DRAM 1加速α-synuclein降解的分子机制及其在帕金森病中的作用

Autophagy is an important pathway in Parkinson's Disease (PD) pathogenesis. DRAM 1 is a newly discovered protein that can regulate autophagy. The present project plans to examine the effect of DRAM 1 in MES23.5 cell stably expressing wild-type α-synuclein or mutant α-synuclein (A53T), which is the mutant gene in inherited PD. This project will study the regulation of α-synuclein degradation by overexpressing or interfering DRAM 1 in model cells and try to elucidate its mechanism primarily focusing on the initiation of macroautophagy, the formation of autophagosome, the fusion of autophagosome and lysosome, and chaperon mediated autophagy, as well as its influence on cell survival. Mean the while, we'll verify if DRAM 1 takes a part in regulating apoptosis in PD with analyzing its influence on both the dissociation of Beclin 1-Bcl2 or Bcl2-Bax complex and the changes of pro-apoptotic proteins, such as Bid/tBid, caspase 3, cychrome C. The successful execution of this project will reveal that upregulation of DRAM 1 can accelerate α-synuclein degradation and tell its role in PD, which can provide a new clue for clinical therapy research.

自噬在帕金森病(PD)的发病中发挥重要作用，DRAM1是一种新的自噬调控蛋白。本项目将利用稳定表达野生型与突变型α-synuclein的MES23.5细胞模型，通过过表达或干扰DRAM1，观察α-synuclein的表达丰度、细胞内亚定位情况，论证DRAM1对其体内蓄积的影响。同时根据自噬起始、自噬囊泡形成、自噬体与溶酶体融合以及分子伴侣自噬途径等过程中的相关蛋白表达、蛋白间相互作用分析DRAM1促进α-synuclein降解的分子机制和对神经细胞生存的影响；通过DRAM1对自噬与凋亡的连接点之一的Beclin1-Bcl2及Bcl2-Bax复合物解离的影响和Bax下游Bid/tBid、caspase3等凋亡指针性蛋白的影响，分析DRAM1在PD是否调控凋亡及可能机制。本项目的顺利开展将能揭示DRAM1上调增加α-synuclein的降解及其在PD中的作用，为临床的治疗研究提供新的探索思路。

自噬在帕金森病(PD)的发病中发挥重要作用，DRAM1 是一种新的自噬调控蛋白。本项目通过考察DRAM 1对α-synuclein 的降解，论证DRAM 1对其体内蓄积的影响。同时验证了DRAM 1能够通过增加自噬流量和上调CMA活性这两个方面来促进α-synuclein 降解从而发挥神经保护作用，并且研究还发现，DRAM1 具有调控自噬与凋亡的双重作用，其连接点为Bax-溶酶体-cathepsin B-tBid，DRAM 1通过与Bax的结合延缓Bax的降解并募集其至溶酶体，促进Cathepsin B的释放，从而激活Bid/tBid、caspase 3 等蛋白启动凋亡。本项目揭示了DRAM 1 上调增加α-synuclein 的降解及其分子机制，PD 模型中能够发挥神经保护作用，为临床的治疗研究提供新的探索思路。