No evidence for association of the inducible nitric oxide synthase promoter polymorphism with Trypanosoma cruzi infection

The purpose of the present study was to address the possible contribution of the (CCTTT)n microsatellite polymorphism in the NOS2 promoter region to the susceptibility to chronic Trypanosoma cruzi infection and to Chagas' disease related cardiomyopathy. We determined the (CCTTT)n genotypes in a sample of 76 serologically positive chagasic individuals and in 78 healthy controls. No statistically significant differences were observed between total chagasic patients and healthy controls with regard to frequency of the (CCTTT)n microsatellite repeat of any given length. Likewise, we found no differences in the distribution of the (CCTTT)n microsatellite repeats between seropositives without manifestations of the disease and those with chagasic cardiomyopathy. Our data suggest that the NOS2 promoter pentanucleotide microsatellite polymorphisms analyzed do not play a major role in the pathogenesis of chronic T. cruzi infection in this Peruvian sample.     

Analysis of a GT microsatellite in the promoter of the foxp3/scurfin gene in autoimmune diseases

The aim of this study was to assess the possible association of the functional (GT)(n) microsatellite polymorphism in the FOXP3 gene with predisposition to several autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ulcerative colitis (UC), Crohn's disease, and celiac disease. We analyzed a case-control cohort composed of 231 SLE patients, 293 RA patients, 528 inflammatory bowel disease (354 Crohn's disease patients and 260 UC patients) patients, 103 celiac disease patients, and 274 healthy controls ethnically matched. Genotyping of (GT)(n) microsatellite was performed by polymerase chain reaction (PCR)-based method combined with fluorescent technology. We found no evidence for association of this polymorphism between controls and these autoimmune disease patients. Additionally, no differences in the genotype and allele distribution were found when patients were stratified according to clinical manifestation. The (GT)(n) microsatellite of the FOXP3 gene may not play a relevant role in the susceptibility to SLE, RA, inflammatory bowel disease, and celiac disease in our population.     

Inducible and endothelial nitric oxide synthase genes polymorphism in inflammatory bowel disease

To assess the influence of inducible and endothelial nitric oxide synthase gene (NOS2A and NOS3) polymorphisms in susceptibility to Crohn's disease (CD) and ulcerative colitis (UC). A total of 505 inflammatory bowel disease (IBD) patients (221 with UC and 284 with CD) and 332 ethnically matched controls were studied. Patients and controls were genotyped by polymerase chain reaction -based techniques for a multiallelic (CCTTT)(n) repeat and biallelic marker (TAAA)(n) in the promoter region of the NOS2A gene and for a T/C polymorphism at position -786 in the promoter region and a polymorphism in exon 7(298Glu/Asp) of the NOS3 gene. There was not association between NOS2A and NOS3 genotypes, alleles or haplotypes frequencies with UC, CD and controls. Our data suggest that NOS2A and NOS3 polymorphisms do not play a major role in IBD predisposition.     

Genetic determinants of rheumatoid arthritis: the inducible nitric oxide synthase (NOS2) gene promoter polymorphism

An association study and a linkage analysis were carried out in parallel in order to investigate the association of the inducible nitric oxide synthase (NOS2) gene promoter polymorphism with rheumatoid arthritis (RA) predisposition and/or outcome including a -954G-C mutation, a di-allelic (TAAA)(n) marker and the highly polymorphic (CCTTT). The -954G-C point mutation occurred non-polymorphic and the di-allelic (TAAA)(n) marker was not associated with RA predisposition. The (CCTTT)(n)locus showed a trend for RA association in the case-control study, however, stratification data by Class II status did not yield significant effect and overall, the family study showed no significant association nor linkage for any of the markers under study using TDT and non-parametric linkage respectively. Finally, no influence was detected regarding any of the clinical parameters tested. After evaluating for the first time the influence of NOS2 promoter polymorphism in RA, it seems to have no major effect on disease susceptibility and/or outcome.     

