Chermesh I, etal., Dig Dis Sci. 2007 Jul;52(7):1632-5. Epub 2007 Mar 24.
Crohn's disease (CD) is a chronic multifactorial inflammatory disease. The prevalence of CD in Ashkenazi Jews is higher than in Sephardic Jews. SLC11A1, also known as Nramp1, is a divalent cation antiporter essential for the elimination of intraphagosomal pathog
ens. SLC11A1 has seven alleles in the promoter region and previous studies have suggested an association between CD and SLC11A1. The aim of this study was to check for a possible association between SLC11A1 promoter alleles and CD in Ashkenazi Jewish patients. DNA samples from healthy Ashkenazi donors and Ashkenazi CD patients were obtained and analyzed for SLC11A1 promoter polymorphism by PCR and DNA sequencing. One hundred thirty-one samples from healthy donors and 131 samples from CD patients were analyzed. Four alleles were identified: approximately 70% of the samples carried allele 3; approximately 30%, allele 2; approximately 1%, allele 1; and <1%, allele 5. There was no difference in allele frequencies between healthy donors and CD patients. No correlation was found between mutations in NOD2/CARD15 and the phenotype of CD. We conclude that the difference in SLC11A1 promoter polymorphism plays no role in CD in Ashkenazi Jews.
Crawford NP, etal., BMC Med Genet. 2005 Mar 9;6:10.
BACKGROUND: Significant evidence suggests that a promoter polymorphism within the gene SLC11A1 is involved in susceptibility to both autoimmune and infectious disorders. The aim of this study was to evaluate whether SLC11A1
has a role in the susceptibility to inflammatory bowel disease (IBD) by characterizing a promoter polymorphism within the gene and two short tandem repeat (STR) markers in genetic proximity to SLC11A1. METHODS: The studied population consisted of 484 Caucasians with IBD, 144 population controls, and 348 non-IBD-affected first-degree relatives of IBD patients. IBD subjects were re-categorized at the sub-disease phenotypic level to characterize possible SLC11A1 genotype-phenotype correlations. Polymorphic markers were amplified from germline DNA and typed using gel electrophoresis. Genotype-phenotype correlations were defined using case-control, haplotype, and family-based association studies. RESULTS: This study did not provide compelling evidence for SLC11A1 disease association; most significantly, there was no apparent evidence of SLC11A1 promoter allele association in the studied Crohn's disease population. CONCLUSION: Our results therefore refute previous studies that have shown SLC11A1 promoter polymorphisms are involved in susceptibility to this form of IBD.
Multiple genetic studies in humans indicate a role for solute carrier family 11a member 1 [SLC11A1; formerly natural resistance-associated macrophage protein 1 (NRAMP1)] in autoimmune disease susceptibility, including ulcerative colitis. Murine Slc11a1
-weight:700;'>Slc11a1 has many pleiotropic effects on macrophage activation and proinflammatory responses. To determine which of these are important in ulcerative colitis, we established a phenotype for oral dextran sulfate sodium (DSS)-induced acute colitis in congenic Slc11a1 wild-type (wt) and mutant (mt) mice on a B10 background. For over 7 days of treatment with 2% DSS in the drinking water, Slc11a1 wt mice showed enhanced acute ulcerative colitis, as demonstrated by significantly greater body weight loss and reduction in colon length, as well as a marked increase in monocyte/macrophage inflammatory infiltrates and histopathology changes in the colon. This was accompanied by a clear, inverse relationship between IFN-gamma and IL-10 responses in Slc11a1 wt compared with mt mice, resulting in a significantly higher ratio of IFN-gamma:IL-10 in wt compared with mt mice in lymph node and splenic T cells. RNase protection assays confirmed the presence of significantly higher IFN-gamma at the RNA level in the colons of wt compared with mt mice at Day 7 of treatment. Interestingly this was accompanied by significantly enhanced RNA levels for the acute-phase protein IL-6, which is known to inhibit the generation of forkhead box P3+ regulatory T cells and help to drive the differentiation of Th17 from naive T cells and not by differences in RNA for IL-12p35 or IL-12p40 molecules that dimerize to form the Th1-inducing cytokine IL-12.
BACKGROUND: Linkage and congenic strain analyses using the nonobese diabetic (NOD) mouse as a model for human type 1 autoimmune diabetes (T1D) have identified several NOD mouse Idd (insulin dependent diabetes) loci, including Slc11a1 (formerly known as Nramp1).
