FIGURE 1.

fos-related antigen-2 (Fra-2)-overexpressing (transgenic (TG)) mice develop vascular remodelling and parenchymal fibrosis. WT: wild-type; RVSP: right ventricular systolic pressure; RV: right ventricle; LV: left ventricle; S: septum; IC: inspiratory capacity; C_rs: compliance of the respiratory system; SR: Sirius red; C_t: cycle threshold; COL1: collagen 1; α-SMA: α-smooth muscle actin; α-TUB: α-tubulin. a) Representative images of whole lung slides stained with Masson's trichrome and magnifications of remodelled vessels in 20-week-old WT and Fra-2 TG mice. Scale bar: 20 µm. Collagen is stained in blue. b) Percentage of nonmuscularised (NM), partially muscularised (PM) and fully muscularised (FM) vessels <100 µm in diameter. n=10; mean±sd. c) RVSP as determined by right heart catheterisation and the Fulton index (RV/(LV+S)) in WT and Fra-2 TG mice. d) Lung function measurements (IC and C_rs) of WT and Fra-2 TG mice. e) Morphometric quantification of collagen on Sirius red-stained WT and Fra-2 TG lung slides. f) Quantitative real-time PCR analysis of Col1a1, Col1a2, Col3a1, Acta2 and Igf1 expression in WT and Fra-2 TG mice. ΔC_t values were normalised to the mean of the WT group (ΔΔC_t). B2m (β₂-microglobulin) and Hmbs (hydroxymethylbilane synthase) were used as reference genes. g) Western blot analysis of COL1 and α-SMA levels in WT and Fra-2 TG mice lung homogenates. α-TUB served as a loading control. h) Immunohistochemical staining of COL1 (brown) and α-SMA (red/pink). B: bronchi; V: vessel. Scale bar: 50 µm. *: p<0.05; **: p<0.01; ***: p<0.001.