Inhibition of Notch signaling pathway promotes the differentiation of bone marrow mesenchymal stem cells into islet / 中华肾脏病杂志

ABSTRACT

Objective To investigate the effect of Notch signaling during bone marrow mesenchymal stem cells (BMSC) differentiating into islet in vitro.Methods The specific inhibitor of γ-secretase DAPT was used to inhibit the Notch signaling pathway.Mter induction,DTZ staining,indirect immunofluorescence staining,RT-PCR and Westenn blotting were used to detect the expression of insulin,glucagon,Pdx-1 and Ngn3.Results (1) Identification of BMSCs:Indirect immunofluorescence staining showed that BMSCs could express CD59 and CD90,which both were makrers of mesenchymal stem cells.Besides,BMSCs could express nerve culluar markers such as NSE,GFAP,suggesting multi-directional differentiation.(2) The result of MTT showed DAPT could inhibit the cell proliferation in a time-dependent manner and a dose-dependent mannar.Besides,DAPT could inhibit the expression of target gene of Notch signal pathway in a time-dependent manner and a dosedependent mannar.After treated by 1,5,20 μmol DAPT,the expression of Hes1 had reached to 92.06％,71.40％ and 46.89％ of controls respectively,suggesting efficiency of inhibition on Notch reached 7.94％,28.6％ and 53.11％ respectively (all P＜ 0.05).(3) Indirect immunofluorescence staining showed the expression of pancreas-specific markers such as insulin and glucagon were much higher in DAPT treated BMSCs than that in controls,which was confirmed by RT-PCR and Western blotting analyses.The proportion of insulin-producing cells differentiated from DAPT treated BMSCs was (74.03 ± 3.96)％,which was higher than that from controls[(36.49 ± 3.24)％,P＜ 0.05].(4)Furthermore,RT-PCR and Western blotting analysis showed that the expressions of Pdx-1 and Ngn3 were earlier than that of insulin and glucagon,and the expressions of Pdx-1 and Ngn3 were higher in DAPT treated BMSCs than that in controls.Conclusions Notch signaling pathway plays a role in the differentiation of BMSCs into islet in vitro.Pharmacological interference with Notch signaling pathway may provide a novel method to obtain islet for therapeutic use.