氧化应激对热休克蛋白70核仁分布的影响

目的：探讨氧化应激对热休克蛋白70（heat shock protein 70, HSP70）核仁分布的影响。方法：采用热休克反应（42℃ 1h，37℃恢复12h）诱导C2C12细胞中HSP70的高表达；构建HSP70与增强绿色荧光蛋白（EGFP）的重组质粒。将重组质粒瞬时转染C2C12肌原细胞后，用免疫印迹技术分别检测热休克反应及基因转染诱导的HSP70表达；在分离纯化核仁和胞质蛋白组分后，分别采用免疫细胞化学、荧光技术及免疫印迹检测氧化应激（0.5mmol/L H2O2）诱导的HSP70的分布改变。结果：免疫印迹显示，热休克反应和瞬时转染重组质粒，均能导致C2C12细胞中HSP70的高表达；荧光示踪显示，过氧化氢处理1h后，可见胞核有较强的荧光；免疫细胞化学及细胞组分蛋白质免疫印迹显示，热休克处理的细胞暴露于过氧化氢1h后，HSP70从细胞质向细胞核及核仁移位。结论： 氧化应激能导致HSP70从胞质向核仁移位。

Oxidative stress-induced accumulation of heat shock protein 70 within nucleolus

OBJECTIVE: To investigate the effect of oxidative stress on the accumulation of heat shock protein 70 (HSP70) within C2C12 myogenic cells. METHODS: Heat shock response (42 degrees C for 1 h and recovery for 12 h at 37 degrees C) was used to induce the expression of heat shock protein 70. We constructed a recombinant plasmid of HSP70 with enhanced green fluorescent protein (EGFP). After being transfected transiently into C2C12 cells, immunoblotting was used to detect the expression of HSP70 induced by heat shock response and transfection. Immunocytochemistry, fluorescent microscopy and immunoblotting were used to detect the translocation of HSP70. RESULTS: Immunoblotting showed that the overexpression of HSP70 was induced by heat shock response and transient transfenction. HSP70 localized within the cytoplasm of the normal cells, but HSP70 translocated from the cytoplasm to the nucleus and the nucleolus at 1 h after the treatment of oxidative stress (0.5 mmol/L H2O2) by using immunocytochemistry, fluorescent microscopy and immunoblotting for cellular partial proteins. CONCLUSION: Oxidative stress may induce the accumulation of heat shock protein 70 within the nucleolus.