Research Paper Volume 8, Issue 8 pp 1670—1689

BMI1 inhibits senescence and enhances the immunomodulatory properties of human mesenchymal stem cells via the direct suppression of MKP-1/DUSP1

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Figure 4. Up-regulation of BMI1 enhances the immunosuppressive effect of hUCB-MSCs. To investigate the immunosuppressive properties of BMI1-overexpressing hUCB-MSCs, (A) hUCB-MNCs were co-cultured with BMI1-overexpressing hUCB-MSCs and (B) the proliferation of hUCB-MNCs was measured with a BrdU proliferation assay kit. (C) PGE2 concentration was measured in the culture supernatant of GFP- and BMI1-overexpressing hUCB-MSCs. (D) COX-2, p-p38 MAP kinase and BMI1 expression levels of BMI1-overexpressing hUCB-MSCs were investigated via western blot analysis after treatment with IFN-γ and TNF-α for 30 minutes. (E) Expression of the phosphorylated form of p38 MAP kinase in GFP- and BMI1-up-regulated hUCB-MSCs was determined via immunocytochemistry after treatment with IFN-γ and TNF-α for 30 minutes. The graph shows the fluorescence intensity of p-p38 in each cells. (F) COX-2 expression was investigated after treatment with IFN-γ and TNF-α for 24 hours. On the right, the graph indicating the fluorescence intensity of COX-2 is presented. The results show 1 representative of 3 independent experiments. Error bars represent mean±s.e.m. from three separate experiments. Error bars represent mean±s.e.m. from three separate experiments. ** P<0.01, *** P<0.005 using Student’s t-test.