【作者】 周若宇；

【导师】 郑冰蓉；

【作者基本信息】 云南大学 ， 遗传学， 2010， 硕士

【摘要】 背景:系统性红斑狼疮是一种以产生自身抗体和免疫复合物为特点的自身免疫性疾病,其病因复杂,是感染、基因及环境各因素间互作的结果。TLR4基因在免疫功能中有重要的作用,一旦被外源或内源性片段,如细菌脂多糖、热休克蛋白等配体所激活,即可通过信号转导激活核转录因子NF-κB,并表达多种细胞因子及趋化因子,是参与天然免疫应答和激活获得性免疫的重要因素。为探究TLR4基因与自身免疫性疾病的联系,我们此次在云南汉族人群中开展系统性红斑狼疮与TLR4基因的相关性研究。材料与方法:553例系统性红斑狼疮病例及564例健康对照样本均采自昆明医学院第二附属医院。553例病例均符合1997年美国风湿病学会(ACR)对系统性红斑狼疮的修订诊断标准。采用PCR-RFLP和直接测序的方法对纳入研究样本的TLR4基因上3个单核苷酸多态位点(rs10759932,rs41426344,rs11536889)进行多态性检测。检测结果用SPSS11.5、Arelequin3.01、HaploView软件进行计算分析,并用logistic模型进行95%置信区间风险度测算。结果:1)在病例和正常对照样本中,TLR4中3个位点均检测到多态性。2)单位点分析结果显示rs11536889位点的基因型、等位基因频率在病例和正常对照样本中无显著差异,提示这一位点与系统性红斑狼疮的发生不相关;3)rs41426344的GC杂合突变基因型,rs10759932位点的等位基因C以及CC纯合突变基因型、CT杂合突变基因型均为患病危险因素,提高系统性红斑狼疮患病的风险性(校正后p<0.05)。4)rs41426344位点无论在病例还是正常对照组中的等位基因G、C及基因型频率与HapMap中R24人群(6个高加索人、6个非洲裔美国人、6个亚洲人和6个美国旧金山海湾区的西班牙人)分布频率相近,说明此位点等位基因的分布在不同人群或地域中没有较大的区别;5)rs10759932位点在正常对照组中得到的T的频率比祖先来自于北欧或西欧的美国犹他州居民(CEU)人群低约40%;rs11536889位点等位基因G的分布频率很接近东亚日本人群,而比欧洲高加索人群低11.05%,比非洲约鲁巴人群低23.55%,这在一定程度上提示,这两个位点的等位基因频率分布可能存在一定的地域或人群差异。结论:在云南汉族人群中,用病例—对照研究方法,对TLR4基因遗传多态与系统性红斑狼疮进行相关性研究,并对云南汉族人群中TLR4基因多态分布频率进行了统计分析,结果显示,TLR4基因上rs41426344和rs10759932位点的遗传多态性与系统性红斑狼疮的发生相关,TLR4基因中rs10759932和rs11536889位点表现出地域、人种的差异。更多还原

【Abstract】 Background and aims: Systemic lupus erythematosus (SLE) is an autoimmune disorder with the feature of autoantibodies production to a multitude of self-antigens. It can cause tissue and organs injury, and lead to many severe complicating diseases. Toll-like receptors 4(TLR4) plays a key role in innate immune and adaptive immune responses. It is predominantly activated by exogenous and endogenous ligands such as bacterial lipopolysaccharides (LPS), heat shock protein, fragment of hyaluronic acid. Activation of TLR4 can leads to activation of nuclear transcription factor such as NF-κB and expression of various inflammatory cytokines, which are important factors to both innate and adaptive immune. The aim of our study is to investigate the association between TLR4 single nucleotide polymorphisms and SLE in Yunnan Han Population.Methods: We recruited 553 SLE cases and 564 healthy controls from the Second Affiliated Hospital of Kunming Medical College. All samples are Han Population in Yunnan province and cases’diagnosis fulfilled the criteria of diagnostic guidelines draw up by America College of Rheumatology (ACR). We used polymerase chain reaction (PCR)-restriction fragment length polymerase (RFLP) and direct sequencing techniques to genotyping. The data is analysed by SPSS11.5, Arlequin 3.01, HaploView. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a logistic model.Results: 1)3 SNPs of TLR4 were all observed polymorphisms. 2)The single-locus analysis of rs11536889 showed it has no relationship with SLE. 3) GC heterozygote of rs41426344 and CT heterozygote, CC homozygote and C allele of rs10759932 may be the risk factors of SLE (adjusted P <0.05). 4) The frequencies of genotype and allele of rs41426344 are very close to the R24 group (6 Caucasian, 6 African American, 6 Asian, 6 Hispanic recruited from San Francisco Bay Area) in HapMap, indicated that might there is no distinct diversity among different population as to the SNP of this site. 5) The frequency of T alellel of rs10759932 in our control group is about 40% less than the CEU population. The G allele frequency of rs11536889 are as the same with Japanese population, while it is 11.05% lower than Caucansian polulation and 23.55% less than Yoruba population. These results showed in a certain extant that these two SNPs distribute variably in different ethnic groups and regions.Conclusion: This is the first time to analyse the relevance of TLR4 gene polymorphisms to SLE in Chinese Han Population in Yunnan Province. The present results show that TLR4 is a candidate gene related to SLE, and the TLR4 SNPs of rs41426344 and rs10759932 have been detected to be associated with SLE susceptibility. Moreover, the polymorphisms frequencies of TLR4 rs10759932 and rs11536889 are significant different among different ethnic groups.更多还原