Nix介导的线粒体自噬在缺血性脑损伤中的作用及与Synphilin-1相关性研究

脑缺血过程伴随线粒体自噬。课题组前期研究表明脑缺血/复灌过程中线粒体自噬发挥了重要的神经保护作用，提示其是一种潜在的脑缺血治疗靶点。线粒体自噬的机制尚未阐明，预实验初步发现Bcl-2家族蛋白Nix在脑缺血/复灌过程中向线粒体聚集，小干扰Nix表达可显著降低缺血/复灌引起的线粒体自噬。提示Nix可能是脑缺血情况下介导线粒体自噬的关键蛋白。为阐明Nix的调控机制，申请人利用TAP结合蛋白质谱技术，发现并鉴定了一种新的Nix结合蛋白Synphilin-1(SYL-1)。小干扰SYL-1降低Nix诱发的线粒体自噬，但在脑缺血条件下SYL-1是否参与上述调控过程有待研究。因此，本研究拟采用体内、外脑缺血模型，利用Nix敲除小鼠，结合药理学、RNA干扰等手段，从多个层面明确Nix介导的线粒体自噬在脑缺血过程中的作用，并阐明其中SYL-1的调控机制，研究结果将为利用线粒体自噬作为脑缺血治疗靶点提供依据。

Mitophagy is activated along with cerebral ischemia. Our previous research demonstrated that mitophagy protected against focal brain ischemia/reperfusion (I/R) in mice. These results suggested that mitophagy could be a potential therapeutic target in ischemic brain injury. The mechanisms underlying mitophagy in this context are still unclear, our preliminary data found that Nix was recruited to mitochondira along with reperfusion. Knockdown of Nix significantly decreased the I/R-induced mitophagy, suggesting a key role of Nix in this process. Furthermore, we found a novel Nix-binding protein, Synphilin-1 by carring out tandem affinity purification assay. Our preliminary data interestingly find that knockdown of SYL-1 reduced Nix-induced mitophagy in Neuro2a cells. However, it is unclear whether SYL-1 is involved in the Nix-related mitophagy in ischemic brains. For this purpose, we aimed to fully identify the involvement and contribution of Nix-related mitophagy in the context of brain I/R. In addition, we intend to explore the underlying mechanisms by which SYL-1 regulates mitophagy in these systems. These investigations will provide significant experimental evidences in taking mitophagy as a novel therapeutic target in cerebral ischemia.