Bone marrow mesenchymal stem cells (BM‑MSCs) 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 (RBP‑JK) on the differentiation of BM‑MSCs into vascular endothelial cells, and to assess the underlying mechanisms. BM‑MSCs were isolated and identified by flow cytometry. Lentiviral vectors encoding RBP‑JK shRNA (shRBPJK) were constructed to knockdown RBP‑JK expression and endothelial differentiation of BM‑MSCs 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 (Flk‑1), 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. BM‑MSCs were separated and transduced with shRBPJK to reduce RBP‑JK expression. Compared with the vector group, the expression of the endothelial cell markers, Flk‑1 and vWF, in vitro tubule formation, and phagocytosis ability increased, while the expression levels of p‑AKT/AKT and p‑NF‑κB/NF‑κB were significantly decreased (P<0.05) in the induced, shRBPJK, and induced + shRBPJK groups. Compared with the induced group, the expression of Flk‑1 and vWF, the number of tubules, and phagocytosis were higher in the induced + shRBPJK group, while the expression levels of p‑AKT/AKT and p‑NF‑κB/NF‑κB were lower (P<0.05). Collectively, the present data indicated that silencing of RBP‑JK promotes the differentiation of MSCs into vascular endothelial cells, and this process is likely regulated by AKT/NF‑κB signaling.
Keywords: rBP-JK; bone marrow mesenchymal stem cells; endothelial cells.