Bone marrow-derived endothelial progenitor cells for neovascular formation.

A certain population of mononuclear cells in the peripheral blood is capable of contributing to new vessel formation by differentiating into endothelial cells. These cells were discovered by Asahara in 1997 and named endothelial progenitor cells (EPCs). In the previous hypothesis, the endothelial cells of newly formed vasculature were considered to be derived only from nearby pre-existing vessels in the adult. However, it is demonstrated that the bone marrow-derived EPCs are incorporated in the foci of both physiological and pathological neovascular formation. Furthermore, clinical usefulness of EPCs from human peripheral blood is also suggested from animal experiments. If EPCs are administered to immunodeficient animals in ischemic disease models, neovascular formation is augmented and ischemia-induced tissue damage or functional disorder is attenuated. These results indicate that administering EPCs could be a new clinical strategy to treat ischemic disease, diabetic retinopathy or neoplasm in which the promotion or inhibition of neovascular formation is critical. In this chapter, we have showed the significance and potential of EPCs in the basic and clinical settings of neovascular formation.