Optimal H(2)O(2) preconditioning to improve bone marrow mesenchymal stem cells’ engraftment in wound healing

BACKGROUND: The transplantation of bone marrow mesenchymal stem cells (BMSCs) is a promising therapeutic strategy for wound healing. However, the poor migration capacity and low survival rate of transplanted BMSCs in wounds weaken their potential application. OBJECTIVE: To identify the optimal protocol for BMSCs preconditioned with H(2)O(2) and improve the therapeutic efficacy using H(2)O(2)-preconditioned BMSCs in wound healing. METHODS: Mouse BMSCs were exposed to various concentrations of H(2)O(2), and the key cellular functional properties were assessed to determine the optimal precondition with H(2)O(2). The H(2)O(2)-preconditioned BMSCs were transplanted into mice with full-thickness excisional wounds to evaluate their healing capacity and tissue engraftment. RESULTS: Treatment BMSCs with 50 μM H(2)O(2) for 12 h could significantly enhance their proliferation, migration, and survival by maximizing the upregulation of cyclin D1, SDF-1, and its receptors CXCR4/7 expressions, and activating the PI3K/Akt/mTOR pathway, but inhibiting the expression of p16 and GSK-3β. Meanwhile, oxidative stress-induced BMSC apoptosis was also significantly attenuated by the same protocol pretreatment with a decreased ratio of Bax/Bcl-2 and cleaved caspase-9/3 expression. Moreover, after the identification of the optimal protocol of H(2)O(2) precondition in vitro, the migration and tissue engraftment of transfused BMSCs with H(2)O(2) preconditioning were dramatically increased into the wound site as compared to the un-preconditioned BMSCs. The increased microvessel density and the speedy closure of the wounds were observed after the transfusion of H(2)O(2)-preconditioned BMSCs. CONCLUSIONS: The findings suggested that 50 μM H(2)O(2) pretreated for 12 h is the optimal precondition for the transplantation of BMSCs, which gives a considerable insight that this protocol may be served as a promising candidate for improving the therapeutic potential of BMSCs for wound healing.