Figure 4. Treatment with T₃ increases ZAG promoter activity in HepG2 cells.

(A) ZAG promoter activity was analyzed in HepG2 cells in luciferase reporter gene assays. Data are expressed as mean ± SD of triplicates. (B) Scheme of the human ZAG promoter with 4 putative TR binding sites. (C) ZAG promoter activity was analyzed in HepG2 cells treated with vehicle or T₃ (100 nM) in luciferase reporter gene assays. Data are expressed as mean ± SD of triplicates. (D) ChIP assays of TR binding to the human ZAG promoter in HepG2 cells treated with vehicle or T₃ (100 nM) for 5 days. The GAPDH and PAI-1 promoters were used as a negative and positive control, respectively. Positive PCR controls of sheared genomic DNA templates indicated the integrity of the input DNA used in the ChIP reactions.