Farsad K, etal., J Cell Biol. 2001 Oct 15;155(2):193-200. doi: 10.1083/jcb.200107075. Epub 2001 Oct 15.
Endophilin 1 is a presynaptically enriched protein which binds the GTPase dynamin and the polyphosphoinositide phosphatase synptojanin. Perturbation of endophilin function in cell-free systems and in a living synapse has implicated endophilin in endocytic vesicle budding (Ringstad, N., H. Gad, P. Lo
w, G. Di Paolo, L. Brodin, O. Shupliakov, and P. De Camilli. 1999. Neuron. 24:143-154; Schmidt, A., M. Wolde, C. Thiele, W. Fest, H. Kratzin, A.V. Podtelejnikov, W. Witke, W.B. Huttner, and H.D. Soling. 1999. Nature. 401:133-141; Gad, H., N. Ringstad, P. Low, O. Kjaerulff, J. Gustafsson, M. Wenk, G. Di Paolo, Y. Nemoto, J. Crun, M.H. Ellisman, et al. 2000. Neuron. 27:301-312). Here, we show that purified endophilin can directly bind and evaginate lipid bilayers into narrow tubules similar in diameter to the neck of a clathrin-coated bud, providing new insight into the mechanisms through which endophilin may participate in membrane deformation and vesicle budding. This property of endophilin is independent of its putative lysophosphatydic acid acyl transferase activity, is mediated by its NH2-terminal region, and requires an amino acid stretch homologous to a corresponding region in amphiphysin, a protein previously shown to have similar effects on lipid bilayers (Takei, K., V.I. Slepnev, V. Haucke, and P. De Camilli. 1999. Nat. Cell Biol. 1:33-39). Endophilin cooligomerizes with dynamin rings on lipid tubules and inhibits dynamin's GTP-dependent vesiculating activity. Endophilin B, a protein with homology to endophilin 1, partially localizes to the Golgi complex and also deforms lipid bilayers into tubules, underscoring a potential role of endophilin family members in diverse tubulovesicular membrane-trafficking events in the cell.
Hojjat-Farsangi M, etal., PLoS One. 2015 Nov 12;10(11):e0142310. doi: 10.1371/journal.pone.0142310. eCollection 2015.
BACKGROUND: ROR1 is a receptor tyrosine kinase expressed in chronic lymphocytic leukemia (CLL) and several other malignancies but absent in most adult normal tissues. ROR1 is considered an onco-fetal antigen. In the present study we analysed spontaneous humoral and cellular immunity against ROR1 in
CLL patients. MATERIALS AND METHODS: Antibodies against ROR1 were analysed in 23 patients and 20 healthy donors by ELISA and Western blot. Purified serum IgG from patients was tested for cytotoxicity against CLL cells using the MTT viability assay. A cellular immune response against ROR1 derived HLA-A2 restricted 9 aa and 16 aa long peptides were analysed using peptide loaded dendritic cells co-cultured with autologous T cells from CLL patients (n = 9) and healthy donors (n = 6). IFN-gamma, IL-5 and IL-17A-secreting T cells were assessed by ELISPOT and a proliferative response using a H3-thymidine incorporation assay. RESULTS: The majority of CLL patients had antibodies against ROR1. Significantly higher titers of anti-ROR1 antibodies were noted in patients with non-progressive as compared to progressive disease. The extracellular membrane-close ROR1 KNG domain seemed to be an immunodominant epitope. Ten patients with high titers of anti-ROR1 binding antibodies were tested for cytotoxicity. Five of those had cytotoxic anti-ROR1 antibodies against CLL cells. ROR1-specific IFN-gamma and IL-17A producing T cells could be detected in CLL patients, preferentially in non-progressive as compared to patients with progressive disease (p<0.05). CONCLUSION: ROR1 seemed to spontaneously induce a humoral as well as a T cell response in CLL patients. The data support the notion that ROR1 might be a specific neo-antigen and may serve as a target for immunotherapy.
The most prominent feature of systemic sclerosis (SSc) and other diseases associated with fibrosis is the prolonged activation of fibroblasts not eliminated by apoptosis, hence characterized by accumulation of more extra cellular matrix (ECM). We tend to verify if microRNA-29a (miR-29a) as an anti-f
ibrotic factor could induce apoptosis in SSc fibroblasts. We did not detect apoptosis in SSc fibroblasts. We found that Bcl-2 expression was upregulated in SSc fibroblasts and the ratio of Bax:Bcl-2 in these cells was significantly lower (p = 0.02) compared to normal fibroblasts. Transfection of both SSc and transforming growth factor-beta (TGF-beta) stimulated fibroblasts by miR-29a mimic, significantly decreased the expression of two anti-apoptotic members of the Bcl-2 family, Bcl-2 (p = 0.0005, p = 0.01) and Bcl-XL (p = 0.0001, p = 0.006), resulted in enhanced Bax:Bcl-2 ratio and induced a high rate of apoptosis. Recently, miR-29 has been introduced as an anti-fibrotic factor with potential therapeutic effect on SSc. Until now, it has not been proposed whether there is a relationship between miR-29a and apoptosis in SSc. According to our results, it seems that miR-29a is a potent inducer of apoptosis in SSc fibroblasts and an attenuator of ECM production in these cells. MiR-29a disrupted the expression profiling of Bcl-2 family proteins (Bax, Bcl-2 and Bcl-XL) which is the central point of dynamic life-death rheostat in many apoptotic pathways. Furthermore, dermal fibroblasts from patients with SSc showed elevation in TNF-alpha mRNA levels, while restoration of miR-29a decreases TNF-alpha production in these cells. Although further molecular studies are necessary to investigate the underlying apoptotic pathways, the present findings suggest that anti-fibrotic and pro-apoptotic properties of miR-29a could provide novel benefits toward the development of fibroblast-specific anti-fibrotic therapies.
