热休克蛋白抑制过氧化氢所致C_2C_(12)细胞凋亡的机制

Mechanisms of heat shock proteins inhibiting C_2C_(12) cell apoptosis induced by hydrogen peroxide

目的 :探讨热休克蛋白抑制活性氧所致C2 C12 细胞凋亡的分子机制。方法 :采用热休克对体外培养的C2 C12 细胞进行预处理 ,以诱导热休克蛋白的表达 ;Hoechst332 5 8染色观察过氧化氢 (H2 O2 )所致的C2 C12 细胞凋亡 ;凋亡蛋白酶活性检测试剂盒和Western blotting检测凋亡蛋白酶 3,8,9的活性 ;细胞组分分离后Western blotting检测细胞色素C的释放。结果 :热休克预处理导致C2 C12 细胞热休克蛋白 70 ,αB 晶状体蛋白表达明显增加 ,同时显著抑制过氧化氢所致细胞色素C从线粒体释放 ,抑制凋亡蛋白酶 3,8,9活化及随后的C2 C12 细胞凋亡。结论 :热休克蛋白通过干预线粒体信号通路与死亡受体通路的活化抑制过氧化氢导致的C2 C12 细胞凋亡 。

Objective To explore the mechanisms of C 2C 12 cell apoptosis induced by hydrogen peroxide (H 2O 2) which is inhibited by heat shock proteins.Methods The expression of heat shock proteins in mouse embryonic myogenic cell line,C 2C 12 cell,was induced by heat shock response.C 2C 12 cell apoptosis induced by 0.5 mmol/L hydrogen peroxide (H 2O 2) was determined by Hoechst 33258 staining.The activities of caspase -3,8,9 were assayed by caspase colorimetric assay kit and Western-blotting.The release of cytochrome C from mitochondria was observed by Western-blotting of cell mitochondria and cytosol fractions.Results The expression of HSP70 and αB-crystallin in C 2C 12 cell significantly increased at 24 hour after the heat shock response. Heat shock response could inhibit the release of cytochrome c from mitochondria to cytoplasm,the activation of caspase -3,8,9 and the subsequent apoptosis induced by H 2O 2 in C 2C 12 cell.Conclusion HSPs can inhibit the C 2C 12 cell apoptosis through interference with the activation of both mitochondrial and death receptor pathways,which can provide new clues for the prevention of cardiovascular diseases.