Figure 11.

H₂S S-sulfhydrylates Keap1 to regulate Nrf2 transcription activity in SM-induced BEAS-2B cells. Cells were treated with SM (100 μM), with or without NaHS (70 μM) or DTT (1 mM) pretreatment. S-sulfhydrylation of Keap1 was detected using the “Tag-Switch” method (A). Cells were collected for isolation of nuclear proteins. Nrf2 protein levels in cells were determined by western blot analysis (B,C). ROS production was detected by fluorescence measurement of the reported DCFH-DA (D). Experiments were repeated three times to insure consistency of results. Data are presented as the mean ± SEM (n = 5). *p < 0.05 vs untreated control; **p < 0.01 vs untreated control; ^##p < 0.01 vs treatment with SM; ^$$p < 0.01 vs treatment with SM plus NaHS.