Smad7 overexpression inhibits steady-state hepcidin expression and abrogates the hepcidin response to BMP and TGF-β. (A) Smad7 overexpression under control and (B-C) stimulatory conditions. Primary murine hepatocytes were transduced with adenoviral vectors expressing Smad7 (AdSmad7) or β-galactosidase (AdLacZ) as a control. Forty-eight hours later, the cells were treated with IL-6 (20 ng/mL, 24 hours), BMP-6 (50 ng/mL, 24 hours), BMP-9 (5 ng/mL, 24 hours), or TGF-β (5 ng/mL, 6 hours) and harvested for the isolation of total RNA. Hepcidin mRNA levels were determined by quantitative real-time PCR and normalized to Gapdh mRNA expression. (A) Under control conditions results are presented as fold change (± SD) compared with samples transduced with control AdLacZ vectors. (B-C) Under stimulatory condition results are presented as fold change (± SD) compared with untreated cells. Results represent a mean of 4 independent experiments. Significant changes are marked by *(P < .05) or ***(P < .001).