Figure 4

AHR directly represses Saa transcription. (a and b) ChIP assay to determine the effect of AHR activation on Saa2 and Saa3 promoters. Hepa1c1c7 cells were treated with TCDD (10 nM for 30 min) before interleukin treatment (2 ng/ml each of IL1B and IL6 for 20 min). Immunoprecipitation was carried out with antibodies for RELA and acetylated histones (K5). Changes at the Saa3 promoter were assessed by PCR (a), whereas changes at Saa2 promoter were analyzed by real-time PCR (b). Data represent one of three independent experiments.