Toll样受体4基因多态性与消化性溃疡和幽门螺杆菌感染的相关性研究

背景：幽门螺杆菌（H．pylori）感染是消化性溃疡的主要病因。脂多糖（LPS）通过TOU样受体（TLR）4激活核因子（NF）-KB，在抗感染免疫应答中起启动和调节作用。TLR4基因发生Asp299Gly突变可中断TLR4介导LPS信号传导。目的：研究我国湖北省汉族人群TLR4基因Asp299Gly多态性与消化性溃疡和肌pylori感染的关系。方法：采用病例对照研究和聚合酶链反应-限制性片段长度多态性（PCR-RFLP）法．检测126例消化性溃疡患者和264名正常对照者的TLR4等位基因Asp299Gly基因型分布。结果：消化性溃疡者肌pylori阳性率（90．5％）显著高于正常对照组（61．7％）（P〈0．0001，OR=5．889，95％CI：3．089-11．216）。在H．pylori感染相关性消化性溃疡组和正常对照组中均未发现TLR4基因Asp299Gly的突变型，其基因型、等位基因以及携带者频率总体分布无显著性差异。结论：本研究未能显示TLR4基因Asp299Gly基因多态性与H.pylori感染、H．pylori相关性消化性溃疡形成有相关性。     

类风湿关节炎与TLR4单核苷酸多态性关联研究的Meta分析

目的探讨类风湿关节炎(RA)与TLR4基因Asp299Gly多态性的关联情况。方法检索已发表的有关RA和TLR4基因Asp299Gly多态性的文献．进行Meta分析。结果3项研究共纳入718例RA患者和1392名正常对照，综合分析显示TLR4基因Asp299Gly多态性不是RA的关联基因，OR=1．23(0．67，2．25)，P=0．5；TLR4基因Asp299Gly多态性分布在男女性RA患者分布差异无统计学意义，OR=0．48(0．22．1．03)，P=0．06：在共同表位基因阳性和阴性患者组差异无统计学意义，OR=0．67(0．40，1．13)，P=0．13；在类风湿因子(RF)阳性和阴性患者组差异无统计学意义，OR=I．02(0．51，2．02)，P=-I；RA患者中，Asp299Asp基因型患者发病早于Asp299Gly基因型者，OR=-4．35(-7．45，-1．25)，P=0．006。结论Meta分析显示，TLR4基因Asp299Gly多态性与RA易感性无关联．但Asp299Asp基因型者起病早于Asp299Gly基因型者。应在东方人群进一步开展随机对照和前瞻的队列研究揭示其在RA发病中的作用。     

TLR4基因多态性与慢性胃炎幽门螺杆菌感染无相关性

目的:研究我国湖北汉族人群TLR4基因 Asp299Gly多态性与慢性浅表性胃炎及幽门螺杆(H pylori)感染的关系．方法:采用病例-对照研究和多聚酶链反应-限制性片段长度多态性(PCR-RFLP)方法,检测 115例慢性浅表性胃炎患者115例和正常对照者2644例的TLR4等位基因Asp299Gly基因型分布．结果:慢性浅表性胃炎患者的H pylori阳性率 89．6％,显著高于正常对照组61．7％(P<0．000 1, OR=5．319．95％CI:2．784-10．162)．在H pylori 感染相关性的慢性胃炎组和正常对照组中 TLR4基因Asp299Gly基因型所有个体均为 AA纯合子,未发现的突变型,其基因型、等位基因以及携带者频率总体分布无显著性差异．结论:TLR4基因Asp299Gly基因多态性与H pylori相性慢性胃炎无明显相关性．     

