT-II) or from depolarization of the smooth muscle fibers by KCl. Specific antagonists prazosin, losartan, BQ-123 and [Orn8]-UII were used at various concentrations for a pharmacological characterization of these latter receptor systems. The primary purpose of the study was to explore mechanisms or factors that may intervene in the development and maintenance of high blood pressure in SHR. Results indicate that isolated aortae of SHR and WKY contain contractile sites (receptors) whose pharmacological profiles (pEC50 for agonists, pA2 for antagonists) are very similar to those of other biological systems and should be considered as typical for the alpha1, AT1, ETA and UT-II receptor types. Aortae taken from SHR 4 (non hypertensive), 8 and 16 weeks old (hypertensive) responded to the vasoconstrictors with reduced maximal contractions compared to those of age-matched WKY. These unexpected reduced responses of aortae, observed with the five vasoconstrictors, may be attributed to a non specific lesions. Maximal contraction of aortae from SHR increased from 4 to 16 weeks for KCI, PHE and U-II, decreased for Ang II, and remained stable for ET-1. There was also an age-dependent increase of maximal contraction induced by U-II in WKY. It is suggested that aortae from SHR undergo early remodelling that leads to reduced contractility in vitro and possibly to vessel rigidity in vivo. The factors involved in this process appear to be of genetic origin since they are present before hypertension: they may contribute to modify aortic compliance and perhaps vascular resistance in hypertensive animals and thus being the cause and not the consequence of high blood pressure.
Genetic control of blood pressure in the SHR strain was studied by three separate experiments which consist of cross analysis between the SHR and Donryu, two-way selecton for high and low blood pressure levels, and successiv
e backcrosses to the parental strains. The results obtained were as follows. 1. The data from genetic crosses between the SHR and Donryu showed the phenotype segregation ratio of 1:1 at the backcross and 1:2:1 at the F2 generation. 2. Two-way selection for high and low blood pressure levels was performed from the F2 generation onward. The separation between the two lines occurred immediately after the first selection. Thereafter, the difference increased gradually with generation. The blood pressure level at the seventh generation of selection became approximately equal to those of the parental strains. 3. Two types of the successive backcross were performed from the F1 hybrids by mating the males showing the highest blood pressure level to Donryu females and the females showing the lowest blood pressure level to SHR males on the other. Bimodality was observed in the distribution of blood pressure levels at each generation. Their phenotypic segregation ratios were accordant with 1:1 on the whole. At the intercross generation during successive backcrosses, a trimodal distribution was observed. 4. These results confirmed that the hypertensive trait of the SHR is regulated by a single major gene and other several genes with minor effect. A gene symbol ht was proposed for this major gene. Concurrently, a congenic strain having the ht gene on the genetic background of the Donryu was developed by the successive backcross system.
Li L, etal., Can J Physiol Pharmacol. 2009 Jan;87(1):56-62. doi: 10.1139/Y08-099.
Sirt1 is a human homologue of the silent information regulator factor 2 (Sir2) and has an NAD+-dependent histone deacetylase activity. This protein is reported to have a pathogenetic role in muscle differentiation, diabetic nephropathy, and heart failure. In this study, we investigated the express
ion of sirt1 in spontaneously hypertensive rat (SHR) to obtain insight into the function of sirt1 in hypertensive cardiovascular hypertrophy. The gene and protein expression of sirt1 was increased in the heart in SHR compared with normotensive WKY rats. Sirt1 mRNA was not different in the aorta between SHR and WKY rats. Sirt1 mRNA expression in heart and aorta was not related to hemodynamic parameters in SHR. Hypertensive left ventricular hypertrophy was significantly and positively related to the expression of heart tissue sirt1 mRNA in SHR. Aortic hypertrophy, however, was not related to sirt1 mRNA in the aorta. The increased sirt1 protein expression was accompanied by severe cardiac hypertrophy in older SHR. These results suggest that the increase of sirt1 gene and protein expression in the heart was associated with cardiac hypertrophy.
Previous studies with chromosome-Y consomic strains of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats suggest that a quantitative trait locus for blood pressure regulation exists on chromosome Y. To test this hypothesis in the SHR
ht:700;'>SHR-Brown Norway (BN) model and to study the effects of chromosome Y on lipid and carbohydrate metabolism, we produced a new consomic strain of SHR carrying the Y chromosome transferred from the BN rat. We found that replacing the SHR Y chromosome with the BN Y chromosome resulted in significant decreases in systolic and diastolic blood pressures in the SHR.BN-Y consomic strain (P<0.05). To elicit possible dietary-induced variation in lipid and glucose metabolism between the SHR progenitor and chromosome-Y consomic strains, we fed rats a high-fructose diet for 15 days in addition to the normal diet. On the high-fructose diet, the SHR.BN-Y consomic rats exhibited significantly increased levels of serum triglycerides and decreased levels of serum HDL cholesterol versus the SHR progenitor rats. Glucose tolerance and insulin/glucose ratios, however, were similar in both strains on both normal and high-fructose diets. These findings provide direct evidence that a gene or genes on chromosome Y contribute to the pathogenesis of spontaneous hypertension in the SHR-BN model. These results also indicate that transfer of the Y chromosome from the BN rat onto the SHR background exacerbates dietary-induced dyslipidemia in SHR. Thus, genetic variation in genes on the Y chromosome may contribute to variation in blood pressure and lipid levels and may influence the risk for cardiovascular disease.
Chen P, etal., Brain Res Bull. 2020 Jan;154:9-20. doi: 10.1016/j.brainresbull.2019.10.003. Epub 2019 Oct 15.
Hypertension is a common complication of metabolic abnormalities associated with cardiovascular system and characterized by sexual dimorphism in mammals. Fibroblast growth factor-21 (FGF-21) plays a critical role in metabolic-disorder related hypertension through the afferent loop of baroreflex. How
ever, the gender difference in FGF-21-mediated blood pressure (BP) regulation via sexual dimorphic expression of FGFRs in the nodose (NG) and nucleus tractus solitarius (NTS) were not elucidated in physiological and genomic form of hypertension. The gene and protein expression of FGFRs were tested by qRT-PCR, immunoblotting and immunostaining; the serum level of FGF21 was tested using ELISA; The BP was monitored while FGF21 was nodose microinjected. The results showed that more potent BP reduction was confirmed in female vs. male rats by nodose microinjection of rhFGF-21 along with higher expression of FGFR2 and FGFR4 in the nodose compared with age-match male and ovariectomized (OVX) rats, rather than other receptor subtypes, which is consistent well with immunohistochemical analysis. Additionally, serum FGF-21 was significantly higher in female-WKY, and this level of FGF-21 was dramatically declined in spontaneous hypertensive rats (SHR) with significant down-regulation of FGFR1/R4 for male-SHR and FGFR2/FGFR4 for female-SHR, respectively. Apparently, high BP of SHR of either sex could be reduced by rhFGF-21 nodose microinjection. These data extends our current understanding that sexual-specific distribution/expression of FGF-21/FGFRs is likely to contribute at least partially to sexual dimorphism of baroreflex afferent function on BP regulation in rats. FGF-21-mdiated BP reduction sheds new light on clinical management of primary/genomic form of hypertension.
The well-known association of hypertension and diabetes mellitus and the lack of suitable animal models to study diabetic hypertension prompted us to transfer 4 chromosomal regions with quantitative trait loci (QTLs) for blood pressure of the spontaneously hypertensive SHR
>SHR rat onto the genetic background of the diabetes-prone and normotensive BB/OK rat. Four congenic strains developed are named as BB. Sa (Chr.1), BB.Bp2 (Chr.18), BB.1K (Chr.20) and BB.Xs (Chr.X). Because the systolic blood pressure is significantly elevated in all congenics, renal related traits were investigated in serum and urine. Comparing BB/OK and their congenic derivatives, significant differences were found in all serum and in 7 out of 8 urine constituents studied. Most significant differences were found between BB/OK and BB.Bp2 rats. Significant differences were also found between the different congenic strains indicating that each congenic strain has its own phenotype and that each chromosomal region contains most probably further QTLs for some of the traits studied.
This study evaluated the contribution of angiotensin peptides acting at various receptor subtypes to the arterial pressure and heart rate of adult 9-wk-old male conscious salt-depleted spontaneously hypertensive rats (SHR). Plasma ANG II and ANG I in salt-deplet
ed SHR were elevated sevenfold compared with peptide levels measured in sodium-replete SHR, whereas plasma ANG-(1-7) was twofold greater in salt-depleted SHR compared with salt-replete SHR. Losartan (32.5 micromol/kg), PD-123319 (0.12 micromol. kg(-1). min(-1)), [d-Ala(7)]ANG-(1-7) (10 and 100 pmol/min), and a polyclonal ANG II antibody (0.08 mg/min) were infused intravenously alone or in combination. Combined blockade of AT(2) and AT((1-7)) receptors significantly increased the blood pressure of losartan-treated SHR (+15 +/- 1 mmHg; P < 0.01); this change did not differ from the blood pressure elevation produced by the sole blockade of AT((1-7)) receptors (15 +/- 4 mmHg). On the other hand, sole blockade of AT(2) receptors in losartan-treated SHR increased mean arterial pressure by 8 +/- 1 mmHg (P < 0.05 vs. 5% dextrose in water as vehicle), and this increase was less than the pressor response produced by blockade of AT((1-7)) receptors alone or combined blockade of AT((1-7)) and AT(2) receptors. The ANG II antibody increased blood pressure to the greatest extent in salt-depleted SHR pretreated with only losartan (+11 +/- 2 mmHg) and to the least extent in salt-depleted SHR previously treated with the combination of losartan, PD-123319, and [d-Ala(7)]ANG-(1-7) (+7 +/- 1 mmHg; P < 0.01). Losartan significantly increased heart rate, whereas other combinations of receptor antagonists or the ANG II antibody did not alter heart rate. Our results demonstrate that ANG II and ANG-(1-7) act through non-AT(1) receptors to oppose the vasoconstrictor actions of ANG II in salt-depleted SHR. Combined blockade of AT(2) and AT((1-7)) receptors and ANG II neutralization by the ANG II antibody reversed as much as 67% of the blood pressure-lowering effect of losartan.
Kloting I, etal., Obes Res 2002 Oct;10(10):1074-7.
OBJECTIVE: The phenotypic characterization of congenic BB.LL rats recombining a segment of the SHR chromosome 4 (D4Mit6-Npy-Spr; 12 cM) into the BB/OK background indicated that these rats were not lymphopenic and did not develop diabetes, but they were significa
ntly heavier (at 16 weeks of age) and showed higher serum triglycerides and total cholesterol concentration. RESEARCH METHODS AND PROCEDURES: BB.LL rats were longitudinally studied for facets of metabolic syndrome (body mass index, blood glucose, serum lipids, insulin, leptin, and systolic and diastolic blood pressure) from 2 to 12 months of age. RESULTS: In this study, it was shown that BB.LL are obese, hyperleptinemic, hyperinsulinemic, and dyslipidemic compared with their parental BB/OK rats. DISCUSSION: It can be concluded that there is a gene(s) in the introgressed segment causing incomplete metabolic syndrome, because they do not develop hypertension and diabetes. To identify the gene(s), the introgressed chromosomal segment must be systematically whittled down to generate recombinants and new subcongenic lines carrying a much smaller segment of the SHR/Mol rat to increase the chance of identification of the appropriate gene(s).
Wang H, etal., Biochem Biophys Res Commun. 2004 Mar 5;315(2):363-8.
This study examined whether retarded angiogenesis in a hypertension animal model was associated with impaired VEGF signaling. Furthermore, we sought to determine whether this impairment could be overcome by VEGF addition. Using a rat sponge implantation model, we confirmed impaired angiogenesis in s
pontaneous hypertensive rats (SHRs). Fourteen days after sponge implantation, the level of angiogenesis in SHRs was approximately half of those in age-matched normotensive Wistar-Kyoto or Sprague-Dawley rats. Significantly, expression of kinase-insert domain-containing receptor (KDR) and membrane type 1 matrix metalloproteinase (MT1-MMP) was reduced in SHRs compared to controls. Immunohistological analysis indicated endothelial proliferation was decreased in SHRs. Gene transfer of human VEGF(121) increased KDR and MT1-MMP expression in SHRs. VEGF(121) also up-regulated endothelial proliferation and angiogenesis. Our results indicate down-regulated KDR and MT1-MMP expression is associated with an impaired angiogenesis in SHRs. VEGF gene transfer is effective in ameliorating the impaired angiogenesis in SHRs.
1. The mechanisms whereby angiotensin converting enzyme inhibitors reverse cardiac remodelling appear to involve angiotensin and/or bradykinin receptors. Previously we reported that cultured rat cardiac fibroblasts express angiotensin II (AII) receptors. In the present study we compared AII receptor
binding, gene expression of angiotensinogen and the AII, Subtype 1A (AT1A) receptor, as well as morphological changes induced by selected hormonal treatments in cultured fibroblasts derived from SHRLJ or WKYLJ rats. 2. Fibroblasts were isolated from adult rat left ventricle by either collagenase B or collagenase P digestion. Collagenase B yielded cell preparations from SHRLJ which grew slower than cells from WKYLJ rats and expressed nearly two-fold fewer AII receptors (compared to WKYLJ) while collagenase P yielded SHRLJ cells with similar binding and growth properties to WKYLJ. A good correlation was observed between receptor binding and AII receptor, type 1A (AT1A) mRNA concentrations. In the presence of steroids collagenase B cells showed a higher tendency to transform towards a preadipocyte cell type, estimated by the formation of lipid containing vacuoles/cell, while collagenase P cells, mainly the SHRLJ type, start to differentiate toward a myofibroblast-like cell type in the presence of AII, as calculated by the expression of alpha-smooth muscle actin. 3. From the results obtained in this study it is evident that a subset of fibroblasts can be isolated from the SHRLJ heart using collagenase B or P which differ in growth rates, AII receptor binding, AT1A and angiotensinogen mRNA levels, morphology and steroid responsiveness when compared to fibroblasts isolated from cardiac WKYLJ tissue.
Diez-Freire C, etal., Physiol Genomics. 2006 Oct 3;27(1):12-9. Epub 2006 Jun 20.
Recently discovered, angiotensin-converting enzyme-2 (ACE2) is an important therapeutic target in the control of cardiovascular diseases as a result of its proposed central role in the control of angiotensin peptides. Thus our objective in the present study was to determine whether ACE2 gene transf
er could decrease high blood pressure (BP) and would improve cardiac dysfunctions induced by hypertension in the spontaneously hypertensive rat (SHR) model. Five-day-old SHR and normotensive WKY rats received a single intracardiac bolus injection of lentiviral vector containing either murine ACE2 (ACE2) or control enhanced green fluorescent protein (EGFP) genes. Systolic BP, cardiac functions, and perivascular fibrosis were evaluated 4 mo after ACE2 gene transduction. ACE2 gene transfer resulted in a significant attenuation of high BP in the SHR (149 +/- 2 mmHg in lenti-ACE2 vs. 180 +/- 9 mmHg in lenti-EGFP, P < 0.01). In contrast, no significant effect of lenti-ACE2 on BP of WKY rats was observed. Lenti-ACE2-treated SHR showed an 18% reduction in left ventricular wall thickness (1.52 +/- 0.04 vs. 1.86 +/- 0.04 mm in lenti-EGFP, P < 0.01). In addition, there was a 12% increase in left ventricular end diastolic and a 21% increase in end systolic diameters in lenti-ACE2-treated SHR. Finally, lenti-ACE2 treatment resulted in a significant attenuation of perivascular fibrosis in the SHR. In contrast, ACE2 gene transfer did not influence any of these parameters in WKY rats. These observations demonstrate that ACE2 overexpression exerts protective effects on high BP and cardiac pathophysiology induced by hypertension in the SHR.
Watanabe T, etal., Biochem Biophys Res Commun 2005 Apr 15;329(3):879-87.
The spontaneously hypertensive rat (SHR) is a model of human insulin resistance syndrome. Quantitative trait loci for cellular defects in glucose and fatty acid metabolism have been mapped to an overlapping region of rat chromosome (RNO) RNO4 in SHR
t-weight:700;'>SHR of the National Institute of Health colony, where a deletion in the Cd36 gene has been implicated as the causative mutation of insulin resistance. The present study has examined the potential presence of RNO4 linkage to a series of metabolic phenotypes in F(2) progeny derived from SHR of a Japanese colony (SHR/Izm) without the Cd36 mutation. Our data demonstrate that 'major' insulin resistance gene(s) are unlikely to exist on RNO4 in SHR/Izm and in vitro phenotypes measured in isolated adipocytes do not cosegregate in the F(2) population studied. Thus, it seems to be difficult to explain the underlying genetic mechanisms of insulin resistance by a single major gene on RNO4.
Spontaneously hypertensive stroke-prone rats suffer spontaneous strokes partly as a result of abnormal cerebrovascular development. This model exhibits prehypertensive, typical hypertensive and malignant hypertensive stages. We had observed that vascular endothelial growth factor and its receptors,
kinase domain region (KDR) and fms-like tyrosine kinase (Flt-1), were upregulated in the frontal cortex of spontaneously hypertensive stroke-prone rats at the typical hypertensive stage. The current study therefore investigated whether the long-term treatment with an endothelin-A/endothelin-B dual receptor antagonist, SB209670, or saline (vehicle) starting at the prehypertensive stage (6 weeks old) could reverse the upregulated vascular endothelial growth factor and its receptors; this upregulation is believed to be a compensatory adaptation for hypertension in the brain of spontaneously hypertensive stroke-prone rats. A 40% upregulation of vascular endothelial growth factor was observed in the brain of vehicle-treated spontaneously hypertensive stroke-prone rats compared with the age-matched genetic control, Wistar-Kyoto rat, and this upregulation was markedly reversed by endothelin antagonism. A similar change was found in KDR and Flt-1 expression. It is worth noting that the vascular endothelial growth factor/KDR signaling system was upregulated in the brain of spontaneously hypertensive stroke-prone rats treated with vehicle at the typical hypertensive stage, whereas the cerebral blood flow did not differ between Wistar-Kyoto and spontaneously hypertensive stroke-prone rats. We concluded that endothelin antagonism reversed the upregulated vascular endothelial growth factor and its receptors in the frontal cortex of spontaneously hypertensive stroke-prone rats at the typical hypertensive stage, and it is suggested that endothelin antagonism can reverse the hypertension-induced neurovascular remodeling in the brain of these rats.
Hom S, etal., Am J Physiol Regul Integr Comp Physiol. 2007 Jan 18;.
Hypertension is involved in the exacerbation of stroke. It is unclear how blood-brain barrier (BBB) tight junction (TJ) and ion transporter proteins critical for maintaining brain homeostasis contribute to cerebral infarction during hypertension development. In the present study, we investigated cer
ebral infarct volume following permanent 4 hr middle cerebral artery occlusion (MCAO) and characterized the expression of BBB TJ and ion transporter proteins in brain microvessels of spontaneously hypertensive rats (SHR) compared to age-matched Wistar-Kyoto rats (WKY) at 5 (pre-hypertension), 10 (early stage hypertension) and 15 (later stage hypertension) weeks of age. Hypertensive SHR show increased infarct volume following MCAO as compared to WKY control. BBB TJ and ion transporter proteins, known to contribute to edema and fluid volume changes in the brain, show differential protein expression patterns during hypertension development. Western blot analysis of TJ protein zonula occludens-2 (ZO-2) showed decreased expression while ion transporter, Na(+)/H(+) exchanger 1 (NHE-1), was markedly increased in hypertensive SHR. Expression of TJ proteins ZO-1, occludin, actin, claudin-5, and Na(+)/K(+)/2Cl(- )cotransporter (NKCC) remain unaffected in SHR compared to control. Selective inhibition of NHE-1 using dimethylamiloride (DMA) significantly attenuated ischemia-induced infarct volume in hypertensive SHR following MCAO, suggesting a novel role for NHE-1 in the brain in the regulation of ischemia-induced infarct volume in SHR. Key words: hypertension, tight junction, NHE, MCAO, ion transport.
Hendley ED and Ohlsson WG, Am J Physiol. 1991 Aug;261(2 Pt 2):H583-9.
Two new strains of inbred rats have been developed. One, WKHA, exhibits hyperactivity, and the other, WKHT, exhibits hypertension. Both of these traits are expressed in the SHR. By crossing spontaneously hypertensive rats (SHR
n>s) with Wistar-Kyoto (WKY) controls, followed by recombinant selected inbreeding, we succeeded in genetically separating the hyperactivity from the hypertension in two new strains. Longitudinal studies indicate a persistence of hypertension without hyperactivity in WKHTs, and hyperactivity without hypertension in WKHAs, over at least 1 year. Ventricular enlargement, another characteristic of SHRs, was observed in adult WKHTs after the onset of hypertension; however, ventricles were already enlarged in normotensive WKHAs at 6 wk. The emergent behavioral profile of WKHAs indicates that they retain the hyperactivity trait and hyperreactivity to stress, and not some of the other behaviors of SHRs, such as poor habituation. Studies in WKHTs suggest that they are an improvement over SHRs as a model of genetic hypertension as they lack some prominent behavioral abnormalities. Nevertheless, the four genetically related strains (WKHA, WKHT, SHR, and WKY), used together, are considered most appropriate for seeking correlations of biological differences with either hypertension or hyperactivity.
Ramos A, etal., Behav Brain Res. 1998 Nov;96(1-2):195-205.
Lewis (LEW) and spontaneously hypertensive rats (SHR) have been shown to differ in a series of fear-related behaviours measured in different anxiety/emotionality tests. In the present study, we have investigated some of the genetic mechanisms underlying these di
fferences. To this end, male and female rats from the two inbred strains were crossed to produce two parental (LEW and SHR), two F1 (LEW or SHR mother), and two F2 (LEW or SHR grandmother) groups. All rats were tested in the elevated plus-maze and in the open field, besides being characterised for systolic blood pressure (BP). LEW rats approached the open arms of the plus-maze and the central area of the open field less than SHRs. The two strains also differed in their BP (SHR > LEW). LEW/SHR differences were found to be due to direct effects of the genes, rather than to indirect maternal and grand-maternal effects. Central locomotion in the open field was shown to be the most heritable of all the traits considered herein. A factor analysis on the segregating F2 population produced three independent factors. The first one was associated to measures of anxiety from the elevated plus-maze, and the second to measures of locomotion in novel environments. Factor scores revealed that the parental strains differ in relation to the first but not to the second factor. This study demonstrates the usefulness of coupling genetic and multifactorial methods to investigate behavioural traits and it confirms LEW and SHR strains as an interesting genetic tool for the study of anxiety.
