The experiment was conducted to study effects of heat stress on Hsc70 import-export nuclear and apoptosis in H9c2 cardiac myocytes.H9c2 cells were exposed to 42 ℃ as the heat stress model,inhibited expression of Hsc70 was performed by transfecting Hsc70 siRNA,the expression of Hsc70 in the cytoplasm and nucleus were detected by Western blot,LDH concentration of cell culture was detected by ELISA,and apoptosis was detected by Annexin V-FITC/PI double staining.The results showed that:in normal H9c2 cardiomyocytes,the level of Hsc70 in cytoplasm was high and that in nucleus was low,the level of Hsp72 in cytoplasm and nucleus was very low.There was no significant difference in the expression of Hsc70 after heat stress.The expression of Hsc70 in nucleus was significantly increased after heat stress 30 and 100 min (P＜0.01),and decreased after heat stress 240 min.After heat stress,the expression of Hsp72 was significantly increased (P＜0.01 or P＜0.05).After Hsc70 inhibited,the level of cytosolic Hsc70 was significantly decreased,and Hsc70 import nucleus decreased significantly after heat stress.After Hsc70 inhibited,there was no significant effect on the expression of Hsp72 in cytoplasm and nucleus.Compared with the heat stress group,the expression of LDH was increased in the heat stress+ Hsc70 siRNA group,and there was a significant difference between the two groups after heat stress 100 min (P＜0.05).After Hsc70 inhibited,H9c2 cells were more prone to apoptosis after heat stress,and there was a significant difference between the two groups in heat stress 30 and 100 min (P＜0.05).In conclusion,heat stress can cause Hsc70 import and export nuclear,and the low level of Hsc70 nucleus can cause of H9c2 cells damage aggravated and the rate of apoptosis increased after heat stress.%旨在探讨热应激对H9c2心肌细胞构成型HSP70(constitutive or cognate HSPs,Hsc70)出入核及细胞凋亡的影响.以42℃作为热应激模型温度,通过转染Hsc70 siRNA抑制Hsc70表达,Western blot检测细胞质和细胞核内Hsc70表达,ELISA检测细胞培养液LDH浓度,Annexin V-FITC/PI双染法检测细胞凋亡.结果表明,正常H9c2心肌细胞质Hsc70表达量较高,细胞核中表达量很低,细胞质和细胞核Hsp72表达量非常低.热应激后细胞质Hsc70表达量无显著差异,而细胞核Hsc70热应激30和100 min后极显著升高(P＜0.01),热应激240 min后开始降低;细胞质和细胞核Hsp72热应激后显著升高(P＜0.05或P＜0.01).Hsc70抑制表达后,细胞质Hsc70水平显著降低,热应激后Hsc70入核明显减少,但仍然有入核现象;Hsc70抑制表达对细胞质和细胞核Hsp72表达无显著影响.与热应激组相比,热应激+Hsc70 siRNA组LDH表达量呈升高趋势,热应激100 min两组出现显著差异(P＜0.05);Hsc70抑制表达后H9c2细胞在热应激后更容易发生凋亡,而且在热应激30和100 min内,两组之间存在显著差异(P＜0.05).结果提示,热应激可诱使Hsc70出入细胞核,Hsc70抑制表达后热应激诱导Hsc70入核显著降低,细胞损伤加重,细胞凋亡升高.
展开▼
