p38 MAPK参与千金藤素诱导的心肌细胞凋亡

p38 MAPK involves in cepharanthine -induced apoptosis in cardiomyocytes

目的:探讨千金藤素(CEP)致Sprague-Dawley(SD)乳大鼠心肌细胞的凋亡作用及其信号途径。方法:应用MTT法检测千金藤素对心肌细胞活性的抑制作用;利用Hoechst 33342染色及Western blotting方法检测凋亡相关信号分子caspase-3,观察CEP致心肌细胞凋亡的作用;采用Western blotting法观测CEP对有丝分裂原活化蛋白激酶(MAPKs)家族3个主要信号分子c-Jn氨基端激酶(JNK)、细胞外信号调节激酶(ERK)、p38MAPK磷酸化水平的影响,并利用ERK和p38 MAPK的特异性抑制剂,分别验证两种分子所介导的信号通路在CEP致心肌细胞凋亡中的作用。结果:(1)CEP能够剂量依赖和时间依赖地抑制心肌细胞的活性。(2)CEP作用于心肌细胞,出现细胞核碎裂现象和caspase-3激活。(3)CEP作用下p38 MAPK和ERK磷酸化水平显著增强,JNK的磷酸化状态未发生显著改变。(4)p38 MAPK磷酸化抑制剂SB203580显著减轻CEP对心肌细胞活性的抑制作用;ERK磷酸化抑制剂PD98059不能影响CEP对心肌细胞活性的抑制作用。结论:p38 MAPK参与CEP致心肌细胞凋亡作用。

AIM：To investigate the apoptotic effect of cepharanthine（CEP）on neonatal rat cardiomyocytes （NRCMs）and the underlying mechanisms.METHODS：MTT assay was used to detect the viability of the cells.CEP-induced apoptosis in NRCMs was evaluated by Hoechst 33342 staining and the expression of activated caspase-3.The phosphorylation levels of mitogen-activated protein kinases（MAPKs）,such as extracellular signal-regulated kinase （ERK）,c-jun N-terminal kinase（JNK）and p38 MAPK,were examined by Western blotting.The specific inhibitors of ERK and p38 MAPK were applied for identifying the roles of the corresponding signal pathways in CEP-induced apoptosis of cardiomyocytes.RESULTS：CEP inhibited the viability of NRCMs in a dose-and time-dependent manners.Positive nuclear fragmentation and activated caspase-3 were found in CEP-treated NRCMs.The phosphorylation levels of ERK and p38 MAPK were significantly elevated in CEP-treated NRCMs,but the change of JNK was not obvious.SB203580, an inhibitor of p38 MAPK,significantly alleviated the apoptotic effect induced by CEP.However,PD98059,an inhibitor of ERK1/2,did not significantly reduce the apoptotic effect.CONCLUSION：p38 MAPK is involved in CEP-induced apoptosis in NRCMs.