浙江汉族人群Toll样受体4基因多态性与幽门螺杆菌相关消化性溃疡的关系

背景：幽门螺杆菌（H.pylori）感染是消化性溃疡的主要病因,然而其致病性存在个体差异,可能与宿主遗传易感性和先天性免疫机制有关。Toll样受体（TLR）在机体的先天性抗感染免疫中起重要作用。目的：探讨浙江汉族人群TLR4基因Asp299Gly多态性与H.pylori相关消化性溃疡的关系。方法：以聚合酶链反应-限制性片段长度多态性（PCR-RFLP）方法检测118例浙江汉族消化性溃疡患者和210名健康对照者的TLR4基因Asp299Gly等位基因和基因型;行快速尿素酶试验和血清H.pyloriIgG检测判断H.pylori感染情况。结果：本组浙江汉族人群TLR4基因Asp299Gly均为AA纯合子基因型,未见突变基因型AG和GG。消化性溃疡组H.pylori感染率为94.9%,显著高于正常对照组的62.4%（P=0.000）;两组Asp299Gly基因型频率差异无统计学意义。结论：浙江汉族人群TLR4基因Asp299Gly多态性与H.pylori相关消化性溃疡无相关性。     

TLR4基因Asp299Gly及TLR2基因Arg753Glu、Arg677Trp多态性与中国湖北汉族炎症性肠病无相关性

目的:研究TLR4基因Asp299Gly及LTLR2基因 Arg753Glu及Arg677Trp多态性在中国汉族人群中的分布,探讨其与炎症性肠病的相关性．方法:采用聚合酶链反应-限制性片段长度多态性方法,检测120例中国湖北汉族炎症性肠病患者与110例正常对照者TLR4 基因ASp299Gly及TLR2基因Arg753Glu及 Arg677Trp基因型,分析该基因多态性与炎症性肠病以及临床亚型的相关性．结果:炎症性肠病患者和健康对照者均未检测出TLR4基因ASp299Gly及TLR2基因 Arg753Glu及Arg677Trp突变型．结论:TLR4基因Asp299Gly及TLR2基因 Arg753Glu及Arg677Trp基因多态性与中国湖北汉族人群炎症性肠病的易感性无相关性．     

TLR4和TNF-α基因多态性与支气管哮喘的相关性研究

目的探讨Toll样受体4和肿瘤坏死因子-α基因多态性与支气管哮喘的关系。方法采用病例对照研究和PCR-DNA测序的方法,检测50例支气管哮喘患者和30例对照组的TLR4的Asp299Gly和TNF-308的基因多态性。结果 （1）在支气管哮喘和健康对照组间,未发现TLR4Asp299Gly突变型。（2）支气管哮喘和正常对照组间未发现存在TNF-308G-A替换多态性。结论 （1）TLR4Asp299Gly基因多态性与支气管哮喘的易感性不相关,TNF-α基因多态性与支气管哮喘的易感性无相关性。     

CD14启动子-260位点基因多态性对糖尿病肾病的影响

目的探讨CD14启动子-260位点基因多态性对糖尿病肾病（DN）的影响。方法应用PCR直接测序法对437例2型糖尿病（T2DM）患者（T2DM组）及145例正常者（对照组）的CD14启动子C-260T基因多态性进行分析。结果两组CD14启动子-260位点基因型分布及等位基因频率均无统计学差异（P〉0．05）;非DN与DN患者比较,其CD14启动子-260位点CC基因与CT＋TT基因有统计学差异（P〈0．05）。结论CD14启动子-260C／T基因多态性与糖尿病发病无相关性,但其CC基因是T2DM患者进展为DN的遗传学风险因素。     

过氧化物酶体增殖活化受体γ基因Pro12Ala和C161T多态性与溃疡性结肠炎的相关性

目的研究过氧化物酶体增殖活化受体γ（PPAR-γ）基因Pro12Ala和C161T位点的多态性与湖北汉族人群溃疡性结肠炎（UC）的相关性。方法采用多聚酶链式反应-限制片段长度多态性分析方法（PCR-RFLP）,对212例UC患者和220例健康对照者进行PPAR-γ基因分型。结果UC患者PPAR-γ基因C161T位点C／T基因型频率,T等位基因频率明显高于正常组（35．4％比25．0％,P=0．015,OR=1．69,95％CI=1．12～2．57;20．1％比12．9％,P=0．006,OR=1．68,95％CI=1．17～2．43）,T等位基因携带者也高于正常对照组（37．7％比25．5％,P=0．007,OR=1．77,95％CI=1．18～2．68）。而Pro12Ala位点基因型频率,等位基因频率UC组与对照组比较差异无统计学意义（P〉0．05）。结论PPAR-γ基因C161T位点基因T等位基因与湖北汉族人群UC的发生存在相关性。     

