Abstract
INTRODUCTION: Transplantation of endothelial progenitor cells (EPCs) restores endothelial function in patients with endothelial dysfunction and initial denudation. The goal of the present study was to determine the effect of cryopreserved human umbilical cord blood (UCB)-derived EPC infusion on the repair of carotid artery injury in nude rats. METHODS: Mononuclear cells (MNCs) from human cryopreserved UCB and peripheral blood (PB) of patients with cardiovascular diseases and healthy volunteers were cultured in a conditioned medium. The in vitro migration, proliferation, adhesion, and survival capacities, as well as paracrine cytokine release of EPCs were investigated. EPC homing, induced reendothelialization, and the effect on neointima formation were also assessed in vivo. RESULTS: Patient-derived PB EPCs (PPB-EPCs) displayed decreased migration, proliferation, adhesion, and survival capabilities as compared to PB-EPCs from healthy volunteers (HPB-EPCs) and cryopreserved UCB-EPCs. However, there was no difference in the release of vascular endothelial growth factor (VEGF) and stromal cell derived factor 1 (SDF-1) between the three groups. Two weeks after transplantation, more labeled UCB-EPCs and HPB-EPCs than PPB-EPCs were found by cell tracking in the injury zone. Administration of PPB-EPCs, HPB-EPCs, and UCB-EPCs enhanced reendothelialization and inhibited neointima formation compared to the saline control. However, UCB-EPC and HPB-EPC infusion showed a greater improvement than PPB-EPCs. CONCLUSIONS: Cryopreserved UCB-MNCs derived EPCs and HPB-EPCs show better responses to cytokines and vascular injury than PPB-EPCs. Thus, cryopreservation and delivery of cryopreserved autogenous UCB-EPCs or HPB-EPCs may be a promising vasculoprotective approach for patients with multiple cardiovascular risk factors.