Figure 5.

NF-E2–related factor–2 (Nrf2) regulation by MIF in vitro and in vivo. (A) Representative Western blots and densitometric analyses of Nrf2 expression in the nuclear extracts of WT and mif^−/− mouse lung homogenates are shown. mif^−/− mice demonstrated significantly reduced Nrf2 expression levels compared with WT control mice, independent of age or irradiation. In addition, 16-month-old mif^−/− mice demonstrated significantly reduced Nrf2 expression compared with 8-week-old mif^−/− mice, independent of irradiation (n = 4/group). *P < 0.05, compared with respective WT control mice. ^#P < 0.05, compared with 8-week-old mif^−/− control mice. (B and C) MIF-silenced endothelial cells (ECs) (short, interfering RNA; siRNA) were treated with H₂O₂ for 2 hours, and cell lysates were subjected to Western blotting for Nrf2. H₂O₂ induced increased Nrf2 expression in ECs, whereas MIF silencing attenuated both basal and H₂O₂-induced Nrf2 expression. Supplementing MIF-silenced cells with recombinant MIF (rMIF) partly restored Nrf2 protein expression in these cells (n = 4/group). *P < 0.05, compared with untreated control cells. ^#P < 0.05, compared with respective untransfected control cells. ^†P < 0.05, rMIF-treated compared with respective MIF-silenced cells.