Robust angiogenic properties of cultured human peripheral blood-derived CD31+ cells

BackgroundRecently, we showed the angio-vasculogenic potential of uncultured human peripheral blood (hPB)-derived CD31+ cells. However, thus far, the angiogenic property of the cultured hPB-derived CD31+ (C-31+) cells is unknown. Thus, this study aimed to assess the angiogenic potency of C-31+ cells on experimental ischemia.MethodsCD31+ and CD31− cells were isolated by magnetic bead separation technique, and cultured in EBM-2 complete medium for 6 days. The expression of multiple angiogenic genes in these cells was measured using qRT-PCR. In addition, endothelial progenitor cell culture and matrigel network formation assays were performed. A mouse model of hindlimb ischemia induced by surgical resection of the right femoral artery was used, and the C-31+ cells were intramuscularly transplanted into the ischemic area. Immunohistochemical analysis was also performed.ResultsC-31+ cells exclusively showed higher colony-forming activity, and gave rise to EPCs. C-31+ cells also induced higher endothelial network formation, and exhibited higher pro-angiogenic and lower inflammatory gene expression. In our ischemic hindlimb model, transplantation of C-31+ cells induced increased blood perfusion (0.652 ± 0.03 vs. 0.47 ± 0.04; P < 0.01) and increased capillary density (85 ± 5.5 vs. 57 ± 4.1; P < 0.01) as compared to C-31− cells. In addition, angiogenic factors were markedly upregulated after the transplantation of C-31+ cells, indicating that C-31+ cells contributed to the neovascularization.ConclusionsThe high angiogenic and therapeutic potential of C-31+ cells observed in our ischemic animal model suggests a novel role of hPB-derived cultured CD31+ cells in the treatment of ischemic cardiovascular diseases.