黄芪总苷通过介导mTOR信号通路抑制H2O2诱导的大鼠心肌细胞自噬和凋亡

目的:探讨黄芪总苷(astragalosides)对过氧化氢(H 2O 2)诱导的大鼠心肌细胞H9c2自噬和凋亡作用的影响及作用机制。方法:建立大鼠心肌细胞H 2O 2氧化应激损伤模型,并用20 mg/L的黄芪总苷和0.1 mg/L的雷帕霉素分别处理对应组细胞。采用流式细胞技术检测细胞凋亡率;采用吖啶橙染色观察细胞自噬情况;采用Western blot检测p-mTOR蛋白、P70S6K蛋白、自噬蛋白(LC3)和凋亡蛋白(cleaved caspase-3和caspase-3)的表达。结果:与模型组和雷帕霉素组比较,黄芪总苷组的细胞凋亡率显著降低( P <0.05);黄芪总苷组的大鼠心肌H9c2细胞形态完整,细胞核染色为黄绿色荧光,染色质分布均匀,细胞形状规则;细胞中p-mTOR蛋白和P70S6K蛋白的表达显著升高( P <0.05),LC3-II/LC-3-I和cleaved caspase-3相对表达量显著降低( P <0.05)。结论:黄芪总苷可通过mTOR信号通路提高心肌细胞成活率,抑制细胞凋亡和自噬,减轻H 2O 2诱导的大鼠心肌细胞氧化应激损伤。

Astragalosides inhibit autophagy and apoptosis of rat cardiomyocytes induced by H2O2 through mTOR signaling pathway

AIM: To investigate the effects of astragalosides on autophagy and apoptosis of rat cardiomyocytes induced by hydrogenperoxide (H 2O 2). METHODS: The injury model of H9c2 cells induced by H 2O 2 was established, and the cells in astragalosides group and rapamycin group were treated with 20 mg/L astragalosides and 0.1 mg/L rapamycin, respectively. The apoptotic rate was detected by flow cytometry. The autophagy was observed by acridine orange staining. Western blot was used to detect the protein levels of p-mTOR, P70S6K, LC3 and caspase-3. RESULTS: Compared with H 2O 2 group and rapamycin group, the viability of H9c2 cells in astragalosides group was significantly increased ( P <0.05). The shape of the H9c2 cells in astragalosides group was complete, the nuclei were stained with yellow-green fluorescence, and the chromatin was distributed evenly. The protein levels of p-mTOR and P70S6K in the H9c2 cells of astragalosides group were significantly increased ( P <0.05), whereas the protein levels of LC3, cleaved caspase-3 and caspase-3 in the H9c2 cells of astragalosides group were decreased significantly ( P <0.05). CONCLUSION: Astragalosides enhance the viability, inhibit the apoptosis, increase the protein levels of p-mTOR and P70S6K, and decrease the protein levels of LC3, cleaved caspase-3 and caspase-3 in the H 2O 2-induced rat myocardial H9c2 cells. The mechanism is related to the mTOR signaling pathway.