In Vitro Differentiation Into Endothelial-like Cells From Diabetic Rat Bone Marrow Mesenchymal Stem Cells

【Objective】To investigate the effect of VEGF and bFGF on the differentiation into endothelial - like cells from diabetic rat bone marrow mesenchymal stem cells(BMSCs) in vitro.【Methods】Diabetic Sprague-dawley rats, an animal model of diabetes, was induced with intraperitoneal injection of 45mg/kg streptozotocin (STZ),After 12 weeks of diabetic duration, bone marrow stromal stem cells in diabetic rats harvested from bone marrow by flushing femur and tibia were isolated by Histopaque density gradient centrifugation and adherent culture. The surface markers were identified with flow cytometry after amplification in vitro.Bone marow mesenehymal stem cells of the 3 passage were also obtained and divided into 2 groups.In the differentiation group,the cells were induced to differentiate in M199 medium containing 10% FBS,VEGF(10ng/mL) and bFGF(2ng/mL);no cytokine was added in the blank control group.Two weeks later,the cell morphology was observed by phase contrast microscopy,The expressions of VEGF-R2 were detected with immunohistochemistry,release of nitrous oxide from culture cells was also detected by nitrous oxide detection reagent respectively; CD34 ,the specific marker of endothelial progenitor cells ,was evaluated with fluorescene activated cell sorter( FACS); Weibel- Palade bodies in the cytoplasm were observed using transmission electron microscopy.【Result】1.Cultured diabetic rat BMSCs at the passage 3 were positive for CD44,CD90 and CD29 (97.8%±0.9%,96.8%±1.4%,97.6%±2.4%,respectively), but negative for CD11b/c and CD34 (13.2%±0.6% and 1.2%±0.5%, respectively).