Figure 2. ProT is involved in CSE-induced emphysema in mice.

(a,b) Six-week-old ProT HET and NT mice were injected intraperitoneally with CSE or saline twice a week for 6 weeks. (c,d) Six-week-old FVB mice were intratracheally injected with lentiviral vectors expressing ProT or luciferase (Luc) shRNA followed by intraperitoneal injections of CSE or saline twice a week for 6 weeks. Subsequently, their lung sections were immunostained for ProT (a,c) and H&E stained for examining alveolar airspace enlargement (b,d), as described in Figure 1. The boxed areas in upper panels (original magnification × 400; Scale bar=100 μm) are magnified and shown in lower panels (a,c) and scale bars on × 100 and × 200 images correspond to 100 and 50 μm, respectively (b,d). Histological changes in the lungs were evaluated for the incidence of emphysema in ProT transgenic or NT mice (0 of 13 for NT-Saline, 3 of 11 for HET-Saline, 10 of 15 for NT-CSE and 10 of 10 for HET-CSE; P<0.0001 between any two of the four treatment groups analysed by the χ²-test) (b), and in ProT knockdown mice (0 of 6 for Luc shRNA-Saline, 0 of 6 for ProT shRNA-Saline, 6 of 9 Luc shRNA-CSE and 1 of 7 ProT shRNA-CSE; P<0.0001 between any two of the four treatment groups analysed by the χ²-test) (d). All immunohistochemical and histochemical data (mean±s.e.m., n=3; Student’s t-test) are representative of three independent experiments.