Abstract
BACKGROUND AND OBJECTIVES: Endothelial progenitor cells (EPC) in one study group are not the same as those in other investigators, suggesting that EPC is not a single type of cell population. In this study, we tried to demonstrate the heterogeneity of EPC.
MATERALS AND METHODS: We cultured total mononuclear cells from human peripheral blood to get two types of EPC sequentially from the same donors; termed early EPC and late EPC.
RESULTS: Early EPC with spindle shape showed a peak at 2-3 weeks and died at 4 weeks, while late EPC with cobblestone shape appeared late at 2-3 weeks, showed exponential growth at 4-8 weeks and were sustained up to 12 weeks. Late EPC expressed VE-cadherin, Flt-1 and KDR at higher levels than early EPC did, and did not express CD45, whereas early EPC did. Late EPC was superior in the production of nitric oxide, the incorporation into HUVEC monolayer and the formation of capillary tubes.
CONCLUSION: We found two different types of EPC that might play different roles in adult neovasculogenesis based on the genetic and functional differences.