TNF microsatellite alleles a2 and b3 are not primarily associated with celiac disease in the Finnish population

Abstract: Recently, an independent association between tumor necrosis factor (TNF) gene polymorphism and ceiiac disease was observed in the Irish population. We tested this association in Finnish patients with celiac disease. The TNF microsatellite alleles a2 and b3 were strongly associated (P_corr<0.0001 for both) with celiac disease when the patients were compared to the random population. However, when the comparison was made with the DQ2-matched controls, no association could be found. We therefore conclude that in Finland the TNFa2 and b3 alleles are associated with DQ2-positive haplotypes rather than celiac disease.     

No evidence for linkage in the promoter region of the inducible nitric oxide synthase gene (NOS2) in a Danish type 1 diabetes population

Exposure of human pancreatic islets to a mixture of cytokines induces expression of inducible nitric oxide synthase (iNOS), impairs beta-cell function and induces apoptosis. Exposing human islets to high amounts of NO from chemical NO-donors causes DNA strand breaks and mitochondrial damage, suggesting that NO is deleterious to human beta-cells. Hence, we consider the gene encoding iNOS in beta-cells, NOS2, a candidate gene for type 1 diabetes in humans. In the present study we have tested three identified polymorphisms within the promoter sequence of the human NOS2 gene in a type 1 diabetic family material comprising 154 affected sib-pair families and 103 affected simplex families (1143 individuals in total). PCR-based amplification of the polymorphic loci were established. Linkage analysis was performed using the extended transmission disequilibrium testing (ETDT). A Bsal RFLP was found not to be polymorphic in 20 type 1 diabetic patients and 14 healthy control subjects and was not analysed further. In affected cases a nine allele CCTTT repeat and a bi-allelic TAAA repeat revealed allelewise Petdt of 0.52 and 0.60, respectively. ETDT applied to (TAAA)n; (CCTTT)n haplotypes demonstrated random transmission from heterozygous parents to affected offspring. In conclusion, the tested polymorphisms within the NOS2 gene promoter did not show evidence for linkage to type 1 diabetes in a Danish family material.     

CA microsatellite polymorphism of the nuclear factor kappa B1 gene in celiac disease

In the present work, we investigate the possible effect of a CAn microsatellite polymorphism in the nuclear factor kappa B1 (NFKB1) gene on predisposition to celiac disease (CD). Seventy‐eight Spanish families with CD were genotyped using a polymerase chain reaction (PCR)‐fluorescent method, and the transmission patterns of different CAn alleles were analysed. Furthermore, in order to type the CAn polymorphism more accurately, samples between 126 and 144 bp were cloned and sequenced. A trend of association with the 132‐bp allele was found (P = 0.02). This allele was more frequently transmitted to affected sibs, although the results of statistical tests were not significant after correction for multiple comparisons. After sequencing, we found that the 132‐, 138‐ and 142‐bp alleles had two As at the end of the CA microsatellite, with the other alleles presenting the described pattern (NCB1 nucleotide U60337) for the microsatellite repeats. These results suggest that the NFKB1 CAn microsatellite does not play a major role in CD susceptibility. In addition, a more detailed molecular characterization of the CA microsatellite is described.     

重组法国梧桐花粉过敏原2( rPla a2) 对诱导型一氧化氮合酶( NOS2)基因启动子活性及基因表达的影响

目的:构建人诱导型一氧化氮合酶(NOS2)基因启动子区,对NOS2 启动子序列进行鉴定并分析其活性;探索重组法国梧桐花粉过敏原2(rPla a2)对人NOS2 基因启动子活性及基因表达的影响。方法:利用PCR 扩增、限制性内切酶双酶切、DNA 连接酶连接、大肠杆菌转化等方法将NOS2 基因启动子区克隆至pGL3-Basic 载体上,将所构建重组报告质粒转染至人胚肾(HEK293T)细胞中,利用双荧光素酶活性分析检测该重组报告质粒启动子活性及检测rPla a2 对人NOS2 基因启动子活性的影响;用实时荧光定量PCR 法检测rPla a2 对人NOS2 基因mRNA 水平的影响。结果:成功构建含有NOS2 启动子的重组报告质粒,与对照(pGL3-Basic) 组相比,含NOS2 启动子区的重组质粒转染组荧光素酶活性显著增高;与不加刺激(NOS2)组相比,加入rPla a2 刺激后含NOS2 启动子区的重组报告质粒转染组荧光素酶活性显著增高,加入rPla a2 刺激后NOS2 mRNA 相对表达水平显著增高。结论:rPla a2 可增强人NOS2 基因启动子活性,并增加其基因表达。     

