[Vascular endothelial cell development and underlying mechanisms].

The cardiovascular system is one of the first organs formed during embryogenesis. Vessel development involves generating primary vascular endothelial tubes by aggregation of angioblasts (vasculogenesis), creating a vascular network through endothelial sprouting (angiogenesis), and pruning primary vascular tubes by recruiting smooth muscle cells to the vessel walls (vessel maturation). Angioblast, the endothelial progenitor, is generated from hemangioblasts that are derived from the Flk1+ mesodermal cells, or directly from the Flk1+ mesodermal cells. Although several factors such as vegf, flk1, cloche, lycat and estrp are essential for angioblast development, much of the signaling pathways underlying the derivation of angioblasts from the hemangioblasts or Flk1+ mesodermal cells remain unknown. This review will summarize our current knowledge, challenge, and future directions on molecular and cellular mechanisms of endothelial cell development.