Inhibition of Notch signaling enhances the functions of the endothelial cells differentiated from rat MSCs

Background Study has shown that rat bone mesenchymal stem cells （MSCs） can be differentiated into endothelial cells by VEGF and b-FGF in vitro. Our previous research found that after rat bone MSCs treated by VEGF and b-FGF gained the phenotypic and functional features of endothelial cell lines, with some differences from endothelial cell lines regard to the stability and self-replicating. This study was to explore the effect of Notch signaling on the functions of MSCs differentiated endothelial cells. Methods Rat bone MSCs were cultivated and treated by VEGF165 and b-FGF for 2 weeks to induce endothelial cell differentiation. The gene of VEGF165 was imported into differentiated endothelial cells. The receptor of Notchl and the ligand of Notch signaling Jaggedl were detected by RT-PCR before and after the transfection. γ-secretase inhibitor was used to block Notch pathway, Cell migration ability was detected by scarification test. Cells were inoculated on semisolid gel to study their ability of capillary-like structure formation. Results After transfection, VEGF165 mRNA was detected on the differentiated endothelial cells. The expression of Jaggedl＇s mRNA was up regulated （1.08 ± 0.01 compared to 1.01 ± 0.02, P 〈 0.01） and there was no change about the Notchl. Cells migration ability was enhanced [number of cells on the scratched area： 44.95 ± 3.14 compared to 41.61 ± 1.42, P 〈 0.05] and the ability of forming capillary-like structure on semisolid gel was not changed. The γ-secretase inhibitor L-685,458 further enhanced the abilities of cell migration [number of cells on the scratched area： 50.28 _ 2.76 compared to 44.95 ±3.14, P 〈 0.05]） and capillary-like structure formation on semisolid gel （cells classification： 4.00 _ 0.63 compared to 3.00 ± 0.63, P 〈 0.05） Conclusions Inhibition of Notch signaling can enhance the functions of the endothelial cells differentiated from rat MSCs.