SMAD3 and pulmonary fibrosis: The silica inhalation-induced pulmonary silicosis mouse model was also established to investigate the effects of emodin treatment at 20 mg/kg on lung fibrosis, and the results showed that emodin increased the expression of Sirt1, which then deacetylated SMAD3 to inhibit TGF-β1/SMAD3 fibrogenic signal transduction, and thus attenuated collagen deposition [79].