Figure 5

Degree of lung fibrosis in wild-type mice and cathepsin K transgenic mice. (A) Cathepsin K transgenic mice (black bars) and wild-type mice (white bars) were administered either saline or bleomycin for 1, 2, and 4 weeks. Subsequently, mice were euthanized and lungs were examined histopathologically as described in Materials and Methods and the degree of lung fibrosis per mouse lung was calculated according to the grading system described by Ashcroft et al. [20]. (B) Representative photomicrographs of Elastica van Gieson-stained lung tissue sections collected from wild-type mice and cath K tg mice at day 28 post-bleomycin treatment. The data are shown as mean ± SD of at least n = 6 mice per group and time point. * indicates significant increase (p < 0.05) compared to cathepsin K tg mice.