Somatic aberrations of mismatch repair genes as a cause of microsatellite‐unstable cancers

Lynch syndrome (LS) is caused by germline mutations in mismatch repair (MMR) genes, resulting in microsatellite‐unstable tumours. Approximately 35% of suspected LS (sLS) patients test negative for germline MMR gene mutations, hampering conclusive LS diagnosis. The aim of this study was to investigate somatic MMR gene aberrations in microsatellite‐unstable colorectal and endometrial cancers of sLS patients negative for germline MMR gene mutations. Suspected LS cases were selected from a retrospective Clinical Genetics Department diagnostic cohort and from a prospective multicentre population‐based study on LS in The Netherlands. In total, microsatellite‐unstable tumours of 40 sLS patients (male/female 20/20, median age 57 years) were screened for somatic MMR gene mutations by next‐generation sequencing. In addition, loss of heterozygosity (LOH) of the affected MMR genes in these tumours as well as in 68 LS‐associated tumours and 27 microsatellite‐unstable tumours with MLH1 promoter hypermethylation was studied. Of the sLS cases, 5/40 (13%) tumours had two pathogenic somatic mutations and 16/40 (40%) tumours had a (likely) pathogenic mutation and LOH. Overall, LOH of the affected MMR gene locus was observed in 24/39 (62%) tumours with informative LOH markers. Of the LS cases and the tumours with MLH1 promoter hypermethylation, 39/61 (64%) and 2/21 (10%) tumours, respectively, demonstrated LOH. Half of microsatellite‐unstable tumours of sLS patients without germline MMR gene mutations had two (likely) deleterious somatic MMR gene aberrations, indicating their sporadic origin. Therefore, we advocate adding somatic mutation and LOH analysis of the MMR genes to the molecular diagnostic workflow of LS. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd     

基于家系的Tim-3基因多态性与儿童变应性哮喘的关联研究

目的 以家系资料为基础,利用遗传不平衡原理探讨染色体5q33.2区Tim-3基因启动子两个多态性位点rs10053538和rs10515746与中国湖北地区汉族儿童变应性哮喘的关系.方法 应用限制性片段长度多态性技术结合测序方法,分析了118个儿童变应性哮喘核心家系Tim-3基因rs10053538和rs10515746的基因型;采用基于家系的关联分析方法,包括单体型相对风险分析(HRR)和传递不平衡检验(TDT),分析基因分型数据;应用Transmit软件构建单体型并进行单体型关联分析.结果 118个核心家庭HRR分析显示Tim-3基因启动子区两个多态性位点rs10053538和rs10515746不使病人具有更高的发病风险(X2=2.430,P>0.05;x2=1.368,P>0.05).118个满足经典TDT分析的核心家庭中,杂合子父母传递给患病子代的等位基因频率不比预期值高(x2=2.042,P>O.05;x2=0.750,P>O.05).Transmit双位点单体型分析也未见父母传递给子女各个单体型的观察值和期望值有明显差异(P>O.05).结论 中国湖北地区汉族人群中,Tim-3基因启动子区两个多态性位点rs10053538和rs10515746与儿童变应性哮喘不具有相关性.     

The CTLA4/CD28 gene region on chromosome 2q33 confers susceptibility to celiac disease in a way possibly distinct from that of type 1 diabetes and other chronic inflammatory disorders

