Laboratory of Stem Cell Differentiation, Stem Cell Research Center, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
J Cell Biol. 2010 Apr 19;189(2):325-38. doi: 10.1083/jcb.200904114.
Molecular mechanisms controlling arterial-venous specification have not been fully elucidated. Previously, we established an embryonic stem cell differentiation system and demonstrated that activation of cAMP signaling together with VEGF induces arterial endothelial cells (ECs) from Flk1(+) vascular progenitor cells. Here, we show novel arterial specification machinery regulated by Notch and beta-catenin signaling. Notch and GSK3beta-mediated beta-catenin signaling were activated downstream of cAMP through phosphatidylinositol-3 kinase. Forced activation of Notch and beta-catenin with VEGF completely reconstituted cAMP-elicited arterial EC induction, and synergistically enhanced target gene promoter activity in vitro and arterial gene expression during in vivo angiogenesis. A protein complex with RBP-J, the intracellular domain of Notch, and beta-catenin was formed on RBP-J binding sites of arterial genes in arterial, but not venous ECs. This molecular machinery for arterial specification leads to an integrated and more comprehensive understanding of vascular signaling.
尚未完全阐明控制动静脉特异性的分子机制。此前，我们建立了胚胎干细胞分化系统，并证明 cAMP 信号的激活与 VEGF 一起诱导 Flk1(+)血管祖细胞分化为动脉内皮细胞（ECs）。在此，我们展示了受 Notch 和 β-catenin 信号调控的新的动脉特化机制。Notch 和 GSK3β 介导的 β-catenin 信号通过磷酸肌醇-3 激酶在 cAMP 下游被激活。VEGF 与 Notch 和 β-catenin 的强制激活完全重建了 cAMP 诱导的动脉 EC 诱导，并且在体外协同增强了靶基因启动子活性，并在体内血管生成过程中增强了动脉基因表达。在动脉 EC 中，而不是在静脉 EC 中，形成了具有 RBP-J、Notch 细胞内域和 β-catenin 的蛋白复合物，该复合物位于动脉基因的 RBP-J 结合位点上。这种动脉特化的分子机制为血管信号提供了一个综合且更全面的理解。
