Fig. 1

Intravenous bleomycin induces subpleural fibrosis associated with pleural cell differentiation and migration. a Histological analysis of lung sections from mice receiving either NaCl or BLM intravenously at D14 and D21. Representative images (insert: NaCl at the corresponding time point. Scale bars : 500 μm). b Ashcroft scoring of lung sections. c Profiles of Picrosirius Red signal according to distance to the pleura at D3, D14 and D21. d Area Under Curve comparison of areas targeting the pleura (left) or subpleural (right) areas at D3, D14 and D21. For collagen quantification, data are represented as mean of Picrosirius Red signal normalized to the NaCl condition at the corresponding time point. Data expressed as mean ± SEM. n = 4 for NaCl groups, n = 6 for BLM groups at D3 and D21, and n = 6 for NaCl and n = 8 for BLM at D14. e Representative images of immunostaining for HSP27, αB-crystallin and KI-67 of lung sections from mice receiving NaCl or BLM at D14 (arrows indicate positive cells. Counterstaining: Harris hematoxylin. Scale bars : 100 μm). f Levels of proMMP-9 and active MMP-2 in PLF was determined by western blot. Representative results from NaCl (n = 3) or BLM (n = 3) treated mice at D14 are shown. g AdLacZ-labeled pleural cells were stained for β-galactosidase activity (blue staining) in lung section from mice receiving intravenously NaCl or BLM at D5 or D10. Representative images are shown (n = 4 NaCl, n = 6 BLM. Scale bars: 200 μm), Insert: magnification; scale bars: 100 μm Arrows indicate pleural cells with modified morphology. Counterstaining: Nuclear fast red). *p ≤ 0.05, **p ≤ 0.01