In vivo and in vitro properties of CD34+ and CD14+ endothelial cell precursors.

Abstract

To begin we will briefly describe the history of how we, in collaboration with Jeffrey Isner’s group, contributed to the ‘rediscovery’ of circulating cells that integrate into the endothelium and function as endothelial cells. A number of years ago Dr. Isner and colleagues were studying the effect of vascular endothelial cell growth factor (VEGF) on reendothelialization of arteries. To test this, they denuded carotid arteries bilaterally and then delivered VEGF protein locally via a double balloon catheter to one of the carotid arteries. Isner and colleagues found that VEGF markedly increased re-endothelialization of the treated artery.’ However, they also observed that the local delivery of VEGF to one artery improved re-endothelialization of the untreated contralateral artery. Since only small amounts of VEGF were administered, systemic levels of VEGF could not have been appreciably elevated even if none of the VEGF remained at the site of administration. What then might account for the increased contralateral re-endothelialization?