Elevated levels of homocysteine is a risk factor for coronary artery disease. The C677T transition in methylenetetrahydrofolate reductase (MTHFR) is associated with increased homocysteine levels in the general population. We analysed the association between the MTHFR C677T polymorphism and serum hom
ocysteine concentrations in patients with coronary artery disease (CAD). Allele frequencies for the 'C' (wild-type) and 'T' alleles were 0.71 and 0.29 in CAD patients and 0.70 and 0.30 in controls, respectively. There was no difference in the distribution of MTHFR genotypes between patients with CAD and control subjects (p > 0.05). In the patient group, homocysteine levels were higher than controls but not significantly (13.99 +/- 7.44 vs. 11.77 +/- 5.18 micromol l(-1); p > 0.05). Serum homocysteine concentration was significantly higher in the TT genotype with respect to CC and CT genotypes in both the control group (p < 0.01) and patient group (p < 0.01). Systolic and diastolic blood pressures in subjects with different MTHFR genotypes did not differ significantly. In conclusion, MTHFR C677T mutation was significantly related to hyperhomocysteinemia. In spite of the clear effect of the MTHFR polymorphism on elevated homocysteine levels, we did not observe any associations among the MTHFR genotypes with a the risk of CAD in the Turkish population.
Moghbelinejad S, etal., Toxicol Lett. 2014 Jan 3;224(1):108-13. doi: 10.1016/j.toxlet.2013.10.010. Epub 2013 Oct 20.
Flavonoids are present in foods such as fruits and vegetables. A relationship between the consumption of flavonoid-rich foods and prevention of human disease including neurodegenerative disorders has been demonstrated. We assessed the effect of rutin (3,3',4',5,7-pentahydroxyflavone-3-rhamnoglucosid
e) on the mitogen-activated protein kinase (MAPK) pathway, memory retrieval and oxidative stress in rats injected with beta-amyloid (Abeta), which is implicated to have an important role in Alzheimer's disease (AD). Abeta was injected bilaterally in the deep frontal cortex of rat brain. Next, rutin and saline were injected (i.p.) for 3 weeks. In comparison to the control group, rutin significantly increased extracellular signal-regulated protein kinase 1 (ERK1), cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) gene expression in the hippocampus of rats. Rutin (100 mg/kg) significantly increased memory retrieval compared to the control group. Malondialdehyde (MDA) level in the hippocampus of the rutin group was significantly lower than those in the control group. The content of sulfhydryl groups in the rutin group was higher than that in the control group. The findings show a possibility that rutin may have beneficial effects against neurotoxicity of Abeta on memory in rats.
Congenital myasthenic syndromes are a heterogeneous group of inherited disorders that arise from impaired signal transmission at the neuromuscular synapse. They are characterized by fatigable muscle weakness. We performed linkage analysis, whole-exome and whole-genome sequencing to determine the und
erlying defect in patients with an inherited limb-girdle pattern of myasthenic weakness. We identify ALG14 and ALG2 as novel genes in which mutations cause a congenital myasthenic syndrome. Through analogy with yeast, ALG14 is thought to form a multiglycosyltransferase complex with ALG13 and DPAGT1 that catalyses the first two committed steps of asparagine-linked protein glycosylation. We show that ALG14 is concentrated at the muscle motor endplates and small interfering RNA silencing of ALG14 results in reduced cell-surface expression of muscle acetylcholine receptor expressed in human embryonic kidney 293 cells. ALG2 is an alpha-1,3-mannosyltransferase that also catalyses early steps in the asparagine-linked glycosylation pathway. Mutations were identified in two kinships, with mutation ALG2p.Val68Gly found to severely reduce ALG2 expression both in patient muscle, and in cell cultures. Identification of DPAGT1, ALG14 and ALG2 mutations as a cause of congenital myasthenic syndrome underscores the importance of asparagine-linked protein glycosylation for proper functioning of the neuromuscular junction. These syndromes form part of the wider spectrum of congenital disorders of glycosylation caused by impaired asparagine-linked glycosylation. It is likely that further genes encoding components of this pathway will be associated with congenital myasthenic syndromes or impaired neuromuscular transmission as part of a more severe multisystem disorder. Our findings suggest that treatment with cholinesterase inhibitors may improve muscle function in many of the congenital disorders of glycosylation.
