Abstract
Mesenchymal stem cells (MSCs) hold potential for the regeneration of damaged tissues in cardiovascular diseases. In this study, we investigated the potential of porcine MSCs to differentiate into endothelial cells (ECs) in vitro. The cultured bone marrow-derived cells were CD11b⁻CD34⁻CD44⁺CD45⁻CD90⁺ and showed mesodermal lineage differentiation, which is characteristic of MSCs. The MSCs were induced to differentiate into ECs using endothelial growth medium (EGM), with and without high concentrations of VEGF (EGM + VEGF; 50 ng/ml). Endothelial basal medium (EBM) without growth factors served as the control. The EC differentiation was assessed by the presence of vWF, ability to take up acetylated LDL, in vitro angiogenesis assay, flow cytometry and qPCR of EC markers vWF, VE-cadherin, PECAM-1, VEGF-R1 and VEGF-R2 after 10 days of stimulation. Cells cultured in EGM + VEGF medium demonstrated higher amounts of DiI-AcLDL-positive cells and enhanced the presence of vWF (90%), VE-Cadherin- (60%) and PECAM-1 (48%)-positive cells, than in EBM. These cells showed profuse sprouting of capillary tubes and closed polygon formation in the angiogenesis assay. There was 1.5-2-fold increase in the mRNA expression of endothelial markers in the cells stimulated with EGM + VEGF medium when compared to control. The results demonstrate the ability of porcine MSCs to differentiate into ECs under in vitro inducing conditions. The differentiated cells would provide new options for re-endothelialization following interventional procedures and tissue engineering.