Embryonic stem cell models in vascular biology.

Embryonic stem cells have become an established tool in vascular biology to study the details of vasculogenesis as well as angiogenesis. There is also a future potential in using embryonic stem cell-derived endothelial cells for therapeutic purposes. It is important to evaluate this model by comparing features of endothelial cells derived from differentiating stem cells and their responsiveness to external stimuli to those of primary endothelial cells and to in vivo models. Through culture of mouse embryonic stem cell we discovered that differentiating stem cells are highly amenable to analyzing biochemical and cell biologic processes that are independent of flow. Endothelial cell function can be studied in the context of mutations or deletions that are embryonically lethal in vivo. Many, if not all, of the features of sprouting angiogenesis in differentiating stem cells closely mimic the in vivo process.