血管生成素-1通过调节PI3K/AKT信号途径抑制H_2O_2诱导小鼠心肌细胞凋亡

Angiopoietin-1 prevents rat cardiomyocytes from H_2O_2-induced apoptosis by regulating the activity of PI3K/Akt

目的观察血管生成素-1(Ang-1)对H2O2诱导小鼠心肌细胞凋亡的影响及其与磷脂酰肌醇3激酶(PI3K)/丝氨酸苏氨酸蛋白激酶(Akt)信号通路活化的关系。方法培养新生小鼠心肌细胞,分为对照组、H2O2诱导组、Ang-1干预组、共同干预组,用Hoechst-33342染色法观察细胞凋亡形态学特征,流式细胞仪检测细胞凋亡率;Western blot检测蛋白p-AKT、AKT、活化caspase-3的表达。结果H2O2可以诱导心肌细胞发生凋亡,凋亡的心肌细胞呈现染色质凝聚、皱缩、碎裂等典型的凋亡形态学特征;与H2O2诱导组相比,对照组、Ang-1干预组的细胞凋亡率均降低(2.13%±0.61%vs48.16%±1.37%P<0.01;31.20%±2.01%vs48.16%±1.37%,P<0.01);共同干预组的细胞凋亡率高于Ang-1干预组(47.42%±2.02%vs31.20%±2.01%,P<0.01),与H2O2诱导组没有统计学差异;与H2O2诱导组相比,Ang-1干预组磷酸化AKT(p-AKT)水平升高,活化caspase-3的表达水平降低,这种差别在共同干预组中不明显。结论Ang-1通过调节PI3K/AKT信号途径对H2O2诱导的小鼠心肌细胞凋亡起到保护作用。

Objective To investigated whether angiopoietin-1（Ang-1） has direct cytoprotective effects on rat cardiomyocytes against oxidative stress and its possible signaling pathway involved.Methods A model for primary culture of cardiomyocytes injuried by H2O2 was established,the cultured cardiomyocytes were divided randomly into four groups.The morphology of cardiomyocytes was observed by Hoechst-33342.Apoptosis of cardiomyocytes was determined by flow cytometry（FCM）.The expression of p-AKT and active-caspase-3 was measured by Western blot analysis.Results The percentage of apoptosis cells in control group and Ang-1 intervention group were 2.13%±0.61%,31.20%±2.01%,compared with the induced group（48.16%±1.37%）was significantly lower（P0.01）,andapoptosis rate of cointervention group was 47.42%±2.02%,has no significant difference as compared with that of induced group.Western blot analysis showed Ang-1 restored the phosphorylation of Akt and inhibited the activation of caspase-3,and these effects were reversed by the presence of LY294002.Conclusion Ang-1 has direct cytoprotective effect on cardiomyocytes against oxidative stress and this effect is mediated through PI3K/Akt pathway and inhibition of caspase-3 cleavage.