Cocaine induces apoptosis in fetal rat myocardial cells through the p38 mitogen-activated protein kinase and mitochondrial/cytochrome c pathways
Cocaine induces apoptosis in fetal rat myocardial cells through the p38 mitogen-activated protein kinase and mitochondrial/cytochrome c pathways
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DOI：
10.1124/jpet.104.073494
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发表时间：
2005-01-01
影响因子：
3.5
通讯作者：
Zhang, LB
中科院分区：
文献类型：
--
作者：
Li, GH;Xiao, YH;Zhang, LB
环磷酰胺诱导胎鼠心肌细胞凋亡。然而，其机制尚不清楚。本研究探讨了p38丝裂原活化蛋白激酶（MAPK）和细胞色素c释放可卡因诱导的胎龄21天的胎心FRMCs的原代培养细胞凋亡的作用。环磷酰胺诱导细胞色素c释放和caspase-9和caspase-3的活性的时间依赖性，同时增加，这之前的细胞凋亡。Caspase-8未被激活。因此，环孢素A和caspase-9和caspase-3抑制剂抑制可卡因诱导的caspase激活和凋亡。在FRMCs中，在15分钟的时间点，考马斯亮蓝刺激p38 MAPK活性的瞬时增加，但在5和15分钟降低细胞外信号调节激酶（ERK）活性。p38 α MAPK抑制剂SB 203580 [4-（4-fluorophenyl）-2-（4-methylsulfinylphenyl）-5-（4-pyridyl）1H-imidazole]抑制可卡因诱导的caspase活化和细胞凋亡。相比之下，p38 β MAPK和丝裂原活化蛋白激酶激酶/ERK抑制剂SB 202190 [4-（4-氟苯基）-2-（4-羟基苯基）-5-（4-吡啶基）-1H-咪唑]和PD 98059（2 '-氨基-3'-甲氧基黄酮）分别在没有可卡因的情况下增加细胞凋亡和增强可卡因诱导的细胞凋亡。SB 203580抑制可卡因诱导的细胞色素c释放和caspase-9和caspase-3的活化，与其抑制细胞凋亡一致。此外，可卡因诱导Bcl-2蛋白水平下降，对Bax水平没有影响。可卡因介导的Bcl-2水平的降低不受SB 203580和半胱天冬酶抑制剂的影响。结果提示，在FRMCs中，p38 α MAPK通过促进细胞色素c的释放，在可卡因诱导的细胞凋亡中起重要作用，其作用是在Bcl-2蛋白介导的调控的下游或独立的。与此相反，p38 β MAPK和ERK保护胎儿心肌细胞免于凋亡。
Cocaine induces apoptosis in fetal rat myocardial cells (FRMCs). However, the mechanisms are not clear. The present study examined the role of p38 mitogen-activated protein kinase (MAPK) and cytochrome c release in the cocaine-induced apoptosis in primary culture of FRMCs prepared from the fetal heart of gestational age of 21 days. Cocaine induced time-dependent, concurrent increases in cytochrome c release and activities of caspase-9 and caspase-3, which preceded apoptosis. Caspase-8 was not activated. In accordance, cyclosporin A and the inhibitors of caspase-9 and caspase-3 inhibited cocaine-induced caspase activation and apoptosis. Cocaine stimulated a transient increase in the p38 MAPK activity at a time point of 15 min but reduced the extracellular signal-regulated kinase (ERK) activity at 5 and 15 min in FRMCs. The p38alpha MAPK inhibitor SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl) 1H-imidazole] inhibited cocaine-induced activation of caspases and apoptosis. In contrast, the p38beta MAPK and mitogen-activated protein kinase kinase/ERK inhibitors SB 202190 [4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)-1H-imidazole] and PD98059 (2'-amino-3'-methoxyflavone), respectively, increased apoptosis in the absence of cocaine and potentiated cocaine-induced apoptosis. Consistent with its inhibition of apoptosis, SB203580 inhibited cocaine-induced cytochrome c release and activation of caspase-9 and caspase-3. In addition, cocaine induced a decrease in Bcl-2 protein levels, with no effect on Bax levels. The cocaine-mediated reduction of Bcl-2 levels was not affected with SB203580 and the caspase inhibitors. The results suggest that in FRMCs, p38alpha MAPK plays an important role in the cocaine-induced apoptosis by promoting cytochrome c release, downstream or independent of Bcl-2 protein-mediated regulation. In contrast, p38beta MAPK and ERK protect fetal myocardial cells against apoptosis.