We compared the effects of long-term treatment with the angiotensin-converting enzyme inhibitor perindopril and triple therapy (hydrochlorothiazide, reserpine, and hydralazine) on the metabolic and renal features in the SHR/N-corpulent (cp) rat, a genetic model
of non-insulin-dependent diabetes mellitus and hypertension. Obese male SHR/N-cp rats (4 to 6 weeks old) were fed a 54% carbohydrate diet containing 18% sucrose and 36% starch. After 2 months on the diet, rats were assigned to one of three groups: one group (n=8) received perindopril (PE); the second group (n=8) received triple therapy (TT); and the third group (n=8) did not receive therapy. Treatment was maintained for 3 to 4 months. Body weight, food intake, and fasting levels of serum glucose and insulin did not differ among the three groups. Control rats exhibited progressive proteinuria in parallel with the rise in systolic blood pressure (SBP). Both PE and TT equally lowered SBP to normal levels and reduced proteinuria in treated rats. However, the reduction of proteinuria was greater and more sustained with PE than with TT (P<.05), whereas the effect of TT on proteinuria was delayed. Plasma renin activity was increased in PE and TT rats compared with control rats (P<.02). Semiquantitative analysis of renal lesions showed that the percentage of glomeruli with mesangial expansion and sclerosis and the tubulointerstitial score (an index of severity of tubulointerstitial lesions, namely tubular atrophy, inflammatory cellular infiltrates, and interstitial fibrosis) was reduced in both PE and TT rats. However, the reduction of glomerulosclerosis and tubulointerstitial lesions was greater in PE than in TT rats (P<.01). The percentage of glomerular sclerosis was positively correlated with the severity score of tubulointerstitial lesions (r=.60, P<.01). We conclude that PE is more effective than TT in halting the progression of proteinuria in the SHR/N-cp rat with non-insulin-dependent diabetes mellitus and hypertension. The antiproteinuric effect of PE is associated with significant reduction in glomerulosclerosis and tubulointerstitial lesions, independent of the effect of treating hypertension.
Lo M, etal., Physiol Genomics 2002 Feb 11;8(1):15-21.
One or more quantitative trait locus (QTL) for blood pressure (BP) exists on rat chromosome 1, in the vicinity of the Sa gene. The present work examined whether this QTL region: 1) alters pressure-natriuresis relationship and 2) affects the BP response to salt load. Male spontaneously hypertensive r
ats (SHR), Wistar-Kyoto (WKY) rats, and rats from an SHR congenic strain that contains a WKY chromosome 1 segment spanning the BP QTL region (SHR. WKY-Sa) were used. In an acute study in anesthetized animals, renal function was measured at several levels of renal perfusion pressure. In a chronic study, BP was measured in freely moving rats using telemetry during normal and high sodium intake (2% NaCl as drinking water for 2 wk). WKY rats showed a significantly higher glomerular filtration rate and increased pressure-natriuresis compared with SHR. SHR.WKY-Sa also demonstrated an increased glomerular filtration rate and enhanced pressure-natriuresis, associated with a lower tubular sodium reabsorption, compared with SHR. These modifications were accompanied by a lower basal BP in SHR.WKY-Sa compared with SHR and a markedly reduced BP response to salt load. These findings suggest that the BP QTL(s) present in this region of chromosome 1 influences BP and salt sensitivity, at least partly, by modulating pressure-natriuresis.
Cao J, etal., Obesity (Silver Spring). 2012 May;20(5):945-53. doi: 10.1038/oby.2011.365. Epub 2011 Dec 22.
High-dietary fat intake is a major risk factor for development of metabolic and cardiovascular-renal dysfunction including obesity, coronary artery disease, hypertension, and chronic renal failure. We examined the effect of a high-fat diet on renal function and morphology in spontaneously hypertensi
ve rats (SHR), a phenotype designed to mimic metabolic syndrome. High-fat diet induced increase (P < 0.05) in blood pressure, body weight, and renal lipid deposition in these rats. This increase in body weight was accompanied by elevations (P < 0.05) of blood glucose and low-density lipoprotein (LDL) levels, a decrease (P < 0.05) in adiponectin and increases (P < 0.05) in plasma monocyte chemotactic protein-1 (MCP-1) along with renal macrophage infiltration. These pathophysiological perturbations were attenuated (P < 0.05) by heme oxygenase-1 (HO-1) induction by treatment with cobalt protoporphyrin (CoPP). Further effects of CoPP included increased (P < 0.05) renal expression of adiponectin along with enhancement (P < 0.05) of pAKT, pAMPK, and p-eNOS in SHRs fed a high-fat diet. Prevention of such beneficial effects of CoPP by the concurrent administration of the heme-HO inhibitor stannous mesoporphyrin (SnMP) corroborates the role of HO system in mediating such effects. Taken together, our results demonstrate that high-fat diet induces a metabolic syndrome-like phenotype in hypertensive rats, which is amenable to rescue by increases in HO-1- and adiponectin-dependent pathways.
Seda O, etal., Folia Biol (Praha). 2005;51(3):53-61.
The SHR and the PD/Cub are two established rodent models of human metabolic syndrome. Introgression of a ca 30 cM region of rat chromosome 8 from PD/Cub onto the genetic background of SHR was previously shown to influence se
veral of the metabolic syndrome-related traits along with causing the PLS in the SHR-Lx congenic strain. In the process of identification of the causative alleles, we have produced several congenic sublines. The differential segment of SHR-Lx PD5 congenic substrain [SHR.PD(D8Rat42-D8Arb23)/Cub] spans approximately 1.4 Mb encompassing only 14 genes. When comparing the metabolic, morphometric and gene expression profiles of the SHR-Lx PD5 vs. SHR, the polydactyly and several distinct metabolic features observed in the original SHR-Lx congenic were still manifested, suggesting that the responsible genes were "trapped" within the relatively short differential segment of PD/Cub origin in SHR-Lx PD5. Particularly, the SHR-Lx PD5 displayed substantial reduction of insulin sensitivity confined to skeletal muscle. Among the candidate genes, the promyelocytic leukaemia zinc-finger Plzf (Zbtb16) transcription repressor is most likely responsible for the Lx mutation resulting in PLS and could also be involved in the alteration of metabolic pathways. The sequence analysis of the Plzf gene revealed a SNP leading to a threonine to serine substitution in SHR at aminoacid position 208 (T208S). In summary, we have isolated a 1.4 Mb genomic region syntenic to human chromosome 11q23, which, apart from causing polydactyly-luxate syndrome (PLS), affects total body weight, adiposity, lipid profile, insulin sensitivity of skeletal muscle and related gene expression as shown in the SHR-Lx PD5 congenic substrain.
Twenty-four male (12 obese and 12 lean) and 21 female (11 obese and 10 lean) SHR/N-cp rats were fed a diet containing either 54% sucrose or starch for periods of 3-4 months. Rats were killed after a 14-16 h fast and liver enzyme activities were determined in bot
h sex groups. Liver glucose-6-phosphatase (G6Pase), fructose 1,6-bisphosphatase (FBPase), phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), malic enzyme (ME), phosphofructokinase (PFK), glucokinase (GK), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels (per total liver capacity) were significantly affected by phenotype (obese > lean). Arginase and ornithine transcarbamylase levels were analysed only in male rats and were found to be elevated in obese rats as compared to lean littermates. Some of the above changes in enzyme levels were exaggerated by sucrose feeding but not the changes in FBPase, PEPCK, ME and GK (in both sexes) plus AST, arginase and arginine synthase activities in male rats and ALT levels in female rats. Results from SHR/N-cp rats published in this paper were compared to results obtained from LA/N-cp rats published previously. Comparison of the non-diabetic obese LA/N-cp with the diabetic obese SHR/N-cp male shows a greater excess in lipogenic capacity of the liver in the LA/N-cp male rat. The SHR/N-cp obese female also shows a greater liver lipogenic capacity as compared with the obese male SHR/N-cp rat. The results suggest that an adaptation of excessive lipogenesis in the liver of obese rats may be an anti-diabetogenic adaptation resulting in increased glucose conversion to lipids, thus reducing blood glucose levels.
Wang Z, etal., Int J Cardiol. 2016 Jul 1;214:348-57. doi: 10.1016/j.ijcard.2016.04.007. Epub 2016 Apr 5.
BACKGROUND: Left ventricular hypotrophy (LVH) is very common in hypertensives even after antihypertensive treatment. Mitofusin 2 (Mfn2) is a critical negative regulator of vascular smooth muscle cell (VSMC) hypertrophy by regulating mitochondrial fusion, ras/raf/MEK signal pathway, et al.
The purpose of this study was to investigate whether candesartan attenuated cardiac remodeling by improving expression and function of mitofusin 2 in SHR. METHODS: Nine weeks old spontaneously hypertensive rats (SHR) were selected and treated with candesartan for eight weeks. Then, heart tissues were investigated for signs of cardiac remodeling, mitochondrial structure and membrane potential, mitochondrial enzyme activities, hydrogen peroxide, mRNA and protein expression of Mfn2/ras/raf/MEK signaling pathway in heart tissues. RESULTS: The results showed that cardiac remodeling was obviously in SHR group: cardiac cell alignment was irregular; cardiac fibers became thick, irregular and enlarged; cell density was reduced in SHR compared to WKY. After candesartan treatment, histopathological structure improved significantly which were consistent with mitochondrial morphology, mitochondrial membrane potential, mitochondrial enzyme activities, hydrogen peroxide, Mfn2/ras/raf/MEK gene and protein expression in cardiac tissues. What's more, although blood pressure was well controlled in a normal range, cardiac remodeling wasn't avoided. In general, candesartan obviously repressed cardiac hypertrophy and cardiac remodeling significantly compared to SHR untreated group, but didn't reverse it. CONCLUSIONS: Mfn2 is negatively associated with cardiac remodeling. Candesartan treatment can improve mitochondrial structure and function and regulate Mfn2/ras/raf/MEK signaling pathway. Mfn2 may be used a potential marker for cardiac remodeling and a novel therapeutic target for target organ damage protection.
Congenic BB.SHR (previously referred to as BB.LL) rats were generated by transferring the segment of chromosome 4 flanked by the D4Mit6 and Spr loci from the spontaneously hypertensive rat (SHR/Mol) onto the genetic backgrou
nd of the diabetes-prone BB/OK rat. In this study, the influence of the above-mentioned region of chromosome 4 on triglyceride, cholesterol, and phospholipid phenotypes after a high-fat, high-cholesterol diet was examined by comparison of BB.SHR congenic rats with BB/OK rats. BB/OK and BB.SHR had comparable concentrations of basal and postdietary serum insulin, as well as of basal total serum triglycerides and had an identical body weight and food intake at the beginning of the test period. However, after 4 weeks on the test diet, BB.SHR rats were significantly heavier than BB/OK rats and had significantly higher food intake and lower total serum triglyceride concentrations. The basal serum leptin level was significantly lower, but postdietary serum leptin concentration did not show a significant difference between the 2 strains. Furthermore, significantly higher basal total serum cholesterol and phospholipid levels were observed in BB.SHR rats, but this difference disappeared after feeding the high-fat, high-cholesterol diet. Postdietary high-density lipoprotein (HDL)(2) cholesterol and phospholipid levels were significantly elevated in BB.SHR rats when compared with BB/OK rats. The 2 strains also differed slightly, but significantly, with respect to the other HDL phospholipid concentrations. In addition to previously described differences between BB/OK and BB.SHR rats, the results of this study clearly show the impact of genes, lying within the transferred segment, on serum lipid phenotypes after high-fat, high-cholesterol diet.
Aneas I, etal., Physiol Genomics. 2009 Mar 3;37(1):52-7. Epub 2009 Jan 6.
To dissect the genetic architecture controlling blood pressure (BP) regulation in the spontaneously hypertensive rat (SHR) we derived congenic rat strains for four previously mapped BP quantitative trait loci (QTLs) in chromosomes 2, 4, and 16. Target chromosoma
l regions from the Brown Norway rat (BN) averaging 13-29 cM were introgressed by marker-assisted breeding onto the SHR genome in 12 or 13 generations. Under normal salt intake, QTLs on chromosomes 2a, 2c, and 4 were associated with significant changes in systolic BP (13, 20, and 15 mmHg, respectively), whereas the QTL on chromosome 16 had no measurable effect. On high salt intake (1% NaCl in drinking water for 2 wk), the chromosome 16 QTL had a marked impact on SBP, as did the QTLs on chromosome 2a and 2c (18, 17, and 19 mmHg, respectively), but not the QTL on chromosome 4. Thus these four QTLs affected BP phenotypes differently: 1) in the presence of high salt intake (chromosome 16), 2) only associated with normal salt intake (chromosome 4), and 3) regardless of salt intake (chromosome 2c and 2a). Moreover, salt sensitivity was abrogated in congenics SHR.BN2a and SHR.BN16. Finally, we provide evidence for the influence of genetic background on the expression of the mapped QTLs individually or as a group. Collectively, these data reveal previously unsuspected nuances of the physiological roles of each of the four mapped BP QTLs in the SHR under basal and/or salt loading conditions unforeseen by the analysis of the F2 cross.
SHR/NDmcr-cp (SHR/NDcp) rats, which carry a nonsense mutation of the leptin receptor gene, are known to spontaneously develop hypertension, obesity and hyperlipidemia, and have therefore found use as an animal model of the m
etabolic syndrome and type 2 diabetes. However, some recent studies on SHR/NDcp rats revealed only mild elevation of blood glucose levels. To investigate whether metabolic factors including blood glucose and histopathological alterations of SHR/NDcp rats deteriorate with a diabetogenic diet, biochemical and histopathological examinations were conducted with animals fed normal or diabetogenic diets for 20 weeks. SHR/NDcp rats receiving the normal diet displayed obesity, hypertension, hyperlipidemia, and mild elevation of blood glucose and HbA1c levels. Urinary glucose excretion was noted in only 1 out of 6 animals. Histologically, macro- and micro-vesicular steatosis in the liver, glomerular and tubular damages in the kidney and islet hyperplasia mainly of beta cells in the pancreas were characteristically noted. In SHR/NDcp rats fed the diabetogenic diet, obesity was more severe, with higher blood glucose and HbA1c levels, increased numbers of animals with urinary glucose excretion, and more pronounced hepatic steatosis and renal tubular changes. However, elevation of blood glucose levels and urinary glucose excretion proved transient. These observations indicate that the diabetic state and associated histopathological alterations in SHR/NDcp rats are exacerbated by feeding a diabetogenic diet, but the effects are limited. Elevated islet function with compensative insulin secretion might be related to amelioration of the hyperglycemic state. Further diet modification could be needed to induce a more prominent and persistent diabetic state in SHR/NDcp rats.
Carswell N, etal., J Nutr. 1989 Mar;119(3):388-94.
The SHR/N-corpulent (cp) rat exhibits some of the metabolic characteristics associated with human noninsulin-dependent diabetes mellitus (NIDDM). To determine the effect of the alpha-glucosidase inhibitor, acarbose (BAY-g-5421), on expression of NIDDM in this mo
del, young male obese and lean littermates were fed for 12 wk diets containing either 54% starch, sucrose, or sucrose plus acarbose (150 mg acarbose/kg diet). Body weight; fasting levels of serum triglyceride, total cholesterol, insulin and glucose; response levels of insulin and glucose following an oral glucose tolerance test (OGTT); and total urinary glucose were determined. Supplementation of the sucrose diet with acarbose reduced final body weight in obese rats, as well as serum triglyceride, total cholesterol, response insulin, and urinary glucose in both phenotypes. Glucosuria was normalized in acarbose-treated obese rats. In addition, acarbose improved the glycemic response following OGTT in both phenotypes. These findings demonstrate that acarbose is effective in moderating the metabolic effects of NIDDM in this diabetic rodent model, and suggest that acarbose may have potential in the management of NIDDM in humans.
The SHR/N corpulent (cp) rat is a genetically obese rat that develops hyperglycemia, hyperinsulinemia, and proteinuria. This study was designed to evaluate the effects of high carbohydrate (CHO) intake on renal function and structure in this animal model and to
determine whether the renal effects are related to the type of CHO ingested. Two groups of 5-wk-old obese male SHR/N-cp rats and lean male littermates were fed diets containing 54% CHO in the form of sucrose or starch. After 12 wk, renal function parameters, including creatinine clearance, urinary glucose excretion, and urinary protein excretion, were measured. Renal morphology was evaluated by semiquantitative light and electron microscopy. On either diet, obese rats had significantly higher urinary glucose and protein excretions than their lean littermates. Mean creatinine clearance (ml/min) in obese rats did not differ significantly from values observed in lean rats. When corrected for body weight, creatinine clearance (ml.min-1.kg-1) tended to be lower in obese than in lean rats, but the difference was significant (P less than .02) only for obese and lean sucrose-fed animals. Obese rats fed sucrose compared with their obese counterparts fed starch had higher body weight (+8%, P less than .05), glucose excretion (+63%, P less than .02), and protein excretion (+242%, P less than .005). In obese rats, protein excretion correlated with glucose excretion (r = .71, P less than .01). Glomerular lesions consisting of mesangial expansion and intercapillary nodules were found in obese but not in lean rats. Moreover, obese rats fed sucrose had a significantly greater number of involved glomeruli than obese rats fed starch.(ABSTRACT TRUNCATED AT 250 WORDS)
Common inbred strains of the laboratory rat can be divided into four major mitochondrial DNA (mtDNA) haplotype groups represented by the BN, F344, LEW, and SHR strains. In the current study, we investigated the metabolic and hemodynamic effects of the SHR
e='font-weight:700;'>SHR vs. F344 mtDNA by comparing the SHR vs. SHR-mt(F344) conplastic strains that are genetically identical except for their mitochondrial genomes. Altogether 13 amino acid substitutions in protein coding genes, seven single nucleotide polymorphisms in tRNA genes, and 12 single nucleotide changes in rRNA genes were detected in F344 mtDNA compared with SHR mtDNA. Analysis of oxidative phosphorylation system (OXPHOS) in heart left ventricles (LV), muscle, and liver revealed reduced activity and content of several respiratory chain complexes in SHR-mt(F344) conplastic rats compared with the SHR strain. Lower function of OXPHOS in LV of conplastic rats was associated with significantly increased relative ventricular mass and reduced fractional shortening that was independent of blood pressure. In addition, conplastic rats exhibited reduced sensitivity of skeletal muscles to insulin action and impaired glucose tolerance. These results provide evidence that inherited alterations in mitochondrial genome, in the absence of variation in the nuclear genome and other confounding factors, predispose to insulin resistance, cardiac hypertrophy and systolic dysfunction.
The effects of lowering blood pressure (BP) by hydralazine (HY) (2 mg/kg) on spontaneous (SA) and post-sigh (PSA) sleep apneas have been studied in spontaneously hypertensive (SHR) rats by monitoring their respiration and sleep by the EEG for 6 hours. Normotensi
ve Wistar-Kyoto (WKY) rats, from which the SHR rat strain was derived, were used as an appropriate control. The SHR rats had more SA (p < 0.02) and PSA (p < 0.0001) apneas/hour than WKY rats during nonrapid eye movement sleep and their mean BP was higher by 40 mm Hg (p < 0.0001) than WKY rats. Administration of HY to SHR rats equalized their BP with the arterial pressure of WKY rats and reduced the SA and the PSA apneas/hour to equivalence with WKY normotensive rats. These results demonstrate that even in the context of lifelong hypertension, acute normalization of BP significantly reduces sleep apneas in rats. They further suggest that improved management of BP may be clinical benefit to patients with apnea who have long-standing hypertension.
Kurdi M, etal., Mol Cell Biochem. 2005 Jan;269(1-2):95-101.
Cytokines from the interleukin-6 (IL-6) family have been reported to play an important synergistic role with angiotensin II in the development of pathological cardiac hypertrophy. Whether their expression pattern changes in vivo, in an angiotensin I-dependent hypertrophied myocardium has not been re
ported. In this study, we addressed that issue using two animal models of angiotensin II-dependent cardiac hypertrophy. Heterozygous transgenic TGR(mRen2)27 (TGR) with an overactive cardiac renin angiotensin system and the closely related spontaneously hypertensive rats (SHR) were compared to their respective control rats. The mRNA levels of IL-6, leukemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF) and cardiotrophin-1 (CT-1) as well as their receptor subunits, glycoprotein 130 (gp130), IL-6 receptor (IL-6R), LIFR, and CNTFR, were measured by semi-quantitative RT-PCR. The protein levels of IL-6, LIF and CT-1 were investigated by western blot. TGR and SHR both displayed significant over expression of mRNA and protein levels for IL-6 and LIF. In TGR, the increased level of LIF was accompanied by a decrease in mRNA levels for LIFR and CNTFR. In SHR, a higher level of mRNA IL-6R was observed. By contrast, the mRNA and protein levels for CT-1 and the mRNA level for gp130 did not vary in these two models. These findings suggest that IL-6 and LIF, but not CT-1, contribute to angiotensin II-dependent left ventricular hypertrophy in the two hypertensive rat models, TGR(mRen2)27 and SHR.
Schulz A, etal., Physiol Genomics. 2012 Jan 18;44(1):110-6. Epub 2011 Nov 22.
