糖基化终产物受体活化介导溶酶体外移抑制足细胞自噬的机制

Podocyte injury is a common pathway in many chronic kidney diseases and high level of autophagy plays a key homeostatic mechanism to maintain podocyte integrity. Activation of receptor of advanced glycation endproducts (RAGE) is an important pathway to podocyte injury. We observed that activated RAGE inhibited podocyte autophagy by promoting peripheral location of lysosome. However, the mechanism of peripheral location of lysosome induced by activated RAGE has not been investigated. .Transcription factor EB (TFEB) is a new regulator of autophagy. Our preliminary results showed that activated RAGE on podocyte blocked TFEB and V-ATPase, a molecule downstream of TFEB related to peripheral location of lysosome. Thus, whether activated RAGE inhibits podocyte autophagy by promoting peripheral location of lysosome through TFEB pathway? To clarify this proposition, we plan to perform ChIP-qPCR, gene transfection, gene silencing, Western blot, immunofluorescence and immunohistochemisty to investigate this pathway. We will study it in vitro first and then in activated-RAGE kidney injury model by using a GFP-LC3 transgenic mice. This study will interpret the mechanism of inhibited podocyte autophagy induced by activated RAGE, which will provide new therapy target for podocyte protection and advanced intervention for chronic kidney disease.

足细胞损伤是多种慢性肾脏病的共同致病途径。高水平自噬对维持足细胞稳态具有重要意义。糖基化终产物受体（RAGE）活化是足细胞损伤的重要途径。我们新观察到，通过促进溶酶体外移，RAGE活化抑制自噬并损伤足细胞。RAGE活化如何介导溶酶体外移，目前还没有研究。.转录因子EB（TFEB）是新发现的一种重要的自噬调控因子。我们的预实验发现，足细胞RAGE活化阻抑TFEB，而抑制TFEB下游的V-ATP酶和溶酶体外移有关。那么，RAGE活化是否通过TFEB信号通路介导溶酶体外移来抑制足细胞自噬？为解决这一问题，本课题拟采用ChIP-qPCR、基因转染、基因沉默、免疫印迹、免疫荧光和免疫组化等技术，在体外研究RAGE活化和溶酶体外移的信号联系，并利用GFP-LC3转基因小鼠构建RAGE活化的肾病模型来进行验证。课题将首次阐明足细胞RAGE信号抑制自噬的机制，为保护足细胞和防治慢性肾脏病提供新的靶点。

足细胞损伤是多种慢性肾脏病的共同致病途径。高水平自噬对维持足细胞稳态具有重要意义。糖基化终产物受体（RAGE）活化是足细胞损伤的重要途径。转录因子EB（TFEB）是新发现的一种重要的自噬调控因子。本项目系列研究发现TFEB对于维持足细胞自噬起到重要作用，其功能参与自噬体生成、自噬溶酶体生成及维持溶酶体功能。RAGE活化后一方面通过提高自噬经典负性调控分子哺乳动物雷帕霉素靶蛋白（mTOR）活性来抑制足细胞自噬轴，另一方面通过降低TFEB活性及核转位来抑制足细胞自噬。同时，RAGE活化诱导的mTOR激活也可以抑制TFEB核转位，这可能与促进mTOR与TFEB的相互作用相关。课题将首次阐明足细胞RAGE信号抑制自噬的机制，为保护足细胞和防治慢性肾脏病提供新的靶点。