Hicks D, etal., Hum Mol Genet. 2014 May 1;23(9):2353-63. doi: 10.1093/hmg/ddt637. Epub 2013 Dec 13.
Bethlem myopathy (BM) [MIM 158810] is a slowly progressive muscle disease characterized by contractures and proximal weakness, which can be caused by mutations in one of the collagen VI genes (COL6A1, COL6A2 and COL6A3). However, there may be additional causal genes to identify as in ∼50% of BM case
s no mutations in the COL6 genes are identified. In a cohort of -24 patients with a BM-like phenotype, we first sequenced 12 candidate genes based on their function, including genes for known binding partners of collagen VI, and those enzymes involved in its correct post-translational modification, assembly and secretion. Proceeding to whole-exome sequencing (WES), we identified mutations in the COL12A1 gene, a member of the FACIT collagens (fibril-associated collagens with interrupted triple helices) in five individuals from two families. Both families showed dominant inheritance with a clinical phenotype resembling classical BM. Family 1 had a single-base substitution that led to the replacement of one glycine residue in the triple-helical domain, breaking the Gly-X-Y repeating pattern, and Family 2 had a missense mutation, which created a mutant protein with an unpaired cysteine residue. Abnormality at the protein level was confirmed in both families by the intracellular retention of collagen XII in patient dermal fibroblasts. The mutation in Family 2 leads to the up-regulation of genes associated with the unfolded protein response (UPR) pathway and swollen, dysmorphic rough-ER. We conclude that the spectrum of causative genes in extracellular matrix (ECM)-related myopathies be extended to include COL12A1.
Ahmadi A, etal., Drug Res (Stuttg). 2013 Dec;63(12):614-9. doi: 10.1055/s-0033-1349128. Epub 2013 Jul 4.
In this study, new glibenclamide analogues (5a-d) with substituted pharmacological triethoxysilyl propan, allyl and ethoxyphenyl groups for cyclohexyl moiety have been synthesized by condensing sulfonamide (4) with related isocyanate or isothiocyanate's compounds. The newly synthesized drugs were ev
aluated for their antihyperglycemic and antihyperlipidemic activities with streptozotocin (STZ)-induced diabetic rats. All showed hypoglycemic and hypolipidemic activities compared to the control animals but 5c and 5d exhibited more and significant lowering blood activities similar to glibenclamide. This was concerned with identical affinities to bind with SUR1 receptor. Moreover, the new drugs displayed high efficiency for reducing serum LDL level which resulted in a high HDL/LDL ratio as a good lipid profile compared to other groups.
Maalhagh M, etal., Glob J Health Sci. 2015 Sep 28;8(6):41-6. doi: 10.5539/gjhs.v8n6p41.
Tumor necrosis factor (TNF) is one of the inflammatory cytokines which has an important role in inflammation and migration of other inflammatory cells to the atherosclerotic plaques. OX40 is a member of the TNF super family receptor protein. OX40 and OX40 ligand are co-stimulators for T-cells and ca
n increase inflammatory response in atherosclerotic plaques. The aim of this study was to determine the association of rs17568 polymorphism in OX40 gene with premature myocardial infarction. This case control study was done on 100 patients with premature acute myocardial infarction (AMI) and a similar number of sex, age and some other cardiovascular risk factor matched healthy people. The OX40 rs17568 polymorphism was genotyped, using PCR-RFLP method. A-allele frequency of rs17568 SNP was lower non-significantly in Premature AMI, compared to healthy subjects (49% vs. 51%). The analysis of rs17568 (A/G) polymorphism showed an odds ratio of 1.127 (95% CI: 0.635-1.999; P= 0.686) for the GG genotype and 5.761 (95% CI: 1.200-27.655; P= 0.029) for the AG genotype, compared to the AA genotype. The results of this study indicate that the rs17568 SNP of OX40 gene is not associated with premature AMI in the evaluated population.
Pathogenic variants in genes encoding aminoacyl-tRNA synthetases cause numerous disorders characterized by involvement of neurons, muscles, lungs and liver. Recently, biallelic FARSB defects have been shown to cause severe growth restriction with combined brain, liver and lung involvement (Rajab int
erstitial lung disease [ILD] with brain calcifications). Herein, for the first time, we present a patient with similar condition associated with biallelic mutations in FARSA (NM_004461.3: c.766T>C:p.Phe256Leu and c.1230C>A:p.Asn410Lys). Both detected FARSA variants are ultrarare and predicted to be damaging by in silico programs. Furthermore, they are both located in the active site of phenylalanyl-tRNA synthetase (PheRS) with Asn410Lys directly affecting a residue forming the wall of the phenylalanine-binding pocket. Clinical features shared between our patient and the FARSB syndrome include ILD with cholesterol pneumonitis, growth delay, hypotonia, brain calcifications with cysts and liver dysfunction. Our findings indicate that a disease similar to a syndrome associated with FARSB defects can also be caused by biallelic FARSA mutations. These findings are consistent with molecular structure of PheRS which is a tetramer including both FARSA and FARSB proteins.
