【作者】 刘文；

【导师】 董亮；

【作者基本信息】 山东大学 ， 内科学， 2012， 硕士

【摘要】 研究背景：支气管哮喘是由多种炎性细胞(如嗜酸性粒细胞、肥大细胞、T淋巴细胞、中性粒细胞等)、气道结构细胞(如平滑肌细胞、气道上皮细胞等)和细胞组分参与的气道的一种慢性变态反应性炎症性疾病,是常见的慢性呼吸系统疾病之一,全球有3亿支气管哮喘患者,我国支气管哮喘患者已超过2000万。许多患者的病程长达十几年至几十年,有些已影响其劳动能力及生活质量,成为患者家庭和全社会沉重的负担。因此,从发病机制入手寻找治疗治愈支气管哮喘的方法已成为亟待解决的社会问题,然而支气管哮喘的发病机制十分复杂,主要包括遗传因素和环境因素两个方面。多数家系聚集、孪生及大的遗传队列研究均证实,支气管哮喘存在着遗传易感性。近些年来实验研究证实发现,一种IL-7样细胞因子,也就是胸腺基质淋巴细胞生成素(TSLP)在支气管哮喘发生、发展中起重要作用。日本学者Michishige等研究发现TSLP的3个单核苷酸多态位点(SNP)(rs3806933、rs2289276和rs2289278)中的rs3806933和rs2289276与儿童及成人支气管哮喘均相关,位点rs2289278与支气管哮喘的肺功能受损相关。研究目的：检测中国汉族人群胸腺基质淋巴细胞生成素(thymic stromal lymphopoietin,TSLP)基因启动子区域的单核苷酸多态(single-nucleotide polymorphism, SNP)位点Rs2289276及Rs2289278的多态性,利用基于群体的病例对照关联分析探讨TSLP基因启动子区域单核苷酸多态与中国汉族哮喘相关性及与肺功能相关性研究。研究方法：收集531例支气管哮喘患者及年龄、性别匹配的正常对照540例,根据知情同意原则采集2m1外周血,提取外周血DNA,进行合酶链反应,采用聚合酶链反应一限制性片断长度多态性(polymerase chain reaction and restriction fragment length polymorphism,PCR-RFLP)方法检测TSLP基因启动子区域SNP位点Rs2289276及Rs2289278的基因型,计算基因型频率及等位基因频率,进行x2检验,探讨两SNP位点与哮喘相关性及等位基因与肺功能相关性。研究结果：Rs2289276位点CC/CT/TT基因型频率在病例组中为0.4706/0.4392/0.0902,在对照组中为0.5604/0.3800/0.0595；Rs2289278位点CC/CT/TT基因型频率在病例组中为0.6502/0.2966/0.0532,在对照组中为0.5795/0.3428/0.0777,两位点的基因型、等位基因分布以及单倍体型分布在哮喘组与对照组之间均有统计学差异(P≤0.05)。Rs2289278位点C等位基因与FEV,/FVC的下降相关(P≤O.05)。研究结论：1.中国汉族人群TSLP基因启动子区域单核苷酸多态Rs2289276和Rs2289278与支气管哮喘易感性相关。2.Rs2289278位点C等位基因与FEV1/FVC的下降相关。3. TSLP基因可能为支气管哮喘的易感基因之一。更多还原

【Abstract】 Background:Asthma is a chronic inflammatory disease of the airway that is mediated by T-helper2(TH2) cells leading to airway inflammation by eosinophils and mast cells, goblet cell hyperplasia, and bronchial hyperresponsiveness. There are nearly300million asthmatic patients in the word,and in China the number is over20million. The course of the disease is from teens to dozens and seriously affect the life quality and labor ability, which make the patients become a burden of the society. Finding the pathology mechanism of bronchial asthma and curing asthma from its pathology mechanism become an important social problem. The pathology mechanism of bronchial asthma is very complicated and it often contains hereditary factors and environmental factors. Thymic stromal lymphopoietin(TSLP) is normally expressed in epithelial cells of the lung and skin.Recent studies have found that high levels of TSLP are associated with airway inflammatory disease in human and mice. TSLP can aggravate asthmatic lung inflammation by activating dendritic cells (DCs)to promote TH2differentiation. TSLP promoter polymorphisms are associated with susceptibility to bronchial asthma in Japanese population. We sought to determine whether single nucleotide polymorphisms (SNPs) in TSLP promoter region are associated with asthma in Chinese han population.Objective:To analyze the polymorphism of two single nucleotide polymorphisms(SNPs) Rs2289276and Rs2289278in TSLP(thymic stromal lymphopoietin)gene promoter region and to evaluate the association between the two SNPs and asthma susceptibility in Chinese Han population by using case-control study.Methods:531asthmatic patients and540age-sex matched normal controls were collected and DNA was extracted from the white blood cells in peripheral blood, then the genotypes of SNPs Rs2289276and Rs2289278in TSLP gene promoter region were detected with polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP), Hardy-Weinberg equilibrium was tested using chi-square test to make sure that all the polymorphisms were at Hardy-Weinberg equilibrium in both asthma patients and normal controls involved in this study. Genotype and allele frequency were calculated and analyzed with Chi-square test to determine whether the polymorphisms were associated with asthma. Association between lung functions and variants within patients with asthma was analyzed by the Jonckheere-Terpstra test. P-values were calculated with SPSS statistical software.Results:Frequencies of CC/CT/TT genotypes at Rs2289276site were0.4706/0.4392/0.0902in the asthmatic patients and0.5604/0.3800/0.0595in the healthy controls. Frequencies of CC/CG/GG genotypes at Rs2289278site were0.6502/0.2966/0.0532in the asthmatic patients and0.5795/0.3428/0.0777in the healthy controls. The genotype and allele frequencies of the two SNPs in asthma patients were significantly different from those in the healthy controls.(Details were showed in table1)Rs2289278C allele was correlated with decreased FEV1:FVC (P≤0.05).Conclusions:TSLP variants are significantly associated with bronchial asthma and decreased lung function. TSLP might be a new therapeutic target molecule for asthma.更多还原