In Vitro Differentiation Of Human Bone Marrow Mesenchymal Stem Cells Into Blood Vessel Endothelial Cells

Objective:The study initial indicate that,bone marrow mesenchymal stem cells (MSCs) have the potential to differentiate into mesenchymal tissues like osteocytes, chondrocytes, and adipocytes in vivo and in vitro. The aim of this study was to investigate the feasibility of human bone marrow MSCs differentiating into endothelial cells (ECs) in vitro,and to provid experiment base of MSCs as seeding cells for vascular tissue engineering and injured tissue repairing by cell transplantation.Methods:The hMSCs were isolated by density gradient centrifugation and amp lificated and identificated in vitro. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) within Dulbecco's-modified Eagle's Medium-Low Glucose (DMEM/F12) were used to induce hMSCs differentiating into vascular endothelial cells. Morphological changes were observed. The induced hMSCs were detected by immunocytochemical and flow cytometry to find whether they had endothelial cell phenotypes.To observe the cability of differentiated cells ingest DiI-ac-LDL.Results: Nearly all MSCs adhered after 24h of plating. Non-adherent cells removed with changes in medium. The adherent elongated with spindle-shaped, triangular or polygonal morphology. They grew in clusters later and reached confluent after 12d. Passaged cells attached several hours after plating. They gradually stretched to spindle-shaped or polygonal morphology. When reached confluence after 5-7d. They became uniformly shaped and densely arranged. Inducting differentiation of MSCs into endothelial-like cells by cultivating MSCs in the presence 10ng/ml bFGF, 10ng/ml VEGF for 24 days, there were no visible difference between two cells in morphology. After 24 days,part of these cells were stained for DiI-ac-LDL. Flow cytometry analysis enhanced signals of expression of CD34, CD45, CD106 ,HLA-DR.Conclusion: The hMSCs can obtain endothelial cell phenotypes after induced by VEGF and bFGF in vitro. However, the induced endothelial-like cells don,t have completely mature endothelial cell functional properties. The hMSCs have potential to differentiate into vascular endothelial cells.