Fig. 9

Activation of TGF-β1 signaling in lung fibroblasts and myofibroblasts in vivo. WT and Opn KO mice were exposed to DM or 40 μg MWCNTs for 7 or 28 days. (a) Induction and nuclear localization of p-Smad2/3 in fibroblasts were examined by double immunofluorescence staining of p-Smad2/3 (red) and Hsp47 (green). (b) Induction and nuclear localization of p-Smad2/3 in myofibroblasts were examined by double immunofluorescence staining of p-Smad2/3 (red) and α-SMA (green). In (a) and (b), blue indicates nuclear staining (scale bar: 20 μm). Representative fibroblasts or myofibroblasts that are positive for nuclear p-Smad2/3 (shown in purple color on the images from the overlapping of red and blue signals) are marked by orange arrows, and negative for nuclear p-Smad2/3 are marked by white arrows. The numbers of p-Smad2/3+ and p-Smad2/3- fibroblasts (Hsp47+) or myofibroblasts (α-SMA+) in MWCNT-exposed WT or Opn KO lungs were counted (n = 4) and presented beside the images