胰高血糖素样肽-1改善过氧化氢诱导的血管内皮氧化损伤

GLP-1 attenuates hydrogen peroxide-induced oxydative damage in HUVEC cells

目的:探讨胰高血糖素样肽-1(GLP-1)对过氧化氢(H2O2)诱导的内皮细胞氧化损伤的保护作用及机制.方法:取人脐静脉内皮细胞(HUVECs),分为正常对照组、H2O2组、GLP-1组、H2O2+浓度10 nmol/L GLP-1组、H2O2+浓度100 nmol/L GLP-1组、H2O2+浓度1 000 nmol/L GLP-1组.采用荧光显微镜检测细胞内活性氧自由基(ROS)水平、观察细胞骨架F-actin变化;采用流式细胞仪检测细胞凋亡比率;Western Blotting检测磷酸化的雷帕霉素靶蛋白(p-m TOR)蛋白水平;实时荧光定量聚合酶链反应(QPCR)检测抗氧化酶:过氧化氢酶(CAT)、超氧化物歧化酶2(SOD2)和谷胱甘肽过氧化物酶1(GPX1)基因的表达变化.结果:H2O2组细胞骨架破坏明显,细胞内ROS含量增加,细胞凋亡率增加;加入GLP-1后,细胞骨架破坏受到显著抑制,ROS含量减少,凋亡率降低.Western Blotting结果显示,H2O2组p-m TOR表达降低,GLP-1可以提高p-m TOR表达,使蛋白水平趋于正常;加入GLP-1受体拮抗剂艾塞纳肽(9~36)后,GLP-1不能上调p-m TOR表达.H2O2作用后,CAT、SOD2和GPX1基因表达降低,而GLP-1可以逆转这些基因表达的降低.结论:GLP-1通过上调抗氧化应激酶对抗H2O2诱导的内皮细胞损伤,且可能是通过活化m TOR通路起保护作用.

Aim：To investigate the protective effect of glucagon-like peptide 1（GLP-1） on endothelial cell oxidative damage induced by hydrogen peroxide and potential mechanism involved. Methods： Human umbilical vein endothelial cells（ HUVEC） were randomized into six groups（ Control,H2O2,GLP-1,H2O2＋10 nmol/L GLP-1,H2O2＋100 nmol/L GLP-1 and H2O2＋1 000 nmol/L GLP-1 groups）. Cell F-actin and intracellular ROS were measured by immunofluorescence microscopy. Cell apoptosis was evaluated with flow cytometry. The p-m TOR protein expression level was tested by Western Blotting. The gene expression of CAT,SOD2 and GPX1 were tested by Quantitative Real-time PCR. Results： H2O2 induced cell F-actin damage,ROS production and apoptosis in HUVEC cells. GLP-1 rescued the cell damage,decreased the ROS and apoptosis. GLP-1 reversed the down-regulation of p-m TOR protein induced byH2O2,whereas exenatide（9-36）,a GLP-1 receptor antagonist,abolished this effect. Moreover,Realtime PCR showed that GLP-1 up-regulated gene expression of CAT,SOD2 and GPX1. Conclusion：GLP-1 can exert anti-oxidative effects on endothelial cells by up-regulation of protective anti-oxidative enzymes,possibly through activating of m TOR.