Advances in TransplantationExperimental studyLocally Transplanted CD34+ Bone Marrow-Derived Cells Contribute to Vascular Healing After Vascular Injury

IntroductionVascular progenitor cells contribute to repair of injured vasculature. In this study, we aimed to investigate the role of bone marrow-derived cells in the intimal formation after arterial injury.Methods and ResultsBalloon injury of the femoral artery of wild-type mice was followed by local delivery of bone marrow-derived cells from GFP transgenic mice. The arteries were collected 1, 4, 7, and 14 days after injury and studied for morphology, localization, and phenotypes of delivered cells. Bone marrow-derived cells were present in the intima only at the early stages of arterial injury and expressed endothelial progenitor cell markers (CD31, CD34, and VEGFR-2). In the areas where intima was thicker, bone marrow-derived cells differentiated to intimal smooth muscle cells but they did not fuse with intimal cells. Delivery of CD34+ cells contributed to a 1.5-fold inhibition of intimal hyperplasia.ConclusionBone marrow-derived endothelial cells differentiated but did not fuse with vascular smooth muscle cells at the early stages of intimal formation and contributed to intimal hyperplasia.