Vascular Progenitor Cells Lineage Controversies

Abstract

The discovery that vascular progenitor cells in peripheral blood can differentiate into endothelial and vascular smooth muscle cells has lead to a major re-evaluation of many traditionally held beliefs about vascular biology. For instance concepts of vascular regeneration and repair previously considered limited to proliferation of existing differentiated cells within the vessel wall have been expanded to include potential for postnatal vasculogenesis from blood-derived, adventitial tissue-derived and bone marrow-derived precursor cells. The significance of these data lays not only in the development of a novel understanding of vascular biology but also in the new insights provided in vascular disease in general and atherosclerosis research in particular. The mechanisms underlying the mobilization, target tissue integration and differentiation of these cells are now being elucidated. Paramount in this endeavour is a more precise understanding of the lineage of various progenitor cell types and development of experimental systems which can rigorously test vascular lineage questions.