Genetic variants in the orthologous region encompassing SLC11A1 in human chromosome 2q35 have been reported to be associated with various immune-related diseases including T1D. Here, we have conducted association analysis of this candidate gene region, and then investigated potential correlations between the most T1D-associated variant and RNA expression of the SLC11A1 gene and its splice isoform. METHODS: Nine SNPs (rs2276631, rs2279015, rs1809231, rs1059823, rs17235409 (D543N), rs17235416 (3'UTR), rs3731865 (INT4), rs7573065 (-237 C --> T) and rs4674297) were genotyped using TaqMan genotyping assays and the polymorphic promoter microsatellite (GT)n was genotyped using PCR and fragment length analysis. A maximum of 8,863 T1D British cases and 10,841 British controls, all of white European descent, were used to test association using logistic regression. A maximum of 5,696 T1D families were also tested for association using the transmission/disequilibrium test (TDT). We considered P SLC11A1 expression overall or with splice isoform ratio using 42 PAXgene whole blood samples from healthy donors by quantitative PCR (qPCR). RESULTS: Using the case-control collection, rs3731865 (INT4) was identified to be the variant most associated with T1D (P = 1.55 x 10-6). There was also some evidence of association at rs4674297 (P = 1.57 x 10-4). No evidence of disease association was obtained at any of the loci using the family collections (PTDT >/= 0.13). We also did not observe a correlation between rs3731865 genotypes and SLC11A1 expression overall or with splice isoform expression. CONCLUSION: We conclude that rs3731685 (INT4) in the SLC11A1 gene may be associated with T1D susceptibility in the European ancestry population studied. We did not observe a difference in SLC11A1 expression at the RNA level based on the genotypes of rs3731865 in whole blood samples. However, a potential correlation cannot be ruled out in purified cell subsets especially monocytes or macrophages.
Comabella M, etal., Mult Scler. 2004 Dec;10(6):618-20.
Solute carrier 11a1 (SLC11A1; formerly NRAMP1, where NRAMP stands for natural resistance-associated macrophage protein) is a proton/bivalent cation antiporter that localizes to late endosomes/lysosomes. SLC11A1 regulates mac
rophage functions that are of potential importance in the induction and/or maintenance of autoimmune diseases such as rheumatoid arthritis, type I diabetes and Crohn's disease. We investigated SLC11A1 gene as a candidate gene for genetic susceptibility to multiple sclerosis (MS) in our population. Four SLC11A1 gene polymorphisms (5'GT repeat, D543N, 1729 + 55del4 and 1729 + 271del4) were analysed in a case-control study of 195 patients with MS and 125 control subjects. We found no evidence of association between SLC11A1 polymorphisms and MS susceptibility in the Spanish population.
Romero-Gomez M, etal., Gut. 2004 Mar;53(3):446-50.
BACKGROUND AND AIMS: The solute carrier family 11 member 1 (SLC11A1) gene (formerly Nramp1) encodes for the protein solute carrier family 11, member 1. It affects susceptibility and clinical outcome of autoimmune and infectious diseases. We investigated the poss
ible role of the functional polymorphism located in the promoter region of SLC11A1 and tumour necrosis factor (TNF) genes in the progression of fibrosis in chronic hepatitis C. METHODS: A total of 242 Caucasian Spanish patients with biopsy proven chronic hepatitis C and 194 healthy control subjects were genotyped for SLC11A1 and TNF promoter polymorphisms. RESULTS: No significant differences in the distribution of frequencies among patient and control groups were observed. The SCL11A1 homozygous 2/2 genotype was rarely detected among patients showing advanced fibrosis (2/82; 2.4%) but was highly represented in those with mild fibrosis (29/160; 18.1%; odds ratio (OR) 8.85 (95% confidence interval (CI) 1.9-55.2, p(c) = 0.002). In patients carrying allele 3 of SLC11A1, the presence of -238 TNF A/G was associated with advanced fibrosis (14/26 (53.8%) v 68/216 (31.4%); OR 2.53 (95% CI 1.03-6.23); p = 0.02). CONCLUSIONS: SLC11A1 gene promoter polymorphism could influence fibrosis progression in chronic hepatitis C in that the homozygous genotype 2/2 exerts a protective effect against cirrhosis development. Also, the combination of TNF -238 A/G and the presence of allele 3 is conducive to progression to pre-cirrhotic or cirrhotic stages of the disease.
