ATO inhibits bleomycin induced lung fibrosis phenotypes in C57BL/6 mice. (A, B) C57BL/6 mice were exposed to bleomycin and ATO as described in Figure 5. Type-1 collagen and α-SMA mRNA expression were induced by bleomycin and this effect was diminished by ATO. (C, D) Increased Type-I collagen protein expression in response to bleomycin treatment was blocked by ATO, and was statistically significant. (E) Representative histology showing that bleomycin induced inflammation and collagen deposition in mouse lungs, and these features were reduced by ATO treatment. (F) Total collagen expression on lung sections was evaluated using the Aperio software scanning system. Bleomycin induced total collagen expression and ATO treatment decreased this effect.