| Objective: The potential role of mesenchymal stem cells(MSC)in the treatment of acute graft-versus-host disease(a GVHD)has attracted much attention.The purpose of this study is to verify that EGF can enhance the efficacy of BMSC in the treatment of a GVHD,and to explore its biological mechanism.Methods: After whole body radiation treatment,the recipient mice were infused with bone marrow and lymphocytes of donor mice to establish a GVHD mouse model.BMSCs was isolated and cultured from bone marrow of BALB/c mice.AGVHD mice were treated with BMSCs only or EGF after BMSCs infusion.The changes of body weight and survival time of mice were observed and recorded.The symptoms of mice were evaluated by Cook’s a GVHD symptom score standard.Infiltration of donor lymphocytes stained with CM-Dil dye was observed in the tissue sections of a GVHD target organs.The concentration of IFN-γ in peripheral blood of mice was detected by ELISA and the Foxp3 expression of Treg cells in peripheral blood of mice was detected by flow cytometry.The effect of EGF on the proliferation of BMSCs was observed by Ed U staining in vitro,and the effect of EGF on the invasion and migration of BMSCs was verified by Transwell method.RT-q PCR and Western-blot were used to analyze the effect of EGF on miR-21 expression and c-jun phosphorylation in BMSCs.Double luciferase reporter gene was used to verify the effect of c-jun on miR-21 promoter.Results: EGF can enhance the efficacy of BMSCs in the treatment of a GVHD,which is characterized by the reduction of weight loss in mice,decreased Cook’s a GVHD score,prolonged survival,the decreased of the concentration of inflammatory factor IFN-γ in peripheral blood,the decrease of lymphocyte infiltration in target organs and the weakening of histological evidence of a GVHD.In mice infused with BMSCs and given EGF,EGF in peripheral blood had a positive effect on the expression of Foxp3 of Treg cells in peripheral blood.At the same time,in vitro experiments showed that EGF enhanced the proliferation,migration and invasion of BMSCs.In the functional experiment,we found that EGF could promote c-jun phosphorylation and miR-21 expression of BMSCs.The dual luciferase reporter gene experiment confirmed that c-jun enhanced the activity of miR-21 promoter.Conclusion: EGF enhances the immunomodulatory activity and the ability of proliferation and homing by promoting the phosphorylation of c-jun and increasing the expression of miR-21 in BMSC.Infusion of BMSCs with administration of EGF could significantly improve a GVHD in mice.In conclusion,EGF can enhance the efficacy of BMSC in the treatment of a GVHD. |