Genes controlling antibacterial resistance may be important in the hygiene hypothesis, which states that lack of bacterial infections during childhood would favor development of allergic disease. We, therefore, studied whether Nramp1 (Slc11a1) alleles, which det
ermine susceptibility (Nramp1(s)) or resistance (Nramp1(r)) to intracellular bacteria, affect the efficacy of heat-killed Mycobacterium vaccae in the treatment of allergic asthma in a mouse model. Treatment of OVA-sensitized Nramp1(s) mice with M. vaccae suppressed airway hyperresponsiveness, airway eosinophilia, Ag-specific IgE, and IL-4 and IL-5 production after OVA aerosol challenge. In contrast, M. vaccae hardly affected these parameters in Nramp1(r) mice. In addition, The Nramp1 gene affected both T cell-mediated responses to M. vaccae in vivo and the level of macrophage activation after stimulation with M. vaccae in vitro. In conclusion, the efficacy of M. vaccae in preventing allergic and asthmatic manifestations in a mouse model is strongly affected by Nramp1 alleles. These findings could have important implications for the future use of mycobacteria and their components in the prevention or treatment of allergic asthma. A new link is described between genes, the environment, and the development of allergy, in which the Nramp1 gene fine tunes the hygiene hypothesis.
Sarcoidosis (SA) is an immune-mediated multisystemic disorder of unknown etiology characterized by the accumulation of lymphocytes, mononuclear phagocytes and epithelioid cell granulomas involved in different organs and tissues. The belief that genetics contribute to SA etiology is supported by twin
studies, disease clustering in families and racial differences in incidence rates. Involvements of SLC11A1 in macrophage function and activation, makes it an attractive candidate gene for immune-mediated and infectious diseases. We investigated the association between SA and four polymorphisms of the SLC11A1 gene, including a single nucleotide change in intron 4 (INT4); a nonconservative single-base substitution at codon 543 (D543N); a TGTG deletion in the 3' untranslated region; and the functional (GT)(n) repeat polymorphism in the 5' region, in 95 Turkish SA patients and 150 healthy controls, by using amplification refractory mutation system-polymerase chain reaction and sequencing. We found significant association between SA and INT4 G/C allele frequency (P = 0.0000; odds ratio 2.75; 95% confidence interval 1.68-4.52) and 5'(GT)(n) allele 2/3 frequency (P = 0.0000; odds ratio 2.69; 95% confidence interval 1.61-4.47) suggesting that SLC11A1 might be a plausible candidate gene for SA.
Velez DR, etal., Int J Tuberc Lung Dis. 2009 Sep;13(9):1068-76.
SETTING: Host defense factors may influence the development of active tuberculosis (TB). OBJECTIVE: To test variants in solute carrier family 11A, member 1 (SLC11A1), for an association with TB. METHODS: A mixed case-control study of TB cases, relatives or close
contact controls, consisting of 474 African-Americans (243 families) and 381 Caucasians (192 families), examined 13 SLC11A1 polymorphisms for association with pulmonary TB using generalized estimating equations adjusting for age and sex. RESULTS: Two associations were observed in Caucasians (rs3731863, P = 0.03, and rs17221959, P = 0.04) and one in African-Americans (rs3731865, P = 0.05). Multilocus analyses between polymorphisms in SLC11A1 and 11 TB candidate genes detected interactions between SLC11A1 and inducible nitric oxide synthase (NOS2A) in Caucasians (rs3731863 [SLC11A1] x rs8073782 [NOS2A], P = 0.009; rs3731863 [SLC11A1] x rs17722851 [NOS2A], P = 0.007) and toll-like receptor 2 (TLR2) in African-Americans (rs3731865 [SLC11A1] x rs1816702, P = 0.005). CONCLUSIONS: No association was detected with 5'(GT)(n) promoter polymorphism previously associated with lower SLC11A1 expression, rs17235409 (D543N), or rs17235416 (3' TGTG insertion/deletion polymorphism). SLC11A1 polymorphism rs3731865 was associated with TB in African-Americans, consistent with previous findings in West Africans. These results suggest that variants in SLC11A1 increase susceptibility to pulmonary TB and interact with other variants that differ by race.
Castellucci L, etal., BMC Med Genet. 2010 Jan 20;11:10.
