采用反义寡核苷酸探讨HSP70对活性氧所致心肌细胞损伤的影响

目的探讨HSP70对活性氧所致心肌细胞急性损伤的保护作用.方法用热休克预处理诱导新生大鼠心肌细胞中HSP70的表达,采用HSP70反义寡核苷酸阻断HSP70的表达,乳酸脱氢酶释放率和细胞总蛋白质合成能力来反映H2O2 0.5 mM所致心肌细胞损伤程度.结果H2O2引起心肌细胞乳酸脱氢酶释放率明显升高,而细胞总蛋白质的合成降低.热休克预处理导致心肌细胞中HSP70表达明显增加,并使H2O:所致心肌细胞LDH释放率显著降低,细胞总蛋白质的合成基本恢复正常水平.HSP70反义寡核苷酸很大程度上阻断了HSP70的表达及热休克预处理的心肌细胞保护作用.结论在热休克预处理减轻过氧化氢所致乳鼠心肌细胞急性损伤的作用中,HSP70发挥了最主要的作用.

Study of effect of HSP70 on acute injury of cardiomyocyte induced by hydrogen peroxide using antisense oligodeoxynucleotides

Objective:To investigate the protective effect of HSP70 against acute injury of cardiomyocyte induced by H2O2. Methods: Neonatal rat cardiomyocytes were treated with heat shock (42 C 30 rmin, recovery for 12hfs) to induce expression of HSP70 and HSP70 antisense oligodeoxynucleotides were transfected to block the expression of HSP70. LDH release rate and total protein synthesis were applied to evaluate the injury of neonatal rat cardiomyocyte induced by H2O2 (0.5 mmol/L). Results: H2O2 could significantly increased LDH release and inhibit totalprotein synthesis. By inducing the expression of HSPs,heat shock pretreatment significantly reduced LDH release and attenuated the inhibition of total protein synthesis induced by H2O2. Moreover, HSP70 antisense oligodeoxynucleotides remarkably blocked the protective effect of heat shock pretreatment against the cellular injuries induced by H2 O2. Conclusion: HSP70 plays a most important role in cytoprotection of heat shock pretreatment against acute injury of cardiomyocyte mediated by H2O2.