Department of Cardiology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China.
J Cell Biochem. 2010 Dec 15;111(6):1619-28. doi: 10.1002/jcb.22895.
Endothelin-1(ET-1) is a potent vasoconstrictor involved in the development of cardiovascular diseases and is an important regulator of heart development. However, the role of ET-1 in cardiac differentiation of mouse embryonic stem cells (mESCs) and the underlying molecular mechanisms remain poorly understood. In the present study, we showed that ET-1 significantly up-regulated gene expression of the cardiac specific transcriptional factors Nkx2.5, GATA4, and conduction system specific marker CX40, with no affect on the gene expression of α-MHC and β-MHC in cardiac differentiation of mESCs. The percentage of beating embryoid bodies (EB) and the Troponin T (TnT) positive area in total EBs was unchanged following ET-1 treatment, while the percentage of spindle cells that stained positively with TnT was increased in the presence of ET-1. Further investigation indicated that the percentage of beating EBs and the TnT positive area were decreased by the extracellular signal-related kinases (ERK)-1/2 inhibitor U0126 and the p38 inhibitor SB203580, but not by the Jun amino-terminal kinases (JNK) inhibitor SP600125. Inhibition of ERK1/2, p38, and JNK pathways also blocked the up-regulation of Nkx2.5 and GATA4 by ET-1, however only inhibition of the ERK1/2 pathway had negatively effects on the increase in CX40 expression in response to ET-1. ET-1 induced an increase in the percentage of spindle cells was also inhibited by U0126. Our results suggest that ET-1 plays a significant role in the cardiac differentiation of mESCs, especially in those cells committed to the conduction system, with the ERK1/2 pathway playing a critical role in this process.
内皮素-1(ET-1)是一种强效的血管收缩剂,参与心血管疾病的发生发展,是心脏发育的重要调节因子。然而,ET-1 在小鼠胚胎干细胞(mESC)的心脏分化中的作用及其潜在的分子机制仍知之甚少。本研究表明,ET-1 可显著上调心脏特异性转录因子 Nkx2.5、GATA4 和传导系统特异性标志物 CX40 的基因表达,而对 mESC 心脏分化中α-MHC 和β-MHC 的基因表达无影响。ET-1 处理后,搏动胚体(EB)的百分比和总 EB 中 Troponin T(TnT)阳性区域无变化,而 ET-1 存在时,TnT 阳性的纺锤形细胞的百分比增加。进一步研究表明,通过细胞外信号调节激酶(ERK)-1/2 抑制剂 U0126 和 p38 抑制剂 SB203580 可降低搏动 EB 的百分比和 TnT 阳性区域,而 Jun 氨基末端激酶(JNK)抑制剂 SP600125 则无此作用。ERK1/2、p38 和 JNK 通路的抑制也阻断了 ET-1 对 Nkx2.5 和 GATA4 的上调,但只有 ERK1/2 通路的抑制对 ET-1 诱导的 CX40 表达增加有负作用。ET-1 诱导的纺锤形细胞百分比增加也被 U0126 抑制。我们的结果表明,ET-1 在 mESC 的心脏分化中起重要作用,特别是在那些向传导系统分化的细胞中,ERK1/2 通路在这个过程中起着关键作用。