BACKGROUND: L. braziliensis causes cutaneous (CL) and mucosal (ML) leishmaniasis. Wound healing neutrophil (PMN) and macrophage responses made following the bite of the vector sand fly contribute to disease progression in mice. To look at the interplay between PMN and macrophages in disease progress
ion in humans we asked whether polymorphisms at genes that regulate their infiltration or function are associated with different clinical phenotypes. Specifically, CXCR1 (IL8RA) and CXCR2 (IL8RB) are receptors for chemokines that attract PMN to inflammatory sites. They lie 30-260 kb upstream of SLC11A1, a gene known primarily for its role in regulating macrophage activation, resistance to leishmaniasis, and wound healing responses in mice, but also known to be expressed in PMN, macrophages and dendritic cells. METHODS: Polymorphic variants at CXCR1, CXCR2 and SLC11A1 were analysed using Taqman or ABI fragment separation technologies in cases (60 CL; 60 ML), unrelated controls (n = 120), and multicase families (104 nuclear families; 88 ML, 250 CL cases) from Brazil. Logistic regression analysis, family-based association testing (FBAT) and haplotype analysis (TRANSMIT) were performed. RESULTS: Case-control analysis showed association between the common C allele (OR 2.38; 95% CI 1.23-4.57; P = 0.009) of CXCR1_rs2854386 and CL, supported by family-based (FBAT; Z score 2.002; P = 0.045) analysis (104 nuclear families; 88 ML, 250 CL cases). ML associated with the rarer G allele (Z score 1.999; P = 0.046). CL associated with a 3' insertion/deletion polymorphism at SLC11A1 (Z score 2.549; P = 0.011). CONCLUSIONS: The study supports roles for CXCR1 and SLC11A1 in the outcome of L. braziliensis infection in humans. Slc11a1 does not influence cutaneous lesion development following needle injection of Leishmania in mice, suggesting that its role here might relate to the action of PMN, macrophage and/or dendritic cells in the wound healing response to the sand fly bite. Together with the CXCR1 association, the data are consistent with hypotheses relating to the possible role of PMN in initiation of a lesion following the delivery of parasites via the sand fly bite. Association of ML with the rare derived G allele suggests that PMN also have an important positive role to play in preventing this form of the disease.
Nishino M, etal., Metabolism. 2005 May;54(5):628-33.
The association of the polymorphism of the Z-DNA-forming repeats in the promoter region of SLC11A1 (solute carrier family 11 member 1), formerly designated NRAMP1 (natural resistance associated macrophage protein 1), with type 1 diabetes was studied in a total o
f 244 Japanese subjects. Three alleles were detected in Japanese subjects. In diabetic patients, allele 2 was less frequent and allele 3 was more frequent, albeit not significantly, than in control subjects. Allele 2 was significantly ( P < .024) less frequent whereas allele 3 was more, albeit not significantly, frequent in the younger onset group than in the control subjects. In patients with a susceptible HLA allele, DRB1*0405 or DRB1*0901 , the frequency of allele 2 was significantly ( P < .013) lower and that of allele 3 tended to be higher than that in patients without either DRB1*0405 or DRB1*0901 . The protective effect of allele 2 against type 1 diabetes and other autoimmune diseases was confirmed by meta-analysis (summary odds ratio, 0.71, 95% confidence interval, 0.53-0.96). Because allele 2 was shown to be associated with low expression of SLC11A1 and protection against another autoimmune disease, rheumatoid arthritis, the negative association of allele 2 with autoimmune type 1 diabetes in the present study suggests that a less active immune system in subjects with allele 2 may protect individuals from autoimmune diseases.
Two lines of mice selected to produce maximal (AIRmax) or minimal (AIRmin) acute inflammatory reactions (AIR) differ in their susceptibility to infection by Salmonella enterica serotype Typhimurium (S. Typhimurium). The LD(50) for AIRmax mice is 1000 times higher than that observed for AIRmin mice,
and higher frequencies of Slc11a1 alleles (known to confer either resistance (R) or high susceptibility (S) to S. Typhimurium) were consistently found in AIRmax and AIRmin mouse lines, respectively. In order to evaluate the effect of the quantitative trait loci (QTL) segregated in AIRmax and AIRmin mice on Slc11a1 dependent susceptibility to S. Typhimurium, the R and S alleles were fixed in homozygosity in AIRmax and AIRmin backgrounds by genotype assisted breedings. These new lines were named AIRmax(RR), AIRmax(SS), AIRmin(RR), and AIRmin(SS). Acute inflammation of Slc11a1(RR) animals was more severe in comparison to their Slc11a1(SS) counterparts, implicating Slc11a1 (or other linked genes) in AIR regulation. The LD(50) of S. Typhimurium was 800-times higher for AIRmax(SS) than for AIRmin(SS), demonstrating that AIR QTL can act as modifiers of the Slc11a1(SS) susceptibility gene. Four microsatellite markers for S. Typhimurium susceptibility QTL described in other mouse lines showed specific allele fixation in AIRmax or AIRmin mice, suggesting that these chromosomal regions also segregate with inflammatory phenotypes.
Ates O, etal., Rheumatol Int. 2009 May;29(7):787-91. Epub 2008 Nov 8.
