Wnt/β-catenin调控肺泡微环境炎性信号在小鼠矽肺模型病理发生中的作用机制研究

Ningxia is an important industry basis of coal and constructive materials in China. Pneumoconiosis caused by dust is the main occupational disease that is as high as by 90.5% in this region, among them 58.9% are silicosis. Silicosis has caused a significantly negative impact on the quality of life and even the live of labors, which is the reason of causing and returning the poor for families with silicosis patients in Ningxia Hui Autonomous region. Therefore there is a scientific and actual significance in studying mechanisms in the development, progression and control of silicosis. It has been recognized that silicosis is a specific disease type of pulmonary fibrosis, and the Wnt/β-catenin signaling has been demonstrate to be involved in the injury repair of lung and the pathogenesis of pulmonary disease. However its role and underlying mechanism of Wnt/β-catenin signaling-regulated inflammary signaling of alveolar microenvironment in the pathogenesis of silicosis require a further investigation. This proposal thus about aims to explore the mechanism and regulatory role of Wnt/β-catenin signaling in alveolar microenvironment druing the pathogenesis of silicosis via an accomplishment of following three specific aims upon the establishment of in vitro alveolar microvironmental model: (1) in vitro study to demonstrate the impact of alveolar epithelia-derived Wnt/β-catenin signaling on silicon dioxide-induced inflammation in alveolar macrophages; (2) in vitro study to demonstrate the impact of interaction between alveolar epithelial Wnt/β-catenin and inflammatory signaling on the interstitial properties of pulmonary fibroblast in alveolar microenvironment; and (3) uncovering the potential mechanisms and pathogenic and immunoregulatory roles of interaction between epithelail Wnt/β-catenin and TLR signaling of macrophage in the pathogenesis of silicon dioxide-induced mouse silicosis using a MyD88-deficient mouse model. An accomplishment of this study will provide a novel insight for further studies of pathogenesis and targets for novel therapy of silicosis disease.

宁夏为我国主要煤炭和建材基地，矽肺占该地区职业病的58.9%，严重影响劳动者的生活质量和生命，是该地区许多家庭致贫和返贫的主要原因。因此对矽肺发生、发展和防治机制的研究，有着重要的科学与现实意义。矽肺是一种特殊类型的肺纤维化疾病，研究表明Wnt/β-catenin参与肺脏的损伤修复和肺脏纤维化的病理发生，但其调控肺泡微环境炎性信号在矽肺病理发生的机制不明。本项目将在构建人肺泡微环境体外模型的基础上，通过(1) 探讨肺泡上皮细胞Wnt/β-catenin调控二氧化硅诱导肺泡巨噬细胞炎性反应的作用机制；(2) 分析肺泡上皮细胞Wnt/β-catenin调控肺泡微环境炎性信号对肺脏成纤维细胞间质化特性的影响；(3)利用MyD88缺陷小鼠，探讨小鼠矽肺模型肺泡微环境 Wnt/β-catenin和TLR交互作用在二氧化硅诱导矽肺的病理发生机制，为深入研究矽肺的致病机制提供新的思路和靶点。

本研究首先构建了矽肺小鼠动物模型，结合矽肺患者临床标本探讨Wnt/β-catenin信号在矽肺纤维化病理发生中的作用，采用腺病毒载体介导的Dickkopf-1（Dkk1）基因（Wnt/β-catenin信号抑制剂）（AdDkk1）转导探讨Dkk1在矽肺基因治疗和抑制肺脏纤维化病理发生中的作用与机制，体外试验采用AdDkk1感染A549和人气道上皮细胞气液相(ALI)模型探讨Dkk1在SiO2诱导的上皮细胞间质转化及异常增殖中的调控作用；在成功建立体外上皮细胞SiO2损伤模型和小鼠矽肺模型的基础上，开展Wnt/β-catenin与Nox4信号相互作用对肺脏上皮细胞间质化，调控内质网应激和氧化还原失衡导致铁死亡的发生的作用机制研究，阐明Wnt经典信号在肺泡微环境中肺泡上皮细胞Wnt/β-catenin和巨噬细胞炎性信号相互作用在矽肺病理发生中的可能调控作用机制。主要取得以下成果：1）构建矽肺小鼠动物模型，结合矽肺患者临床标本探讨Wnt/β-catenin信号在矽肺纤维化病理发生中的作用；2）采用腺病毒载体介导的Dkk1基因转导探讨Dkk1在矽肺基因治疗和抑制肺脏纤维化病理发生中的作用与机制；3）揭示Wnt/β-catenin与Nox4信号相互作用对肺脏上皮细胞间质化的作用机制。这些发现对进一步探讨Wnt 信号在肺泡上皮细胞和巨噬细胞中的相互作用及矽肺病理发生中的调控作用机制提供有效治疗靶点，进而对阐明肺脏疾病病理发生机理有重要的理论意义。在项目实施期间，课题组发表论著10篇，其中SCI论文8篇，北大核心2篇；会议摘要1篇；授权国家发明专利1项，实用新型专利专利2；培养完成博士研究生2名，硕士研究生1名，顺利高质量超额完成项目的研究计划的总体设计目标，达到了预期的目的。