转化生长因子β1-509C／T基因多态性与大肠癌的关系

目的研究转化生长因子β1（TGF—β1）基因-509位点C／T的多态性,并探讨其与大肠癌易感性的关系。方法采用聚合酶链反应-限制性片段长度多态性方法,检测70例大肠癌组和102例对照组TGF—β1基因-509位点C／T等位基因及基因型分布,并对该基因多态性与大肠癌临床病理特征之间的关系进行分析。同时采用酶联免疫吸附试验（ELISA）检测大肠癌组和对照组血清TGF—β1水平。结果TGF—β1等位基因频率及基因型频率在大肠癌组和对照组的总体分布比较无显著性差异。大肠癌组按Dukes分期后,发现DukesC＋D期大肠癌患者-509CT／TT基因型频率明显高于DukesA＋B期患者（64．9％比39．4％,P=0．033,OR=2．840,95％CI：1．075～7．501）。DukesC＋D期大肠癌患者与DukesA＋B期相比,-509T等位基因频率有增高趋势（41．9％比27．3％,P=0．07,OR=1．922,95％CI：0．943～3．917）,但差异无显著性。大肠癌患者血清TGF—β1水平显著高于对照组。结论TGF—β1-509位点基因多态性与大肠癌无关,可能与大肠癌临床分期有关。     

新疆维汉民族CD14基因C(-260)→T多态性与冠心病、血脂的关系

目的研究新疆地区维汉民族患者CD14基因启动子C（-260）→T位点多态性的分布特点及其与冠心病（CHD）、血脂的相关关系。方法采用聚合酶链反应-限制性片段长度多态性（PCR—RFLP）技术的分析方法，检测了390例新疆地区维汉患者CD14基因启动子C（-260）→T多态性，同时检测其血脂水平；以冠状动脉造影为“金标准”，区分CHD组及对照组。结果新疆地区汉族患者中CD14基因启动子-260位点CC、CT和TT基因型频率在CHD组和对照组分别为20．33％、52．70％、26．97％和37．58％、43．63％、18．79％，等位基因C、T频率分别为46．68％、53．32％和59．40％、40．60％。该基因多态性的分布在维汉民族间差异均无统计学意义；与国外不同种族相比，仅与捷克人群差异有统计学意义（P〈0．05）。同时该位点多态性与血脂水平间不存在相关关系（P〉0．05）。结论CD14基因C（-260）→T位点多态性与新疆地区维汉人群CHD发病具有相关性，T等位基因可能是CHD的遗传易感基因；该位点多态性在维汉民族间的分布差异无统计学意义；与捷克、德国、日本、美国等不同种族人群进行比较，该位点多态性仅与捷克人群差异有统计学意义。该多态性不同基因型间血脂水平差异无统计学意义，其致CHD机制可能与血脂代谢无关。     

Polymorphism of CD14 gene but not the mutation of TLR4 gene is associated with colorectal cancer in Chinese patients

Objectives: Toll‐like receptor 4 and CD14 are components of the lipopolysaccharide receptor complex. Our study aimed to investigate an association between TLR4 Asp299Gly and CD14‐260 polymorphisms in Chinese patients with colorectal cancer. Method: By a method of polymerase chain reaction–based restriction fragment length polymorphism (PCR‐RFLP), we genotyped TLR4 Asp299Gly and CD14‐260 polymorphisms in 110 unrelated patients with colorectal cancer and 160 healthy controls from the Chinese Han population. Results: We found significant differences in CD14 genotypes between healthy controls and patients with colorectal cancer. The frequency of the C/C genotype in healthy controls (15.6%) was significantly lower than in the group of colorectal cancer patients (32%). The frequency of the C/T genotype in healthy controls (48.1%) was significantly higher than that in the group of colorectal cancer patients (31%). No TLR4 Asp299Gly mutation was detected in any patients or healthy controls in the Chinese Han population. Conclusions: These findings indicated that the polymorphism of CD14 but not TLR4 Asp299Gly mutation was associated with Chinese patients with colorectal cancer, and the CD14 gene may contribute to the predisposition to colorectal cancer. Screening for the CD14 C‐260T genotype is likely to be a useful tool for risk assessment or prognostication for colorectal cancer in the Chinese Han population.     

