Austin Anita F, Compton Leigh A, Love Joseph D, Brown Christopher B, Barnett Joey V
Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6600, USA.
Dev Dyn. 2008 Feb;237(2):366-76. doi: 10.1002/dvdy.21421.
Cells derived from the epicardium are required for coronary vessel development. Transforming growth factor beta (TGFbeta) induces loss of epithelial character and smooth muscle differentiation in chick epicardial cells. Here, we show that epicardial explants from embryonic day (E) 11.5 mouse embryos incubated with TGFbeta1 or TGFbeta2 lose epithelial character and undergo smooth muscle differentiation. To further study TGFbeta Signaling, we generated immortalized mouse epicardial cells. Cells from E10.5, 11.5, and 13.5 formed tightly packed epithelium and expressed the epicardial marker Wilm's tumor 1 (WT1). TGFbeta induced the loss of zonula occludens-1 (ZO-1) and the appearance of SM22alpha and calponin consistent with smooth muscle differentiation. Inhibition of activin receptor-like kinase (ALK) 5 or p160 rho kinase activity prevented the effects of TGFbeta while inhibition of p38 mitogen activated protein (MAP) kinase did not. These data demonstrate that TGFbeta induces epicardial cell differentiation and that immortalized epicardial cells provide a suitable model for differentiation.
冠状动脉血管发育需要来源于心外膜的细胞。转化生长因子β（TGFβ）可诱导鸡心外膜细胞上皮特性丧失和平滑肌分化。在此，我们表明，用TGFβ1或TGFβ2孵育的胚胎第11.5天（E11.5）小鼠胚胎的心外膜外植体丧失上皮特性并发生平滑肌分化。为了进一步研究TGFβ信号传导，我们构建了永生化小鼠心外膜细胞。来自E10.5、E11.5和E13.5的细胞形成紧密堆积的上皮，并表达心外膜标志物威尔姆斯瘤1（WT1）。TGFβ诱导紧密连接蛋白1（ZO-1）丧失以及与平滑肌分化一致的平滑肌肌动蛋白α（SM22α）和钙调蛋白的出现。抑制激活素受体样激酶（ALK）5或p160 Rho激酶活性可阻止TGFβ的作用，而抑制p38丝裂原活化蛋白（MAP）激酶则无效。这些数据表明，TGFβ诱导心外膜细胞分化，并且永生化心外膜细胞为分化提供了合适的模型。
