Keap1/Nrf2/ARE信号通路调控线粒体分裂对脑缺血再灌注损伤的作用研究

NF-E2-related factor 2 (Nrf2) is a regulatory factor of the body' own anti-oxidative stress. In the oxidative stress state, activation of the Keap1 / Nrf2 / ARE signaling pathway initiates an endogenous antioxidant system. The most important organelles. Mitochondrial dynamics, especially mitochondrial splitting, plays an important role in cerebral ischemia-reperfusion injury by inhibiting the opening of MCU and MPTP, reducing calcium overload and reducing intracellular reactive oxygen species (ROS) levels, Drp1 phosphorylation, inhibition of mitochondrial division, thereby reducing the cerebral ischemia and reperfusion process of neuronal apoptosis. It is not clear whether the initiation of Nrf2 affects mitochondrial dynamics through certain nuclear transcription factors during cerebral ischemia-reperfusion. In order to study the relationship between them, we proposed to use NRf2 KO mice to establish the in vitro and in vivo models of cerebral ischemia and reperfusion. The mechanism of regulation of mitochondria by Keap1 / Nrf2 / ARE pathway was studied by neurobiology combined with molecular biology technique. This study combines the classical oxidative stress pathway with mitochondrial cleavage to provide a theoretical basis for cerebral ischemia-reperfusion injury.

NF-E2相关因子2（Nrf2）是一种自身抗氧化应激的调节因子，在氧化应激状态下通过激活Keap1/Nrf2/ARE信号通路，启动内源性抗氧化体系，线粒体是此过程中最为重要的细胞器。我们课题组前期的研究发现，线粒体分裂是导致脑缺血再灌注损伤的重要原因，通过抑制MCU和mPTP的开放，减轻钙超载及降低细胞内活性氧（ROS）水平，抑制Drp1的磷酸化，可以抑制线粒体分裂，从而减轻脑缺血再灌注过程中神经元的凋亡程度。在脑缺血再灌注时，Nrf2的启动是否通过某些特定的核转录因子来影响线粒体分裂尚不清楚。我们拟应用NRf2 KO小鼠建立脑缺血再灌注的体内外模型，应用神经生物学和分子生物学等技术，研究Keap1/Nrf2/ARE通路对脑缺血再灌注损伤中线粒体分裂的调控机制。本研究将经典氧化应激途径与线粒体分裂结合起来，为脑缺血再灌注损伤提供理论基础。

Keap1/Nrf2/ARE信号通路作为经典的氧化应激调控通路，在脑缺血再灌注的发生机制中发挥重要作用。线粒体形态的改变与其功能密切相关，过度分裂是导致细胞凋亡的重要原因，但关于线粒体分裂的具体机制仍不清楚。本研究旨在探讨在脑缺血再灌注损伤中Keap1/Nrf2信号通路对线粒体分裂的作用及可能机制。在原代培养的Wistar大鼠海马神经元缺氧复氧模型上，通过抑制Nrf2探讨Keap1/Nrf2通路在脑缺血再灌注损伤中对线粒体分裂的作用及机制。结果表明，在脑 I/R 中，Keap1/Nrf2/ARE 信号通路能够调控线粒体分裂，Nrf2蛋白被抑制后，线粒体分裂相关蛋白Drp1、 Fis1明显升高，线粒体形态损伤更严重，凋亡率亦更高，且Sestrin2基因过表达可下调胞浆Keap1蛋白水平、促进Nrf2核移位而激活Keap1/Nrf2通路，从而抑制线粒体分裂，减少细胞凋亡，减轻脑损伤。本研究为脑缺血再灌注损伤提供了新的理论基础和治疗靶点。