Fig. 6. The effect of H₂O₂ on Sp1 DNA-binding activity and AhR promoter activity.

Panel A: Wild-type and hCatTg MAECs were treated with the indicated concentrations of H₂O₂ for 2 h. The level of Sp1 bound to the AhR promoter region was detected using ChIP analysis and expressed as the ratio of input controls. Panel B: Wild-type and hCatTg MAECs were co-transfected with an AhR promoter (AhR P2)-luciferase reporter plasmid and a β-galactosidase expression plasmid, and treated with the indicated concentrations of H₂O₂ for 18 h. The luciferase activity was measured using a luminescence assay and expressed relative to the luminosity of the β-galactosidase assay. Values represent the mean ± SEM of five independent experiments in which MAECs from four mice were pooled. *P<0.01 vs. wild-type cells treated with same concentration of H₂O₂, ^†P <0.05 vs. the same genotype cells without H₂O₂ treatment.