Figure 2.
Effect of exogenous Smad7 on bleomycin-induced lung fibrosis in mice. (a) Lung fibrosis was induced by continuous subcutaneous infusion of bleomycin (100 mg/kg for 7 days) from days 0–7 in C57BL/6 mice. Mice were infected with recombinant adenovirus (AdCMV-Smad6 or AdCMV-Smad7) by intratracheal injection with 109 pfu/mouse at day 0. Mice were sacrificed after 4 weeks, and the lungs were fixed in 10% formalin and stained with hematoxylin/eosin/safranin O. Left: treatment with bleomycin plus AdCMV-Smad6. Note the thickened continuous interalveolar septa. Right: treatment with bleomycin plus AdCMV-Smad7. Note the absence of thickened interalveolar septa, although some increased cellularity in interalveolar septa was observed. (b) Scoring of lung fibrosis. Fibrotic changes in mouse lung (S0–S3 = score 0–3, respectively) were graded according to the criteria described in Methods.