Hemangioblasts and their progeny.

In the developing embryo, the hemangioblast, a mesodermal precursor, gives rise to hematopoietic and endothelial cells. Recent work has shown that during postnatal life, a subset of hematopoietic progenitor cells also displays this dual differentiation capacity and can function as endothelial progenitor cells that contribute to neovascularization. Thus, this subset might be useful for therapy of various hematopoietic and vascular diseases. Here, we describe a two-step culture system that results in the generation of endothelial and hematopoietic cells from adult progenitor cells with hemangioblastic potential. We have developed growth conditions that allow retroviral gene marking of the adult hemangioblast. This culture system is amenable for single-cell analyses at distinct stages of endothelial and hematopoietic differentiation from mobilized CD133+ progenitor cells.