Intravenous transfusion of endothelial progenitor cells reduces neointima formation

AIM: To investigate the feasibility of transplanting endothelial progenitor cells(EPCs) obtained from spleen in vascular endothelium repairmen after vascular injury.METHODS: EPCs were isolated by using a Ficoll density gradient centrifugation,and were cultured in plate.The endothelial characteristics of EPCs were identified by immunochemical staining and fluorescent labeling.Dil-Ac-LDL labeled spleen-derived EPCs were transplanted into the rats by intravenous injection directly after induction of arterial injury and again 24 hours later.Rats received FITC-labeled lectin intravenously before euthanasia.The distribution of fluorescent labeled EPCs was traced.The morphology of arterial intima and media was studied by optical microscopy and image analysing system.RESULTS: The adherent cells were considered EPCs that showed spindle shape and form blood-siland-like structures during development.The adherent cells had many endothelial characteristics.Fluorescent labeling showed that the intravenously injected EPCs specifically restricted to the vascular injury site,and lectin binding confirmed the endothelial phenotype.The ratio of neointimal/media area in EPCs transplantation group was obviously reduced than that in injury group and M199 group(0.82±0.09 vs 1.52±0.21,1.48±0.19,P0.01).The PCNA positive expression cells were evidently decreased compared with injury group and M199 group(19.25±3.96 vs 31.42±5.23,29.37±3.16,P0.05).CONCLUSION: EPCs incorporate into the process of injured carotid reendothelialization.EPCs transplantation induces an increase in the circulating EPCs,accelerates the process of endothelial repairmen and reduces neointima formation.