辛伐他汀对缺氧/复氧诱导的心肌细胞凋亡的拮抗作用及其作用机制

Protective effects and mechanism of simvastatin on hypoxia/reoxygenation-induced apoptosis in rat cardiomyocyte

目的:探讨辛伐他汀对缺氧/复氧诱导的心肌细胞损伤的拮抗作用及潜在机制。方法:分离培养Sprague-Dawley(SD)大鼠(乳鼠)心肌细胞,随机分为对照组、缺氧2 h/复氧4 h(H/R4h)组、不同浓度(0.1、1.0及10μmol/L)的辛伐他汀干预组及Toll样受体4(TLR4)中和性抗体MTS510组(浓度为10μg/L)。H/R4h组给予缺氧2 h后,随即复氧4 h。细胞处理后,进行PI-AnnexinV染色用流式细胞仪检测心肌细胞的凋亡率,用ELISA法检测心肌乳酸脱氢酶(LDH)的活性;用免疫印迹法测TLR4蛋白的含量。结果:与H/R4h组相比,辛伐他汀干预组可显著降低心肌细胞的凋亡率(16.0%vs.28.6%,P<0.01)及LDH的活性(P<0.01),并呈剂量依赖性。中浓度的辛伐他汀组开始出现拮抗作用,峰值出现在高浓度辛伐他汀组,加入MTS510阻断剂可降低心肌细胞的凋亡率及LDH的活性(P<0.01)。结论:辛伐他汀对H/R造成的心肌细胞损伤具有拮抗作用,并呈剂量依赖性,其作用机制可能与TLR4信号通路有关。

AIM： To explore the protective effects and mechanism of simvastatin on hypoxia/reoxygenation-induced cardiac injury.METHODS： Cultured cardiomyocytes from neonatal rats subjected to hypoxia for 2 h and reoxygenation for 4 h were divided randomly into four groups： control group,hypoxia 2h/reoxygenation 4 h group（H/R 4 h）,simvastatin（SIM） pretreated group（concentration： 0.1 μmol/L,1 μmol/L,10 μmol/L）,and neutralizing antibody group of TLR4： MTS510（10 μg/L）.Cardiomyocyte apoptosis was detected by flow cytometry,concentration of LDH was measured by ELISA and expression of TLR4 protein was measured by Western blot.RESULTS： Compared with that in control and H/R 4 h groups,H/R-induced apoptosis was markedly attenuated in SIM group in a dose-dependent manner.Protective effects of simvastatin began at 0.1 μmol/L and the maximal effects reached at 10 μmol/L.After the addition of neutralizing antibody of TLR4,cardiocyte apoptosis and activities of LDH decreased.CONCLUSION： Simvastatin protects hypoxia/reoxygenation-induced cardiac injury in a dose-dependent manner,and the protective effects are in association with TLR4 signalling pathway.