Genetic polymorphism in CD14 gene,a co-receptor of TLR4 associated with non-alcoholic fatty liver disease

AIM To evaluate the pathogenic role of toll-like receptor(TLR) gene polymorphisms in patients with nonalcoholic fatty liver disease(NAFLD).METHODS Two hundred and fifty subjects(NAFLD = 200, healthy volunteers = 50) underwent polymerase chain reaction and restriction fragment length polymorphism to assess one polymorphism in the toll-like receptor 2(TLR2) gene(A753G), two polymorphisms in the TLR4 gene(TLR4 Asp299 Gly and Thr399 Ile allele), and two polymorphisms in the cluster of differentiation 14(CD14)(C-159 T and C-550T) gene, a co-receptor of TLR4. Association of TLR gene polymorphisms with NAFLD and its severity was evaluated by genetic models of association.RESULTS On both multiplicative and recessive models of gene polymorphism association, there was significant association of CD14 C(-159) T polymorphism with NAFLD; patients with TT genotype had a 2.6 fold increased risk of developing NAFLD in comparison to CC genotype. There was no association of TLR2 Arg753 Gln, TLR4 Asp299 Gly, Thr399 Ile, and CD14 C(-550) T polymorphisms with NAFLD. None of the TLR gene polymorphisms had an association with histological severity of NAFLD.CONCLUSION Patients with CD14 C(-159) T gene polymorphism, a co-receptor of TLR4, have an increased risk of NAFLD development.     

Association of the ASP299GLY TLR4 polymorphism with COPD

Bacterial infection and colonization plays an important role in COPD. The inflammatory response to these bacteria is mediated by Toll-like receptors. The Asp299Gly polymorphism of the Toll-like receptor-4 (TLR4) has been shown to be associated with decreased lipopolysaccharide (LPS) signal transduction resulting in impaired antimicrobial defense. Because altered TLR4 signalling may facilitate bacterial infection, we clinically phenotyped and genotyped 152 patients with COPD (including 24 non-smokers), and 444 healthy controls for the presence of the Asp299Gly polymorphism. Frequencies of the TLR4 Gly allele (4% vs. 8% in controls, odds ratio (OR) 2.24 (95% confidence interval (95%CI) 1.17-4.3)) as well as TLR4 Gly genotype (6% vs. 13% in controls, OR 2.39 (95%CI 1.20-4.79)) were significantly decreased among the patients with COPD. The TLR4 Gly allele was not detected at all in a subgroup of non-smoking patients (n=24). We conclude that the frequency of the Asp299Gly polymorphism is decreased in COPD patients. Unaltered LPS signal transduction by TLR4 may be important for the development of COPD.     

Deficient host-bacteria interactions in inflammatory bowel disease? The toll-like receptor (TLR)-4 Asp299gly polymorphism is associated with Crohn's disease and ulcerative colitis

