脑缺血再灌注损伤程度与自噬相关基因LC3、mTOR表达的相关性研究

Correlation between the degree of cerebral ischemia-reperfusion injury and the expression of LC3 and m TOR

目的探讨局灶性脑缺血再灌注损伤（cerebral ischemia reperfusion,CIR）程度与自噬微管相关蛋白轻链3抗体-Ⅱ（Autophagy microtubule associated protein light chain 3 antibody-Ⅱ,LC3-Ⅱ）、雷帕霉素靶蛋白抗体（Rapamycin target protein antibody,m TOR）表达的相关性。方法采用线栓阻断法阻塞大脑中动脉2 h制作大鼠局灶性脑缺血再灌注模型;观察各组间的神经功能缺失评分、TTC梗死体积;应用免疫印迹、免疫荧光法检测大脑顶叶的LC3-Ⅱ、m TOR的表达。结果 TTC染色显示,梗死体积在缺血再灌24 h达高峰。WB、免疫荧光显示,LC3-Ⅱ在IR中表达增加,且在缺血再灌24 h表达最高;m TOR在缺血再灌24 h、48 h表达最低。相关性分析显示,TTC染色梗死体积与LC3-Ⅱ表达水平高度正相关。结论脑缺血再灌注损伤程度可能与LC3、m TOR的表达水平相关。

Objective To investigate the correlation between the degree of focal cerebral ischemiareperfusion injury and the expression of LC3-Ⅱ and m TOR. Methods The models of focal cerebral ischemia-reperfusion in rats were established by occlusion of the middle cerebral artery. Neurological deficit score and TTC infarct volume were observed among groups. The expressions of LC3-Ⅱ and m TOR in different groups were detected by immunoblotting and immunofluorescence. Results Immunoblotting and immunofluorescence showed that LC3-Ⅱ had the highest expression in 24 hours after ischemia and reperfusion（IR 24 h）, and m TOR was the lowest in IR 24 h and IR 48 h. Correlation analysis showed that the infarcted volume of TTC was positively correlated with the expression level of LC3-II. Conclusion IR may activate the autophagy of the parietal neurons of the brain by increasing the expression level of LC3-II and decreasing the expression level of m TOR. The degree of cerebral ischemia-reperfusion injury may be related to the expression level of LC3 and m TOR.