MITEN-712靶向调控线粒体自噬对青光眼视网膜神经节细胞进行性死亡的挽救作用及其机制

Glaucoma is the first blindness disease in the world which characterized by progressive retinal ganglion death. Up to date, there is no effective neuroprotective drugs or methods in clinic. Mitochondria damage is critical to cell death. Mitophagy is an important method to selectively remove damaged mitochondria via PINK1/Parkin pathway. We have found previously: 1. Cumulative mtDNA mutations play an important role during the progressive death in glaucoma. 2. Mitophagy decreased obviously in RGC in glaucoma. 3. Natural small compound MITEN-712 regulating Parkin and mitophagy has been acquired by drug screening. In this project, by using multi-disciplinary technical methods, we study the neuroprotective effect of MITEN-712 by preventing the progressive death in glaucomatous rat model and its mitophay mechanisms. Furthermore, by using Parkin-/-mouse and primary cultured RGC, we also study the molecular mechanisms and signal transduction pathway of MITEN-712 targeting regulation of Parkin and activing mitophagy. The goal of this project is to seek the effective drug to preventing the progressive RGC death.

青光眼视神经病变是以视网膜神经节细胞（RGC）进行性死亡为病理基础的不可逆致盲眼病。临床尚无有效阻止RGC进行性死亡的手段。线粒体受损是细胞死亡的重要开关。PINK1/Parkin介导的线粒体自噬是选择性清除受损线粒体和保护细胞的重要途径。我们前期基础：1.线粒体DNA突变累积是RGC进行性死亡的重要原因，2.青光眼RGC中线粒体自噬显著降低，3.药物筛选已获得调控Parkin和线粒体自噬的小分子化合物MITEN-712。基于此，本课题拟进一步以慢性高眼压大鼠为对象，利用多学科技术深入研究MITEN-712阻止RGC进行性死亡的有效性及其线粒体自噬机制；利用Parkin基因敲除小鼠，探讨MITEN-712激活PINK1/Parkin介导线粒体自噬的分子机制；采用PCR-array高通量手段阐明MITEN-712靶向调控Parkin的信号通路。旨在为临床有效防治青光眼提供新途径和理论依据。

本课题旨在深入研究小分子化合物MITEN-712对青光眼视网膜神经节细胞进行性死亡的保护作用，及其调控PINK1/Parkin通路促进线粒体自噬、改善线粒体功能的关键分子机制。探索青光眼神经保护的有效药物和解决方案。课题在四年项目期间基本按照计划任务书开展和实施，有序进行了MITEN-712挽救青光眼模型鼠视网膜神经节细胞进行性死亡的有效性和安全性研究，并与已有的报道的神经保护剂积雪草酸进行对比研究，进一步明确了MITEN-712的安全性和高效保护作用。在此基础上，深入研究了MITEN-712挽救视网膜神经节细胞进行性死亡的线粒体自噬机制，以及激活PINK1/Parkin通路促进受损线粒体自噬的关键分子机制。同时，本课题在研究过程中还发现了MITEN-712高效保护视网膜神经节细胞的新机制，即MITEN-712可通过抑制TRPV4通道，抑制青光眼视网膜muller细胞的过度激活和促炎因子的释放，从而通过改善视网膜微环境对视网膜神经节细胞起到保护作用。此外，本项目还发现了5-HT1A受体通过抑制胞内cAMP-PKA信号通路易化突触前GABA的释放，参与了青光眼RGC损伤过程，是青光眼一种新病理机制。