The effects of endothelial progenitor cells on rat atherosclerosis

Atherosclerosis (AS) is a progressive disease characterized by endothelial injury and lipid aggregation in the arterial walls. Studies have reported that endothelial progenitor cells (EPCs) derived from the bone marrow (BM) might provide an endogenous repair mechanism by differentiating into endothelial cells to replace the dysfunctional endothelium. Our study aims to investigate the effect of EPCs derived from rat BM on AS. EPCs transduced by recombinant adeno-associated virus-green fluorescent protein (GFP) were transplanted into a rat AS model. After 2 months of transplantation, the localization of GFP-labeled cells, morphology, and lipid content in the aorta were examined. GFP-labeled EPCs were found in the endothelial monolayer of the artery vessel in the GFP/EPC group. Hematoxylin and eosin staining suggested that the lipid deposits in the aortic endothelium in the EPC/GFP group were less compared with those in the untreated group. Oil Red O staining of liver slices showed that lipid droplets were obviously decreased in the GFP/EPC group. The endothelial nitric oxide synthase and apolipoprotein E mRNA levels in the GFP/EPC group were significantly higher, but the intercellular cell adhesion molecule-1 mRNA level was significantly lower compared with the control group. The results suggest that EPCs derived from the BM can repair the injured endothelium and promote an atherosclerotic lesion regression. Therefore, EPCs may provide a useful tool for the treatment of AS.