BACKGROUND AND AIMS: Elicitation of an innate immune response to bacterial products is mediated through pattern recognition receptors (PRRs) such as the toll-like receptors (TLRs) and the NODs. The recently characterised Asp299Gly polymorphism in the lipopolysaccharide (LPS) receptor TLR4 is associated with impaired LPS signalling and increased susceptibility to Gram negative infections. We sought to determine whether this polymorphism was associated with Crohn's disease (CD) and/or ulcerative colitis (UC). METHODS: Allele frequencies of the TLR4 Asp299Gly polymorphism and the three NOD2/CARD15 polymorphisms (Arg702Trp, Gly908Arg, and Leu1007fsinsC) were assessed in two independent cohorts of CD patients (cohort 1, n = 334; cohort 2, n = 114), in 163 UC patients, and in 140 controls. A transmission disequilibrium test (TDT) was then performed on 318 inflammatory bowel disease (IBD) trios. RESULTS: The allele frequency of the TLR4 Asp299Gly polymorphism was significantly higher in CD (cohort 1: 11% v 5%, odds ratio (OR) 2.31 (95% confidence interval (CI) 1.28-4.17), p = 0.004; and cohort 2: 12% v 5%, OR 2.45 (95% CI 1.24-4.81), p = 0.007) and UC patients (10% v 5%, OR 2.05 (95% CI 1.07-3.93), p = 0.027) compared with the control population. A TDT on 318 IBD trios demonstrated preferential transmission of the TLR4 Asp299Gly polymorphism from heterozygous parents to affected children (T/U: 68/34, p = 0.01). Carrying polymorphisms in both TLR4 and NOD2 was associated with a genotype relative risk (RR) of 4.7 compared with a RR of 2.6 and 2.5 for TLR4 and NOD2 variants separately. CONCLUSION: We have reported on a novel association of the TLR4 Asp299Gly polymorphism with both CD and UC. This finding further supports the genetic influence of PRRs in triggering IBD.     

Has toll-like receptor 4 been prematurely dismissed as an inflammatory bowel disease gene? Association study combined with meta-analysis shows strong evidence for association

OBJECTIVES: Published association studies of the TLR4 Asp299Gly polymorphism and inflammatory bowel disease (IBD) in caucasian populations have inconsistent results. We tested two TLR4 variants for association with IBD in the New Zealand caucasian population and assessed the cumulative evidence for association of TLR4 Asp299Gly and IBD. METHODS: The TLR4 Asp299Gly and Thr399Ile polymorphisms were genotyped and tested for case-control frequency differences in a New Zealand white cohort of 389 Crohn's disease (CD) patients, 405 ulcerative colitis (UC) patients, and 416 population controls. Meta-analysis using a random effects model was performed to test whether 299Gly carriage was associated with UC, CD, or phenotypes of CD patients. RESULTS: There were no significant allele or genotype frequency differences between cases and controls or between CD phenotypes in our New Zealand data. Meta-analysis did not identify any significant associations between CD phenotypes and 299Gly carriage. However, meta-analysis demonstrated significantly higher 299Gly carrier frequencies in CD patients (odds ratio 1.45, 95% CI 1.11-1.90) and in IBD patients (odds ratio 1.36, 95% CI 1.01-1.84) compared to controls. CONCLUSIONS: The meta-analysis provides evidence that Asp299Gly is associated with CD and IBD in whites. Only the Asp299Gly polymorphism has been consistently genotyped in previous TLR4 studies with IBD patients, therefore other TLR4 variants with stronger associations with IBD may exist. Additional well-powered studies of Asp299Gly and other TLR4 variants are urgently needed.     

Lack of association of single nucleotide polymorphisms in toll-like receptors 2 and 4 with enthesitis-related arthritis category of juvenile idiopathic arthritis in Indian population

Toll-like receptors 2 and 4 are over expressed in patients with enthesitis-related arthritis and cause increased production of pro-inflammatory cytokines. This aberrant functioning could be due to polymorphisms in TLR2 and TLR4. Hence, we genotyped ERA patients for Arg753Gln and Arg677Trp polymorphism in TLR2 gene and Asp299Gly and Thr399Ile polymorphism in TLR4 gene. DNA was extracted from blood from ERA patients and healthy controls. All four polymorphisms were studied by PCR–RFLP method. 200 healthy controls and 97 ERA patients were enrolled. All healthy controls and patients had wild-type allele for Arg753Gln and Arg677Trp TLR2 polymorphism. Regarding TLR4, Asp299Gly polymorphism A allele frequency was 90 % in controls and 96 % in patients (OR 2.7, 95 % CI 0.81–8.8). GG homozygous genotype was detected in one healthy control and was absent from patients. The TLR4 Thr399Ileu variant was not detected in patients. Out of 200 healthy controls, 10 were heterozygous (5 %) and only one was homozygous for rare variant (0.5 %). Polymorphisms in TLR2 and TLR4 are not associated with ERA.     

