热休克蛋白60对热应激H 9C 2心肌细胞凋亡的影响及机理研究

The mechanism and effects of Hsp60 on the apoptosis of heat-stressed H9C2 cardiomyocytes

[目的]观察热应激过程中胞外热休克蛋白60(Hsp60)对H9C2大鼠心肌细胞凋亡的影响,并探讨其作用机制。[方法]将H9C2心肌细胞随机分为热应激0 h、1 h、2 h和4 h四组,对其进行相应时间的热应激处理,通过流式细胞仪检测H9C2心肌细胞的凋亡情况;将H9C2心肌细胞随机分为对照组和热应激组,热应激组心肌细胞进行2 h的热应激处理,通过ELISA方法检测细胞培养上清液中Hsp60的含量;将H9C2心肌细胞随机分为anti-Hsp60(-)和anti-Hsp60(+)两组,在培养基中分别加入等量的山羊抗鼠IgG和Hsp60抗体,0.5 h后,对其进行2 h的热应激处理,通过流式细胞术和荧光定量PCR检测H9C2心肌细胞的凋亡情况;在anti-Hsp60(-)和anti-Hsp60(+)的基础上,将p38、ERK和JNK的抑制剂SB203580、PD98059、SP600125分别加入细胞培养上清液,通过Western Blotting技术检测H9C2心肌细胞p-p38/p38,p-ERK/ERK,p-JNK/JNK的变化。[结果]随着热应激时间的延长,H9C2心肌细胞的凋亡率显著升高;热应激导致细胞培养上清液中Hsp60显著升高;与anti-Hsp60(-)组相比,anti-Hsp60(+)组心肌细胞的凋亡率显著升高,p-ERK/ERK比值显著降低,p-JNK/JNK比值显著升高。加入SB203580、PD98059、SP600125后,anti-Hsp60(+)组细胞凋亡率分别表现为无显著差异,显著降低,显著升高。[结论]细胞外微量的Hsp60可缓解热应激导致的H9C2大鼠心肌细胞凋亡,其机制与ERK、JNK的激活有关。

[Objective]The present study was aimed to explore the effect of extracellular Hsp60 on H9C2 cardiomyocyte apoptosis in rats under heat-stress condition.[Methods]The equal amount of IgG or Hsp60 antibodies was incorporated into H9C2 cardiomyocytes medium.The medium with IgG served as control treatment.Two mixtures were treated with heat stress at(42±1)℃for 2 h.The apoptosis of H9C2 cardiomyocytes in different treatments were determinedby flow cytometry and fluorescence quantitative PCR.The variation of p-p38/p38,p-ERK/ERK,p-JNK/JNK were detected by Western Blotting techniques.[Results]Compared to IgG antibody group,both the apoptosis rate of cardiomyocytes and p-JNK/JNK ratio in the Hsp60 group were significantly enhanced(P<0.01);while the p-ERK/ERK ratio was dramatically decreased(P<0.01).Adding SB203580,PD 98059,or SP600125 into the medium resulted in non-significant difference,significant decrease,or significant increase of apoptosis rate,respectively.[Conclusion]Micro-amounts of extracellular Hsp60 produce a protective effect on heat-stressed cardiomyocytes.The underlying mechanism might be related to the activation of ERK and JNK.