Figure 4

Qualitative and quantitative analysis of lung histology and Masson’s trichrome staining during BLM-induced lung fibrosis. (A-C) Representative microphotographs of lung histology. Chrna7^+/+ and Chrna7^−/− mice were intratracheally challenged with BLM (1.5 mg/kg) and euthanized at 14 d. Saline-challenged Chrna7^+/+ mice were used as control. The lungs were removed for H&E staining. (A) Chrna7^+/+ + saline, (B) Chrna7^+/+ + BLM and (C) Chrna7^−/− + BLM. Objective magnification × 20, bar 50 µm. (D, E) Qualitative and quantitative analysis of lung histology. (D) Qualitative analysis of histology by Ashcroft scoring system. (E) Measurements of aerated lung area by Image-Pro Plus software. N = 3–4 in each group. **p < 0.01 and *p < 0.05 in each comparison. Data are mean ± SD. (F-H) Representative microphotographs of Masson’s trichrome staining. Chrna7^+/+ and Chrna7^−/− mice were intratracheally challenged with BLM (1.5 mg/kg) and euthanized at 14 d. Saline-challenged Chrna7^+/+ mice were used as control. The lungs were removed for Masson’s trichrome staining. Green arrows indicate positive peribronchial and interstitial staining. Objective magnification × 20, bar 50 µm. (F) Chrna7^+/+ + saline, (G) Chrna7^+/+ + BLM and (H) Chrna7^−/− + BLM. (I, J) Quantitative analysis of Masson’s trichrome staining. (I) Measurements of blue-stained area. (J) Measurements of mean optical density of blue-stained area by Image-Pro Plus software. N = 5 in each group. **p < 0.01 in compared groups. Data are mean ± SD.