The role of Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms and CARD15/NOD2 mutations in the susceptibility and phenotype of Crohn's disease

BACKGROUND: We investigated the influence of 2 common Toll-like receptor 4 (TLR4) polymorphisms on susceptibility and disease characteristics of Crohn's disease (CD). METHODS: Genomic DNA from 204 patients with CD and 199 unrelated controls was analyzed for the presence of 2 single nucleotide polymorphisms in the TLR4 gene, resulting in the amino acid substitutions Asp299Gly and Thr399Ile. In addition, the carrier status for the 3 common CD-associated CARD15/NOD2 gene mutations, Arg702Trp, Gly908Arg, and 1007fs, was determined. The frequency of the different genotypes was compared, and a detailed genotype-phenotype correlation was performed. RESULTS: An almost 2-fold increase in the frequency of the TLR4 Asp299Gly phenotype was observed in patients with CD (14.2%) compared with healthy controls (7.5%, P = 0.038, odds ratio = 2.03). The prevalence of a stricturing phenotype was increased in patients heterozygous for 1 of the TLR4 polymorphisms studied (Asp299Gly, 34.5%; Thr399Ile, 36.7%) compared with patients with wild-type TLR4 (17.1% and 16.7%; P = 0.04 and 0.02, respectively). The presence of the Asp299Gly polymorphism in the absence of CARD15/NOD2 mutations was a particularly strong predictor of the stricturing disease phenotype that was present in 47.4% of the patients with Asp299Gly+/NOD2- compared with 10.1% of the patients with the Asp299Gly-/NOD2+ status (P = 0.0009; P = 0.0004 for Thr399Ile+/NOD2- versus Thr399Ile-/NOD2+). In contrast, there was a trend toward a higher prevalence of the penetrating phenotype in the TLR4-/NOD2+ group (71.6%) compared with the TLR4+/NOD2- group (47.4%, P = 0.059). CONCLUSIONS: The TLR4 Asp299Gly polymorphism is a risk factor for CD. TLR4 and CARD15/NOD2 mutations may contribute to distinct disease phenotypes.     

Variant Toll-like receptor4 (Asp299Gly and Thr399Ile alleles) and Toll-like receptor2 (Arg753Gln and Arg677Trp alleles) in colorectal cancer

The innate immune system recognizes the presence of bacterial products through the expression of a family of membrane receptors known as Toll-like receptors (TLRs). Polymorphisms in TLRs have been shown to be associated with increased susceptibility to diseases such as inflammatory bowel disease. The aim of this study was to determine whether there was a correlation between polymorphisms of TLR4 (Asp299Gly; Thr399Ile) and TLR2 (Arg677Trp; Arg753Gln) genes and risk of colorectal cancer. DNA from 60 colorectal carcinoma patients from 3 major races in Malaysia (22 Malays, 20 Chinese and 18 Indians) and blood from 50 apparently healthy individuals were evaluated. Control group were matched to study group by race and age. The polymorphisms were determined by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). Genotyping results showed two out of sixty tumour specimens (3.3%) harbored both variant TLR4 Asp299Gly and Thr399Ile alleles. In contrast, DNA isolated from blood cells of 50 apparently healthy individuals harbored wild type TLR4. In the case of TLR2 Arg753Gln genotyping, all of the fifty normal and 60 tumours were of the wild type genotype. TLR2 Arg677Trp genotyping showed a heterozygous pattern in all samples. However, this may not be a true polymorphism of the TLR2 gene as it is likely due to a variation of a duplicated ( pseudogene) region. There was only a low incidence (2/60; 3.3%) of TLR4 polymorphism at the Asp299Gly and Thr399Ile alleles in colorectal cancer patients. All normal and tumour samples harbored the wild type TLR2 Arg753 allele. Our study suggests that variant TLR4 (Asp299Gly and Thr399Ile alleles) as well as TLR2 (Arg753Gln allele) are not associated with risk of colorectal cancer.