SMAD3 and renal fibrosis: Western blot analysis clearly revealed that the inhibitory effect of Smad7 on renal fibrosis and inflammation was associated with the restoration of exogenous Smad7, thereby inhibiting TGF-β/Smad signaling by suppressing the phosphorylation of Smad3 and upregulation of TGF-β1 (Fig. 6A and 6B and Fig.S6) and attenuating NF-κB signaling by lowering phosphorylated IκBα and NF-κB/p65 in the AAN kidney (Fig. 6C and 6D).