Clinical potential of adult vascular progenitor cells.

Cell therapy to treat vascular and cardiovascular diseases has evolved over the past decade with improved understanding of progenitor cell mobilization, recruitment, and differentiation. The beneficial effects seen in several preclinical studies have prompted translation of adult vascular progenitor therapy to clinical trials. To date, progenitor cells isolated from bone marrow and peripheral blood have been tested in the context of acute myocardial infarction and chronic ischemic cardiomyopathy, with moderate benefit. This therapeutic effect occurs despite a relatively small number of injected progenitor cells and short-term residence in the target zone. Thus, indirect benefits, such as paracrine factors released from these cells, have been suggested as significant contributors to therapeutic efficacy. Several additional vascular progenitors of endothelial, smooth muscle, mesenchymal, and cardiac origin have been identified that may contribute to vasculogenesis. Indeed, a unifying paradigm for the most effective cell therapy strategies to date appears to be robust support of angiogenesis. Here we discuss a number of progenitor cells that currently show potential as cardiovascular therapeutics, either singly or in combination. We look at emerging cell types and disease targets that may be exploited for therapeutic benefit and future strategies that may maximize clinical efficacy.