AtRA-induced TGF-β₂ expression in IECs is mediated via ATF2.

<p><i>A</i>. Western blots show phospho- and total ATF2 in IEC6 cells, depicted as a function of the duration of atRA treatment. Bar-diagram (means ± SE) summarizes densitometric data normalized against β-actin. <i>B</i>. Fluorescence photomicrographs (magnification 630x) show increased nuclear localization of phospho-ATF2 (red) in IEC6 cells treated with atRA × 2h. Nuclear staining (blue) was obtained with DAPI. <i>C</i>. AtRA treatment increases phospho-ATF2 binding to the TGF-β₂ promoter. Bar diagram (means ± SE) shows data from chromatin immunoprecipitation (ChIP) assay of phospho-ATF2 binding to the TGF-β₂ promoter region. Quantification of phospho-ATF2 binding was performed using real-time PCR and is shown as % input. To calculate % input, ChIP results for the specific antibody were determined using a standard curve of input DNA from the same cells. Control IgG ChIP results were subtracted from specific antibody ChIP results. <i>Inset</i>: Agarose gel showing enrichment of phospho-ATF2 on the TGF-β₂ promoter. Data represent 3 separate experiments; * <i>p</i><0.05, ** <i>p</i><0.01.