Toll样受体4信号通路分子群单核苷酸多态性与游离脂肪酸交互作用参与2型糖尿病发生的分子机制研究

Type 2 diabetes mellitus (T2DM) is a chronic systemic metabolic disease in which hyperglycemia is caused by insulin resistance and defects in islet beta cell insulin secretion. T2DM is a complex, polygenic disease that results from the interplay of genetic and environmental factors. Toll-like receptor 4 (TLR4) signaling pathway and free fatty acids are important risk factors for T2DM occurrence. Single nucleotide polymorphism (SNP), one of the most common human genetic variations, is closely related to the susceptibility of complex diseases such as diabetes, osteoporosis, and cancer. Studies have shown that TLR4 SNPs are significantly correlated with T2DM risk, but the molecular mechanism by which SNPs contributed to T2DM is still unclear. This project aims to conduct a large sample of case - control study to explore SNPs in the TLR4 signaling pathway that can be used for assessing the risk of T2DM, and further to elucidate its molecular mechanisms. (1)This study focus on analyze the comprehensive index including to the peripheral blood samples of T2DM patients, high-throughput SNP detection method, combined with the epidemiological data and clinical information of T2DM patients, bioinformatics and statistical methods to investigate the relationship of SNPs in TLR4 signaling pathway with T2DM, further systematically to define whether the correlation is associated with fatty acid profiles. (2)The second part of the project intends to use the cell model to elucidate the molecular mechanisms by which SNPs in the TLR4 signaling pathway interacted with some specific free fatty acid contributed to T2DM. This study will provide a theoretical basis for the assessment of risk of T2DM by TLR4 signaling pathway molecules group SNPs and will establish the important foundation for future clinical diagnosis and treatment of T2DM.

2型糖尿病（T2DM）是由遗传和环境因素共同参与引起的慢性全身性代谢疾病。Toll样受体4（TLR4）信号通路与脂肪酸是T2DM发生的重要因素。单核苷酸多态性（SNP）是一种最常见的可遗传变异，与复杂性疾病的易感性密切相关。已有研究表明TLR4 SNPs与T2DM显著相关，但分子机制尚不清楚。本项目拟进行大样本的病例－对照研究，寻找能够用于评估T2DM发病风险的SNPs，并阐明其分子机制。①利用T2DM患者外周血液标本，通过高通量的SNP检测方法，结合患者流行病学资料，采用生物信息学及统计学方法，系统的研究TLR4信号通路分子群SNPs与T2DM的相关性，并明确这种相关性是否与脂肪酸谱有关联；②利用细胞模型阐明SNPs与特定脂肪酸交互作用参与T2DM发生的分子机制。本研究将为TLR4信号通路分子群SNPs评估T2DM的发病风险提供理论依据，并为以后临床诊断和治疗T2DM奠定较为重要的基础。

2型糖尿病(T2DM)是由遗传和环境因素共同参与引起的慢性全身性代谢疾病。Toll样受体4（TLR4）信号通路与脂肪酸是T2DM发生的重要因素。单核苷酸多态性(SNP)是一种最常见的可遗传变异，与复杂性疾病的易感性密切相关。本项目以1000例T2DM和1000例健康人为研究对象，收集了研究对象外周血提取DNA，对研究对象进行了流行病学调查和膳食调查，采用生物信息法，筛选了可能与T2DM发病风险相关的TLR4信号通路分子群SNPs；高通量SNP检测方法检测了18个TLR4信号通路分子群SNPs；气相色谱－质谱联用（GC-MS）技术平台检测检测了研究对象17种血清游离脂肪酸；结合患者流行病学资料，采用生物信息学及统计学方法，研究了TLR4信号通路分子群SNPs与T2DM发病风险的关系，并阐明其分子机制。利用胰岛细胞MIN6细胞系通过转染有关SNPs,研究了筛选出的SNPs对细胞凋亡、细胞周期和胰岛素分泌的影响。结果发现：T2DM患者与健康人群在流行病学方面的差异与以往的研究结果基本一致；最终从TLR4相关SNPs中筛选出最有可能与T2DM发病风险有关的5个SNPs；单因素二元logistics回归分析表明，有6种脂肪酸C16:0、C18:0、C20:0、C22:0、C20:2 (n-6)、C20:4 (n-6)与T2DM发病呈正相关，6种脂肪酸C18:1 (n-9)、C18:2 (n-6)、C18:2 (n-6)、C18:2 (n-6)、C22:6 (n-3)和γ-C18:3 (n-3)与T2DM发病呈负相关；分析SNPs与T2DM相关性发现，rs10983755、rs7873784、rs10759932和rs11536889等4个SNPs与T2DM发病风险相关；rs10983755、rs7873784、rs10759932和rs11536889等与4个SNP与游离脂肪酸C18:0、C20:5 (n-3)、C22:6(n-3)、C18:2(n-6)脂肪酸之间只存在很弱的相关关系；miRNA-30a可能是调控TLR4表达的关键因素，有可能用于T2DM的预测。细胞验证发现，SNPs转染MIN6细胞系后，细胞活力有所下降，凋亡相关蛋白及其mRNA的表达没有显著变化，经葡萄糖刺激后，MIN6细胞的胰岛素分泌没有增加。本研究为TLR4信号通路分子群SNPs评估T2DM的发病风险提