Purification and culture of human blood vessel-associated progenitor cells

Multilineage progenitor cells, diversely designated as MSC, MAPC, or MDSC, have been previously extracted from long-term cultures of fetal and adult organs (e.g., bone marrow, brain, lung, pancreas, muscle, adipose tissue, and several others). The identity and location, within native tissues, of these elusive stem cells are described here. Subsets of endothelial cells and pericytes, which participate in the architecture of human blood vessels, exhibit, following purification to homogeneity, developmental multipotency. The selection from human tissues, by flow cytometry using combinations of positive and negative cell surface markers, of endothelial and perivascular cells is described here. In addition, a rare subset of myoendothelial cells that express markers of both endothelial and myogenic cell lineages and exhibit dramatic myogenic and cardiomyogenic potential has been identified and purified from skeletal muscle. The culture conditions amenable to the long-term proliferation of these blood vessel-associated stem cells in vitro are also described.