RohA信号通路介导miR-133b调控脑缺血再灌注后血脑屏障通透性

miR-133b Regulates Blood-Brain Barrier Permeability after Cerebral Ischemia-Reperfusion Mediated by RohA Signaling Pathway

目的:探究miR-133b在脑缺血再灌注后血脑屏障通透性调控中的作用及其机制。方法:采用大脑中动脉闭塞再灌注(MCAO/R)小鼠模型,小鼠脑内注射miR-133b agomir进行miR-133b过表达,TTC染色检测miR-133b过表达对小鼠脑梗死体积的影响;实时定量PCR检测MCAOR小鼠缺血侧脑组织及外周血miR-133b表达水平;采用悬挂实验评估miR-133b过表达对MCAO/R模型小鼠神经功能改善的影响;Western blot及ELISA检测miR-133b过表达对MCAO/R模型小鼠脑内RohA、claudin-5、ZO-1表达水平的影响;采用伊文思蓝渗透法评估小鼠血脑屏障通透性。结果:在MCAO/R模型小鼠缺血侧脑皮层组织与血浆中的miR-133b表达水平均降低,miR-133b过表达可显著减少MCAO/R小鼠脑梗死的体积,改善小鼠神经功能损害;miR-133b过表达可使MCAO/R小鼠脑内缺血区RohA、claudin-5、ZO-1蛋白表达显著降低。结论:小鼠脑缺血再灌注后体内miR-133b表达水平下降,miR-133b过表达具有降低脑缺血再灌注后脑血屏障通透性,发挥抗脑缺血作用,其机制可能是通过RohA信号通路介导的。

Objective: To investigate the role and mechanism of miR-133b in the regulation of blood-brain barrier permeability after cerebral ischemia-reperfusion. Methods: Mouse model of middle cerebral artery occlusion/reperfusion (MCAO/R) was established. miR-133b Agomir was injected into the brain, and the expression levels of miR-133b in the peripheral blood and infarcted brain tissue were detected by RT-PCR. The effect of miR-133b overexpression on cerebral infarction volume was detected by TTC staining, and the effect of miR-133b overexpression on neurological function was evaluated by suspension test in MCAO/R model mice. The effects of miR-133b on the expression of RohA, Claudin-5 and Zo-1 in the brain of MCAO mice were detected by Western blot and ELISA respectively, and the permeability of blood-brain barrier was evaluated by Evans Blue Penetration method. Results: the expression of miR-133b was significantly decreased in the plasma and ischemic cerebral cortex of MCAO/R model mice. While the overexpression of miR-133b could significantly reduce the cerebral infarction volume and ameliorate the neurological impairment in the MCAO/R mice. Overexpression of miR-133b significantly decreased the expression levels of RohA, Claudin-5 and Zo-1 in ischemic penumbra of mice. Conclusion: The expression of miR-133b is significantly decreased after cerebral ischemia-reperfusion in mice. Overexpression of miR-133b can decrease the permeability of cerebral blood barrier after cerebral ischemia-reperfusion, which plays an anti-cerebral ischemia role. The mechanism may be mediated by RohA signaling pathway.