大鼠侧脑室注射VEGF重组质粒预防脑缺血再灌注损伤及其对PI3K／AKT通路的影响

Injection of pIERS2-EGFP/VEGF Plasmid via the Lateral Ventricle Prevents Cerebral Ischemia Reperfusion Injury through PI3K/AKT Pathway in Rats

目的：探讨血管内皮生长因子（VEGF）重组质粒预先导入鼠脑能否有效预防缺血性脑梗塞并初探其可能的作用机制。方法将pIERS2-EGFP/VEGF重组质粒预先注入质粒组大鼠侧脑室，通过大脑中动脉（MCA）线栓法制备大鼠局灶性缺血2h/再灌注24h模型，采用TTC染色法测量梗塞灶大小；用电镜观察鼠脑神经元超微结构的变化；并通过Western印迹方法检测各组鼠脑中P-AKT蛋白的表达。结果①VEGF质粒组右脑梗死体积较缺血组明显减小（P＜0．01）。②与缺血组相比，质粒组神经元损伤和水肿程度明显降低。③与正常组相比，缺血组与质粒组的P-AKT表达量均显著增加（P＜0．01），且质粒组比缺血组增加显著（P＜0．01）。结论VEGF重组质粒的导入能有效预防缺血性脑梗塞，推测该机制可能是VEGF蛋白的表达能进一步活化PI3K/AKT信号通路。该研究为缺血性脑梗塞的二级预防提供一条新思路。

Objective To investigate whether the plasmid of vascular endothelial growth factor （VEGF） injected in the rat brain in advance can alleviate ischemic cerebral infarction efficiently and the underlying mechanism.Methods pIERS2-EGFP/VEGF plasmid was intracerebroventricularly injected into rats.Focal cerebral ischemia was made by middle cerebral artery occlusion （MCAO） for 2 h in these rats.TTC staining was used to measure the infarct volume ; electron microscopy was carried out to observe the changes of ultrastructure in rat brain neurons ; Western-blotting was em-ployed to detect the expression of P-AKT protein.Results ① The volume of the cerebral infarction in the plasmid group was reduced obviously compared with the ischemia group （P 〈0.01） .② Ul-trastructural analysis showed that the neuron damage and edema in the plasmid group were signifi -cantly abated compared with ischemia group.③ The expression of P-AKT was significantly increased in ischemia and plasmid groups compared with normal group （P 〈0.01）; it was increased signifi-cantly in the plasmid group relative to the ischemia group （P 〈0.01） .Conclusion Intracerebrov-entricular injection of pIERS2-EGFP/VEGF plasmid into rats can alleviate ischemic cerebral infarc -tion efficiently.The effect may be closely related to the activation of PI3K/AKT pathway by VEGF protein.The study provides a new idea for the secondary prevention of ischemic cerebral infarction .