Inbred Munich Wistar Fromter [MWF/FubRkb (RGD:724569), MWF] rats develop progressive albuminuria with age that is under polygenetic influence. We previously identified a major albuminuria quantitative trait locus (QTL) on rat chromosome (RNO)8 in MWF. To test the independent role of QTL(s) for album
inuria development on RNO8, we generated a consomic SHR-Chr 8(MWF)/Rkb (SHR-8(MWF)) strain by transferring RNO8 from MWF into the albuminuria-resistant background of the spontaneously hypertensive rat [SHR/FubRkb (RGD:631696; SHR)]. Young male MWF, SHR, and SHR-8(MWF) were sham-operated or unilaterally nephrectomized (Nx) at 6 wk and followed up to 24 wk of age, respectively. Systolic blood pressure was significantly lower in SHR-8(MWF) Sham compared with SHR Sham (-19.4 mmHg, P = 0.03) at 24 wk. In contrast, transfer of MWF-RNO8 into SHR induced a significant elevation of urinary albumin excretion (UAE) between weeks 12 and 24 in SHR-8(MWF) compared with SHR Sham animals (P < 0.0001, respectively). Nx resulted in a significant increase in UAE in both strains during follow-up (P < 0.0001, respectively), with significant higher values in SHR-8(MWF) compared with SHR (P < 0.005, respectively). Renal structural changes as determined by glomerulosclerosis (GSI) and tubulointerstitial damage index (TDI) were significantly higher in consomic animals either at Sham (TDI) or Nx (GSI) conditions (P < 0.05, respectively). These data confirm the independent role of MWF QTL(s) on RNO8 for both albuminuria and structural kidney damage. Moreover, this study shows for the first time the induction of albuminuria by transferring one or more albuminuria QTL into a resistant recipient background in a consomic rat strain.
Sun C, etal., Hypertension. 2007 Mar;49(3):528-34. Epub 2007 Jan 29.
Macrophage migration inhibitory factor acts via its intrinsic thiol-protein oxidoreductase activity to negatively regulate the neuronal chronotropic actions of angiotensin II in normotensive rat neurons. Because the chronotropic action of angiotensin II is potentiated in spontaneously hypertensive r
at neurons, we investigated whether this negative regulatory mechanism is absent in these rats. Angiotensin II (100 nM) elicited an approximately 89% increase in neuronal firing in Wistar-Kyoto rat hypothalamus and brain stem cultured neurons and an increase in intracellular macrophage migration inhibitory factor levels in the same cells. The chronotropic action of angiotensin II was significantly greater (approximately 212% increase) in spontaneously hypertensive rat neurons, but angiotensin II failed to alter macrophage migration inhibitory factor expression in these cells. Intracellular application of recombinant macrophage migration inhibitory factor (0.8 nM) or its specific neuronal overexpression via Ad5-SYN-MIF (1x10(7) infectious units) significantly attenuated the chronotropic action of angiotensin II in spontaneously hypertensive rat neurons, similar to results from Wistar-Kyoto rat neurons. In contrast, C60S-macrophage migration inhibitory factor (0.8 nM), which lacks thiol-protein oxidoreductase activity, failed to alter the chronotropic action of angiotensin II in neurons from either rat strain. Thus, whereas macrophage migration inhibitory factor has the potential to depress the chronotropic action of angiotensin II in spontaneously hypertensive rat neurons, it is unlikely that this regulatory mechanism occurs, because angiotensin II does not increase the expression of this protein. The lack of this regulatory mechanism may contribute to the increased chronotropic action of angiotensin II in spontaneously hypertensive rat neurons.
The human insulin resistance syndromes---type 2 diabetes, obesity, combined hyperlipidemia, and essential hypertension---are genetically complex disorders whose molecular basis is largely unknown. The spontaneously hypertensive rate (SHR) is a model of these hum
an syndromes. In the SHR/NCrlBR strain, a chromosomal deletion event that occurred at the Cd36 locus during the evolution of this SHR strain has been proposed as a cause of defective insulin action and fatty acid metabolism. In this study, three copies of the Cd36 gene, one transcribed copy and two pseudogenes, were identified in normal rat strains, but only a single gene in SHR/NCrlBR. Analysis of SHR genomic sequence localized the chromosomal deletion event between intron 4 of the normally transcribed copy of the gene and intron 4 of the second pseudogene. The deletion led to the creation of a single chimeric Cd36 gene in SHR/NCrlBR. The boundaries of the recombination/deletion junction identified within intron 4 were surrounded by long interspersed nuclear elements (LINEs) and DNA topoisomerase I recognition sequences. An 8-bp deletion at the intron 14/exon 15 boundary of the second pseudogene abolishes the putative splice acceptor site and is the cause of an aberrant 3' UTR previously observed in SHR/NCrlBR. We conclude that in SHR/NCrlBR, the complex trait of insulin resistance and defective fatty acid metabolism is caused by Cd36 deficiency, resulting from a chromosomal deletion caused by unequal recombination. This demonstrates that chromosomal deletions caused by unequal recombination can be a cause of quantitative or complex mammalian phenotypes.
OBJECTIVES: A congenital nephron deficit has been linked to the progression of arterial hypertension and to the development of chronic kidney disease. The Munich Wistar Frömter (MWF) inbred rat develops hypertension, progressive albuminuria, and exhibits an inherited nephron deficit of ab
out 27% compared to spontaneously hypertensive rats (SHRs) with low-grade albuminuria. Introgression of rat chromosome (RNO)6 from SHRs into MWF rats markedly suppresses albuminuria and abolishes the nephron deficit in 4-week-old MWF-6 rats. Differences in early nephrogenesis may account for the nephron deficit in MWF rats. METHODS: We compared ureteric bud branching morphogenesis and nephron induction in E15.5-E16.0 stage-matched rat embryos between MWF rats, SHRs, and consomic MWF-6 rats. RESULTS: Comparative analysis of three-dimensional reconstructions of the ureteric bud tree suggested normal qualitative branching morphogenesis. Surprisingly, the number of ureteric bud tips was higher in MWF rats compared to SHRs (+22%; P = 0.004). However, the nephron number induced per ureteric bud tip was markedly lower in MWF rats compared to SHRs (-46%; P < 0.0001). This deficit was partially corrected in MWF-6 rats (+18% vs. MWF; P = 0.02). In gene expression analysis of 59 candidate genes involved in kidney development, hepatocyte growth factor (Hgf) gene expression was significantly reduced in embryonic kidneys of MWF and MWF-6 rats (approximately -70%; P < 0.004) compared to SHRs. CONCLUSIONS: These results suggest a reduced efficiency of nephron induction in MWF rats during the early stages of nephrogenesis that is partially dependent on genetic loci on RNO6. In addition, Hgf that maps to RNO4 may represent an interesting candidate gene that contributes to the nephron deficit in MWF rats.
Atef ME and Anand-Srivastava MB, Am J Physiol Heart Circ Physiol. 2016 Mar 1;310(5):H608-18. doi: 10.1152/ajpheart.00659.2015. Epub 2016 Jan 8.
We showed previously that vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHRs) exhibit overexpression of Gqalpha/PLCbeta1 proteins, which contribute to increased protein synthesis through the activation of MAP kinase signaling. Becaus
e oxidative stress has been shown to be increased in hypertension, the present study was undertaken to examine the role of oxidative stress and underlying mechanisms in enhanced expression of Gqalpha/PLCbeta1 proteins and VSMC hypertrophy. Protein expression was determined by Western blotting, whereas protein synthesis and cell volume, markers for VSMC hypertrophy, were determined by [(3)H]-leucine incorporation and three-dimensional confocal imaging, respectively. The increased expression of Gqalpha/PLCbeta1 proteins, increased protein synthesis, and augmented cell volume exhibited by VSMCs from SHRs were significantly attenuated by antioxidants N-acetyl-cysteine (NAC), a scavenger of superoxide anion, DPI, an inhibitor of NAD(P)H oxidase. In addition, PP2, AG1024, AG1478, and AG1295, inhibitors of c-Src, insulin-like growth factor receptor (IGFR), epidermal growth factor receptor (EGFR), and platelet-derived growth factor receptor (PDGFR), respectively, also attenuated the enhanced expression of Gqalpha/PLCbeta1 proteins and enhanced protein synthesis in VSMCs from SHRs toward control levels. Furthermore, the levels of IGF-1R and EGFR proteins and not of PDGFR were also enhanced in VSMCs from SHRs, which were attenuated significantly by NAC, DPI, and PP2. In addition, NAC, DPI, and PP2 also attenuated the enhanced phosphorylation of IGF-1R, PDGFR, EGFR, c-Src, and EKR1/2 in VSMCs from SHRs. These data suggest that enhanced oxidative stress in VSMCs from SHRs activates c-Src, which through the transactivation of growth factor receptors and MAPK signaling contributes to enhanced expression of Gqalpha/PLCbeta1 proteins and resultant VSMC hypertrophy.
Kloting N, etal., Physiol Genomics 2004 Aug 11;18(3):325-30.
Congenic BB.SHR (D4Got41-Npy-Tacr1; BB.4S) rats develop an incomplete metabolic syndrome with obesity, hyperleptinemia, and dyslipidemia compared with their progenitor strain, the diabetes-prone BB/OK rat. To narrow down the underlying gene(s), two subcongenic B
B.SHR rat lines, briefly termed BB.4Sa and BB.4Sb, were generated. Male BB.4S (n = 20), BB.4Sa (n = 24), and BB.4Sb (n = 26) were longitudinally characterized for facets of the metabolic syndrome and analyzed for expression of genes located in the region of interest in liver and blood. Body weight gain was comparable, serum triglycerides and leptin were significantly increased, and total cholesterol and HDL-cholesterol ratio were decreased in BB.4S compared with both subcongenics. Serum insulin was significantly higher in BB.4S and BB.4Sa than in BB.4Sb. The adiposity index showed a graduated decrease from BB.6S to BB.4Sb. Obvious differences in relative expression were found in 6 of 10 genes in liver and in 2 of 9 genes in blood. Only one gene, the eukaryotic translation initiation factor 2alpha kinase 3 (Eif2ak3 also called Perk or Pek), was significantly less expressed in liver and in blood of both subcongenic BB.4Sa and BB.4Sb compared with their "parental" BB.4S rats. Based on the phenotype and genotype in BB.4S and its subcongenic derivatives, the most important region on chromosome 4 can be said to lie between D4Got72 and Tacr1. Eif2ak3 is mapped in this region. Considering the function of Eif2ak3, it may be a candidate gene for the development of glucose intolerance found in both subcongenics but not in BB.4S. Allelic variants between BB/OK and SHR could influence Eif2ak3 function, possibly leading not only to glucose intolerance but also to the disturbances in hepatic and renal function found in human Wolcott-Rallison syndrome.
Wendt N, etal., J Hypertens. 2007 Jan;25(1):95-102.
OBJECTIVES: Unlike Dahl salt-sensitive (SS) rats, some strains of spontaneously hypertensive (SHR) rats develop only minor organ damage even when exposed to high-salt diet. In previous linkage studies, we identified quantitative trait loci on rat chromosome 19 (
RNO19) linked to the SHR allele suggesting a protective effect against salt-induced hypertensive organ damage in SS. METHODS: To test the relevance of this finding, we generated and characterized a consomic strain SS-19SHR in which RNO19 from SHR was introgressed into the susceptible background of SS. We compared the effects of low-salt (0.2% NaCl) and high-salt (4% NaCl) diet exposure for 8 weeks on the development of hypertension and target organ damage in male consomic and SS animals (n=14-20, each). RESULTS: Systolic blood pressure, relative left ventricular weight and urinary protein excretion were significantly lower in SS-19SHR compared to SS under both low-salt and high-salt diet (P < 0.05, respectively). Left ventricular atrial natriuretic peptide mRNA expression showed a more pronounced 4.5-fold increase in SS compared to SS-19 (two-fold) after high-salt (P < 0.05). In comparison to low diet, high-salt exposure induced a significant increase in vascular aortic hypertrophy index, left ventricular interstitial fibrosis (+210%) and perivascular fibrosis (+195%) in SS but not in consomic SS-19SHR (P < 0.05, respectively). CONCLUSIONS: These results demonstrate a strong protective effect of RNO19 from SHR on the development of hypertension, salt-sensitivity, cardiovascular and renal organ damage in SS. In particular, we demonstrate a genetic effect protecting against the development of cardiac fibrosis in salt-sensitive hypertension.
Yang LE, etal., Am J Physiol Renal Physiol. 2007 Oct;293(4):F1197-208. Epub 2007 Jul 25.
To determine the effects of long-term angiotensin-converting enzyme inhibition (ACEI) and blood pressure (BP) lowering on renal sodium transporter abundance and distribution in spontaneously hypertensive rats (SHR), 9-wk SHR
were treated with enalapril (30 mg.kg(-1).day(-1)) for 4 wk. BP decreased from 156 +/- 4 to 96 +/- 8 mmHg. Na(+)/H(+) exchanger isoform 3 (NHE3) and Na(+)-P(i) cotransporter type 2 (NaPi2) localized to the body of the microvilli (MV) in normotensive rat strains. In untreated SHR, NHE3 partially retracted from the body to base of the MV and NaPi2 retracted to subapical vesicles. After enalapril treatment of SHR, NHE3 fully retracted to the base of the MV and, by density gradient fractionation, NHE3, NaPi2, dipeptidyl peptidase IV, myosin VI, Na-Cl cotransporter, and cortical Na-K-Cl cotransporter redistributed from low-density (apical enriched) to high-density (endosome enriched) membranes. Enalapril decreased total abundance of myosin VI (to 0.51 +/- 0.18 of untreated), ACE (0.67 +/- 0.22), and cortical NaPi2 (0.83 +/- 0.10). Normalizing SHR BP with HRH (7.5 mg/day hydralazine, 0.15 mg/day reserpine, and 3 mg/day hydrochlorothiazide) did not change Na(+) transporter density distribution or abundance. We conclude that lowering BP to normal levels in SHR does not normalize Na(+) transporter distribution, rather, chronic ACEI treatment provokes retraction of Na(+) transporters and associated proteins from transport-relevant domains of apical membranes and/or reduces their abundance.
Romanowska K, etal., Acta Pol Pharm. 2008 Nov-Dec;65(6):723-9.
Antinociceptive action of diclofenac (non-opioid analgesic) was investigated in male and female normotensive (WKY) and genetically established hypertensive (SHR) and normotensive WAG. The drug was administered subcutaneously in doses of 10 mg/kg body weight and
per os 20 mg/kg and 40 mg/kg. Statistically significant differences in pain threshold were reported between male and female rats of investigated strains. Phase of sex cycle in female rats was determined along with the pain threshold level. Arterial hypertension control in WAG and SHR female rats performed in parallel showed considerable changes in blood pressure after diclofenac administration in the estrus phase. There were several correlated effects in blood pressure and pain threshold after drugs administration. The results obtained may explain the non-uniformity in antinociceptive action of analgesics in both sexes during long-term therapy in different strains.
Sharma U, etal., Clin Exp Hypertens. 2002 Apr;24(3):141-53.
The present study evaluated the association between a testosterone-induced elevation in blood pressure (BP) and renal tyrosine hydroxylase activity in SHR/y and Wistar-Kyoto male rats. The SHR/y rat is a consomic strain havi
ng the Y chromosome of the Spontaneously Hypertensive Rat and autosomes and the X chromosome from normotensive Wistar-Kyoto (WKY). Rats were castrated at 4-6 weeks and divided into control and sham groups (n = 6/group) with testosterone and blank sham implants respectively. BP and blood were taken every 2 weeks for estimation of serum testosterone and catecholamines. The animals were terminated at 16-18 weeks and kidneys were removed for the estimation of tyrosine hydroxylase activity. The testosterone treated rats had higher BP, plasma testosterone levels, kidney weights, but lower renal tyrosine hydroxylase activity than the sham treated controls. Hence, chronic testosterone treatment inhibits renal tyrosine hydroxylase activity in WKY and SHR/y rats.
BACKGROUND: Sitosterolemia is a recessively inherited disorder in humans that is associated with premature atherosclerotic disease. Mutations in ABCG5 or ABCG8, comprising the sitosterolemia locus, STSL, are now known to cause this disease. Three in-bred strains of rats, WKY, SHR
t:700;'>SHR and SHRSP, are known to be sitosterolemic, hypertensive and they carry a missense 'mutation' in a conserved residue of Abcg5, Gly583Cys. Since these rat strains are also know to carry mutations at other genetic loci and the extent of phytosterolemia is only moderate, it is important to verify that the mutations in Abcg5 are causative for phytosterolemia and whether they contribute to hypertension. METHODS: To investigate whether the missense change in Abcg5 is responsible for the sitosterolemia we performed a segregation analysis in 103 F2 rats from a SHR x SD cross. Additionally, we measured tail-cuff blood pressure and measured intestinal lipid transport to identify possible mechanisms whereby this mutation causes sitosterolemia. RESULTS: Segregation analysis showed that the inheritance of the Gly583Cys mutation Abcg5 segregated with elevated plant sterols and this pattern was recessive, proving that this genetic change is responsible for the sitosterolemia in these rat strains. Tail-cuff monitoring of blood pressure in conscious animals showed no significant differences between wild-type, heterozygous and homozygous mutant F2 rats, suggesting that this alteration may not be a significant determinant of hypertension in these rats on a chow diet. CONCLUSION: This study shows that the previously identified Gly583Cys change in Abcg5 in three hypertension-susceptible rats is responsible for the sitosterolemia, but may not be a major determinant of blood pressure in these rats.
Moniwa N, etal., Biol Chem. 2006 Feb;387(2):203-9.
An angiotensin-converting enzyme inhibitor (ACE-I) reduces cardiac remodeling and a bradykinin B2 receptor (B2R) antagonist partially abolishes this ACE-I effect. However, bradykinin has two different types of receptor, the B1 receptor (B1R) and B2R. Although B1R is induced under several pathologica
l conditions, including hypertension, the role of cardiac B1R in hypertension is not clear. We therefore investigated the role of cardiac B1R in stroke-prone spontaneously hypertensive rats (SHR-SP) and Wistar-Kyoto (WKY) rats. The B1R mRNA expression level in the heart was significantly higher in SHR-SP than in WKY rats. Chronic infusion of a B1R antagonist for 4 weeks significantly elevated blood pressure and left-ventricular weight of SHR-SP. Morphological analysis indicated that cardiomyocyte size and cardiac fibrosis significantly increased after administration of the B1R antagonist. The phosphorylation of mitogen-activated protein (MAP) kinases, including ERK, p38, and JNK, was significantly increased in the hearts of SHR-SP rats receiving the B1R antagonist. The TGF-beta1 expression level was significantly increased in SHR-SP rats treated with the B1R antagonist compared to that in WKY rats. The B1R antagonist significantly increased phosphorylation of Thr495 in endothelial nitric oxide synthase (eNOS), which is an inhibitory site of eNOS. These results suggest that the role of B1R in the heart may be attenuation of cardiac remodeling via inhibition of the expression of MAP kinases and TGF-beta1 through an increase in eNOS activity in a hypertensive condition.
BACKGROUND AND OBJECTIVES: The spontaneous hypertensive rat (SHR) is a widely studied model of hypertension that exhibits metabolic abnormalities, which share features with the human metabolic syndrome. Genetic linkage studies have revealed a defective CD36 gen
e, encoding a membrane fatty acid (FA) transporter, in hyperinsulinemia of the SHR. However, there is no unifying mechanism that can explain these phenotypes as a consequence of a defective CD36 gene. Impaired fatty acid uptake is compensated by increased glucose uptake. We hypothesized that (1) the abundant intracellular glucose is not oxidized proportionally and (2) the correction of the uncoupling of glucose oxidation to its cellular entry might be effective against the pathophysiology of CD36-defective SHR. Therefore, we attempted to activate glucose oxidation with the repletion of thiamine, a coenzyme for multiple steps of glucose metabolism. METHODS AND RESULTS: In one series of experiments, intracellular glucose fate was assessed by the ratio of [(14)C]glucose/[(3)H]deoxyglucose radioactivity, which suggested that glucose oxidation was uncoupled from its cellular entry in SHR. Protein O-GlcNAcylation was intense in the hearts of CD36-defective SHR compared with that of wild-type CD36 rats [Wister Kyoto rats (WKY)], indicating the shunt of glucose through the hexosamine biosynthetic pathway (HBP). In another series of studies, 4-week-old SHR were maintained with water containing 0.2% thiamine for 10 weeks. Systolic blood pressure, plasma insulin and norepinephrine levels were significantly lower in the thiamine-group, as compared with the untreated-group. In epididymal adipose tissue, thiamine repletion down-regulated the expression levels of mRNA transcripts for UDP-N-acetylglucosamine:peptide glycosyltransferase, angiotensinogen, angiotensin type 1 receptor, transforming growth factor-beta1 and plasminogen activator inhibitor-1. CONCLUSIONS: The hearts of CD36-defective SHR exhibited uncoupling of glucose oxidation from its cellular entry, accompanied with the enhanced protein O-GlcNAcylation, suggesting increased glucose shunt through the HBP. Thiamine repletion in CD36-defective SHR resulted in (1) the correction of the uncoupling of glucose oxidation to its cellular entry, concomitant with reduced protein O-GlcNAcylation, (2) the down-regulation of the expression of mRNAs involved in HBP, the renin-angiotensin system and adipokines in epididymal adipose tissue, and (3) the attenuation of the hypertension and hyperinsulinemia. We propose that interventions targeting glucose oxidation with thiamine repletion may provide a novel adjunctive approach to attenuate metabolic abnormalities and related hypertension.
Ezrokhi M, etal., Int J Mol Sci. 2021 Jun 7;22(11):6142. doi: 10.3390/ijms22116142.
