氟非尼酮通过线粒体-自噬-NLRP3炎性体轴抑制肾间质纤维化的机制研究

Renal interstitial fibrosis(RIF) is the necessary stage of the development from chronic kidney disease to end-stage renal disease. RIF is the key factor influencing the prognosis of patients and is short of effective treatments. Fluofenidone is a new anti-renal interstitial fibrosis drug, and has entered the clinical trial stage ofⅠphase. We have confirmed that fluofenidone can inhibit NLRP3 inflammasome mediated inflammation and renal interstitial fibrosis, and literature reports the lack of NLRP3 can effectively prevent the progress of renal fibrosis. It has known that mitochondrial ROS is the key to activating the NLRP3 inflammasome, and autophagy can suppress the NLRP3 inflammasome activation by eliminating damaged mitochondrial. Both are closely related to the renal interstitial fibrosis. We hypothesized that the mitochondrial-autophagy-NLRP3 inflammasome axis may be the important targets of fluofenidone in anti-renal interstitial fibrosis. In this project, we firstly observe mitochondrial damage, autophagy and NLRP3 inflammasome activation in UUO rats and macrophages, and explore the effect of fluofenidone on mitochondrial-autophagy-NLRP3 inflammasome axis in the process of renal interstitial fibrosis. We will further define the molecular mechanisms of fluorofenidone in anti-renal interstitial fibrosis, providing theoretical basis for the clinical applications of fluorofenidone and the development of other anti-fibrotic drugs.

肾间质纤维化是慢性肾脏病进展至终末期肾病的必经阶段，是决定患者预后的重要因素，但缺乏有效治疗药物。氟非尼酮是一种具有抗肾间质纤维化作用的新型药物，已进入Ⅰ期临床试验阶段。前期我们已证实，氟非尼酮能够抑制NLRP3炎性体介导的炎症反应及肾间质纤维化，且文献报道NLRP3基因缺失能有效阻止肾纤维化的进展。已知线粒体ROS是激活NLRP3炎性体的关键信号，自噬通过清除受损线粒体抑制NLRP3炎性体的活化，且二者与肾间质纤维化密切相关。由此我们提出假设：线粒体-自噬-NLRP3炎性体轴可能是氟非尼酮抗肾间质纤维化作用的重要靶标。本课题首先观察线粒体损伤、自噬及NLRP3炎性体活化在肾间质纤维化动物模型和巨噬细胞中的作用，探讨氟非尼酮对肾间质纤维化过程中线粒体-自噬-NLRP3炎性体轴的影响，进一步明确氟非尼酮抗肾间质纤维化的作用机制，为氟非尼酮在临床上的应用和其他抗纤维化新药的开发提供理论基础。

肾间质纤维化是慢性肾脏病进展至终末期肾病的必经阶段，是决定患者预后的重要因素，但缺乏有效治疗药物。氟非尼酮是一种具有抗肾间质纤维化作用的新型药物，已进入Ⅰ期临床试验阶段。前期我们已证实，氟非尼酮能够抑制NLRP3炎性体介导的炎症反应及肾间质纤维化，但具体作用机制尚不清楚。本项目研究发现氟非尼酮有效的改善了UUO大鼠肾间质纤维化的程度，降低了Ⅰ、Ⅲ型胶原的表达，减轻了UUO大鼠肾组织中线粒体损伤，增加了肾组织中线粒体复合体酶的活性，通过抑制PI3K-AKT-mTOR信号通路促进自噬的发生，从而抑制NLRP3炎性体的活化。在体外培养的小鼠腹腔原代巨噬细胞中，氟非尼酮促进自噬的发生，抑制线粒体ROS和DNA的产生，维持线粒体稳态，降低了MAVS、VADC蛋白的表达，抑制NLRP3炎性体的活化，减少IL-1β的分泌，发挥抗炎作用。本项目通过观察线粒体损伤、自噬及NLRP3炎性体活化在UUO大鼠肾间质纤维化模型和体外巨噬细胞中的作用，探讨氟非尼酮对肾间质纤维化过程中线粒体-自噬-炎性体轴的影响，进一步明确了氟非尼酮抗肾间质纤维化的作用机制，为氟非尼酮在临床上的应用和其他抗纤维化新药的开发提供理论基础。