Silencing of RBP‑JK promotes the differentiation of bone marrow mesenchymal stem cells into vascular endothelial cells

Bone marrow mesenchymal stem cells (BMMSCs) are important for postnatal angiogenesis and are suitable for use in construction of blood vessels by tissue engineering. The present study aimed to investigate the influence of recombination signal binding protein for immunoglobulin kappa J region (RBPJK) on the differentiation of BMMSCs into vascular endothelial cells, and to assess the underlying mechanisms. BMMSCs were isolated and identified by flow cytometry. Lentiviral vectors encoding RBPJK shRNA (shRBPJK) were constructed to knockdown RBPJK expression and endothelial differentiation of BMMSCs was induced. The experimental groups were treated with: empty lentiviral vector (vector group), growth factors (bFGF and VEGF; induced group), shRBPJK (shRBPJK group), and growth factors + shRBPJK (induced + shRBPJK group). The expression of endothelial markers, vascular endothelial growth factor receptor 2 (Flk1), and von Willebrand factor (vWF) were detected by immunofluorescence. Additionally, in vitro blood vessel formation and phagocytosis were assessed using acetylated LDL, Dil complex and the underlying molecular mechanisms evaluated by western blotting. BMMSCs were separated and transduced with shRBPJK to reduce RBPJK expression. Compared with the vector group, the expression of the endothelial cell markers, Flk1 and vWF, in vitro tubule formation, and phagocytosis ability increased, while the expression levels of pAKT/AKT and pNFkappaB/NFkappaB were significantly decreased (P<0.05) in the induced, shRBPJK, and induced + shRBPJK groups. Compared with the induced group, the expression of Flk1 and vWF, the number of tubules, and phagocytosis were higher in the induced + shRBPJK group, while the expression levels of pAKT/AKT and pNFkappaB/NFkappaB were lower (P<0.05). Collectively, the present data indicated that silencing of RBPJK promotes the differentiation of MSCs into vascular endothelial cells, and this process is likely regulated by AKT/NFkappaB signaling.