miR-148a调控Wnt5A拮抗剂基因甲基化修饰在结核感染过程中的机制研究

项目名称： miR-148a调控Wnt5A拮抗剂基因甲基化修饰在结核感染过程中的机制研究

项目编号： No.81472026

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 应斌武

作者单位： 四川大学

项目金额： 80万元

中文摘要： 已有研究表明Wnt5A、miRNA可能是结核感染过程中重要的分子调控靶点，但具体调控机制尚不清楚。课题组前期发现miR-148a在肺结核患者中表达下调；进一步的实验证实DNMT1是miR-148a 调控的靶基因；Wnt5A拮抗剂基因启动子呈高度甲基化修饰。基于前期研究，课题组提出结核分枝杆菌感染下调miR-148a表达，下调的miR-148a导致其靶基因DNMT高表达，后者通过调控Wnt5A拮抗剂基因甲基化修饰使其抑制功能缺失或减弱，介导Wnt5A通路异常激活，致过度炎症损伤，参与调控结核感染的过程。本研究拟用RT-PCR、MSP、siRNA转染、Western blot、原位杂交等技术，从细胞和整体水平较全面的探讨miR-148a调控Wnt5A拮抗剂基因甲基化修饰，异常激活Wnt信号通路，参与结核感染炎性反应的分子机制。本研究将为进一步找寻潜在的结核诊疗分子靶点提供新的方向。

中文关键词： 分子诊断；结核；微小RNA；信号通路；甲基化

英文摘要： Previous studies have shown that Wnt5A, miRNA may be molecular targets for tuberculosis infection, however, the mechanism is not clear. Our group found that the lower expression of miR-148a in patients with pulmonary tuberculosis (PTB); bioinformatics and functional experiment demonstrated that DNMT1 was the target gene regulated by miR-148a, and Wnt5A antagonist gene promoter was heavily methylated in PTB. Based on previous research, we proposed Mycobacterium tuberculosis infection activated miR-148a, inducing lower expression of miR-148a and up-regulation of DNMT expression, overexpression of DNMT induced Wnt5A antagonist gene promoter hypermethylation and silencing, leading to activation of the abnormal Wnt pathway mediated by Wnt5A, caused to excessive inflammatory injury in the tuberculosis infection . We will explore the mechanism that hypermethylation of Wnt5A antagonist gene promoter and subsequent excessive activation of Wnt5A signaling pathway mediated by miR-148a in the tuberculosis infection from the cellular and overall perspective, using RT-PCR, MSP, siRNA transfection, Western blot, in situ hybridization techniques. This study will provide a new direction to find potential molecular targets for diagnosis and treatment of tuberculosis.

英文关键词： molecular diagnosis;tuberculosis;miRNA;signaling pathway;methylation