7,8-Dihydroxyflavone Suppresses Oxidative Stress-Induced Base Modification in DNA via Induction of the Repair Enzyme 8-Oxoguanine DNA Glycosylase-1
Figure 4
DHF induces OGG1 expression via the PI3K/Akt signaling pathway and improves cell survival. (a) Cells were treated with 40 μM DHF for 1 h and then incubated with 1 mM H2O2 for an additional 12 h. Cell lysates were electrophoresed, and Akt and phospho-Akt were detected using specific antibodies. (b) Cells were pretreated with 50 μM LY294002 or 1 μM Akt inhibitor IV for 1 h and then treated with 40 μM DHF for an additional 24 h. OGG1 was detected by western blotting. (c) Confocal images of Nrf2 antibody and FITC-conjugated secondary antibody staining indicate the location of Nrf2 protein (green); DAPI staining indicates the nucleus (blue). The merged images of DHF treatment in PI3K or Akt inhibitor-treated cells reveal the cytosolic location of Nrf2 protein. (d) Cells were pretreated with 50 μM LY294002 or 1 μM Akt inhibitor IV for 1 h, treated with 40 μM DHF for 1 h, and then incubated with 1 mM H2O2 for an additional 24 h. Cell viability was assessed by the MTT assay. *Significantly different from control cells (); #significantly different from H2O2-treated cells (); significantly different from H2O2-treated cells pretreated with DHF ().