Natural resistance associated macrophage protein 1 (NRAMP1), also named as solute carrier family 11 member A1 gene (SLC11A1), has multiple pleiotropic effects on macrophage activation pathways such as up-regulation of the CXC chemokine KC, tumor necrosis factor
alpha (TNF-alpha), interleukin-1 b (IL-1 b), inducible nitric oxide syntase (iNOS), and major histocompatibility complex (MHC) class II expression. Since NRAMP1 plays a role in the up-regulation of the TNF-alpha, iNOS and MHC expression, it may also be a candidate gene for Behcet's syndrome (BS). We analyzed the association of NRAMP1 polymorphisms [(GT)( n ), INT4, 3'UTR and D543N] in 102 Turkish patients with BS and 102 healthy subjects by using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). We found a significant association between BS and NRAMP1 INT4 G/C allele frequency (p = 0.004, OR = 1.88, 95% CI = 1.21-2.93). However, there were no significant differences in the distribution of allele frequencies of NRAMP1 (GT)( n ), 3'UTR, D543N polymorphisms between BS patients and healthy controls. There was also no correlation between NRAMP1 polymorphisms and clinical manifestations of BS. Our study suggests that NRAMP1 may be one of the plausible candidate genes for BS. However, it is likely that INT4 polymorphism is not disease-specific and seems to be common to immune-mediated diseases.
A systematic review and meta-analyses were undertaken to investigate the association of SLC11A1 genetic variants with disease occurrence. Literature searching indentified 109 publications to include in the meta-analyses assessing the association of 11 SLC11A1
le='font-weight:700;'>SLC11A1 variants with autoimmune and infectious disease. The (GT)n promoter alleles 2 and 3 (rs534448891), which alter SLC11A1 expression, were significantly associated with tuberculosis (OR=1.47 (1.30-1.66), OR=0.76 (0.65-0.89), respectively) and infectious disease (OR=1.25 (1.10-1.42), OR=0.83 (0.74-0.93), respectively). However, although no association was observed with autoimmune disease, a modest significant association was observed with type 1 diabetes (allele 2 OR=0.94 (0.89-0.98)). On the basis of a stronger association of (GT)n allele 2 with tuberculosis, compared with the protective effect of allele 3, we hypothesise that allele 2 is likely the disease-causing variant influencing disease susceptibility. Significant associations were observed between the 469+14G/C polymorphism (rs3731865) and autoimmune disease (OR=1.30 (1.04-1.64)) and rheumatoid arthritis (OR=1.60 (1.20-2.13)) and between the -237C/T polymorphism (rs7573065) and inflammatory bowel disease (OR=0.60 (0.43-0.84)). Further, significant associations were identified between the 469+14G/C, 1730G/A and 1729+55del4 polymorphisms (rs3731865, rs17235409 and rs17235416, respectively) and both infectious disease per se and tuberculosis. These findings show a clear association between variants in the SLC11A1 locus and autoimmune and infectious disease susceptibility.
van Crevel R, etal., J Infect Dis. 2009 Dec 1;200(11):1671-4.
Differences in host immune genes may predispose to tuberculosis caused by particular Mycobacterium tuberculosis genotypes. We examined this hypothesis in Indonesia by spoligotyping M. tuberculosis isolates recovered from 336 patients with pulmonary tuberculosis and typing the patients' SLC11A1
font-weight:700;'>SLC11A1 gene (formerly known as "NRAMP1"), which is involved in susceptibility to tuberculosis. The M. tuberculosis Beijing genotype, which comprised 29.8% of all isolates, was strongly associated with 2 polymorphisms in SLC11A1: the D543N G allele (odds ratio [OR], 2.15; P=.005) and the 3' untranslated region (3'UTR) insertion/insertion genotype (OR, 2.5; P=.001). This finding supports the hypothesis of coevolution of M. tuberculosis and the human immune system.
BACKGROUND: The etiology of type 1 diabetes mellitus (T1DM) is still unknown; numerous studies are performed to unravel the environmental factors involved in triggering the disease. SLC11A1 is a membrane transporter that is expressed in late endosomes of antigen
presenting cells involved in the immunopathogenic events leading to T1DM. Mycobacterium avium subsp. paratuberculosis (MAP) has been reported to be a possible trigger in the development of T1DM. METHODOLOGY/PRINCIPAL FINDINGS: Fifty nine T1DM patients and 79 healthy controls were genotyped for 9 polymorphisms of SLC11A1 gene, and screened for the presence of MAP by PCR. Differences in genotype frequency were evaluated for both T1DM patients and controls. We found a polymorphism in the SLC11A1 gene (274C/T) associated to type 1 diabetic patients and not to controls. The presence of MAP DNA was also significantly associated with T1DM patients and not with controls. CONCLUSIONS/SIGNIFICANCE: The 274C/T SCL11A1 polymorphism was found to be associated with T1DM as well as the presence of MAP DNA in blood. Since MAP persists within macrophages and it is also processed by dendritic cells, further studies are necessary to evaluate if mutant forms of SLC11A1 alter the processing or presentation of MAP antigens triggering thereby an autoimmune response in T1DM patients.