The treatment of type 2 diabetes patients with bromocriptine-QR, a unique, quick release micronized formulation of bromocriptine, improves glycemic control and reduces adverse cardiovascular events. While the improvement of glycemic control is largely the result of improved postprandial hepatic gluc
ose metabolism and insulin action, the mechanisms underlying the drug's cardioprotective effects are less well defined. Bromocriptine is a sympatholytic dopamine agonist and reduces the elevated sympathetic tone, characteristic of metabolic syndrome and type 2 diabetes, which potentiates elevations of vascular oxidative/nitrosative stress, known to precipitate cardiovascular disease. Therefore, this study investigated the impact of bromocriptine treatment upon biomarkers of vascular oxidative/nitrosative stress (including the pro-oxidative/nitrosative stress enzymes of NADPH oxidase 4, inducible nitric oxide (iNOS), uncoupled endothelial nitric oxide synthase (eNOS), the pro-inflammatory/pro-oxidative marker GTP cyclohydrolase 1 (GTPCH 1), and the pro-vascular health enzyme, soluble guanylate cyclase (sGC) as well as the plasma level of thiobarbituric acid reactive substances (TBARS), a circulating marker of systemic oxidative stress), in hypertensive SHR rats held on a high fat diet to induce metabolic syndrome. Inasmuch as the central nervous system (CNS) dopaminergic activities both regulate and are regulated by CNS circadian pacemaker circuitry, this study also investigated the time-of-day-dependent effects of bromocriptine treatment (10 mg/kg/day at either 13 or 19 h after the onset of light (at the natural waking time or late during the activity period, respectively) among animals held on 14 h daily photoperiods for 16 days upon such vascular biomarkers of vascular redox state, several metabolic syndrome parameters, and mediobasal hypothalamic (MBH) mRNA expression levels of neuropeptides neuropeptide Y (NPY) and agouti-related protein (AgRP) which regulate the peripheral fuel metabolism and of mRNA expression of other MBH glial and neuronal cell genes that support such metabolism regulating neurons in this model system. Such bromocriptine treatment at ZT 13 improved (reduced) biomarkers of vascular oxidative/nitrosative stress including plasma TBARS level, aortic NADPH oxidase 4, iNOS and GTPCH 1 levels, and improved other markers of coupled eNOS function, including increased sGC protein level, relative to controls. However, bromocriptine treatment at ZT 19 produced no improvement in either coupled eNOS function or sGC protein level. Moreover, such ZT 13 bromocriptine treatment reduced several metabolic syndrome parameters including fasting insulin and leptin levels, as well as elevated systolic and diastolic blood pressure, insulin resistance, body fat store levels and liver fat content, however, such effects of ZT 19 bromocriptine treatment were largely absent versus control. Finally, ZT 13 bromocriptine treatment reduced MBH NPY and AgRP mRNA levels and mRNA levels of several MBH glial cell/neuronal genes that code for neuronal support/plasticity proteins (suggesting a shift in neuronal structure/function to a new metabolic control state) while ZT 19 treatment reduced only AgRP, not NPY, and was with very little effect on such MBH glial cell genes expression. These findings indicate that circadian-timed bromocriptine administration at the natural circadian peak of CNS dopaminergic activity (that is diminished in insulin resistant states), but not outside this daily time window when such CNS dopaminergic activity is naturally low, produces widespread improvements in biomarkers of vascular oxidative stress that are associated with the amelioration of metabolic syndrome and reductions in MBH neuropeptides and gene expressions known to facilitate metabolic syndrome. These results of such circadian-timed bromocriptine treatment upon vascular pathology provide potential mechanisms for the observed marked reductions in adverse cardiovascular events with circadian-timed bromocriptine-QR therapy (similarly timed to the onset of daily waking as in this study) of type 2 diabetes subjects and warrant further investigations into related mechanisms and the potential application of such intervention to prediabetes and metabolic syndrome patients as well.
Sundaram A, etal., Hypertens Res. 2013 Mar;36(3):213-8. doi: 10.1038/hr.2012.163. Epub 2012 Oct 25.
Although oxidative stress has been implicated in the pathogenesis of hypertension in spontaneously hypertensive rats (SHRs), there is little information on the levels of primary antioxidant enzymes status (AOEs) in pre-hypertensive SHR
>SHR. This study therefore determined the activities of primary AOEs and their mRNA levels, levels of hydrogen peroxide (H2O2), malondialdehyde (MDA) and total antioxidant status (TAS) in whole kidneys of SHR and age-matched Wistar-Kyoto (WKY) rats aged between 2 and 16 weeks. Compared with age-matched WKY rats, catalase (CAT) activity was significantly higher from the age of 2 weeks (P<0.001) and glutathione peroxide (GPx) activity was lower from the age of 3 weeks (P<0.001) in SHR. CAT mRNA levels were significantly higher in SHR aged 2, 4, 6 and 12 weeks. GPx mRNA levels were significantly lower in SHR at 8 and 12 weeks. Superoxide dismutase activity or its mRNA levels were not different between the two strains. H2O2 levels were significantly lower in SHR from the age of 8 weeks (P<0.01). TAS was significantly higher in SHR from the age of 3 weeks (P<0.05). MDA levels were only significantly higher at 16 weeks of age in the SHR (P<0.05). The data suggest that altered renal CAT and GPx mRNA expression and activity precede the development of hypertension in SHR. The raised CAT activity perhaps contributes to the higher TAS and lower H2O2 levels in SHR. In view of these findings, the precise role of oxidative stress in the pathogenesis of hypertension in SHR needs to be investigated further.
The cholinergic marker vesicular acetylcholine transporter (VAChT) was investigated in different cerebral areas of spontaneously hypertensive rats (SHR) by immunochemistry (Western blot analysis) and by immunohistochemistry. SHR
pan> were used as an animal model of hypertensive brain damage. The sensitivity of manipulation of cholinergic system on VAChT was assessed in rats treated for four weeks with the acetylcholinesterase (AChE) inhibitor galantamine (3 mg/Kg/day). VAChT concentrations were increased in the brain of control SHR compared to age-matched normotensive Wistar-Kyoto rats. This increase probably represents an up-regulation of VAChT to oppose cholinergic deficits reported in SHR and is countered by galantamine administration. The possibility that cholinergic neurotransmission enhancement may represent a therapeutic strategy in cerebrovascular disease is discussed.
Hafez MM, etal., Biol Res. 2015 Jun 11;48:30. doi: 10.1186/s40659-015-0022-y.
BACKGROUND: Carbon tetrachloride (CCl4) induces hepatotoxicity in animal models, including the increased blood flow and cytokine accumulation that are characteristic of tissue inflammation. The present study investigates the hepato-protective effect of rutin on CCl4-induced hepatotoxicity in rats.
RESULTS: Forty male Wistar rats were divided into four groups. Group I (control group) received 1 mL/kg of dimethyl sulfoxide intragastrically and 3 mL/kg olive oil intraperitoneally twice a week for 4 weeks. Group II received 70 mg/kg rutin intragastrically. Groups III and IV received CCl4 (3 mL/kg, 30 % in olive oil) intraperitoneally twice a week for 4 weeks. Group IV received 70 mg/kg rutin intragastrically after 48 h of CCl4 treatment. Liver enzyme levels were determined in all studied groups. Expression of the following genes were monitored with real-time PCR: interleukin-6 (IL-6), dual-specificity protein kinase 5 (MEK5), Fas-associated death domain protein (FADD), epidermal growth factor (EGF), signal transducer and activator of transcription 3 (STAT3), Janus kinase (JAK), B-cell lymphoma 2 (Bcl2) and B-cell lymphoma-extra-large (Bcl-XL). The CCl4 groups showed significant increases in biochemical markers of hepatotoxicity and up-regulation of expression levels of IL-6, Bcl-XL, MEK5, FADD, EGF, STAT3 and JAK compared with the control group. However, CCl4 administration resulted in significant down-regulation of Bcl2 expression compared with the control group. Interestingly, rutin supplementation completely reversed the biochemical markers of hepatotoxicity and the gene expression alterations induced by CCl4. CONCLUSION: CCl4 administration causes alteration in expression of IL-6/STAT3 pathway genes, resulting in hepatotoxicity. Rutin protects against CCl4-induced hepatotoxicity by reversing these expression changes.
Liu AW, etal., Clin Cancer Res. 2011 Feb 15;17(4):710-20. doi: 10.1158/1078-0432.CCR-10-0331. Epub 2010 Dec 30.
PURPOSE: Mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) is overexpressed in many types of cancer. Herein, we aimed to investigate its expression pattern, clinical significance, and biological function in hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: MAP4
K4 expression was examined in 20 fresh HCCs and corresponding nontumor liver tissues. Immunohistochemistry for MAP4K4 was performed on additional 400 HCCs, of which 305 (76%) were positive for hepatitis B surface antigens. The clinical significance of MAP4K4 expression was analyzed. MAP4K4 downregulation was performed in HCC cell lines HepG2 and Hep3B with high abundance of MAP4K4, and the effects of MAP4K4 silencing on cell proliferation in vitro and tumor growth in vivo were evaluated. Quantitative real-time PCR arrays were employed to identify the MAP4K4-regulated signaling pathways. RESULTS: MAP4K4 was aberrantly overexpressed in HCCs relative to adjacent nontumor liver tissues. This overexpression was significantly associated with larger tumor size, increased histologic grade, advanced tumor stage, and intrahepatic metastasis, as well as worse overall survival and higher early recurrence rate. Knockdown of the MAP4K4 expression reduced cell proliferation, blocked cell cycle at S phase, and increased apoptosis. The antitumor effects of MAP4K4 silencing were also observed in vivo, manifested as retarded tumor xenograft growth. Furthermore, multiple tumor progression-related signaling pathways including JNK, NFκB, and toll-like receptors were repressed by MAP4K4 downregulation. CONCLUSIONS: MAP4K4 overexpression is an independent predictor of poor prognosis of HCC patients, and inhibition of its expression might be of therapeutic significance.
Lei L, etal., Neurol Sci. 2010 Oct;31(5):603-8. doi: 10.1007/s10072-010-0341-2. Epub 2010 Jun 15.
We investigated the effects of short hairpin RNA (shRNA) on myelin protein zero (MPZ) gene expression in Schwann cells (SCs) in vitro and determined the effects of the MPZ gene suppression on the survival of SCs. The MPZ-specific shRNA was introduced into a lentiviral vector for expression under th
e U6 promoter, and the viral vector-based shRNAs were used to infect cultured SCs. The efficiency of MPZ knockdown was analyzed by real time-PCR (RT-PCR) and western blotting. Flow cytometric analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) were used to determine the cell cycle and the amount of apoptosis of SCs. We found that MPZ shRNAs significantly inhibited the expression of the MPZ gene and induced SC apoptosis in vitro. These results provided interesting experimental evidence for understanding the mechanism of demyelinating neuropathies caused by MPZ gene malfunction.
OBJECTIVE: This study aimed to examine the effects of salt loading, with or without simultaneous angiotensin receptor blocker (ARB) treatment, on the systemic and tissue renin-angiotensin system (RAS) in spontaneously hypertensive rats (SHRs). METHOD: Evaluation
was performed early (4 weeks) in the course of salt loading in order to examine initial mediating events of cardiovascular and renal damage produced by salt excess. Four groups of rats were studied. Group 1 received regular rat chow (normal-salt diet); group 2 received normal-salt diet and an ARB (losartan, 30 mg/kg per day); group 3 received high-salt (8%) chow; and group 4 received high-salt diet and losartan. RESULTS: High-salt diet increased systolic pressure to 193 +/- 1 mmHg compared to 180 +/- 2 in normal-salt diet group. Losartan reduced SBP in SHRs fed normal-salt diet but did not reduce SBP in the SHRs fed high-salt diet (192 +/- 2 mmHg). High-salt diet markedly increased urinary protein excretion from 27 +/- 4 to 64 +/- 13 mg/day and this increase was ameliorated by losartan (40 +/- 9 mg/day). In SHRs on high-salt diet, plasma angiotensin II concentration increased three to four-fold, whereas urinary angiotensinogen excretion increased 10-fold; and these changes were significantly reduced by losartan. High-salt diet accelerated glomerular injury and interstitial fibrosis in SHRs which were reduced by losartan. CONCLUSION: These results demonstrate that the activity of RAS was either not suppressed or, even augmented, after 4 weeks of salt loading despite high salt intake and increased SBP. The data suggest that an augmented intrarenal RAS during high-salt diet may contribute to the development of renal injury in this experimental model.
Tang K, etal., Can J Physiol Pharmacol. 2012 Oct;90(10):1394-402. doi: 10.1139/y2012-114. Epub 2012 Oct 15.
Myocardial ischemia and reperfusion (MI/R) injury is associated with activation of the complement system. Complement activation generates a series of bioactive substances, including early (C3a, C3b) and terminal (C5a, C5b-9) components. The terminal complement components are key mediators of MI/R i
njury. This study investigated whether C5 shRNA preconditioning has protective effects following MI/R injury and its potential mechanism. Rats were injected with C5 shRNA 2 days before induction of ischemia. The effects of C5 shRNA were evaluated by the assessment of heart function, infarct size, histopathology, inflammatory cytokine levels, and the plasma level of troponin T. Akt phosphorylation was assessed by immunoblotting. C5 shRNA efficiently inhibited C5 expression both in vitro and in vivo, and attenuated MI/R injury. C5 shRNA preconditioning significantly decreased the level of troponin T and the production of pro-inflammatory cytokine. The infarct size was decreased by 40% in C5 shRNA treated rats. Akt phosphorylation increased after C5 shRNA preconditioning. These results suggest that C5 shRNA preconditioning in rats has protective effects following MI/R injury; this may be partly effected by mediating the activation of the PI3K pathway and by phosphorylation of Akt.
Shinzawa K and Tsujimoto Y, J Cell Biol 2003 Dec 22;163(6):1219-30. Epub 2003 Dec 15.
Apoptosis is defined on the basis of morphological changes like nuclear fragmentation and chromatin condensation, which are dependent on caspases. Many forms of caspase-independent cell death have been reported, but the mechanisms are still poorly understood. We found that hypoxic cell death was ind
ependent of caspases and was associated with significant nuclear shrinkage. Neither Bcl-2 nor Apaf-1 deficiency prevented hypoxic nuclear shrinkage. To understand the molecular mechanism of the nuclear shrinkage, we developed an in vitro system using permeabilized cells, which allowed us to purify a novel member of the phospholipase A2 (PLA2) family that induced nuclear shrinkage. Purified PLA2 induced nuclear shrinkage in our permeabilized cell system. PLA2 inhibitors prevented hypoxic nuclear shrinkage in cells and cell death. Hypoxia caused elevation of PLA2 activity and translocation of intracellular PLA2s to the nucleus. Knockdown of the Ca2+-independent PLA2 delayed nuclear shrinkage and cell death. These results indicate that Ca2+-independent PLA2 is crucial for a caspase-independent cell death signaling pathway leading to nuclear shrinkage.
Karnabi E, etal., Biochem Biophys Res Commun. 2009 Jul 10;384(4):409-14. doi: 10.1016/j.bbrc.2009.04.150. Epub 2009 May 5.
Cav1.2 (alpha1C) and Cav1.3 (alpha1D) L-type Ca channels are co-expressed in the heart. To date, there are no pharmacological or biophysical tools to separate alpha1D from alpha1C Ca currents (I(Ca-L)) in cardiomyocytes. Here, we established a physiological model to study alpha1D I(Ca-L) in native
myocytes using RNA interference. Transfection of rat neonatal cardiomyocytes (RNC) with alpha1C specific siRNA resulted in low silencing efficiency (50-60%) at the mRNA and protein levels. The use of lentivirus shRNA resulted in 100% transfection efficiency and 92% silencing of the alpha1C gene by real-time PCR and Western blot. Electrophysiological experiments showed that the total I(Ca-L) was similarly reduced by 80% in lentivirus transfected cells. Both biochemical and functional data demonstrated high transfection and silencing efficiency in the cardiomyocytes using lentiviral shRNA. This novel approach allows for the assessments of the roles of alpha1C and alpha1D Ca channels in native myocytes and could be used to examine their roles in physiological and pathological settings.
Dendritic spine morphology is thought to play important roles in synaptic development and plasticity, and morphological derangements in spines are correlated with several neurological disorders. Here, we identified an interaction between Spine-Associated RapGAP (SPAR), a postsynaptic protein that re
organizes actin cytoskeleton and drives dendritic spine head growth, and PDLIM5/Enigma Homolog (ENH), a PDZ-LIM (postsynaptic density-95/Discs large/zona occludens 1-Lin11/Isl-1/Mec3) family member. PDLIM5 has been implicated in susceptibility to bipolar disorder, major depression, and schizophrenia, but its function in neurological disease is poorly understood. We show that PDLIM5 is present in the postsynaptic density, where it promotes decreased dendritic spine head size and longer, filopodia-like morphology. Conversely, RNA interference against PDLIM5 or loss of PDLIM5 interaction with SPAR caused increased spine head diameter. Furthermore, PKC activation promoted delivery of PDLIM5 into dendritic spines and increased its spine colocalization with SPAR. These data reveal new postsynaptic functions for PDLIM5 in shrinkage of dendritic spines that may be relevant to its association with psychiatric illness.
1. We established a new animal model of metabolic syndrome, SHRSP fatty (fa/fa) rats, by crossing stroke-prone spontaneously hypertensive rats of the Izumo strain (SHRSP/Izm) to Zucker fatty (ZF) (fa/fa) rats. 2. The SHR
tyle='font-weight:700;'>SHRSP fatty (fa/fa) rats have a missense mutation of the leptin receptor gene and plasma leptin concentrations are augmented. The SHRSP fatty (fa/fa) rats develop obesity and hypertension simultaneously. 3. Plasma metabolic parameters, including glucose, insulin and total cholesterol and triglyceride levels, were markedly elevated in SHRSP fatty (fa/fa) rats compared with SHRSP/Izm rats. Plasma triglyceride concentrations in SHRSP fatty (fa/fa) rats were significantly elevated compared with those in ZF (fa/fa) rats. The weight of adipose tissues in SHRSP fatty (fa/fa) rats was greater than that of SHRSP/Izm rats. The phenotype of SHRSP fatty (fa/fa) rats is similar to that of human metabolic syndrome.
Loebel DA, etal., Biol Open. 2016 Jan 15;5(2):130-9. doi: 10.1242/bio.014415.
Early development of the gut endoderm and its subsequent remodeling for the formation of organ buds are accompanied by changes to epithelial cell shape and polarity. Members of the Rho-related family of small GTPases and their interacting proteins play multiple roles in regulating epithelial morphog
enesis. In this study we examined the role of Cdc42 in foregut development and organ bud formation. Ablation of Cdc42 in post-gastrulation mouse embryos resulted in a loss of apical-basal cell polarity and columnar epithelial morphology in the ventral pharyngeal endoderm, in conjunction with a loss of apical localization of the known CDC42 effector protein PARD6B. Cell viability but not proliferation in the foregut endoderm was impaired. Outgrowth of the liver, lung and thyroid buds was severely curtailed in Cdc42-deficient embryos. In particular, the thyroid bud epithelium did not display the apical constriction that normally occurs concurrently with the outgrowth of the bud into the underlying mesenchyme. SHROOM3, a protein that interacts with Rho GTPases and promotes apical constriction, was strongly expressed in the thyroid bud and its sub-cellular localization was disrupted in Cdc42-deficient embryos. In Shroom3 gene trap mutant embryos, the thyroid bud epithelium showed no apical constriction, while the bud continued to grow and protruded into the foregut lumen. Our findings indicate that Cdc42 is required for epithelial polarity and organization in the endoderm and for apical constriction in the thyroid bud. It is possible that the function of CDC42 is partly mediated by SHROOM3.
Shen H, etal., Int J Clin Exp Pathol. 2015 Aug 1;8(8):8968-75. eCollection 2015.
Ovarian carcinoma is one of the most common and lethal malignancies in the world. Replication factor C (RFC) plays an important role in DNA replication, DNA damage repair, and checkpoint control during cell cycle progression in all eukaryotes. Our previous study found that one unit of RFC complex, R
FC3, is over-expressed in ovarian tumor tissues. However, its role in the development of ovarian carcinoma remains unclear. Western blot and real-time RT-PCR analysis were used to measure the expression of RFC3 in ovarian cancer cells. Lentivirus-mediated RFC3-specific shRNA was used to knock down RFC3 expression in ovarian cancer cells. Furthermore, the effect of RFC3 on tumor cellular proliferation and growth were examined, respectively. The expression level of RFC3 was remarkably up-regulated in ovarian cancer OVCAR-3 cells. With MTS and cell growth assays, the viability and proliferation of RFC3 knocking-down OVCAR-3 cell line were shown to be effectively restrained. Down-regulation of RFC3 expression arrested the cell cycle of OVCAR-3 cell in the S-phase and induced apoptosis. This study suggests that RFC3 may play an important role in the the process of ovarian carcinoma, and that it may be a potential biological treatment target in the future.
Zhang LQ, etal., Cell Mol Biol (Noisy-le-grand). 2015 Nov 30;61(7):102-9.
Ovarian cancer is one of the three most common gynecological malignant tumors. The mortality rate of ovarian cancer is high because of the insidious disease onset and the lack of effective methods for early diagnosis. In this study, we assessed the potential of SPOCK1 as a significant biomarker for
ovarian cancer development. We determined that the expression of SPOCK1 was evidently high in ovarian cancer tissues and the cell lines OVCAR3 and SKOV3. The knockdown of SPOCK1 by specific shRNA significantly inhibited cell proliferation and colony formation in both OVCAR3 and SKOC3 cells. In a xenograft model of ovarian cancer, the mice implanted with SPOCK1 knockdown SKOV3 cells exhibited a slower tumor growth rate. The dissected tumors also weighed less in the SPOCK1-depleted mice group. Furthermore, the knockdown of SPOCK1 evidently inhibited the wound recovery process. Concomitantly, cell migration was inhibited by up to 67% after the knockdown of SPOCK1 in OVCAR3 cells and 75% in SKOV3 cells. Invasion capability also decreased by up to 80% in OVCAR3 cells and 83% in SKOV3 cells after SPOCK1 knockdown. Moreover, the knockdown of SPOCK1 caused a decrease of its known target, i.e., matrix metalloproteinase-2. Interestingly, it also reduced phosphorylated ERK and AKT. These data suggest that SPOCK1 is a potential biomarker that promotes ovarian cancer growth and metastasis. The biological behavior of SPOCK1 in ovarian cancer may be related to the ERK and AKT signaling pathways.
Genome-wide association studies (GWAS) identify regions of the genome correlated with disease risk but are restricted in their ability to identify the underlying causative mechanism(s). Thus, GWAS are useful "roadmaps" that require functional analysis to establish the genetic and mechanistic stru
cture of a particular locus. Unfortunately, direct functional testing in humans is limited, demonstrating the need for complementary approaches. Here we used an integrated approach combining zebrafish, rat, and human data to interrogate the function of an established GWAS locus (SHROOM3) lacking prior functional support for chronic kidney disease (CKD). Congenic mapping and sequence analysis in rats suggested Shroom3 was a strong positional candidate gene. Transferring a 6.1-Mb region containing the wild-type Shroom3 gene significantly improved the kidney glomerular function in FHH (fawn-hooded hypertensive) rat. The wild-type Shroom3 allele, but not the FHH Shroom3 allele, rescued glomerular defects induced by knockdown of endogenous shroom3 in zebrafish, suggesting that the FHH Shroom3 allele is defective and likely contributes to renal injury in the FHH rat. We also show for the first time that variants disrupting the actin-binding domain of SHROOM3 may cause podocyte effacement and impairment of the glomerular filtration barrier.
