FIGURE 2.

SIRT1 activity is down-regulated by TNBS in vivo and by TGF-β in epithelial cells in vitro. (A–C) Colitis was induced in C57B/6 mice by TNBS as described in section “Materials and Methods.” SIRT1 activity was determined by a colorimetric kit. Expression levels of SIRT1 and DBC1 were examined by qPCR and Western. N = 5 mice for each group. (D–F) IEC-6 cells were treated with TGF-β (2 ng/ml) and harvested at indicated time points. SIRT1 activity was determined by a colorimetric kit. Expression levels of SIRT1 and DBC1 were examined by qPCR and Western. All experiments were performed in triplicate wells and repeated three times. One representative experiment is shown.