The effect of the gene region on chromosome 2q33 containing the CD28 and the cytotoxic T-lymphocyte associated (CTLA4) genes has been investigated in several diseases with chronic inflammatory nature. In addition to celiac disease (CD), type I diabetes, Grave's disease, rheumatoid arthritis and multiple sclerosis have all demonstrated associations to the A/G single nucleotide polymorphism (SNP) in exon 1, position +49 of the CTLA4 gene. The purpose of this study was to investigate this gene region in a genetically homogeneous population consisting of 107 Swedish and Norwegian families with CD using genetic association and linkage methods. We found a significant association with preferential transmission of the A-allele of the exon 1 +49 polymorphism by using the transmission disequilibrium test (TDT). Suggestive linkage of this region to CD was moreover demonstrated by non-parametric linkage (NPL) analysis giving a NPL-score of 2.1. These data strongly indicates that the CTLA4 region is a susceptibility region in CD. Interestingly, of the several chronic inflammatory diseases that exhibit associations to the CTLA4 +49 A/G dimorphism, CD appears to be the only disease associated to the A allele. This suggests that the +49 alleles of the CTLA4 gene are in linkage disequilibrium with two distinct disease predisposing alleles with separate effects. The peculiar association found in the gut disorder CD may possibly relate to the fact that the gastrointestinal immune system, in contrast to the rest of the immune system, aims to establish tolerance to foreign proteins.     

Prevalence of endothelial nitric oxide synthase gene polymorphisms in patients with atopic asthma

BACKGROUND: Asthma is a common multifactorial disease, the aetiology of which is attributable to both environmental and genetic factors. The endothelial nitric oxide synthase (NOS3) gene has been implicated in asthma pathogenesis. OBJECTIVE: This study investigated associations of 27 base-pair tandem repeat polymorphism in intron 4 and the Glu298Asp (G894T) variant of the NOS3 gene with atopic asthma in a Czech population. METHODS: Polymerase chain reaction was used to determine the NOS3 genotypes in subjects with atopic asthma (n = 163) and random controls (n = 209). RESULTS: The NOS3 allele or genotype distributions did not differ significantly between the control and asthma groups. However, the common genotype (bb) of the NOS3 polymorphism in intron 4 was found to be significantly associated with total IgE levels (P = 0.006), specific IgE levels for feathers (P = 0.0002) and a positive skin prick test for hay (P = 0.004). In one atopic patient, we identified an additional 27-bp repeat in the NOS3 gene (NOS3c), which occurred in heterozygous combination with the NOS3b allele (NOS3b/c genotype). In addition, we describe a new polymorphism (A5495G) in the NOS3 gene, which was in almost complete linkage disequilibrium with the NOS3 repeat polymorphism in intron 4. The Glu298Asp variant was not associated with asthma and/or related atopic phenotypes in our study. CONCLUSION: Neither the NOS3 'b' allele nor the NOS3 'b/b' genotype showed any general association with atopic asthma, but they were associated with atopy-related phenotypes. We conclude that the NOS3 gene polymorphisms may act as disease modifiers in atopic asthma phenotype in our population.     

Genetic variation in nitric oxide synthase 2A (NOS2A) and risk for multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system with a strong genetic component. Variation in the major histocompatibility complex on chromosome 6p21, specifically the HLA-DRB1*15 haplotype, is the strongest genetic factor for MS, yet it is estimated to account for only a portion of risk for the disease. Previous evidence has implicated the nitric oxide synthase gene (NOS2A) encoding inducible NOS on chromosome 17q11 as a potential MS susceptibility gene. To determine whether variation in the NOS2A gene contributes to MS risk, we investigated a total of 50 polymorphisms within or flanking the locus for evidence of association using a comprehensive analytical strategy. A total of 6265 members from 1858 well-characterized MS families were utilized. No evidence for overtransmission of any individual single-nucleotide polymorphism allele or haplotype to the MS-affected individuals was observed. Furthermore, different transmission rates were not observed in either DRB1*15-positive or DRB1*15-negative family subgroups, or when extreme clinical outcomes characterizing disease progression were examined. The very largest study of NOS2A variation in MS, to date, excludes even a modest role for this locus in susceptibility.     