Hensel J, etal., Mol Cancer Res. 2015 Sep;13(9):1306-15. doi: 10.1158/1541-7786.MCR-15-0130. Epub 2015 Jun 15.
Next-generation sequencing (NGS) of human bladder cancer has revealed many gene alterations compared with normal tissue, with most being predicted to be "loss of function." However, given the high number of alterations, evaluating the functional impact of each is impractical. Here, we develop and us
e a high-throughput, in vivo strategy to determine which alterations are loss of function in tumor growth suppressors. Genes reported as altered by NGS in bladder cancer patients were bioinformatically processed by MutationTaster and MutationAssessor, with 283 predicted as loss of function. An shRNA lentiviral library targeting these genes was transduced into T24 cells, a nontumorigenic human bladder cancer cell line, followed by injection into mice. Tumors that arose were sequenced and the dominant shRNA constructs were found to target IQGAP1, SAMD9L, PCIF1, MED1, and KATNAL1 genes. In vitro validation experiments revealed that shRNA molecules directed at IQGAP1 showed the most profound increase in anchorage-independent growth of T24 cells. The clinical relevance of IQGAP1 as a tumor growth suppressor is supported by the finding that its expression is lower in bladder cancer compared with benign patient urothelium in multiple independent datasets. Lower IQGAP1 protein expression associated with higher tumor grade and decreased patient survival. Finally, depletion of IQGAP1 leads to increased TGFBR2 with TGFbeta signaling, explaining in part how reduced IQGAP1 promotes tumor growth. These findings suggest IQGAP1 is a bladder tumor growth suppressor that works via modulating TGFbeta signaling and is a potentially clinically useful biomarker. IMPLICATIONS: This study used gene mutation information from patient-derived bladder tumor specimens to inform the development of a screen used to identify novel tumor growth suppressors. This included identification of the protein IQGAP1 as a potent bladder cancer growth suppressor.
Kumar A, etal., Biochem Biophys Res Commun. 2018 Jun 7;500(3):731-737. doi: 10.1016/j.bbrc.2018.04.144. Epub 2018 Apr 23.
CXCL8 belongs to proinflammatory chemokines that are predominantly involved in neutrophil chemotaxis and degranulation. Several studies have suggested that secretion of CXCL8 from cancer cells have a profound effect on tumor microenvironment. In this study, in continuation to our previous work of un
derstanding the global picture of invasion related genes in colorectal liver metastases, we clearly show an up-regulation of CXCL8 expression in the tumor cells at the invasion front as compared to the tumor cells in the inner parts of the tumor. Furthermore, ShRNA mediated down-regulation of CXCL8 resulted in inhibition of cell proliferation, viability and invasion in vitro and a near complete growth reduction of tumor in vivo. We showed that CXCL8 secreted by tumor cells at the invasion front were able to promote migration through angiogenesis by upregulating VEGFA and invasion via the AKT/GSK3β/β-catenin/MMP7 pathway by upregulating BCL-2 confirming the key role of CXCL8 during tumor progression.
Uterine leiomyomas (fibroids) are the most common benign tumors in women of reproductive age. These tumors are three to four times more prevalent in African American women, who also have a 10 times higher incidence of hypovitaminosis D than white women. Recent studies have demonstrated the antitumo
r effects of 1,25-dihydroxyvitamin D3 on several cancers, but its effects on uterine leiomyomas are still unknown. To determine the antitumor and therapeutic effects of 1,25-dihydroxyvitamin D3 on uterine leiomyomas, female Eker rats (14-16 mo old) harboring uterine leiomyomas were randomized into control and experimental groups and were given vehicle versus 1,25-dihydroxyvitamin D3 (0.5 mug/kg per day) subcutaneously for 3 wk, respectively. At the end of the experiment, the rats were euthanized, and the leiomyoma tumors were analyzed. Treatment with 1,25-dihydroxyvitamin D3 significantly reduced leiomyoma tumor size in Eker rats. It also reduced leiomyoma size by suppressing cell growth and proliferation-related genes (Pcna, cyclin D1 [Ccnd1], Myc, Cdk1, Cdk2, and Cdk4), antiapoptotic genes (Bcl2 and Bcl2l1 [Bcl-x]), and estrogen and progesterone receptors. Additionally, immunohistochemistry revealed decreased expression of PCNA and MKI67 (a marker of proliferation) and increased expression of caspase 3 in 1,25-dihydroxyvitamin D3-treated Eker rat leiomyomas. Toxicity analyses using serum samples showed similar levels of SGOT, SGPT, calcium, and total bilirubin in 1,25-dihydroxyvitamin D3-treated and vehicle-treated control Eker rats. These results support that 1,25-dihydroxyvitamin D3 is an antitumor agent that may be a potential safe, nonsurgical therapeutic option for the treatment of uterine leiomyomas.
Pu XY, etal., J Urol. 2014 Sep;192(3):990-6. doi: 10.1016/j.juro.2014.02.042. Epub 2014 Feb 24.
PURPOSE: We investigated whether injecting shRNA constructs targeting IGFBP-3 in the penis of old rats would improve erectile function. MATERIALS AND METHODS: The most validated IGFBP-3 shRNA plasmid vector (pGPU6/GFP/Neo-shIGFBP-3) was prepared and injected in penile corpus cavernosum tissue. A to
tal of 30 old (age 24 months) male Sprague Dawley(R) rats were randomly divided into 3 groups, including 10 each that received phosphate buffered saline only (100 mul), pGPU6/GFP/Neo-shNC (100 mug) and the most validated plasmid constructs pGPU6/GFP/Neo-shIGFBP-3 (100 mug). At 4 weeks the erectile response was measured as intracavernous pressure. The percent of smooth muscle in corpus cavernosum tissue was evaluated. Nitric oxide synthase activity and the cGMP concentration in penile tissue were also analyzed. IGFBP-3 was estimated in penile tissue by Western blot, real-time reverse transcriptase-polymerase chain reaction and immunohistochemistry. RESULTS: pGPU6/GFP/Neo-shIGFBP-3 corrected the impaired erectile response in aged rats compared with the response in those injected with phosphate buffered saline and pGPU6/GFP/Neo-shNC (each p <0.01). The percent of cavernous smooth muscle was increased in the pGPU6/GFP/Neo-shIGFBP-3 group. Nitric oxide synthase activity and the cGMP concentration were also significantly increased in rats treated with pGPU6/GFP/Neo-shIGFBP-3. IGFBP-3 shRNA effectively reduced IGFBP-3 mRNA and protein expression in penile corpus cavernosum tissue. CONCLUSIONS: Decreasing IGFBP-3 expression by plasmid expressed shRNA improved erectile function in aged rats. The therapy may modulate smooth muscle integrity and increase the cGMP concentration. This may be a new direction for treating erectile dysfunction in clinical practice.
The rat is an important animal model in biomedical research, but gene targeting technology is not established for this species. Therefore, we aimed to produce transgenic knockdown rats using shRNA technology and pronuclear microinjection. To this purpose, we employed a tetracycline-inducible shRNA e
xpression system targeting the insulin receptor (IR). Doxycycline (DOX) treatment of the resulting transgenic rats led to a dose-dependent and reversible increase in blood glucose caused by ubiquitous inhibition of IR expression and signalling. We could neither detect an interferon response nor disturbances in microRNA processing after DOX treatment excluding toxic effects of shRNA expression. Low dose DOX treatment induced a chronic state of diabetes mellitus. In conclusion, we have developed a technology which allows the specific, inducible, and reversible suppression of any gene of interest in the rat. Our first transgenic rat line generated with this method represents an inducible model for diabetes mellitus.
Qazi Y, etal., Invest Ophthalmol Vis Sci. 2012 May 14;53(6):2837-44. doi: 10.1167/iovs.11-9139.
PURPOSE: To determine the efficacy of a plasmid containing a small hairpin RNA expression cassette (pSEC.shRNA) against VEGF-A-loaded poly(lactic co-glycolic acid) nanoparticles (PLGA NPs) in the sustained regression of murine corneal neovascularization. METHODS: PLGA nanoparticles were loaded with
pSEC.shRNA.VEGF-A plasmids using the double emulsion-solvent evaporation method. KNV was induced in BALB/c mice by mechanical-alkali injury. Four weeks after induction of KNV, the mice were randomly divided to receive one of four treatments intrastromally: pSEC.shRNA.VEGF-A PLGA NPs (2 mug plasmid); naked pSEC.shRNA.VEGF-A plasmid only (2 mug plasmid); control blank PLGA NPs (equivalent dry weight of NPs); and vehicle. Two and five days after intervention, corneas were harvested to determine VEGF-A gene and protein expression using reverse transcriptase polymerase chain reaction and ELISA, respectively. Four weeks after intervention, corneas were photographed, mice sacrificed, and the corneal whole mounts were immunostained for CD31 (panendothelial cell marker). Immunofluorescence microscopy was performed and the neovascular area was quantitated. RESULTS: VEGF-A mRNA (49.6 +/- 12.4 vs. 82.9 +/- 6.0%, P < 0.01) and protein (4.0 +/- 5.2 vs. 20.0 +/- 7.5 rhog VEGF-A/mg total protein, P < 0.05) expression were significantly reduced in pSEC.shRNA.VEGF-A PLGA NP-treated corneas as compared with control blank NP. The pSEC.shRNA.VEGF-A PLGA NP-treated corneas showed significant regression in the mean fractional areas of KNV (0.125 +/- 0.042; 12.5%, P <0.01) compared with both naked plasmid only (0.283 +/- 0.004; 28.3%) and control (blank NPs = 0.555 +/- 0.072, 55.5%) at 4 weeks post-treatment. CONCLUSIONS: The pSEC.shRNA.VEGF-A-loaded PLGA NPs are an effective, nonviral, nontoxic, and sustainable form of gene therapy for the regression of murine KNV.
Ajiro M, etal., Int J Biol Sci. 2015 Sep 3;11(11):1248-56. doi: 10.7150/ijbs.13011. eCollection 2015.
Gene silencing techniques are widely used to control gene expression and have potential for RNAi-based therapeutics. In this report, transgenic mouse lines were created for conditional knockdown of Srsf3 (SRp20) expression in liver and mammary gland tissues by expressing Srsf3-specific shRNAs driven
by a U6 promoter. Although a small portion of the transgenic mouse littermates were found to produce siRNAs in the targeted tissues, most of the transgenic littermates at two months of age failed to display a knockdown phenotype of Srsf3 expression in their liver and mammary gland tissues where an abundant level of Srsf3 siRNAs remained. We saw only one of four mice with liver/mammary gland expressing Srsf3 siRNA displayed a suppressed level of Srsf3 protein, but not the mRNA. Data indicate that the host resistance to a gene-specific siRNA targeting an essential gene transcript can be developed in animals, presumably as a physiological necessity to cope with the hostile perturbation.
Mao LJ, etal., Tumour Biol. 2015 Nov;36(11):9073-81. doi: 10.1007/s13277-015-3658-x. Epub 2015 Jun 19.
Recent studies suggest that SATB1 is a promising therapeutic target for prostate cancer. To develop novel SATB1-based therapeutic agents for prostate cancer, in this study, we aimed to construct ZD55-SATB1, an oncolytic adenovirus ZD55 carrying shRNA targeting SATB1, and investigate its effects on
the inhibition of prostate cancer growth and metastasis. ZD55-SATB1 was constructed and used to infect human prostate cancer cell lines DU145 and LNCaP. The inhibitory effect of ZD55-SATB1 on SATB1 expression was evaluated by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. The cytotoxicity of ZD55-SATB1 was detected by MTT assay. Cell invasion was detected by Matrigel invasion assay. The in vivo antitumor activities of ZD55-SATB1 were evaluated in xenograft mouse model. We found that ZD55-SATB1 selectively replicated and significantly reduced SATB1 expression in DU145 and LNCaP cells. ZD55-SATB1 effectively inhibited the viability and invasion of DU145 and LNCaP cells in vitro and inhibited prostate cancer growth and metastasis in xenograft nude mice. In conclusion, replicative oncolytic adenovirus armed with SATB1 shRNA exhibits effective antitumor effect in human prostate cancer. Our study provides the basis for the development of ZD55-SATB1 for the treatment of prostate cancer.
The synaptic protein alpha-synuclein (alpha-syn) is associated with a number of neurodegenerative diseases, and homology analyses among many species have been reported. Nevertheless, little is known about the cDNA sequence and protein structure of alpha-syn in tree shr
ews, and this information might contribute to our understanding of its role in both health and disease. We designed primers to the human alpha-syn cDNA sequence; then, tree shrew alpha-syn cDNA was obtained by RT-PCR and sequenced. Based on the acquired tree shrew alpha-syn cDNA sequence, both the amino acid sequence and the spatial structure of alpha-syn were predicted and analyzed. The homology analysis results showed that the tree shrew cDNA sequence matches the human cDNA sequence exactly except at nucleotide positions 45, 60, 65, 69, 93, 114, 147, 150, 157, 204, 252, 270, 284, 298, 308, and 324. Further protein sequence analysis revealed that the tree shrew alpha-syn protein sequence is 97.1 % identical to that of human alpha-syn. The secondary protein structure of tree shrew alpha-syn based on random coils and alpha-helices is the same as that of the human structure. The phosphorylation sites are highly conserved, except the site at position 103 of tree shrew alpha-syn. The predicted spatial structure of tree shrew alpha-syn is identical to that of human alpha-syn. Thus, alpha-syn might have a similar function in tree shrew and in human, and tree shrew might be a potential animal model for studying the pathogenesis of alpha-synucleinopathies.
Song HW, etal., PLoS One. 2015 Mar 19;10(3):e0118549. doi: 10.1371/journal.pone.0118549. eCollection 2015.
RNA interference (RNAi) is widely used to determine the function of genes. We chose this approach to assess the collective function of the highly related reproductive homeobox 3 (Rhox3) gene paralogs. Using a Rhox3 short hairpin (sh) RNA with 100% complementarity to all 8 Rhox3 paralogs, expressed f
rom a CRE-regulated transgene, we successfully knocked down Rhox3 expression in male germ cells in vivo. These Rhox3-shRNA transgenic mice had dramatic defects in spermatogenesis, primarily in spermatocytes and round spermatids. To determine whether this phenotype was caused by reduced Rhox3 expression, we generated mice expressing the Rhox3-shRNA but lacking the intended target of the shRNA-Rhox3. These double-mutant mice had a phenotype indistinguishable from Rhox3-shRNA-expressing mice that was different from mice lacking the Rhox3 paralogs, indicating that the Rhox3 shRNA disrupts spermatogenesis independently of Rhox3. Rhox3-shRNA transgenic mice displayed few alterations in the expression of protein-coding genes, but instead exhibited reduced levels of all endogenous siRNAs we tested. This supported a model in which the Rhox3 shRNA causes spermatogenic defects by sequestering one or more components of the endogenous small RNA biogenesis machinery. Our study serves as a warning for those using shRNA approaches to investigate gene functions in vivo.
Yao Z, etal., Int J Mol Med. 2015 Nov;36(5):1393-9. doi: 10.3892/ijmm.2015.2350. Epub 2015 Sep 21.
Hepatocellular carcinoma (HCC) is one of the most common and lethal malignancies worldwide. Replication factor C (RFC) plays an important role in DNA replication and checkpoint control during the cell cycle. RFC is comprised of one large subunit [replication factor C, subunit 1 (RFC1)] and four sm
all subunits [replication factor C, subunits 2-5 (RFC25)]. The role of RFC3 in the development of HCC is, as of yet, not fully understood. In the present study, western blot analysis and reverse-transcription-quantitative PCR were used to measure the expression levels of replication factor C, subunit 3 (RFC3) in HCC tissues and HCC cells. Lentivirus-mediated RFC3-specific short hairpin RNA (shRNA) was used to knock down the expression of RFC3 in HCC cells in order to examine the effects of RFC3 on HCC cell proliferation and growth. Furthermore, the expression levels of cell cyclerelated proteins were also measured in the HCC cells in which RFC3 was knocked down. Our results revealed that the expression level of RFC3 was markedly upregulated in the HCC tissues and cells. In addition, MTS and cell growth assays were used to determine the viability and proliferation of the HCC cells in which RFC3 was knocked down, and the results revealed that both cell viability and proliferation were effectively suppressed. The downregulation of RFC3 expression led to HCC cell cycle arrest in the S phase, partly by regulating the epression of cell cycle-related proteins, such as p21, p53, p57 and cyclin A. The results of the present study suggest that RFC3 plays an important role in the development of HCC, and may thus be a potential biological target in the treatment of HCC.
Wang M, etal., Int J Clin Exp Pathol. 2015 Jun 1;8(6):7040-4. eCollection 2015.
OBJECTIVE: To study the effects of RhoA siRNA on the malignant phenotypes of human colorectal cancer cell line LoVo. METHODS: The siRNA expression vector pGPU6/GFP/Neo-shRNA-RhoA targeting the mRNA of RhoA and vector pGPU6/GFP/Neo-NC (as a control) were constructed, and then transfected into LoVo ce
lls. The expression of Survivin was detected by real-time fluorescent quantitative polymerase chain reaction and Western blot. The malignant phenotypes of transfected LoVo cells, including invasive activities and adhesive capabilities, were analyzed. RESULTS: RhoA mRNA and protein level were decreased after the pshRNA-RhoA transfection. The cell adhesion rates significantly decreased in the cells transfected with pshRNA-RhoA. The migrating number of LoVo cells (26.5 +/- 0.9) transfected with pshRNA-RhoA was also significantly decreased as compared with the control group (53.7 +/- 1.4). CONCLUSIONS: The sequence specific shRNA against RhoA constructed in the study can block the expression of RhoA in LoVo cell effectively and specifically; Blocking the expression of RhoA in LoVo cells transfected with pshRNA-RhoA can reduce their invasive and adhesive capabilities.
Zhang MX, etal., Zhonghua Zhong Liu Za Zhi. 2008 May;30(5):325-9.
OBJECTIVE: To construct a CXCR4 specific recombinant plasmid vector and study its inhibiting effect on invasion capacity in vitro of human breast cancer MDA-MB-231 cell line and its metastatic potential to the lung in nude mice. METHODS: A CXCR4 specific recombinant plasmid vect
or was constructed and transfected into the cultured MDA-MB-231 cell line with lipofectamine 2000. RT-PCR and Western blot were used to detect the mRNA and protein expression of CXCR4, respectively. Invasion capability in vitro of the cells was evaluated by Boyden chamber. The cell proliferation capacity was detected by MTT method. The nude mouse model of lung metastasis was established by injection of MDA-MB-231 cells into the tail vein. The animals were sacrificed at 6 weeks after the tumor cells injection. Whole lung tissues were harvested, embedded in paraffin, sectioned serially, and the HE-stained paraffin sections were examined pathologically to evaluate the presence and number of metastatic tumors. RESULTS: The CXCR4 mRNA expression rate was 29.5% +/- 3.8% in the CXCR4-shRNA group, significantly lower than that of the control group (69.7% +/- 2.6%, P < 0.01) and mock-control group (67.8% +/- 3.5%, P < 0.01). The CXCR4 protein expression rate was 15.4% +/- 1.1% in the CXCR4-shRNA group, significantly lower than that of the control group (39.0% +/- 2.4%, P < 0.01) and mock-control group (35.9% +/- 3.9%, P < 0.01). Silencing of CXCR4 by shRNA lead to a significant decrease in breast cancer cell invasion and proliferation capacity in vitro. Furthermore, tumor cells with CXCR4 shRNA permanent transfcetion had a much lower lung metastatic potential in nude mice than control cells and mock control cells in vivo. CONCLUSION: CXCR4 shRNA can inhibit the expression of CXCR4 and decrease the invasion and lung metastatic potential of human breast cancer cells.
X-chromosome inactivation is the process that evolved in mammals to equalize levels of X-linked gene expression in XX females relative to XY males. Silencing of a single X chromosome in female cells is mediated by the non-coding RNA Xist. Although progress has been made toward identifying factors
that function in the maintenance of X inactivation, the primary silencing factors are largely undefined. We developed an shRNA screening strategy to produce a ranked list of candidate primary silencing factors. Validation experiments performed on several of the top hits identified the SPOC domain RNA binding proteins Rbm15 and Spen and Wtap, a component of the m6A RNA methyltransferase complex, as playing an important role in the establishment of Xist-mediated silencing. Localization analysis using super-resolution 3D-SIM microscopy demonstrates that these factors co-localize with Xist RNA within the nuclear matrix subcompartment, consistent with a direct interaction.
Kagota S, etal., Can J Physiol Pharmacol. 2013 Feb;91(2):124-33. doi: 10.1139/cjpp-2012-0226. Epub 2013 Feb 15.
Metabolic syndrome is known to increase the risk of abnormal cardiac structure and function, which are considered to contribute to increased incidence of cardiovascular disease and mortality. We previously demonstrated that ventricular hypertrophy and diastolic dysfunction occur in SHR
-weight:700;'>SHRSP.Z-Lepr(fa)/IzmDmcr (SHRSP fatty) rats with metabolic syndrome. The aim of this study was to investigate the possible mechanisms underlying abnormal heart function in SHRSP fatty rats. The amount of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) 2a, phospholamban (PLB) protein, and Ser(16)-phosphorylated PLB was decreased in cardiomyocytes from SHRSP fatty rats compared with those from control Wistar-Kyoto rats at 18 weeks of age, and the PLB-to-SERCA2a ratio was increased. Left ventricular developed pressure was unchanged, and coronary flow rate and maximum rate of left ventricular pressure decline (-dP/dt) was decreased in SHRSP fatty rats. Treatment with telmisartan reversed the abnormalities of PLB amount, coronary flow rate, and -dP/dt in SHRSP fatty rats. These results indicate that abnormal amounts of intracellular Ca(2+) regulatory proteins in cardiomyocytes, leading to reduced intracellular Ca(2+) reuptake into the sarcoplasmic reticulum, may play a role in the diastolic dysfunction in SHRSP fatty rats and that these effects are partially related to decreased coronary circulation. Telmisartan may be beneficial in protecting against disturbances in cardiac function associated with metabolic syndrome.