Systemic sclerosis (SSc), also termed "scleroderma," is a progressive, systemic disease of unknown origin characterized by excessive fibrosis, vascular abnormalities and immune dysfunction. Nramp 1 gene has multiple pleiotropic effects on macrophage activation pathways, including up-regulation of th
e chemokine/cytokine genes KC, tumor necrosis factor alpha, interleukin-1 b, inducible nitric oxide syntase, and major histocompatibility complex class II expression, as well as tumoricial activity and antimicrobial activity. All of these pleiotropic effects are important for resistance to infection, but they may also be involved in the induction and maintenance of autoimmune diseases. We analyzed four natural resistance associated macrophage protein 1 (NRAMP1) gene polymorphisms including 5' promoter (GT)n microsatellite, INT4 (469 + 14G/C), 3'UTR (1729 + 55del4), and D543N (codon 543, Asp to Asn) in 52 systemic sclerosis patients with interstitial lung involvement and 136 healthy controls. We found a significant association between INT4, (GT)n polymorphisms (p = 0.006 and 0.027, respectively), and SSc. Our findings suggest that NRAMP1 is a plausible candidate gene for SSc.
BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the digestive tract. Genetic factors and an abnormal immune response to infections are suspected to be involved in inflammatory bowel diseases. METHODS: In the present study 300 blood samples from CD pa
tients (n = 100), UC patients (n = 100), and healthy controls (n = 100) were taken from a population-based case-control study. PCR assays and capillary electrophoresis were used to detect alpha 1 antitrypsin M, S, and Z alleles and the C-to-T transition at the -237 nucleotide position of the SLC11A1 promoter. Additionally, length polymorphism of (gt)n alleles in the promoter region and TGTG and CAAA insertion/deletion in the untranslated region (3' UTR) of the SLC11A1 gene were evaluated. RESULTS: The Z allele only for AAT was associated (P < 0.05) with CD. No other significant results were detected for AAT alleles. For SLC11A1, alleles 1 and 2 were significant (P < 0.05) for UC, but only allele 3 was significant (P < 0.05) for CD. There was a significant (P < 0.05) association of a CAAA insertion with CD but not for deletion in the 3' UTR. No differences (P < 0.05) were detected for TAAA. CONCLUSIONS: Because AAT and SLC11A1 proteins directly or indirectly function as inhibitors of human leukocyte elastase, mutations in the AAT and SLC11A1 genes may change the balance between elastase produced by leukocytes during phagocytosis.
De Franco M, etal., PLoS One. 2014 Feb 5;9(2):e88302. doi: 10.1371/journal.pone.0088302. eCollection 2014.
AIRmax (maximal inflammation) and AIRmin (minimal inflammation) mice show distinct susceptibilities to pristane-induced arthritis (PIA). The Slc11a1 gene, which regulates macrophage and neutrophil activity, is involved in this infirmity. AIRmax (SS) mice homozy
gous for the non-functional Slc11a1 S (gly169asp) allele obtained by genotype-assisted crosses from AIRmax and AIRmin mice are more susceptible than mice homozygous for the Slc11a1 resistant (R) allele. The present work sought to identify the quantitative trait loci (QTL) regulating PIA and to examine the interactions of these QTL with Slc11a1 alleles in modulating PIA. Mice were given two ip injections of 0.5 mL pristane at 60 day intervals, and the incidence and severity of PIA was scored up to 160 days. Genome-wide linkage studies were performed to search for arthritis QTL in an F2 (AIRmax x AIRmin, n = 290) population. Significant arthritis QTL (LODscore>4) were detected on chromosomes 5 and 8, and suggestive QTL on chromosomes 7, 17 and 19. Global gene expression analyses performed on Affymetrix mouse 1.0 ST bioarrays (27k genes) using RNA from arthritic or control mice paws showed 419 differentially expressed genes between AIRmax and AIRmin mice and demonstrated significantly (P<0.001) over-represented genes related to inflammatory responses and chemotaxis. Up-regulation of the chemokine genes Cxcl1, Cxcl9, Cxcl5, Cxcl13 on chromosome 5 was higher in AIRmax(SS) than in the other lines. Macrophage scavenger receptor 1 and hemeoxigenase (decycling) 1 genes on chromosome 8 were also expressed at higher levels in AIRmax(SS) mice. Our results show that the gene expression profiles of the two arthritis QTL (on chromosomes 5 and 8) correlate with Slc11a1 alleles, resulting in enhanced AIRmax(SS) mice susceptibility to PIA.
Sechi LA, etal., World J Gastroenterol. 2006 Nov 28;12(44):7161-4.
