Prdx6-iPLA2活性通过激活NLRP3炎性复合体促进脑缺血再灌注损伤的作用及机制研究

The NLRP3 inflammasome, which plays an important role in the innate immune system-induced inflammatory injury, is believed to be a significant factor affecting brain injury and its prognosis. Therefore, actively searching for the key molecular targets of NLRP3 inflammasome activation and elucidating its mechanism of action will likely become the key breakthrough in resisting inflammatory injury of cerebral ischemia-reperfusion. Combined with the existing literature and the previous research results of our team, this project proposed that Prdx6-iPLA2 activity as an important upstream regulator of NLPR3 inflammasome activation after cerebral ischemia-reperfusion injury may be through direct activation of TLR4/NF-κB Signal pathway, and activate NOX2/ROS signaling pathway, affecting the pre-excitation and activation of NLRP3 inflammasome, resulting in cerebral ischemia-reperfusion injury, causing neuronal death. In this study, a rat middle cerebral artery transient ischemic reperfusion model and an ischemia/reperfusion model of microglial/primary-neuronal co-culture were established. Meanwhile, lentivirus overexpression, interference technology, and other molecular biology methods were used to investigate the proinflammatory effect of Prdx6-iPLA2 activity in cerebral ischemia-reperfusion injury in many aspects and to elucidate the activation effect of Prdx6-iPLA2 on NLRP3 inflammasome, providing a new direction and a new target for the prevention and treatment of ischemic stroke.

NLRP3炎性复合体在固有免疫系统诱导的炎性损伤中扮演着重要的角色，被认为是影响脑损伤及其预后的重要因素。因此，积极寻找NLRP3 炎性复合体激活的关键分子靶点并阐明其作用机制，将有可能成为抵抗缺血再灌注损伤的突破口。结合文献报道及课题组前期研究结果，本项目提出：脑缺血后，Prdx6-iPLA2活性作为NLPR3炎性复合体激活的重要正调控因子，可能通过TLR4/NF-κB及NOX2/ROS信号通路，影响NLRP3炎性复合体的激活，促进脑缺血再灌注损伤，引起神经细胞死亡。本课题采用大鼠大脑中动脉暂时性缺血再灌注模型及小胶质细胞/原代神经元共培养的氧糖剥夺模型，同时应用RNA干扰、药理阻滞及多种分子生物学方法，从多个环节探究Prdx6-iPLA2活性在脑缺血再灌注损伤中的促炎作用，并阐明Prdx6-iPLA2活性对NLRP3 炎性小体的激活作用，为缺血性脑卒中的防治提供新方向和新靶点。

脑缺血再灌注损伤(IRI)是由缺血后再灌注引起的。NLRP3炎性复合体在固有免疫系统诱导的炎性损伤中扮演着重要的角色，被认为是影响脑损伤及其预后的重要因素。积极寻找关键分子靶点并阐明其作用机制，将有可能成为抵抗缺血再灌注损伤的突破口。本研究提出：脑缺血后，Prdx6-iPLA2活性作为NLPR3炎性复合体激活的重要正调控因子，可能通过TLR4及NOX2/ROS信号通路，影响NLRP3炎性复合体的激活，促进脑缺血再灌注损伤，引起神经细胞死亡。本研究采用大鼠大脑中动脉暂时性缺血再灌注模型及PC12细胞的氧糖剥夺模型，同时应用RNA干扰、药理阻滞及多种分子生物学方法，从多个环节探究Prdx6-iPLA2活性在脑缺血再灌注损伤中的促炎作用，并阐明Prdx6-iPLA2活性对NLRP3 炎性小体的激活作用。研究结果表明PRDX6-iPLA2活性的特异性抑制剂MJ33可通过抑制Prdx6-iPLA2活性，从而抑制NOX2/ROS/NLRP3信号轴，进而减轻PC12细胞在OGD/R后的炎性损伤。同时MJ33可通过抑制Prdx6- iPLA2活性，进而抑制TLR4/ MyD88信号通路参与缺血再灌注时 NLRP3炎性复合体的激活，减轻脑缺血再灌注后的炎性损伤。自噬功能紊乱或过度可能是有害的，并导致神经元凋亡。进一步的研究发现PRDX6基因敲除也可能通过增强PINK1/Parkin通路介导的线粒体自噬功能而加重脑缺血再灌注损伤，从而增加神经细胞凋亡。以上研究可能为缺血性脑卒中的防治提供新方向和新靶点。