Endothelial colony-forming cell role in neoangiogenesis and tissue repair

Purpose of review Patients suffering from vascular disease often have impaired angiogenic ability contributing to impaired tissue repair. One potential therapy is to deliver cells that can aid in angiogenesis. This review will discuss the ability of endothelial progenitor cells (EPCs), which have been reported to contribute to neoangiogenesis in both physiological and pathological conditions, to contribute to neoangiogenesis in tissue repair. Recent findings In recent years, various reports have described conflicting roles for EPC in vessel formation. Currently there are three different assays for outgrowth of EPC all resulting in the isolation of different cell populations. This confusion is partially due to limited functional characterization of putative EPC populations. One population, endothelial colony-forming cell (ECFC), has been shown to possess all the characteristics of a true endothelial progenitor. Summary The review overviews the role of putative EPC populations in angiogenesis and tissue repair. Whereas all EPC populations have been shown to play a role in angiogenesis, only ECFC have demonstrated the ability to form de-novo blood vessels in vivo. Additionally ECFC have been shown to play a role in neovascularization in several preclinical rodent models suggesting that it may be an excellent cell source for treatment of patients with diminished vascular function.