A current model posits that cofilin-dependent actin severing negatively impacts dendritic spine volume. Studies suggested that increased cofilin activity underlies activity-dependent spine shrinkage, and that reduced cofilin activity induces activity-dependent s
pine growth. We suggest instead that both types of structural plasticity correlate with decreased cofilin activity. However, the mechanism of inhibition determines the outcome for spine morphology. RNAi in rat hippocampal cultures demonstrates that cofilin is essential for normal spine maintenance. Cofilin-F-actin binding and filament barbed-end production decrease during the early phase of activity-dependent spine shrinkage; cofilin concentration also decreases. Inhibition of the cathepsin B/L family of proteases prevents both cofilin loss and spine shrinkage. Conversely, during activity-dependent spine growth, LIM kinase stimulates cofilin phosphorylation, which activates phospholipase D-1 to promote actin polymerization. These results implicate novel molecular mechanisms and prompt a revision of the current model for how cofilin functions in activity-dependent structural plasticity.
Yang B, etal., Kidney Int. 2014 Feb;85(2):289-306. doi: 10.1038/ki.2013.290. Epub 2013 Aug 7.
Venous neointimal hyperplasia (VNH) causes hemodialysis vascular access failure. Here we tested whether VNH formation occurs in part due to local vessel hypoxia caused by surgical trauma to the vasa vasorum of the outflow vein at the time of arteriovenous fistula placement. Selective targeting of th
e adventitia of the outflow vein at the time of fistula creation was performed using a lentivirus-delivered small-hairpin RNA that inhibits VEGF-A expression. This resulted in significant increase in mean lumen vessel area, decreased media/adventitia area, and decreased constrictive remodeling with a significant increase in apoptosis (increase in caspase 3 activity and TUNEL staining) accompanied with decreased cellular proliferation and hypoxia-inducible factor-1α at the outflow vein. There was significant decrease in cells staining positive for α-smooth muscle actin (a myofibroblast marker) and VEGFR-1 expression with a decrease in MMP-2 and MMP-9. These results were confirmed in animals that were treated with humanized monoclonal antibody to VEGF-A with similar results. Since hypoxia can cause fibroblast to differentiate into myofibroblasts, we silenced VEGF-A gene expression in fibroblasts and subjected them to hypoxia. This decreased myofibroblast production, cellular proliferation, cell invasion, MMP-2 activity, and increased caspase 3. Thus, VEGF-A reduction at the time of arteriovenous fistula placement results in increased positive vascular remodeling.
Baik SH, etal., Exp Mol Med. 2016 Mar 25;48:e222. doi: 10.1038/emm.2015.126.
MicroRNAs (miRNAs) are negative regulators of gene expression, and miRNA deregulation is found in various tumors. We previously reported that suppression of adenine nucleotide translocase 2 (ANT2) by short hairpin RNA (shRNA) inhibits hepatocellular carcinoma (HCC) development by rescuing miR-636
expression. However, the tumor-suppressive mechanisms of ANT2 shRNA are still poorly understood in HCC. Here, we hypothesized that miRNAs that are specifically downregulated by ANT2 shRNA might function as oncomiRs, and we investigated the roles of ANT2 shRNA-regulated miRNAs in the pathogenesis of HCC. Our data show that miR-19a and miR-96, whose expression is regulated by ANT2 suppression, were markedly upregulated in HCC cell lines and clinical samples. Ectopic expression of miR-19a and miR-96 dramatically induced the proliferation and colony formation of hepatoma cells in vitro, whereas inhibition of miR-19a and miR-96 reduced these effects. To investigate the in vivo function, we implanted miR-96-overexpressing HepG2 cells in a xenograft model and demonstrated that the increase in miR-96 promoted tumor growth. We also found that miR-19a and miR-96 inhibited expression of tissue inhibitor of metalloproteinase-2. Taken together, our results suggest that ANT2-regulated miR-19a and miR-96 play an important role in promoting the proliferation of human HCC cells, and the knockdown of ANT2 directly downregulates miR-19a and miR-96, ultimately resulting in the suppression of tumor growth.
INTRODUCTION: Over-expression of penile neuronal nitric oxide synthase (PnNOS) from a plasmid ameliorates aging-related erectile dysfunction (ED), whereas over-expression of the protein inhibitor of NOS (PIN), that binds to nNOS, increases ED. AIM: To improve this form of gene t
herapy for ED by comparing the electrical field response of short hairpin RNA (shRNA) for PIN with that of antisense PIN RNA. MAIN OUTCOME MEASURE: Both shRNA and antisense RNA gene therapy vectors increased intracavernosal pressure in aged rats. METHODS: PIN small interfering RNA (siRNA), and plasmid constructs for cytomegalovirus promoter plasmid vector (pCMV-PIN), pCMV-PIN antisense RNA, pSilencer2.1-U6-PIN-shRNA; and pSilencer2.1-U6-randomer-shRNA were prepared and validated by transfection into HEK293 cells, determining the effects on PIN expression by Western blot. Plasmid constructs were then injected, followed by electroporation, into the penile corpora cavernosa of aged (20-month-old) Fisher 344 rats and, 1 month later, the erectile response was measured by intracavernosal pressure increase following electrical field stimulation (EFS) of the cavernosal nerve. PIN was estimated in penile tissue by Western blot and real-time reverse transcriptase-polymerase chain reaction. Cyclic guanosine monophosphate (cGMP) measurements were conducted by competitive enzyme immunoassay (EIA). Immunohistofluorescence detected PIN in corporal tissue sections. RESULTS: In cell culture, PIN siRNA and plasmid-expressed pU6-PIN-shRNA effectively reduced PIN expression from pCMV-PIN. pSilencer2.1-U6-PIN-shRNA corrected the impaired erectile response to EFS in aged rats and raised it above the value for young rats, more efficiently than pCMV-PIN antisense RNA. PIN mRNA expression in the penis was decreased by >70% by the shRNA but remained unaffected by the antisense RNA, whereas PIN protein expression was reduced in both cases, particularly in the dorsal nerve. PIN antisense increased cGMP concentration in treated tissue by twofold. CONCLUSION: pSilencer2.1-U6-PIN-shRNA gene therapy was more effective than the antisense PIN mRNA in ameliorating ED in the aged rat, thereby suggesting that PIN is indeed a physiological inhibitor of nNOS and nitrergic neurotransmission in the penis.
Yamagata K, etal., Neuroscience. 2014 May 16;267:277-85. doi: 10.1016/j.neuroscience.2014.02.039. Epub 2014 Mar 6.
In stroke-prone spontaneously hypertensive rats (SHRSP/Izm), ischemia induces swelling of astrocytes, a process that subsequently leads to neuronal death. Following ischemic insult, arginine vasopressin (AVP) can induce edema and l-serine released by astrocytes
supports the survival of neuronal cells. The purpose of this study was to examine whether AVP contributed to the regulation of l-serine production following ischemic stroke. Here, we used cultured astrocytes from SHRSP/Izm rats and Wistar Kyoto rats (WKY/Izm) to examine whether AVP changed the production of l-serine and/or altered gene expression levels of the neural amino acid transporter (Slc1a4), 3-phosphoglycerate dehydrogenase (Phgdh) and serine racemase (SRR). Furthermore, using astrocytes from the congenic rat SHRpch1_18 strain having quantitative trait loci (QTL) of stroke, we examined expression of those genes under conditions of hypoxia and reoxygenation (H/R). The expression levels of ASCT1 protein, the genes described above and l-serine levels were determined by Western blotting (WB), RT-PCR, real-time quantitative RT-PCR and HPLC. AVP increased the production of l-serine and the expression of Slc1a4 in WKY/Izm and SHRSP/Izm astrocytes. The production of l-serine and the expression of Slc1a4 were lower in SHRSP/Izm than in WKY/Izm cells. This difference was not seen with Phgdh. In the SHRpch1_18 strain, the expression of Slc1a4 and Phgdh significantly decreased after H/R. AVP-mediated enhanced expression of ASCT1 was blocked by the addition of bumetanide. These results suggest that the AVP-mediated attenuated expression of ASCT1 in astrocytes is associated with reduced l-serine production in SHRSP/Izm astrocytes. We hypothesize that reduction of gene expression by AVP might be related to the induction of stroke in the SHRpch1_18 rat strain.
The purpose of this study was to evaluate whether the spontaneously hypertensive rat SHRSP.Z-Lepr(fa)/IzmDmcr (SHRSP fatty) is a useful animal model to clarify molecular mechanisms that underlie metabolic syndrome. We invest
igated histopathologic changes in the cardiovascular organs and metabolic characteristics of SHRSP fatty rats, which are congenic rats from a cross between SHRSP and Zucker fatty (ZF) rats. The aortic wall and cardiac, carotid, and renal arteries from SHRSP and SHRSP fatty rats were thicker than those of ZF rats. The renal cortex in SHRSP and SHRSP fatty rats showed severe glomerulosclerosis. Pancreatic islands in SHRSP fatty and ZF rats showed marked hyperplasia. Steady-state plasma glucose concentrations were higher in SHRSP fatty than in ZF rats. Non-fasting triglyceride levels in SHRSP fatty rats were higher than in ZF rats. DNA synthesis in cultured vascular smooth muscle cells (VSMCs) from SHRSP fatty and SHRSP rats was significantly higher than that in VSMCs from Wistar-Kyoto (WKY) or ZF rats. Levels of platelet-derived growth factor A-chain and transforming growth factor-beta1 mRNAs were higher in VSMCs from SHRSP fatty and SHRSP than from ZF rats. Microarray analysis identified five genes that were significantly upregulated and four genes that were significantly downregulated in visceral adipose tissue of SHRSP fatty rats compared with levels in control strains (SHRSP and ZF rats). These findings suggest that the combination of hypertension and obesity accelerates vascular remodeling, dyslipidemia, and insulin resistance in metabolic syndrome. The phenotype of SHRSP fatty is similar to that of human metabolic syndrome, and therefore, studies of these rats may help clarify the molecular mechanisms that underlie metabolic syndrome in humans.
Rick FG, etal., J Urol. 2012 Apr;187(4):1498-504. doi: 10.1016/j.juro.2011.11.081. Epub 2012 Feb 17.
PURPOSE: Benign prostatic hyperplasia often affects aging men. Antagonists of the neuropeptide growth hormone-releasing hormone reduced prostate weight in an androgen induced benign prostatic hyperplasia model in rats. Luteinizing hormone-releasing hormone antagonists also produce marked, protracted
improvement in lower urinary tract symptoms, reduced prostate volume and an increased urinary peak flow rate in men with benign prostatic hyperplasia. We investigated the influence of a combination of antagonists of growth hormone-releasing hormone and luteinizing hormone-releasing hormone on animal models of benign prostatic hyperplasia. MATERIALS AND METHODS: We evaluated the effects of the growth hormone-releasing hormone antagonist JMR-132, given at a dose of 40 mug daily, the luteinizing hormone-releasing hormone antagonist cetrorelix, given at a dose of 0.625 mg/kg, and their combination on testosterone induced benign prostatic hyperplasia in adult male Wistar rats in vivo. Prostate tissue was examined biochemically and histologically. Serum levels of growth hormone, luteinizing hormone, insulin-like growth factor-1, dihydrotestosterone and prostate specific antigen were determined. RESULTS: Marked shrinkage of the rat prostate (30.3%) occurred in response to the combination of growth hormone-releasing hormone and luteinizing hormone-releasing hormone antagonists (p<0.01). The combination strongly decreased prostatic prostate specific antigen, 6-transmembrane epithelial antigen of the prostate, interleukin-1beta, nuclear factor-kappabeta and cyclooxygenase-2, and decreased serum prostate specific antigen. CONCLUSIONS: A combination of growth hormone-releasing hormone antagonist with luteinizing hormone-releasing hormone antagonist potentiated a reduction in prostate weight in an experimental benign prostatic hyperplasia model. Results suggest that this shrinkage in prostate volume was induced by the direct inhibitory effects of growth hormone-releasing hormone and luteinizing hormone-releasing hormone antagonists exerted through their respective prostatic receptors. These findings suggest that growth hormone-releasing hormone antagonists and/or their combination with luteinizing hormone-releasing hormone antagonists should be considered for further development as therapy for benign prostatic hyperplasia.
While chronic kidney disease seems to be an independent risk factor for cognitive decline, its impact on cerebral amyloid-β (Aβ) depositions, one hallmark of Alzheimer's Disease (AD) pathology, has not been investigated. Utilizing 80 male nontransgenic spontaneously hypertensive stroke prone rats (<
span style='font-weight:700;'>SHRSP) at various ages (12 to 44 weeks), tubulointerstitial renal damage, prevalence of cerebral microhemorrhages and Aβ accumulations were quantified. Using age-adjusted general linear models we investigated the main and interaction effects of renal damage and cerebral microhemorrhages on cerebral Aβ load. In addition, using post mortem human brain tissue of 16 stroke patients we examined the co-localization of perivascular Aβ deposits and small vessel wall damage. Statistical models revealed an age-independent main effect of tubulointerstitial kidney damage on brain Aβ accumulations, which was reinforced by the consecutive presence of cerebral microhemorrhages. Moreover, cerebral microhemorrhages independently predicted brain Aβ burden in SHRSP. In up to 69% of all human cases perivascular Aβ deposits were detected in the direct vicinity of small vessel wall damage. Our results support the associations between vascular pathology and Aβ deposition, and demonstrate a relationship between chronic kidney disease and cerebral Aβ pathology. Hence, our data suggest that prevention of chronic renal damage may reduce cerebral Aβ pathology.
The stroke-prone spontaneously hypertensive rat (SHRSP) showed an exaggerated response to a high-fat, high-cholesterol (HFC) diet, and the resulting reactive hypercholesterolemia was suggested to exacerbate the atherogenic process in this rat. We thus performed
a quantitative trait locus (QTL) analysis on the serum cholesterol level of SHRSP before and after the HFC diet, with the final goal being the identification of the genetic mechanisms of its reactive hypercholesterolemia. Three hundred fifty-eight F2 rats between SHRSP and Wistar-Kyoto rat were employed in the study. The serum cholesterol and apoprotein E were measured before and after 2 wk of feeding with the HFC diet. Multiple QTLs for the basal cholesterol level were identified on chromosomes 1 and 5, whereas those for the postdietary cholesterol level were on chromosomes 7, 15, and 16. The cholesterol QTLs before and after HFC diet did not overlap with one another, implying that the involved metabolic processes were considerably different between the two conditions. Supporting this, VLDL and LDL cholesterol were the major components of the postdietary serum cholesterol, whereas the basal cholesterol level consisted mainly of HDL cholesterol. A substantial difference of the QTLs between males and females was observed, especially after the HFC diet. The QTL on chromosome 15 had an inverse effect on the cholesterol level, suggesting that the congenic substitution of the SHRSP fragment with that of Wistar-Kyoto rats could induce a greater cholesterol level in SHRSP. This observation is significant in establishing a new model for atherosclerosis with hypertension in rats.
Liu C, etal., Am J Hum Genet. 2023 Mar 2;110(3):516-530. doi: 10.1016/j.ajhg.2023.01.016. Epub 2023 Feb 15.
Primate-specific genes (PSGs) tend to be expressed in the brain and testis. This phenomenon is consistent with brain evolution in primates but is seemingly contradictory to the similarity of spermatogenesis among mammals. Here, using whole-exome sequencing, we identified deleterious variants of X-li
nked SSX1 in six unrelated men with asthenoteratozoospermia. SSX1 is a PSG expressed predominantly in the testis, and the SSX family evolutionarily expanded independently in rodents and primates. As the mouse model could not be used for studying SSX1, we used a non-human primate model and tree shrews, which are phylogenetically similar to primates, to knock down (KD) Ssx1 expression in the testes. Consistent with the phenotype observed in humans, both Ssx1-KD models exhibited a reduced sperm motility and abnormal sperm morphology. Further, RNA sequencing indicated that Ssx1 deficiency influenced multiple biological processes during spermatogenesis. Collectively, our experimental observations in humans and cynomolgus monkey and tree shrew models highlight the crucial role of SSX1 in spermatogenesis. Notably, three of the five couples who underwent intra-cytoplasmic sperm injection treatment achieved a successful pregnancy. This study provides important guidance for genetic counseling and clinical diagnosis and, significantly, describes the approaches for elucidating the functions of testis-enriched PSGs in spermatogenesis.
Huang Z, etal., Sci Rep. 2015 Aug 4;5:12807. doi: 10.1038/srep12807.
The high mobility group box 1 (HMGB1), which is a highly conserved and evolutionarily non-histone nuclear protein, has been shown to associate with a variety of biological important processes, such as transcription, DNA repair, differentiation, and extracellular signalling. High HMGB1 expression has
been reported in many cancers, such as prostate, kidney, ovarian, and gastric cancer. However, there have been few studies of the function of HMGB1 in the malignant biological behaviour of bladder urothelial carcinoma (BUC), and the potential mechanism of HMGB1 in the pathogenesis of BUC remains unclear. Thus, in this study, we constructed plasmid vectors that are capable of synthesizing specific shRNAs targeting HMGB1 and transfected them into BUC cells to persistently suppress the endogenous gene expression of HMGB1. The expression of HMGB1, the bioactivity of BUC cells, including proliferation, apoptosis, cell cycle distribution, migration and invasion, and the effects of HMGB1 knockdown on downstream signalling pathways were investigated. Our data suggest that HMGB1 promotes the malignant biological behaviour of BUC, and that this effect may be partially mediated by the NF-kappaB signalling pathway. HMGB1 may serve as a potential therapeutic target for BUC in the future.
Lu P, etal., Int J Clin Exp Pathol. 2012;5(7):698-706. Epub 2012 Sep 5.
OBJECTIVE: To investigate the effects of RNA interference targeting AGT on early atherosclerotic lesion in the hypertensive state. METHODS: Hypertension and atherosclerosis rats were treated with GPE nanoparticles carrying AGT shRNA. Systolic blood pressure and heart rate were measured for 2 consec
utive weeks. Three days after treatment, the mRNA and protein expressions of AGT in the liver were measured by PCR and western blot assay, respectively. The blood levels of AGT and Ang II were determined by ELISA. H&E staining and electron microscopy were performed. RESULTS: Three days after AGT shRNA treatment, the mRNA and protein expressions of AGT in the liver were markedly reduced and the blood levels of AGT and Ang II dramatically decreased as compared to the remaining 3 groups (P < 0.05). Three days after AGT shRNA treatment, the blood pressure was reduced by 27 +/- 4 mmHg when compared with that at baseline (P < 0.05). About 11 days after AGT shRNA treatment, the blood pressure began to increase. The blood pressure remained unchanged in the remaining 3 groups. Microscopy showed the atherosclerotic lesions were markedly attenuated in AGT shRNA treated rats but the liver and kidney functions remained stable (P > 0.05) when compared with the remaining 3 groups. CONCLUSION: Transfection with GPE nanoparticle carrying AGT shRNA can stably lower the blood pressure and improve the atherosclerotic lesions which lead to the delayed development of early atherosclerotic lesions in hypertension rats with concomitant atherosclerosis.
Que L, etal., Oncol Rep. 2016 Jan;35(1):89-98. doi: 10.3892/or.2015.4374. Epub 2015 Nov 2.
Integrin-linked kinase (ILK), a highly conserved intracellular protein of serine/threonine protein kinase activities, which is associated with the integrin and growth factor receptor signaling pathway, is involved in the regulation of cell proliferation, apoptosis, differentiation, migration and epi
thelial-mesenchymal transition (EMT). Findings of a previous study showed that ILK overexpression was strongly correlated with a more aggressive tumor phenotype, recurrence and poor survival for oral squamous cell carcinoma (OSCC) patients, as well as some EMT markers. In order to investigate the underlying mechanisms involved, a lentivirus-mediated short hairpin RNA (shRNA) was employed to downregulate ILK. The results showed that the knockdown of ILK inhibited cell growth, adhesion and invasion ability in vitro, and OSCC cells deficient of ILK were blocked in the S phase and underwent apoptosis. Additionally, ILK shRNA inhibited EMT by impairing the expression of Snail, Slug and Twist2 and enhacning E-cadherin expression. ILK shRNA suppressed the phosphorylation of downstream signaling targets Akt and GSk-3beta. In addition, the knockdown of ILK inhibited tumor growth, invasion and metastasis of xenograft tumors in vivo. These results suggested that ILK is a promising therapeutic target for the treatment of OSCC.
Zapata J, etal., Nat Commun. 2017 Mar 6;8:14536. doi: 10.1038/ncomms14536.
Shrm4, a protein expressed only in polarized tissues, is encoded by the KIAA1202 gene, whose mutations have been linked to epilepsy and intellectual disability. However, a physiological role for Shrm4 in the brain is yet to
be established. Here, we report that Shrm4 is localized to synapses where it regulates dendritic spine morphology and interacts with the C terminus of GABAB receptors (GABABRs) to control their cell surface expression and intracellular trafficking via a dynein-dependent mechanism. Knockdown of Shrm4 in rat severely impairs GABABR activity causing increased anxiety-like behaviour and susceptibility to seizures. Moreover, Shrm4 influences hippocampal excitability by modulating tonic inhibition in dentate gyrus granule cells, in a process involving crosstalk between GABABRs and extrasynaptic δ-subunit-containing GABAARs. Our data highlights a role for Shrm4 in synaptogenesis and in maintaining GABABR-mediated inhibition, perturbation of which may be responsible for the involvement of Shrm4 in cognitive disorders and epilepsy.
