自噬减轻GSDMD介导的小管上皮细胞线粒体损伤和肾脏纤维化的研究

线粒体受损释放DNA（mtDNA）可促发炎症反应。我们发现敲除小管上皮细胞（TEC）自噬基因Atg5可加重小鼠肾脏炎症反应和纤维化，抑制自噬增加TGF-β1诱导的mtDNA释放和cGAS蛋白水平；GSDMD可易位至线粒体，下调其表达能阻抑mtDNA释放和纤维化；敲除Atg5增加梗阻性肾病组织GSDMD蛋白水平，Atg5与GSDMD存在相互作用。提示自噬可抑制GSDMD介导的线粒体损伤，但机制不清。本项目拟应用基因敲除小鼠的慢性肾病模型，证实自噬、GSDMD表达、线粒体损伤与纤维化的关系；应用上述小鼠原代TEC，上调/沉默HK-2细胞Atg5/GSDMD表达，明确两者调控mtDNA释放和炎症反应的作用，研究自噬靶向调控线粒体损伤的关键分子和机制；前瞻性探讨Atg5和GSDMD表达与慢性肾病的联系。本研究有助于揭示自噬靶向抑制线粒体损伤和炎症反应的作用和机制，为临床防治肾脏纤维化提供科学依据。

Mitochondrial release of DNA (mtDNA) triggered inflammatory response. We found that specific knockout of the autophagy gene Atg5 in mouse tubular epithelial cells (TEC) aggravated renal inflammation and fibrosis, and inhibition of autophagy increased mitochondrial release of mtDNA and the level of cGAS protein in the cytoplasm induced by TGF-β1.Besides, Gasdermin-D (GSDMD) can translocate to mitochondria, and down-regulation of its expression inhibited mtDNA release and fibrosis. Ablation of Atg5 increased the level of GSDMD protein in the mice renal tissues of obstructive kidney disease, and there was an interaction between Atg5 and GSDMD, suggesting that autophagy inhibited GSDMD-mediated mitochondrial damage, but the mechanism was unclear. This project intends to verify the relationship among autophagy, GSDMD expression, mitochondrial damage and fibrosis by applying the gene knockout mice of chronic kidney disease models. Using the above-mentioned mouse primary TEC and HK-2 cells that upregulate/silence Atg5/GSDMD expression, respectively, to clarify the role of Atg5/GSDMD in regulating mtDNA release and inflammatory response, and to study the key molecules and mechanisms of autophagy targeting mitochondrial damage. Furthermore, we will prospectively investigate the association between Atg5 and GSDMD expression and chronic kidney disease. Our study will be helpful to reveal the role and mechanism of autophagy targeting in ameliorating mitochondrial damage and inflammatory response and provide scientific basis for clinical prevention and treatment of renal fibrosis.