Objective: To investigate the differentiation status of autologous bone marrow mononuclear cells (BM-MNC) and peripheral endothelial progenitor cells (EPC) transplanted into myocardial ischemia reperfusion injury region in swine.
Methods: BM-MNC marked with PKH26 (n = 9), EPC marked with CM-DiI (n = 7), phosphate buffer saline (control, n = 7) were transplanted into myocardial ischemia reperfusion injury region of swine by intracoronary artery injection. Specimens were harvested 4 weeks after injection for histological analysis (HE, immunochemical stain for vWF, alpha-sarcomeric-actin and fibronectin antibody). Cell differentiation was observed under transmission electronmicroscope.
Results: The number of small blood vessels was similar between BM-MNC group and EPC group (13.39 +/- 6.96/HP vs.12.39 +/- 4.72/HP, P < 0.05), but was significantly higher than that of control group (P < 0.05). Responsive intensity of immunochemical stain for fibronectin antibody was significantly lower in BM-MNC and EPC groups than that in control group. Responsive intensity of immunochemical stain for alpha-sarcomeric-actin antibody was similar among the three groups. Cluster cells were observed in one swine from BM-MNC group which might relate to the proliferation of stem cells in situ. Immature endothelial cells and myocytes were also detected by transmission electronmicroscope in BM-MNC and EPC group.
Conclusion: BM-MNC and EPC transplanted into myocardial ischemia reperfusion injury region in swine stimulated the formation of blood vessels and inhibited fibrogenesis.