Cardiomyocytes exposed to ischemia followed by reperfusion undergo apoptosis, some of which is induced via the mitochondrial pathway, and some of which is induced via the death-receptor ligand pathway. FLICE-inhibitory protein (FLIP) is a cellular protein that, in overexpression experiments in other
cell types, has been shown to be capable of either inducing or protecting from death-receptor-mediated apoptosis, depending on the extent of overexpression. To examine the role of endogenous FLIP in neonatal cardiomyocytes we have used short hairpin-induced (shRNA) silencing generated from a transfected plasmid. Silencing of FLIP increases the background level of apoptosis detected by TUNEL assay in primary cardiomyocytes and sensitizes the cells to apoptosis induced by simulated ischemia/reoxygenation (IR). This result indicates that previous observations of decreased FLIP levels and increased apoptosis in cardiac infarcts is more than just correlative, but reflects an innate protective role of FLIP in cardiomyocytes. We also found that mitochondrial activity, as determined by MitoTracker red staining, is reduced in the absence of FLIP, and further decreases after exposure to simulated IR. Conversely, overexpression of FLIP somewhat prevents the decrease in mitochondrial activity after simulated IR. Thus, FLIP may confer protection from simulated ischemia/reperfusion through more than one pathway.
André ND, etal., Mol Med Rep. 2015 Dec;12(6):8320-6. doi: 10.3892/mmr.2015.4487. Epub 2015 Oct 26.
Metastasis is a key factor that limits survival in the majority of patients with cancer. Thus, numerous efforts have been made to elucidate the molecular mechanisms involved in this phenomenon. B16‑F10 melanoma cells have been demonstrated to be highly metastatic to the lungs in mice. The aim of the
current study was to investigate the role of CXC motif chemokine receptor 4 (CXCR4) in the metastatic potential of B16‑F10 melanoma cells in mice. In vitro transfection of B16‑F10 tumor cells with CXCR4 short hairpin RNA (shRNA) expressing plasmids (CXCR4 shRNA) significantly reduced the expression levels of CXCR4 mRNA (80%) and protein (68%), compared with the control. In addition, these results demonstrated that pulmonary metastasis was significantly inhibited (85%) in mice inoculated with CXCR4 shRNA‑transfected B16‑F10 melanoma cells. The polycation‑based nanoparticle (jetPEI) was used to investigate the effect of CXCR4 knockdown in vivo on the metastatic potential of B16‑F10 melanoma cells. The number of pulmonary metastatic nodules was significantly reduced (50%) in animals that received a retro‑orbital injection of jetPEI‑CXCR4‑1 shRNA. The current study demonstrated that CXCR4 serves a role in the metastatic potential of B16‑F10 melanoma cells. Currently there is a great interest in the development of antagonists for the therapeutic targeting of CXCR4 expression. Taking the results of the current study and the fact that CXCR4 is highly conserved between humans and mice into account, this experimental model of metastasis with B16‑F10 melanoma cells may aid in the discovery of CXCR4 antagonists with clinical implications.
Herold MJ, etal., Proc Natl Acad Sci U S A. 2008 Nov 25;105(47):18507-12. Epub 2008 Nov 18.
Currently, tools to generate loss-of-function mutations in rats are limited. Therefore, we have developed a lentiviral single-vector system for the temporal control of ubiquitous shRNA expression. Here, we report transgenic rats carrying an insulin receptor-specific shRNA transcribed from a regulata
ble promoter and identified by concomitant EGFP expression. In the absence of the inducer doxycycline (Dox), we observed no siRNA expression. However, Dox treatment at very low concentrations led to a rapid induction of the siRNA and ablation of INSR protein expression. As anticipated, blood glucose levels increased, whereas insulin signaling and glucose regulation were impaired. Importantly, this phenotype was reversible (i.e., discontinuation of Dox treatment led to INSR re-expression and remission of diabetes symptoms). The lentiviral system offers a simple tool for reversible gene ablation in the rat and can be used for other species that cannot be manipulated by conventional recombination techniques.
Akt2 overexpression correlates with chemoresistance of colorectal cancer (CRC). However, the cellular functions and precise signals elicited by Akt2 in LSCC have not been elucidated. Here, we transfected a CRC cell line HCT116 with Akt-2 targeted shRNA in order to establish a cell line with Akt2 kno
ckdown. In vitro experiments showed that knockdown Akt2 in HCT116 cells was associated with decrease in cell proliferation as well as enhanced cell apoptosis. Furthermore, our results demonstrated that Akt2 knockdown correlated with elevated chemosensitivity of HCT116 cells to paclitaxel. Importantly, we found that knockdown of AKt2 resulted in downregulation of MDR-1 and MRP-1. Our findings may lead to a better understanding of the biological effect of Akt2 and may provide mechanistic insights for developing potential therapeutic strategies targeting AKt2.
It has been well documented that survivin has multiple functions including cytoprotection, inhibition of cell death, and cell cycle regulation, particularly at the mitotic stage of the cell cycle, all of which favor cancer survival. Its expression in normal tissue is developmentally regulated, and a
ny type of deregulation in survivin expression favors cancer survival. Gastric cancer is one of the most common malignancies and the second most common cause of cancer-related mortality worldwide. The molecular mechanisms involved in the transformation and progression of gastric cancer remain unclear. In the present study, we investigated the effect of lentiviral vector-mediated survivin shRNA delivery in gastric cancer cell lines. Lentiviral-mediated survivin shRNA was used to knock down survivin expression in gastric cancer cell lines SGC-7901, MGC-803 and MKN-28. The Tauranswell chemotaxis and the CCK-8 assays were used to assess the migration and proliferation of the tumor cells, respectively. TUNEL assay was used to detect apoptosis. Quantitative real-time PCR and western blot analysis were used to quantify mRNA and protein levels, respectively. Our results demonstrated that lentiviral-mediated RNAi markedly suppressed the survivin expression in all three gastric cancer cell lines. Significant decrease in survivin mRNA and protein expression were detected in the gastric cancer cell lines stably transfected with the lentiviral survivin shRNA vector, and knockdown of survivin also significantly inhibited the proliferation and migration in the gastric cancer cells and tumorigenicity in a xenograft animal model. Our results indicated that aberrant high cytoplasmic survivin expression in gastric cancer cells is associated with increased proliferation index and tumor growth. In conclusion, our results suggest that lentiviral-mediated gene therapy has the potential to be developed into a novel therapeutic strategy for the treatment of gastric cancer.
Liu L, etal., Stroke Res Treat. 2011;2011:534257. doi: 10.4061/2011/534257. Epub 2011 Jun 9.
Phosphodiesterase 4D (PDE4D) is a member of the large superfamily of phosphodiesterases. PDE4D polymorphisms have been found to associate with ischemic stroke. Proliferation and migration of vascular smooth muscle cells (VSMCs) play a critical role in the pathogenesis of atherosclerosis. In this stu
dy, infection of VSMCs with lentivrius particles carrying shRNA direct against PDE4D significantly inhibited platelet-derived growth factor-induced VSMC proliferation and migration, and the inhibitory effects were not associated with global intracellular cAMP level. Our results implicate that PDE4D has an important role in VSMC proliferation and migration which may explain its genetic susceptibility to ischemic stroke.
Fu Y, etal., J Ovarian Res. 2015 Aug 21;8:59. doi: 10.1186/s13048-015-0173-z.
BACKGROUND: In a previous analysis on the patients with ovarian cancers, we have found that clusterin is a biomarker associated with ovarian cancer in vivo and may be a prognostic factor associated with adverse outcome. Here, we explored the effect of lentivirus-mediated shRNA interference of clust
erin, investigated whether clusterin was associated with adverse outcome of ovarian cancer cells in vitro. METHODS: OVCAR-3 and TOV-21G cell lines were infected with the lentivirus for delivering clusterin shRNA, and the stably transfected cells were selected. The effect of clusterin silencing was detected by western blotting assay. The proliferation, clonability, migration, invasion and cell cycle of two cell lines were detected separately by MTT assay, clone formation assay, scratch assay, transwell assay and fluorescence-activated cell sorting. RESULTS: Following clusterin silencing with shRNA, the expression of clusterin in two cell lines were decreased. And the proliferation, clonability, migration, invasion of these two cell lines were down-regulated apparently. The cell cycle of two cell lines was disturbed, cells in G1 phase was increased, but cells in G2 and S phase was decreased. CONCLUSIONS: The expression of clusterin is significantly correlated with the biological characteristics of ovarian cancer cells, it may be a potential molecular for ovarian cancer treatment.
Hu C, etal., J Drug Target. 2016;24(5):422-32. doi: 10.3109/1061186X.2015.1082567. Epub 2015 Sep 4.
Emerging evidences suggest that cancer stem cells (CSCs) are responsible for tumor growth, metastasis and treatment resistance. Nanog is one of the transcription factors that are essential for stem cellular physiology process. Previous studies reported that Nanog was detected in breast cancer and ot
her solid tumors and indicated that it has oncogenic characteristics. However, expression feature of Nanog in breast cancer stem cells (BCSCs) enriched population and its biological function in BCSCs is poorly understood. In this study, CD44¿+¿CD24- fraction sorting with Fluorescence Activated Cell Sorter and mammosphere culture were used for enriching BCSCs. We report here that Nanog was highly expressed in CSCs-enriched population from the breast cancer cells, as well as stemness-associated genes. In addition, we employed the lentivirus-mediated shRNA targeting Nanog to investigate function of Nanog in BCSCs. We found that targeted inhibition of Nanog could suppress proliferation and colony formation in breast cancer cells. Further studies showed that targeted inhibition of Nanog resulted in a decrease of BCSCs activities, including mammosphere formation, CD44¿+¿CD24- proportion and expressions of stemness-associated genes. These data therefore suggest that Nanog possesses important function in BCSCs and targeted inhibition of Nanog may provide a novel means of targeting and eliminating BCSCs.
An abnormal increase in left ventricular (LV) mass, i.e., LV hypertrophy (LVH), represents an important target organ damage in arterial hypertension and has been associated with poor clinical outcome. Genetic factors are contributing to variation in LV mass in addition to blood pressure and other fa
ctors such as dietary salt intake. We set out to map quantitative trait loci (QTL) for LV mass by comparing the spontaneously hypertensive stroke-prone (SHRSP) rat with LVH and normotensive Fischer rats (F344) with contrasting low LV mass. To this end we performed a genome-wide QTL mapping analysis in 232 F2 animals derived from SHRSP and F344 exposed to high-salt (4% in chow) intake for 8 wk. We mapped one major QTL for LV mass on rat chromosome 1 (RNO1) that demonstrated strong linkage (peak logarithm of odds score 8.4) to relative LV weight (RLVW) and accounted for approximately 19% of the variance of this phenotype in F2 rats. We therefore generated a consomic SHRSP-1(F344) strain in which RNO1 from F344 was introgressed into the SHRSP background. Consomic and SHRSP animals showed similar blood pressures during conventional intra-arterial measurements, while RLVW was already significantly lower (-17.7%, P<0.05) in SHRSP-1(F344) in response to a normal-salt diet; a similar significant reduction of LV mass was also observed in consomic rats after high-salt intake (P<0.05 vs. SHRSP). Thus, a major QTL on RNO1 was confirmed with significant impact on LV mass in the hypertensive background of SHRSP.
Babiarz JE, etal., Genes Dev. 2008 Oct 15;22(20):2773-85. doi: 10.1101/gad.1705308.
Canonical microRNAs (miRNAs) require two processing steps: the first by the Microprocessor, a complex of DGCR8 and Drosha, and the second by a complex of TRBP and Dicer. dgcr8Delta/Delta mouse embryonic stem cells (mESCs) have less severe phenotypes than dicer1Delta/Delta mESCs, suggesting a physiol
ogical role for Microprocessor-independent, Dicer-dependent small RNAs. To identify these small RNAs with unusual biogenesis, we performed high-throughput sequencing from wild-type, dgcr8Delta/Delta, and dicer1Delta/Delta mESCs. Several of the resulting DGCR8-independent, Dicer-dependent RNAs were noncanonical miRNAs. These derived from mirtrons and a newly identified subclass of miRNA precursors, which appears to be the endogenous counterpart of shRNAs. Our analyses also revealed endogenous siRNAs resulting from Dicer cleavage of long hairpins, the vast majority of which originated from one genomic locus with tandem, inverted short interspersed nuclear elements (SINEs). Our results extend the known diversity of mammalian small RNA-generating pathways and show that mammalian siRNAs exist in cell types other than oocytes.
The cells in the organ of Corti do not exhibit spontaneous cell regeneration; hair cells that die after damage are not replaced. Supporting cells can be induced to transdifferentiate into hair cells, but that would deplete their numbers, therefore impairing epithelium physiology. The loss of p27Kip1
function induces proliferation in the organ of Corti, which raises the possibility to integrate it to the strategies to achieve regeneration. Nevertheless, it is not known if the extent of this proliferative potential, as well as its maintenance in postnatal stages, is compatible with providing a basis for eventual therapeutic manipulation. This is due in part to the limited success of approaches to deliver tools to modify gene expression in the auditory epithelium. We tested the hypothesis that the organ of Corti can undergo significant proliferation when efficient manipulation of the expression of regulators of the cell cycle is achieved. Lentiviral vectors were used to transduce all cochlear cell types, with efficiencies around 4 % for hair cells, 43 % in the overall supporting cell population, and 74 % within lesser epithelial ridge (LER) cells. Expression of short hairpin RNA targeting p27Kip1 encoded by the lentiviral vectors led to measurable proliferation in the organ of Corti and increase in LER cells number but not hair cell regeneration. Our results revalidate the use of lentiviral vectors in the study and in the potential therapeutic approaches for inner ear diseases, as well as demonstrate that efficient manipulation of p27Kip1 is sufficient to induce significant proliferation in the postnatal cochlea.
Kozaki Y, etal., J Physiol Sci. 2015 Sep;65(5):417-25. doi: 10.1007/s12576-015-0380-9. Epub 2015 May 14.
Repeated cold stress (RCS) is known to transiently induce functional disorders associated with hypotension and hyperalgesia. In this study, we investigated the effects of RCS (24 and 4 °C alternately at 30-min intervals during the day and 4 °C at night for 2 days, followed by 4 °C on the next 2 cons
ecutive nights) on the thresholds for cutaneous mechanical pain responses and on peripheral expression of "pain-related genes" in SHRSP5/Dmcr rats, which are derived from stroke-prone spontaneously hypertensive rats. To define genes peripherally regulated by RCS, we detected changes in the expression of pain-related genes in dorsal root ganglion cells by PCR-based cDNA subtraction analysis or DNA microarray analysis, and confirmed the changes by RT-PCR. We found significantly changed expression in eight pain-related genes (upregulated: Fyn, St8sia1, and Tac 1; downregulated: Ctsb, Fstl1, Itpr1, Npy, S100a10). At least some of these genes may play key roles in hyperalgesia induced by RCS.
Taghavi S, etal., Colloids Surf B Biointerfaces. 2016 Apr 1;140:28-39. doi: 10.1016/j.colsurfb.2015.12.021. Epub 2015 Dec 17.
In this study, single-walled carbon nanotubes (SWCNTs) were covalently attached to poly(ethylene glycol) (PEG) and polyethylenimine (PEI) 10 kDa, or its derivatives, to fabricate efficient carriers for gene delivery. PEI 10 kDa was modified by alkylcarboxylation of its primary amines with a series o
f omega-bromo-alkylcarboxylic acids to provide a range of vectors with increased lipophilicity. PEI 10 kDa or its alkylcarboxylate derivatives were conjugated to SWCNT-PEG to develop vectors possessing effective DNA condensation ability which can interact with cell membrane via both nano-needle mechanism and electrostatic interactions produced by SWCNT and PEI, respectively. The results demonstrated that SWCNT-PEG-PEI and SWCNT-PEG-derivatives of PEI could condense DNA into particle size less than 150 nm with positive surface charges between 6.3-30.8 mV. To improve the antitumor efficacy, we developed a targeted gene delivery system using a 5 TR1 aptamer. The most efficient vector, which was prepared by attachment of SWCNT-PEG to modified PEI 10 kDa with 10-bromodecanoic acid (10%), showed 8.5-10 folds enhancement in transfection activity at C/P ratio 6 as compared to the gold standard PEI 25 kDa at C/P ratio of 0.8. We also showed that the selected polyplex could efficiently and selectively transfer plasmid shRNA to MUC1 positive cells.
Li FY, etal., J Gastroenterol Hepatol. 2009 May;24(5):920-6. Epub 2008 Nov 20.
BACKGROUND AND AIM: Chronic proliferative cholangitis (CPC) is currently considered as a pathological basis and major cause for the high recurrence rate of intrahepatic stones. Since CPC is a form of chronic proliferative disease, this study was designed to preliminarily investigate the inhibitory e
ffect of proliferating cell nuclear antigen (PCNA) shRNA on the hyperplastic behavior and lithogenic potentiality of CPC. METHODS: The rat model of CPC was given an intralumenal administration of 0.5 mL PCNA shRNA through a 20-gauge venous retained needle. PCNA shRNA-mediated effects on CPC-associated hyperplastic behavior and lithogenic potential were assessed by investigating histological changes, immunohistochemistry for Ki-67, biochemistry for beta-glucuronidase, real-time polymerase chain reaction, and western blot analysis of PCNA, procollagen I, and mucin-3. RESULTS: PCNA shRNA treatment could efficiently inhibit the mRNA and protein expressions of the proliferation-related gene, PCNA, and Ki-67, which efficiently inhibited the hyperplastic behavior of the biliary epithelium, submucosal gland, and collagen fibers in the diseased bile duct wall. This novel treatment could efficiently inhibit the formation of acidic mucus glands, the expression of mucin-3 mRNA, and the secretion of endogenous beta-glucuronidase, thus effectively inhibiting the lithogenic potentiality of CPC. A further analysis revealed that PCNA shRNA-1 might display a more robust inhibitory effect on CPC-associated hyperplastic behavior and lithogenic potential than other gene sequences targeted in this study. CONCLUSIONS: PCNA shRNA-1 treatment could effectively inhibit the hyperplastic behavior and lithogenic potentiality of CPC, which might facilitate the prevention of stone recurrence and biliary restenosis.
Seda O, etal., Physiol Genomics 2003 Jan 15;12(2):73-8.
The favorable metabolic effects of thiazolidinediones are supposedly related to the peroxisome proliferator-activated receptor-gamma (PPARgamma)-driven changes in lipid metabolism, particularly in free fatty acid (FFA) trafficking. The fatty acid translocase CD36 is one of the proposed PPARgamma tar
gets to mediate this action. We assessed the effect of rosiglitazone (RSG, Avandia) administration in two inbred rat strains, BN/Cub and BN.SHR4 congenic strain, differing in 10 cM proximal segment of chromosome 4. Rats were fed high-sucrose diet with or without RSG for 1 wk. In BN.SHR4, which carries defective Cd36 allele of SHR origin, RSG failed to improve glucose tolerance (assessed by the oral glucose tolerance test), did not lower triglyceridemia, nor induced increases in epididymal and retroperitoneal adipose tissue weights and adipose tissue glucose utilization, effects observed in BN/Cub. On the other hand, the RSG-treated BN.SHR4 showed lower concentrations of FFA and substantial increase in glycogen synthesis and glucose oxidation in skeletal muscle. Altogether, these results support involvement of CD36 in RSG action, suggesting this pharmacogenetic interaction may be of particular importance in CD36-deficient humans.
Jin H, etal., Oncol Res. 2014;22(3):167-76. doi: 10.3727/096504015X14298122915664.
Emerging evidence suggests a potential role of cellular inhibitor of apoptosis protein 1 (cIAP1) in the development of human ovarian cancer. However, its function in the progression of ovarian cancer has not been clearly determined. Our study aimed to investigate the effect of cIAP1 gene depletion o
n the chemosensitivity of ovarian cancer cells. We developed a novel short hairpin RNA (shRNA) plasmid specifically targeting cIAP1. Cell proliferation, invasion, and apoptosis of the shRNA-transfected cells were evaluated using MTT, Transwell chamber, and flow cytometric assays, respectively. The concentration of MMP-9 in the supernatant was detected by ELISA. Targeted depletion of cIAP1 by shRNA significantly reduced expression levels of cIAP1 mRNA and protein, leading to inhibition of cell proliferation and invasion capability in SKOV3 cells. At the same time, cIAP1 downregulation decreased the secretion of MMP-9. shRNA depletion of cIAP1 enhanced chemosensitivity of ovarian cancer cells to Taxol and carboplatin-induced apoptosis. cIAP1 is associated with tumor progression in human ovarian cancer. Therefore, cIAP1 might be a potential target for therapeutic anticancer drugs.
Li X, etal., J Toxicol Sci. 2016 Feb;41(1):45-53. doi: 10.2131/jts.41.45.
Recent research has revealed a role for Ambra1, an autophagy-related gene-related (ATG) protein, in the autophagic pro-survival response, and Ambra1 has been shown to regulate Beclin1 and Beclin1-dependent autophagy in embryonic stem cells and cancer cells. However, whether Ambra1 plays an important
role in the autophagy pathway in ovarian cancer cells is unknown. In this study, we hypothesized that Ambra1 is an important regulator of autophagy and apoptosis in ovarian cancer cells. We firstly confirmed autophagic activity in ovarian cancer OVCAR-3 cells which were treated with cisplatin by assessing endogenous microtubule-associated protein 1 light chain 3 (LC3) localization and the presence of autophagosomes and LC3 protein levels in OVCAR-3 cells. Cell apoptosis and viability were measured by annexin-V and PI staining and MTT assays. We then knocked down Ambra1 expression with transfection with the plasmid expressing the small hairpin RNA (shRNA) targeting AMBRA1, then re-evaluated autophagy in the OVCAR-3 cells subject to cisplatin treatment, and re-determined the sensitivity of OVCAR-3 cells to cisplatin. Results demonstrated that cisplatin treatment induced autophagy in OVCAR-3 cells in association with Ambra1 upregulation in the ovarian cancer cells. When Ambra1 expression was reduced by shRNA, the ovarian cancer cells were more sensitive to cisplatin. In conclusion, Ambra1 is a crucial regulator of autophagy and apoptosis in ovarian cancer cells subject to cisplatin to maintain the balance between autophagy and apoptosis. And the Ambra1-targeting inhibition might be an effective method to sensitize ovarian cancer cells to chemotherapy.
Jan M and Medh JD, Biochem Biophys Res Commun. 2015 Jun 19;462(1):33-7. doi: 10.1016/j.bbrc.2015.04.098. Epub 2015 Apr 27.