一氧化氮合酶2A基因启动子-969(G→C)多态性与肝硬化门静脉高压的相关性

目的探讨一氧化氮合酶2A(nitricoxidesynthase2A,NOS2A)基因启动子-969(G→C)多态性与肝硬化门静脉高压的相关性。方法采用病例对照和聚合酶链反应-限制性片段长度多态性技术,检测106例乙肝后肝硬化患者和108名健康对照者NOS2A基因启动子-969(G→C)多态性,比较等位基因及基因型频率;应用逆转录-聚合酶链反应和Western印迹技术,检测肝硬化组织NOS2AmRNA和蛋白表达。构建NOS2A基因启动子-969(G→C)多态性荧光素酶重组质粒,瞬时转染,分析多态性的功能。结果在门静脉高压症组C等位基因和GC基因型频率为16.9%、33.8%,比正常对照组高(8.8%、17.6%),差异有显著性(P<0.05,OR=2.42),相关分析呈正相关(r=0.18)。单纯肝硬化组与对照组的C等位基因和GC基因型频率相比,差异无显著性(P>0.05)。C等位基因携带者比G等位基因携带者肝硬化组织NOS2AmRNA及蛋白表达明显增强,GC基因型启动子的活性显著升高。Logistic多元逻辑回归分析显示这一多态性是形成门静脉高压症新的独立危险因素。结论NOS2A基因启动子-969(G→C)多态性与门静脉高压症相关,导致启动子活性增强,是形成门静脉高压症的新的危险因素。     

Association of plasma nitric oxide concentration and endothelial nitric oxide synthase T-786C gene polymorphism in coronary artery disease

Nitric oxide (NO) is synthesized from l-arginine by endothelium nitric oxide synthase (NOS3) and plays important roles in many physiologic and pathologic processes. NO involved in the pathogenesis of coronary atherosclerosis. In the present study we hypothesized that polymorphisms of NOS gene might be associated with increased risk of coronary artery disease (CAD) and plasma NO concentrations. The eNOS gene polymorphism was investigated in 241 unrelated CAD patients with positive coronary angiograms and 261 ages matched control subjects without a history of symptomatic CAD. The NOS3 gene polymorphisms were analyzed by RFLP. Plasma NO, lipid profile and other risk factors were also assessed. The genotype frequencies for T-786C polymorphism differed significantly between CAD patients and controls (p=0.041). The mean plasma NO(x) concentrations showed significant differences according to genotypes of T-786C polymorphism in total population only. The mean plasma NO(x) increased in those individuals that are homozygote for C allele in promoter compared with those individuals are heterozygote for this allele and homozygote for T allele in total population and Controls, but no in CAD patients. The present study provides evidences that T-786C polymorphism of the NOS3 gene is associated with CAD. T-786C polymorphism was not associated with increased plasma NO in CAD patients.     

Allergy prevalence in adult celiac disease

BACKGROUND: Celiac disease is considered to arise from an inappropriate T-cell-mediated immune response against ingested gluten in genetically predisposed people, whereas the T(H)2-type lymphocytes are mostly involved in IgE-mediated reactions. The matter of possible coexistence of T(H)1- and T(H)2-type diseases is still debated. OBJECTIVE: This study was aimed to evaluate the allergy prevalence in a large series of adults with untreated celiac disease and their families at the moment of diagnosis. We also evaluated whether 1 year of gluten-free diet had any effect on allergy prevalence in our cohort. METHODS: At the moment of celiac disease diagnosis a standardized questionnaire was administered for detailed information on presence and type of any allergy symptoms in 1044 adult patients with celiac disease, 2752 relatives, and 318 spouses. Those reporting any allergy underwent tests with dosage of serum levels of total IgE and search for serum specific IgE with a standard makeup of 20 antigens and PRICK tests in selected individuals. At follow-up visit patients with celiac disease were administered the same allergy questionnaire. RESULTS: One hundred seventy-three patients with celiac disease (16.6%), 523 relative (19%), and 43 spouses (13.5%) had at least 1 allergy (P=not significant). Atopic dermatitis was more frequent in patients with celiac disease (3.8%) and their relatives (2.3%) than in spouses (1.3%). The presence of allergy in general and atopic dermatitis was not affected by presence of overt malabsorption or duration of undiagnosed disease. Follow-up data showed no change in allergy prevalence in the cohort examined. CONCLUSION: Allergy prevalence in a large series of patients with celiac disease is not different from that of their relatives and spouses. However, atopic dermatitis was about 3 times more frequent in patients with celiac disease and 2 times more frequent in their relatives than in spouses. One year of gluten-free diet did not change allergy prevalence in the celiac group under investigation.     

