胚胎干细胞向心肌细胞分化中内皮细胞的作用

Effect of endothelial cells during embryonic stem cells differentiating to cardiomyocytes

目的:研究胚胎干细胞向心肌细胞分化过程中,内皮细胞与心肌细胞之间的功能性联系。方法:通过检测CGR8-GFP小鼠胚胎干细胞系心肌α-肌球蛋白重链(α-MHC)荧光蛋白表达情况变化,观察抑制内源性内皮细胞、添加外源性内皮细胞以及两者并存情况下,胚胎干细胞分化所得心肌细胞数量的变化。结果:(1)在胚胎干细胞分化过程中,加入外源性内皮细胞后,心肌细胞形成明显增多。(2)特异性抑制内源性内皮细胞,心肌细胞形成明显减少。(3)外源性内皮细胞与胚胎干细胞共培养能够部分挽救由于内源性内皮细胞抑制所导致的心肌细胞形成障碍。结论:在胚胎干细胞分化过程中,内源性内皮细胞对于促进心肌细胞形成起着至关重要的作用,是形成心肌细胞发育微环境的关键因子。在胚胎干细胞向心肌细胞分化过程中,外源性内皮细胞可以刺激心肌细胞形成,从而得到大量心肌细胞,具有潜在的临床应用价值。

Objective.. To investigate the relationship between cardiomyocytes and endothelial cells during embryonic stem（ES） cells differentiation. Methods..CGR8-GFP is a mouse ES cell line in which EGFP expression is under the control of cardiac muscle specific s-myosin heavy chain （MHC） promoter. With normal differentiation media, ES cells differentiate to cardiomyocytes by using ＂hanging drop＂ method. During this process, we calculate the numbers of cardiomyocytes with addition of different numbers of exogenous endothelial cells or inhibition of endogenous endothelial cells and both of above conditions. Results： （1） During embryonic stem cells differentiation, exogenous endothelial cells could stimulate and advance ES cell-derived cardiogenesis. （2） With inhibition of endogenous endothelial cells induced by an angiogenesis inhibitor-Endostatin, ES cell-derived cardiogenesis is dramatically retarded. The endostatin^s effect is in dose-dependent manner. （3） Exogenous endothelial cells co-culturing with ES cells could partially rescue the retarded cardiogenesis caused by endostatin inducing inhibition of endogenous endothelial cells. Conclusion.. （1）These findings identify the endothelial cell as a critical component of the cardiogenesis niche, even during E$ cells differentiation. （2） Exogenous endothelial cells could stimulate and advance ES cell-derived cardiogenesis.