AIM: To study the association between Crohn's disease (CD), Mycobacterium avium subspecies paratuberculosis (MAP), and genetic factors by examining the role of natural resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms (now SLC11A1) in Sardin
ian patients with CD and controls. METHODS: Thirty-seven CD patients and 34 controls with no inflammatory bowel disease (IBD) were recruited at the University of Sassari after giving written consent. Six SCL11A1 polymorphisms previously reported to be the most significantly associated with IBD were searched. M. paratuberculosis was identified by IS900 PCR and sequencing. Logistic regression was used to calculate odds ratios (OR) for the associations among CD, presence of MAP, and 6 loci described above. RESULTS: For the first time, a strong association was observed between polymorphisms at NRAMP1 locus 823C/T and CD. While CD was strongly associated with both NRAMP1 and MAP, NRAMP1 polymorphisms and MAP themselves were not correlated. CONCLUSION: Combined with previous work on the NOD2/CARD15 gene, it is clear that the interplay of genetic, infectious, and immunologic factors in the etiology of CD is complex.
Mice selected for the maximum acute inflammatory reaction (AIRmax) are highly susceptible to pristane-induced arthritis (PIA), whereas mice selected for the minimum response (AIRmin) are resistant. These lines show distinct patterns of leukocyte infiltration and R and S allele frequency disequilibri
um of the solute carrier family 11a member 1 (Slc11a1) gene. In order to study the interactions of the Slc11a1 R and S alleles with the inflammation modulating Quantitative Trait Loci (QTL) during PIA development, homozygous AIRmax(RR), AIRmax(SS), AIRmin(RR) and AIRmin(SS) lines were produced by genotype-assisted breedings. These mice received two intraperitoneal injections of 0.5 ml pristane at 60-day intervals, and the subsequent development of arthritis was assessed for 210 days. Cytokine-secreting cell profiles were investigated using enzyme-linked immunospot. Arthritis incidence in AIRmax(RR) mice reached 29%, whereas PIA incidence in AIRmax(SS) mice was 70% by day 180. AIRmin(RR) mice were resistant, whereas 13.3% of AIRmin(SS) mice became arthritic. The presence of the defective S allele also increased arthritis severity, although acute inflammation was higher in mice bearing the R allele. A predominant Th0/Th2-type response in Slc11a1(SS) mice was observed. These results indicate that Slc11a1 is a strong candidate for the QTL modulating acute inflammation and for PIA.
BACKGROUND: Polymorphisms of the solute carrier family 11 member 1 (Slc11a1) gene have previously been associated with susceptibility to infectious disease, anti-tumor defenses, and autoimmune diseases. We postulated that polymorphisms of the gene may also be as
sociated with susceptibility to post-transplant lymphoproliferative disease (PTLD), a disease thought to be related to an impaired immune response to Epstein-Barr virus (EBV) in immunosuppressed patients. METHODS: Whole blood samples were obtained from 45 pediatric patients who underwent liver transplantation. Polymerase chain reaction (PCR) was used to amplify a 3' region of the gene that includes an exon 15 single-nucleotide substitution (referred to as D543N) and a 4-bp deletion polymorphism (referred to as 3'-UTR). PCR products were digested using AvaII and FokI restriction enzymes for the D543N and 3'-UTR polymorphisms, respectively. PTLD disease status and EBV virus serum titers of all patients were obtained from hospital records. RESULTS: Six of the 45 pediatric transplant recipients developed PTLD. An association was found between 3'-UTR polymorphisms of Slc11a1 and incidence of PTLD after liver transplantation (P = 0.005). In addition, post-transplant serum EBV titers were higher (P = 0.009) for recipients with certain Slc11a1 polymorphisms. No association was found between the D543N polymorphism and incidence of PTLD. CONCLUSION: 3'-UTR polymorphisms of the Slc11a1 gene appear to be associated with susceptibility to PTLD and the immune response to EBV in pediatric liver transplant recipients. Genotyping of pediatric patients undergoing liver transplantation may enable early identification of patients at high risk for developing high EBV titers and/or PTLD.
Stewart LC, etal., World J Gastroenterol. 2010 Dec 7;16(45):5727-31.