An investigation of NOS2A promoter polymorphisms in Australian multiple sclerosis patients

As with other major autoimmune diseases, susceptibility to multiple sclerosis (MS) is believed to result from the complex interaction of a number of genes, each with modest effect. Extensive research of experimental autoimmune encephalomyelitis in mice and several direct MS studies have implicated NOS2A, which encodes the inducible form of nitric oxide synthase, and the genetic region encoding NOS2A, 17q11.2, has been identified in a number of genome wide screens as being potentially associated with MS. We investigated four single nucleotide polymorphisms in the proximal promoter region of NOS2A, in a case-control group of 100 Australian MS patients and 100 controls and in 203 MS patients and their unaffected parents. We found a trend toward excess transmission of the -277A allele (tag for the AGCC haplotype) to HLA-DRB1*1501-positive MS patients (P (uncorrected)=0.05). We initially discovered a trend toward over-representation of the AGCC haplotype in HLA-DRB1*1501-positive compared to HLA-DRB1*1501-negative MS patients in the case-control cohort. However, when combined with the probands from the transmission disequilibrium analysis, this trend was nullified. Nonetheless, despite the lack of significant evidence of association for the NOS2A promoter polymorphisms with MS, the gene remains an interesting candidate for MS susceptibility, particularly with regard to the HLA-DRB1*1501 haplotype.     

A family-based study does not confirm the association of MYO9B with celiac disease in the Italian population

Association between Myosin IXB (MYO9B) gene polymorphisms and celiac disease (CD) was recently detected by a case-control association study in the Dutch, but not confirmed in the British and Swedish/Norwegian populations. We tested the association between CD and the three most associated single nucleotide polymorphisms (SNPs) in the Dutch study by the transmission disequilibrium test in the Italian population. A total of 252 pediatric patients and 504 parents were genotyped. No transmission distortion was detected either for the single SNPs or for their haplotypic combinations. Control allele frequencies, calculated from untransmitted alleles, were significantly different from those of the Dutch control population. Conversely, allele frequencies were very similar in Italian, British, Swedish/Norwegian and Dutch patients. In conclusion, MYO9B is not involved in CD susceptibility in the Italian population. The difference with the Dutch result might be explained by an imperfect selection of the Dutch controls.     

Lack of evidence for a significant association between nonsyndromic cleft lip with or without cleft palate and the retinoic acid receptor alpha gene in the Japanese population

 Nonsyndromic cleft lip with or without cleft palate (NSCLP) is one of the most common craniofacial malformations. Both genetic and environmental factors are thought to be involved in the pathogenesis. The retinoic acid receptor α (RARA) is one of the candidate genes for the pathogenesis of NSCLP. An association between a Pst I restriction fragment length polymorphism or D17S579 microsatellite marker polymorphism of the RARA gene and NSCLP was previously suggested, but no nucleotide change that may influence the gene expression or the protein sequence has been reported to date. To investigate the possible association between the RARA gene and NSCLP in Japanese patients, we performed a transmission disequilibrium test (TDT) using three microsatellite markers at the RARA locus in 48 parent–offspring trios. The allele-wise TDT did not show evidence of an association between the RARA gene and NSCLP. We also screened nucleotide changes in eight patients with family histories using exon-by-exon direct sequencing. We found a novel nucleotide change (1161C>T) that is located in exon 1 of the RARA gene in one patient whose father also had the disease. Because the 1161C>T was inherited from the patient's healthy mother, the mutation was not considered to be responsible for NSCLP. We then screened all probands for the nucleotide changes in the promoter region of the RARA gene using denaturing high-performance liquid chromatography. A novel nucleotide length polymorphism of a thymidine tract was identified in three patients. No association between this polymorphism and NSCLP was observed. Our findings suggest that the RARA gene variations do not contribute to the development of NSCLP in the Japanese population. Received: January 15, 2002 / Accepted: February 25, 2002