In previous studies, we demonstrated that down-regulation of lipoprotein lipase in L6 muscle cells increased insulin-stimulated glucose uptake. In the current study, we used RNA interference technology to silence the LPL gene in L6 cells and generate a LPL-knock-down (LPL-KD) cell line. ShRNA transf
ected cells showed a 88% reduction in the level of LPL expression. The metabolic response to insulin was compared in wild-type (WT) and LPL-KD cells. Insulin-stimulated glycogen synthesis and glucose oxidation were respectively, 2.4-fold and 2.6-fold greater in LPL-KD cells compared to WT cells. Oxidation of oleic acid was reduced by 50% in LPL-KD cells compared to WT cells even in the absence of insulin. The contribution of LPL in regulating fuel metabolism was confirmed by adding back purified LPL to the culture media of LPL-KD cells. The presence of 10 µg/mL LPL resulted in LPL-KD cells reverting back to lower glycogen synthesis and glucose oxidation and increased fatty acid oxidation. Thus, LPL depletion appeared to mimic the action of insulin. These finding suggests an inverse correlation between muscle LPL levels and insulin-stimulated fuel homeostasis.
Wang H, etal., PLoS One. 2015 May 19;10(5):e0127224. doi: 10.1371/journal.pone.0127224. eCollection 2015.
Y-box binding protein-1 (YB-1), a member of cold-shock protein superfamily, has been demonstrated to be associated with tumor malignancy, and is proposed as a prognostic marker in multiple carcinomas. However, the role of YB-1 in neuroblastoma has not been well studied. To investigate the functional
role of YB-1 in neuroblastoma, we established a YB-1-silenced neuroblastoma cell strain by inhibiting YB-1 expression using a shRNA knockdown approach. YB-1-silenced neuroblastoma SH-SY5Y cells exhibited a pronounced reduction in cell proliferation and an increased rate of apoptosis in vitro and in vivo xenograft tumor model. At molecular level, YB-1 silencing resulted in downregulation of Cyclin A, Cyclin D1 and Bcl-2, as well as upregulated levels of Bax, cleaved caspase-3 and cleaved PARP-1. We further demonstrated that YB-1 transcriptionally regulated Cyclin D1 expression by chromatin-immunoprecipitation and luciferase reporter assays. In addition, xenograft tumors derived from neuroblastoma SH-SY5Y cell line were treated with YB-1 shRNA plasmids by intra-tumor injection, and YB-1 targeting effectively inhibited tumor growth and induced cell death. In summary, our findings suggest that YB-1 plays a critical role in neuroblastoma development, and it may serve as a potential target for neuroblastoma therapy.
Herp, a mammalian protein with a ubiquitin-like domain, can be strongly upregulated by endoplasmic reticulum (ER) stress during ER-associated protein degradation. However, the other cellular functions of Herp remain unclear. We explored the effect of Herp on ER stress and inflammatory responses in R
AW 264.7 macrophages that had been exposed to tunicamycin or thapsigargin. We successfully constructed recombinant lentiviral vectors for Herp short-hairpin RNA (shRNA) expression to better understand the contribution made by Herp to other signaling pathways. Western blotting revealed that the recombinant Herp lentiviral shRNA vector significantly inhibited the expression of the Herp protein in the thapsigargin-treated RAW 264.7 macrophages. The reverse transcription quantitative polymerase chain reaction results showed that knockdown Herp inhibited the expression of ER stress-related genes during exposure to tunicamycin or thapsigargin. In RAW 264.7 macrophages, knockdown Herp markedly attenuated the expression of inflammatory cytokines when exposed to tunicamycin; however, it strongly enhanced the expression of inflammatory cytokines when exposed to thapsigargin. We concluded that Herp lentiviral shRNA vectors had been successfully constructed; knockdown Herp inhibited ER stress and had a different effect on inflammatory responses in RAW 264.7 macrophages depending on whether they were exposed to tunicamycin or thapsigargin.
Moriya T, etal., Environ Health Prev Med. 2012 Mar 11.
OBJECTIVES: The aim of this study was to identify the molecular mechanisms underlying high-fat and high-cholesterol (HFC) diet-induced steatohepatitis and associated liver fibrosis progression in a novel stroke-prone, spontaneously hypertensive 5/Dmcr (SHRSP5/Dm
cr) rat model. METHODS: SHRSP5/Dmcr rats were given the control or HFC-diet for 2, 8, and 16 weeks. Plasma and hepatic gene expression of key molecules involved in fatty acid oxidation, inflammation, oxidative stress, and fibrosis were subsequently analyzed. RESULTS: Rats fed the HFC-diet showed increased plasma tumor necrosis factor-alpha (TNF-alpha) and hepatic p50/p65 signals, but reduced hepatic Cu(2+)/Zn(2+)-superoxide dismutase across the treatment period and reduced plasma total adiponectin at 8 weeks. In HFC-diet-fed rats, transforming growth factor-beta1 (TGF-beta1) was elevated prior to the appearance of obvious liver fibrosis pathology at 2 weeks, followed by elevations in platelet-derived growth factor-B (PDGF-B) and alpha-smooth muscle actin (alpha-SMA), corresponding to evident liver fibrosis, at 8 weeks and by alpha(1) type I collagen production at 16 weeks. The HFC-diet increased hepatic total cholesterol accumulation, although hepatic triglyceride declined by 0.3-fold from 2 to 16 weeks due to reduced hepatic triglyceride synthesis, as suggested by the diacylglycerol acyltransferase 1 and 2 measurements. CONCLUSIONS: TNF-alpha and p50/p65 molecular signals appeared to be major factors for HFC-diet-induced hepatic inflammation and oxidative stress facilitating liver disease progression. While the up-regulation of TGF-beta1 prior to the appearance of any evident liver fibrosis could be an early signal for progressive liver fibrosis, elevated PDGF-B and alpha-SMA levels signified evident liver fibrosis at 8 weeks, and subsequent increased alpha(1) type I collagen production and reduced triglyceride synthesis indicated extensive liver fibrosis at 16 weeks in this novel SHRSP5/Dmcr model.
Van Sluijters DA, etal., Eur J Biochem 1999 Dec;266(2):653-9.
Breakdown of plasma-membrane sphingomyelin caused by TNF-alpha is known to inhibit glucose metabolism and insulin signalling in muscle and fat cells. In hepatocytes, conversion of glucose to glycogen is strongly activated by amino acid-induced cell swelling. In order to find out whether breakdown of
plasma-membrane sphingomyelin also inhibits this insulin-independent process, the effect of addition of sphingomyelinase was studied in rat hepatocytes. Sphingomyelinase (but not ceramide) inhibited glycogen synthesis, caused cell shrinkage, decreased the activity of glycogen synthase a, but had no effect on phosphorylase a. Cell integrity was not affected by sphingomyelinase addition as gluconeogenesis and the intracellular concentration of ATP were unchanged. As a control, glycogen synthesis was studied in HepG2 cells. In these cells, the basal rate of glycogen production was high, could not be stimulated by amino acids, nor be inhibited by sphingomyelinase. Regarding the mechanism responsible for the inhibition of glycogen synthase a, sphingomyelinase did not affect amino acid-induced, PtdIns 3-kinase-dependent, phosphorylation of p70S6 kinase, but caused an increase in intracellular chloride, which is known to inhibit glycogen synthase phosphatase. It is concluded that the decrease in cell volume, following the breakdown of sphingomyelin in the plasma membrane of the hepatocyte, may contribute to the abnormal metabolism of glucose when TNF-alpha levels are high.
Zhu J, etal., Mol Med Rep. 2016 Feb;13(2):1602-10. doi: 10.3892/mmr.2015.4739. Epub 2015 Dec 30.
Castration-resistant prostate cancer (CRPC) remains an obstacle in the current treatment provided for prostate cancer (PCa). Survivin, an apoptosis inhibitor, has been found to be involved in the progression of PCa, and is a promising candidate target for CRPC therapy. Micro (mi)RNAs are involved in
the progression of PCa through the regulation of multiple genes. One of the objectives of the present study was to investigate the effect of miRNA (miR)494 on the expression of survivin, as well as on PCa growth. The present study also aimed to assess whether co-transfecting miR494 with survivin short hairpin (sh)RNA has synergistic effects on suppressing PCa proliferation or the expression of survivin. Gene Expression Omnibus datasets with clinical PCa miRNA expression profiles were utilized to analysis the expression of miR494 in Ca, compared with normal prostate samples. PC3 cells, a CRPC cell line, were transfected with either an miR494 expression adenovirus, a survivin shRNA adenovirus or the two together, to examine their effect on PCa growth and the expression of survivin in vitro and in vivo. miR494 was downregulated in PCa tissue samples and in the PC3 cell line. miR494 targeted survivin at the translational level in PCa. Overexpression of miR494 and silencing survivin RNA through the use of survivin shRNA inhibited the expression of survivin and attenuated PC3 cell growth in vitro and in vivo. Notably, cotransfecting miR494 with survivin shRNA had synergistic effects on suppressing prostate cancer proliferation via further suppression of the expression of survivin. These results suggested that using multiple methods to inhibit the function of survivin may have improved efficacy for treating PCa.
Chen M, etal., Cancer Lett. 2016 Jun 28;376(1):155-64. doi: 10.1016/j.canlet.2016.03.037. Epub 2016 Mar 24.
Various studies have indicated that long non-coding RNAs (lncRNAs) play vital roles in the cancer development and progression. LncRNA hypoxia inducible factor 1alpha antisense RNA-2 (HIF1A-AS2) is upregulated in gastric carcinomas and knockdown of HIF1A-AS2 expression by siRNA could inhibit cell pr
oliferation in vitro and tumorigenesis in vivo. Inspired by these observations, we hypothesized that HIF1A-AS2 possibly plays the analogous roles in bladder cancer. In our study, we first reported that HIF1A-AS2 was up-regulated in bladder cancer tissues and cells, and HIF1A-AS2 expression level in bladder cancer tissues is positively associated with advanced clinical pathologic grade and TNM phase. Cell proliferation inhibition, cell migration suppression and apoptosis induction were observed by silencing HIF1A-AS2 in bladder cancer T24 and 5637 cells. Overexpression of HIF1A-AS2 in SV-HUC-1 cells could promote cell proliferation, cell migration and anti-apoptosis. Besides, we utilized the emerging technology of medical synthetic biology to design tetracycline-inducible small hairpin RNA (shRNA) vector which specifically silenced HIF1A-AS2 in a dosage-dependent manner to inhibit the progression of human bladder cancer. In conclusion, our data suggested that HIF1A-AS2 plays oncogenic roles and can be used as a therapeutic target for treating human bladder cancer. Synthetic "tetracycline-on" switch system that quantitatively controlled the expression of HIF1A-AS2 in bladder cancer can inhibit the progression of bladder cancer cells in a dosage-dependent manner. Our findings provide new insights into the role of the lncRNA HIF1A-AS2 in the bladder cancer.
Zhuang C, etal., Oncotarget. 2015 Dec 1;6(38):41194-203. doi: 10.18632/oncotarget.5880.
Recent studies show that long non-coding RNAs (lncRNAs) may be significant functional regulators in tumor development, including bladder cancer. Here, we found that PVT1 was upregulated in bladder cancer tissues and cells. Further experiments revealed that PVT1 promoted cell proliferation and suppre
ssed cell apoptosis. Furthermore we also used the emerging technology, synthetic biology, to create tetracycline-inducible small hairpin RNA (shRNA) vectors which silenced PVT1 in a dosage-dependent manner to inhibit the progression of bladder cancer. In conclusion, data suggest that PVT1 could be an oncogene and may be a therapeutic target in bladder cancer. Synthetic "tetracycline-on" switch system can be used to quantitatively control the expression of PVT1 in bladder cancer in response to different concentration of doxycycline to suppress the progression of bladder cancer.
Jia X, etal., Life Sci. 2012 Jun 14;90(23-24):934-43. doi: 10.1016/j.lfs.2012.04.029. Epub 2012 Apr 30.
AIMS: Eicosapentaenoic acid (EPA) can ameliorate certain liver lesions involved in non-alcoholic steatohepatitis (NASH). A previous study has found that stroke-prone spontaneously hypertensive 5/Dmcr (SHRSP5/Dmcr) rats fed a high fat-cholesterol (HFC) diet devel
oped fibrotic steatohepatitis with histological similarities to NASH. This study evaluated the potential effects and mechanisms of action of EPA supplementation using this rodent model. MAIN METHODS: Male rats were randomly assigned to groups that were fed with either the stroke-prone (SP) diet or HFC diet with or without EPA for 2, 8 and 14 weeks, respectively. The liver histopathology, biochemical features, mRNA and protein levels, and nuclear factor-kappaB (NF-kappaB) DNA binding activity were determined. KEY FINDINGS: The SP diet-fed rats presented normal livers. Conversely, the HFC diet-fed rats developed microvesicular/macrovesicular steatosis, inflammation, ballooning degeneration and severe fibrosis. At 2 weeks, the administration of EPA inhibited hepatic inflammatory recruitment by blocking the phosphorylation of inhibitor of kappaB-alpha (IkappaBalpha), which antagonizes the NF-kappaB activation pathway. The dietary supplementation of EPA for 8 weeks ameliorated hepatic triglyceride accumulation and macrovesicular steatosis by inhibiting the HFC diet-induced decrease in the protein levels of enzymes involved in fatty acid beta-oxidation including carnitine palmitoyltransferase 1, very long chain acyl-CoA dehydrogenase and peroxisomal bifunctional protein. Although the administration of EPA elicited no histologically detectable effects on severe fibrosis at 14 weeks, it restored an HFC diet-induced decline in hepatic adenosine triphosphate (ATP) levels and suppressed ballooning degeneration, suggesting that EPA may inhibit HFC diet-induced ATP loss and cell death. SIGNIFICANCE: Initial amelioration of the inflammation and steatosis in the rats after EPA supplementation indicates a possibility to treat steatohepatitis. Additionally, this study provides new insights into the roles of EPA in hepatic ATP depletion and subsequent hepatocellular injury during severe fibrosis.
Koletsky RJ, etal., Ann N Y Acad Sci. 2003 Dec;1009:251-61.
Hypertension is commonly accompanied by obesity, hyperlipidemia, and insulin resistance in humans, a cluster of abnormalities known as metabolic syndrome X. With the notable exception of inhibitors of the renin-angiotensin system, which have mildly beneficial effects on insulin resistance, most anti
hypertensive agents worsen one or more components of metabolic syndrome X. Second-generation centrally acting antihypertensive agents such as rilmenidine and moxonidine have mixed effects on components of metabolic syndrome X, which might reflect in part actions on two different receptors: I(1)-imidazoline and alpha(2)-adrenergic. Using a rat model of metabolic syndrome X, we sought to separate the influence of these two receptors on glucose and lipid metabolism by using selective antagonists. Rilmenidine and moxonidine acutely raised glucose and lowered insulin, thereby further worsening glucose tolerance. These effects were entirely mediated by alpha(2)-adrenergic receptors. Rilmenidine and moxonidine also lowered glucagon, an effect that was mediated solely by I(1)-imidazoline receptors since it was potentiated by alpha(2)-blockade, but eliminated in the presence of I(1)-antagonists. Lowering of triglyceride and cholesterol levels followed the same pattern as glucagon, implicating I(1)-imidazoline receptors in lipid-lowering actions. Chronic treatment with moxonidine reproduced the beneficial effects on glucagon and lipids while the acute hyperglycemic response did not persist. Thus, alpha(2)-adrenergic receptors mediate an acute deterioration of glucose tolerance, whereas in contrast I(1)-imidazoline receptors appear to mediate the persistent long-term improvements in glucose tolerance. The therapeutic action of I(1)-imidazoline agonists may be primarily mediated through reduced glucagon secretion.
BACKGROUND: Uterine leiomyomas (fibroids) are the most common pelvic tumors in women. We assessed the potential therapeutic utility of Ro 41-0960, a synthetic catechol-O-methyl transferase inhibitor (COMTI), in the Eker rat. METHODS: We randomized uterine fibroid-bearing Eker rats for treatment with
Ro 41-0960 (150 mg/kg/12 h) versus vehicle for 2 and 4 weeks. The fibroids were measured by caliper and subjected to histological evaluation. Urinary levels of 2-hydroxy estrogen (E(2)), 16-hydroxy E2 and DPD (osteoporosis marker) and serum liver enzymes were evaluated. Expressions of Cyclin D1, proliferating cell nuclear antigen (PCNA), Poly [ADP-ribose] polymerase1 (PARP1), tumor suppressor gene (P53) and transforming growth factor (TGFbeta3) were assessed in fibroids using immunohistochemical analysis or RT-PCR. Apoptosis was confirmed using terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL). RESULTS: Ro 41-0960-treated rats exhibited fibroid volumes of 86 +/- 7% and 105 +/- 12% of initial burden, at 2 and 4 weeks post-treatment, respectively, significantly lower than control group (240 +/- 15% and 300 +/- 18%; P< 0.01). Ro 41-0960 increased the urinary 2-hydroxy E2/16-hydroxy E(2) ratio, level of p53 mRNA and TUNEL positivity (P< 0.05) and decreased PARP1, PCNA and cyclin D1 proteins and TGFbeta3 mRNA (P< 0.05). Ro 41-0960 did not change normal tissue histology, liver functions or urinary DPD level. CONCLUSIONS: Ro 41-0960 (COMTI) arrested growth/shrunk uterine fibroids in Eker rats. This result may be related to modulation of estrogen-dependent genes involved in apoptosis, proliferation and extracellular matrix deposition via accumulation of 2-hydroxy estrogen. The efficacy and safety of Ro 41-0960 in rats suggest its candidacy for treatment of uterine fibroids.
Rat models of hypertension, eg, spontaneously hypertensive stroke-prone rats (SHRSP), display reduced angiotensin-converting enzyme 2 (ACE2) mRNA and protein expression compared with control animals. The aim of this study was to investigate the role of ACE2 in t
he pathogenesis of hypertension in these models. Therefore, we generated transgenic rats on a SHRSP genetic background expressing the human ACE2 in vascular smooth muscle cells by the use of the SM22 promoter, called SHRSP-ACE2. In these transgenic rats vascular smooth muscle expression of human ACE2 was confirmed by RNase protection, real-time RT-PCR, and ACE2 activity assays. Transgene expression leads to significantly increased circulating levels of angiotensin-(1-7), a prominent product of ACE2. Mean arterial blood pressure was reduced in SHRSP-ACE2 compared to SHRSP rats, and the vasoconstrictive response to intraarterial administration of angiotensin II was attenuated. The latter effect was abolished by previous administration of an ACE2 inhibitor. To evaluate the endothelial function in vivo, endothelium-dependent and endothelium-independent agents such as acetylcholine and sodium nitroprusside, respectively, were applied to the descending thoracic aorta and blood pressure was monitored. Endothelial function turned out to be significantly improved in SHRSP-ACE2 rats compared to SHRSP. These data demonstrate that vascular ACE2 overexpression in SHRSP reduces hypertension probably by locally degrading angiotensin II and improving endothelial function. Thus, activation of the ACE2/angiotensin-(1-7) axis may be a novel therapeutic strategy in hypertension.
Gene therapy has great potential for human diseases. Development of efficient delivery systems is critical to its clinical translation. Recent studies have shown that microbubbles in combination with ultrasound (US) can be used to facilitate gene delivery. An aim of this study is to investigate whet
her the combination of US-targeted microbubble destruction (UTMD) and polyethylenimine (PEI) (UTMD/PEI) can mediate even greater gene transfection efficiency than UTMD alone and to optimize ultrasonic irradiation parameters. Another aim of this study is to investigate the biological effects of PHD2-shRNA after its transfection into H9C2 cells. pEGFP-N1 or eukaryotic shPHD2-EGFP plasmid was mixed with albumin-coated microbubbles and PEI to form complexes for transfection. After these were added into H9C2 cells, the cells were exposed to US with various sets of parameters. The cells were then harvested and analyzed for gene expression. UTMD/PEI was shown to be highly efficient in gene transfection. An US intensity of 1.5 W/cm2, a microbubble concentration of 300mul/ml, an exposure time of 45s, and a plasmid concentration of 15mug/ml were found to be optimal for transfection. UTMD/PEI-mediated PHD2-shRNA transfection in H9C2 cells significantly down regulated the expression of PHD2 and increased expression of HIF-1alpha and downstream angiogenesis factors VEGF, TGF-beta and bFGF. UTMD/PEI, combined with albumin-coated microbubbles, warrants further investigation for therapeutic gene delivery.
Cohen A, etal., PLoS One. 2014 May 9;9(5):e97216. doi: 10.1371/journal.pone.0097216. eCollection 2014.
Dynorphins, endogenous opioid peptides that arise from the precursor protein prodynorphin (Pdyn), are hypothesized to be involved in the regulation of mood states and the neuroplasticity associated with addiction. The current study tested the hypothesis that dynorphin in the nucleus accumbens (NAcc)
mediates such effects. More specifically, we examined whether knockdown of Pdyn within the NAcc in rats would alter the expression of depressive-like and anxiety-like behavior, as well as cocaine locomotor sensitization. Wistar rats were injected with adeno-associated viral (AAV) vectors encoding either a Pdyn-specific short hairpin RNA (AAV-shPdyn) or a scrambled shRNA (AAV-shScr) as control. Four weeks later, rats were tested for anxiety-like behavior in the elevated plus maze test and depressive-like behavior in the forced swim test (FST). Finally, rats received one daily injection of saline or cocaine (20 mg/kg, i.p.), followed by assessment of locomotion for 4 consecutive days. Following 3 days of abstinence, the rats completed 2 additional daily cocaine/saline locomotor trials. Pdyn knockdown in the NAcc led to a significant reduction in depressive-like behavior in the FST, but had no effect on anxiety-like behavior in the elevated plus maze. Pdyn knockdown did not alter baseline locomotor behavior, the locomotor response to acute cocaine, or the initial sensitization of the locomotor response to cocaine over the first 4 cocaine treatment days. However, following 3 days abstinence the locomotor response to the cocaine challenge returned to their original levels in the AAV-shPdyn rats while remaining heightened in the AAV-shScr rats. These results suggest that dynorphin in a very specific area of the nucleus accumbens contributes to depressive-like states and may be involved in neuroadaptations in the NAcc that contribute to the development of cocaine addiction as a persistent and lasting condition.