AIM: To test for association of SLC11A1 with inflammatory bowel disease (IBD) and Mycobacterium avium subspecies paratuberculosis (MAP) status in a Caucasian cohort. METHODS: five hundred and seven Crohn's disease (CD) patients, 474 ulcerative colitis (UC) patie
nts, and 569 healthy controls were genotyped for SLC11A1 1730G>A and SLC11A1 469+14G>C using pre-designed TaqMan SNP assays. chi(2) tests were applied to test for association of single nucleotide polymorphisms (SNPs) with disease, and the presence of MAP DNA. RESULTS: SLC11A1 1730G>A and SLC11A 1469+14G>C were not associated with CD, UC, or IBD. The SLC11A1 1730A minor allele was over-represented in patients who did not require immunomodulator therapy (P = 0.002, OR: 0.29, 95% CI: 0.13-0.66). The frequency of the SLC11A1 469+14C allele was higher in the subset of study participants who tested positive for MAP DNA (P = 0.02, OR: 1.56, 95% CI: 1.06-2.29). No association of SLC11A1 1730G>A with MAP was observed. CONCLUSION: Although SLC11A1 was not associated with IBD, association with MAP suggests that SLC11A1 is important in determining susceptibility to bacteria implicated in the etiology of CD.
Pedroza LS, etal., Lupus. 2011 Mar;20(3):265-73. Epub 2011 Jan 13.
Systemic lupus erythematosus (SLE) is an autoimmune disorder of the connective tissue with a wide and heterogeneous spectrum of manifestations, with renal and neurological involvement usually related to worse prognosis. SLE more frequently affects females of reproductive age, and a high prevalence a
nd renal manifestation seem to be associated with non-European ethnicity. The present study aims to investigate candidate loci to SLE predisposition and evaluate the influence of ethnic ancestry in the disease risk and clinical phenotypic heterogeneity of lupus at onset. Samples represented by 111 patients and 345 controls, originated from the city of Belem, located in the Northern Region of Brazil, were investigated for polymorphisms in HLA-G, HLA-C, SLC11A1, MTHFR, CASP8 and 15 KIR genes, in addition to 89 Amerindian samples genotyped for SLC11A1. We also investigated 48 insertion/deletion ancestry markers to characterize individual African, European and Amerindian ancestry proportions in the samples. Predisposition to SLE was associated with GTGT deletion at the SLC11A1 3'UTR, presence of KIR2DS2 +/KIR2DS5 +/KIR3DS1 + profile, increased number of stimulatory KIR genes, and European and Amerindian ancestries. The ancestry analysis ruled out ethnic differences between controls and patients as the source of the observed associations. Moreover, the African ancestry was associated with renal manifestations.
The purpose of this study was to assess the likelihood that variation in the promoter region of the solute carrier family 11 member 1 gene (SLC11A1) contributes to inflammatory bowel disease (IBD) susceptibility in the South African population. The study cohort
included 102 IBD patients, 47 with Crohn's disease (CD) and 55 with ulcerative colitis, and 192 population-matched controls. Mutation analysis revealed two novel alleles for the 5'-(GT)n repeat polymorphism, t(gt)5ac(gt)5ac(gt)6ggcaga(g)6 (allele 8) and t(gt)5ac(gt)5ac(gt)8ggcaga(g)6 (allele 9), and one previously documented point mutation -237C-->T. A significantly decreased frequency of the -237C-->T promoter polymorphism was observed in the patient group with IBD (p<0.001) and CD (p<0.0006) compared with the population-matched control group. These findings may be related to previous in vitro studies, which demonstrated that the point mutation at nucleotide position -237 represents a functional polymorphism that affects regulation of the upstream 5'-(GT)n repeat polymorphism differentially upon iron loading. Our findings raise the possibility that iron dysregulation mediated by allelic effects of SLC11A1 may contribute to IBD susceptibility.
Salinas-Delgado Y, etal., Drug Metabol Personal Ther. 2015 Sep;30(3):211-4. doi: 10.1515/dmpt-2015-0019.
BACKGROUND: Polymorphisms in SLC11A1/NRAMP1 have shown an important association with susceptibility to tuberculosis and progression to active disease. However, whether there is an association of these polymorphisms with treatment failure is unknown. The aim of
this study was to determine the association of SLC11A1 polymorphisms with treatment failure in Mexican subjects with pulmonary tuberculosis. METHODS: Thirty-three subjects with treatment failure were paired by age and body mass index with 33 patients who successfully completed treatment and were considered cured. We assessed the polymorphisms of SLC11A1 in the regions of D543N and INT4 via polymerase chain reaction real-time TaqMan(R) single nucleotide polymorphism (SNP) genotyping. RESULTS: We found that D543N (G/A genotype) was associated with treatment failure in patients with pulmonary tuberculosis [odds ratio (OR) 11.61, 95% confidence interval (CI) 3.66-36.78]. When adjusted by gender, this association remained significant in males (OR 11.09, 95% CI 3.46-35.51). CONCLUSIONS: In our male population, the presence of the D543N polymorphism of SLC11A1 is a risk factor for treatment failure. This finding should be confirmed in other populations.
