热休克蛋白70通过Bcl-2抑制氧化应激所致C2C12细胞凋亡

Heat Shock Protein 70 Protected Against Oxidative Stress-Induced Apoptosis in C2C12 Myogenic Cells by Upregulation of Bcl-2

目的探讨C2C12肌原细胞内热休克蛋白70对Bcl-2表达的影响及Bcl-2对热休克蛋白70抗细胞凋亡作用的影响。方法应用Western Blotting观察Bcl-2在转染热休克蛋白70真核表达质粒(pcDNA3.1-HSP70)或其反义寡核苷酸C2C12肌原细胞中的表达;采用基因瞬间转染技术使热休克蛋白70过表达的C2C12肌原细胞内Bcl-2表达抑制,应用流式细胞术检测H2O2处理所致细胞凋亡的发生情况。结果转染热休克蛋白70真核表达质粒的C2C12肌原细胞中,热休克蛋白70和Bcl-2的表达明显高于空载体转染组(P<0.01);而转染热休克蛋白70反义寡核苷酸后,热休克蛋白70和Bcl-2的表达明显低于随机寡核苷酸转染组(P<0.01);热休克蛋白70过表达的C2C12肌原细胞分别转染Bcl-2反义寡核苷酸及随机寡核苷酸,0.5 mmol/L H2O2处理24 h,Bcl-2反义寡核苷酸转染组的细胞凋亡率明显高于随机寡核苷酸转染细胞组。结论热休克蛋白70能上调C2C12肌原细胞内Bcl-2的表达;热休克蛋白70的抗细胞凋亡功能可能与其上调Bcl-2表达相关。

Aim To explore the effect of heat shock protein 70（HSP70） on Bcl-2 expression and investigate the role of Bcl-2 in HSP70＇s anti-apoptosis in C2C12 cells. Methods Westen Blotting were used to identify the expression of Bcl-2 in the C2C12 cells transfected with pcDNA3.1-HSP70 or HSP70＇s antisense oligonucleotide.The apoptosis were analysed by flow cytometry in the HSP70-overexpressed C2C12 cells which were transfected with Bcl-2＇s antisense oligonucleotide and then treated with H2O2（0.5 mmol/L）. Results The expression of HSP70 and Bcl-2 was increased in the C2C12 cells transfected with pcDNA3.1-HSP70,but the expression of HSP70 and Bcl-2 was decreased in the C2C12 cells transfected with HSP70＇s antisense oligonucleotide.In the HSP70-overexpressed C2C12 cells transfected with Bcl-2＇s antisense oligonucleotide,H2O2-induced apoptosis rate was higher than that in the cells transfected with Bcl-2＇s scramble oligonucleotide. Conclusion HSP70 contributed to the upregulation of Bcl-2 expression;Bcl-2 played an important role in HSP70-mediated protection against H2O2-induced apoptosis.