SCO-spondin蛋白调控网络参与脑卒中的作用机制研究

The overexpressed protein Subcommissural Organ Spondin(SSPO) in neurons can relieve injuries induced by oxidative stress, and promote dendrite/neurite regrowth of neurons upon cerebral Ischemia/Reperfusion (I/R).However, the mechanism remains unclear. Our preliminary studies showed that miR-145-5p increased sharply in acute time and decreased in chronic time, the highly expressed miR-145-5p inhibited Nurr1 expression. New evidences reveal that SSPO was transcripted by Nurr1 and ZNF423. The project proposed the hypothesis that “multiple signaling net of miR-145-5p—Nurr1/ZNF423—SSPO regulate the injury and reparation of neurons upon cerebral Ischemia/Reperfusion”. In this study, multiple molecular techniques including EMSA, confocal fluorescence microscope, Co-IP、GST pull-down、ChIP、RNAi and deletion mutation will be applied to decipher the mechanism that the axis signaling of miR-145-5p—Nurr1—SSPO impaired the anti-oxidative functions, however the other signaling of miR-145-5p—ZNF423—SSPO promote neurons reparation during chronic time of stroke. This study will provide novel strategies and targets for stroke treatment.

连合下器蛋白SCO-spondin（SSPO）高表达可减轻神经元细胞氧化应激损伤，促进脑缺血再灌注（I/R）后神经元细胞轴突生长，但机制不清。最近课题组研究表明：miR-145-5p在I/R损伤急性期呈高表达，慢性期呈低表达，而miR-145-5p高表达抑制Nurr1。SSPO受到转录因子Nurr1、ZNF423的调控。故我们推测“miR-145-5p—Nurr1/ZNF423—SSPO网络在脑缺血再灌注神经元的损伤与修复调控中起着重要作用”，本课题将通过相关实验技术明确miR-145-5p— Nurr1—SSPO信号通路削弱SSPO的抗氧化应激作用以及miR-145-5p— ZNF423—SCO-spondin信号通路促进慢性期神经元修复的分子新机制，为治疗脑卒中分子靶向治疗提供新思路和新靶点。

脑卒中是我国高发病率、高死亡率的重大疾病，寻找促进神经元修复的因子是本研究的重点，急需发现新的神经保护剂。SCO-spondin衍生肽NX210在大鼠脑缺血再灌注损伤中的作用及机制尚不清楚，所以，阐明其作用及机制是解决问题的关键。Integrin-β1介导的PI3K/Akt信号通路参与调控脑缺血再灌注损伤后和修复。SCO-spondin衍生肽NX210是否激活了Integrin-β1介导的PI3K/Akt信号通路亟待研究。因此，本课题在体内和体外分别采用大鼠大脑中动脉闭塞/再灌注和原代神经元氧葡萄糖剥夺/复糖复氧模型。探讨SCO-spondin衍生肽NX210对神经元脑缺血再灌注损伤后炎症、氧化应激、凋亡、Integrin-β1介导的PI3K/Akt信号通路和神经功能的影响。结果发现SCO-spondin衍生肽NX210可通过上调Integrin-β1介导的PI3K/Akt信号通路的表达，减少神经元氧化应激损伤和凋亡，但对炎症没有影响，从而促进神经功能恢复。我们的研究结果为缺血性脑卒中提供了新的靶点和可靠的理论依据。结合本课题的研究结果，我们共发表SCI论著9篇，在投SCI论著2篇；培养学术型博士研究生5名，硕士研究生5名。