自噬逃脱线粒体DNA介导TLRs-MyD88-NFκB信号通路在呼吸机相关性肺损伤中的作用机制

项目名称： 自噬逃脱线粒体DNA介导TLRs-MyD88-NFκB信号通路在呼吸机相关性肺损伤中的作用机制

项目编号： No.81460016

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 潘灵辉

作者单位： 广西壮族自治区肿瘤防治研究所

项目金额： 45万元

中文摘要： 前期研究表明：在VILI中TLR9、MyD88、NF-κB及炎性因子表达上调，但TLRs在VILI中的作用机制尚未清楚。有报道认为细胞受刺激后，线粒体DNA活化TLR9，募集趋化嗜中性粒细胞脱颗粒，造成器官损伤。我们假设：压力牵张导致细胞线粒体损伤，逃逸线粒体DNA介导信号传导，诱发炎症反应，导致VILI。为了阐明假设，建立VILI动物模型，研究mtDNA及DNaseⅡ的表达，阐明细胞自噬与VILI的作用机制；提取肺巨噬细胞、中性粒细胞、肺泡上皮细胞，检测mtDNA的表达，分析mtDNA的细胞来源；应用TLR9的激动剂、抑制剂及应用慢病毒转染、自噬诱导剂和自噬抑制剂分别作用于动物体内及体外肺巨噬细胞，研究mtDNA与炎性因子释放及TLRs表达，探讨mtDNA与TLRs/MyD88/NF-κB信号通路介导炎症反应的相关性,阐明VILI发生的分子机制，为有效防治VILI提供新的理论依据。

中文关键词： 呼吸机相关性肺损伤；线粒体DNA；细胞自噬；toll样受体；信号通路

英文摘要： It is demonstrated in our previous studies that TLR9, MyD88, NF-κB, IL-1β, IL-6 up-regulate significantly in the experimental VILI, but the roles of TLR ligands in the VILI have not yet been fully elucidated. Several studies have convincingly shown that neutrophil degranulation accumulation recruit by activated TLR9 via mitochondrial DNA after cell damage result in inflammatory response, contribute to organ damage. We sought to propose the hypothesis that, pressure tension will cause mitochondria damage and the escape of mitochondrial DNA thus mediate signal transduction which leads to inflammatory response, and eventually VILI. In order to elucidate the assumption, lung tissue and cells of mtDNA and DNase Ⅱ expressions were detected in models of VILI to clarify the mechanism of cell autophagy in VILI. And to investigate the source of mtDNA in the VILI, pulmonary macrophages, neutrophils, alveolar epithelial cells were extracted and detection of their mtDNA were required. Pulmonary macrophage in vivo and vitro were stimulated with agonists and inhibitor of TLR9, autophagy inducers and autophagy inhibitors respectively to detect the expressions of mtDNA, inflammatory cytokines and TLRs , and to investigate the relation between mtDNA and TLRs/MyD88/NF-κB signaling pathway which mediated inflammatory response. This research will further clarify the molecular mechanism of VILI, which would provide new clues of treatment for VILI.

英文关键词： VILI;mitochondrial DNA;autophagy;TLRs;signaling pathway