Apelin/APJ信号系统对脑缺血后血管内皮细胞修复及机制的研究

目的探讨Apelin/APJ信号系统对脑缺血损伤的血管内皮细胞的修复作用.方法采用电凝烧灼法制备局灶性大脑皮质梗死模型,通过侧脑室注射腺病毒Ad-Apelin或对照病毒Ad-RFP.实验动物随机分为4组,分别为假手术(sham)组、脑梗死组(MCAO)、Ad-Apelin+脑梗死组(Ad-Apelin)组、Ad-RFP+脑梗死组(Ad-RFP)组.使用神经功能mNSS评分、Western blot、免疫组织化学、qPCR等技术检测Apelin过表达对小鼠神经功能、血-脑脊液屏障、血管新生及血管内皮细胞Notch、VEGF、Ang-Ⅰ/Ⅱ信号通路的影响.结果与Ad-RFP组相比,Ad-Apelin组小鼠mNSS评分明显降低,脑组织含水量明显降低,脑组织伊文思兰渗出明显减少.与Ad-RFP组相比,Ad-Apelin组新生血管内皮细胞特异标志物CD105表达上调,血管内皮细胞DLL4、VEGF、VEGFRⅡ、Notch1、AngⅠ、AngⅡ蛋白表达量明显升高.结论Apelin过表达后可通过上调Notch、VEGF、Ang-Ⅰ/Ⅱ信号通路促进脑血管内皮细胞修复及血管新生.

Effect and mechanism of Apelin/APJ signaling system on vascular endothelial cell repair after cerebral ischemia

Objective To investigate the repair effect of Apelin/APJ signaling system on vascular endothelial cells after cerebral ischemia.Methods Focal cerebral cortex infarction models were prepared by electrocoagulation and cauterization.Adenovirus Ad-Apelin or control virus Ad-RFP were injected into the lateral ventricle.The experimental animals were randomly divided into four groups,namely sham operation group(Sham),cerebral infarction group(MCAO),Ad-Apelin+cerebral infarction group(Ad-Apelin)and Ad-RFP+cerebral infarction group(Ad-RFP).mNSS neurological function score,Western blot,immunohistochemistry,qPCR were used to detect the effect of Apelin on neural function,blood-brain barrier,angiogenesis and Notch,VEGF,AngⅠ/Ⅱsignaling pathways.Results Compared with Ad-RFP group,mNSS score,brain water content,and evans blue overflow of Ad-Apelin group were decreased.Compared with Ad-RFP group,the expression of CD105,which is the specific marker of new vascular endothelial cells,was upregulated in Ad-Apelin group.Expression of DLL4,VEGF and VEGFRⅡ,Notchl,AngⅠ,AngⅡin vascular endothelial cells were also upregulated.Conclusion Apelin protects the blood brain barrier and promote endothelial cell repair and angiogenesis through the Notch,VEGF,AngⅠ/Ⅱsignaling pathways.