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 3. Low oxygen environment increases the BMI1-dependent immunomodulatory properties of hUCB-MSCs. (A, B) The culture supernatant from normoxic- and hypoxic-cultured hUCB-MSCs was collected after treatment with IFN-γ and TNF-α for 72 hours. (A) hUCB-MNCs were cultured with each supernatant after being activated with concanavalin A. After 3 days, the proliferation of MNCs was determined using a BrdU assay kit. (B) PGE2 concentration was measured using an ELISA kit. (C) Proteins were extracted after collecting the supernatant, and a western blot analysis was performed with the indicated antibodies. Representative blots are shown. (D) The effect on the immunosuppressive properties of BMI1-down-regulated hUCB-MSCs was investigated via a co-culture experiment. (E) Proliferation levels of hUCB-MNCs were measured using a BrdU assay kit. (F) PGE2 concentration levels were measured from the culture supernatant of control- and shBMI1-induced hUCB-MSCs. (G) Western blot analysis of COX-2 signaling factors was conducted. Error bars represent mean±s.e.m. from three separate experiments. * P<0.05, ** P<0.01, *** P<0.005 using Student’s t-test.