Fig. 4: Metabolically active mesothelial cell differentiation genes drive fibrosis.

a Treatment scheme for candidate gene overexpression in lung mesothelium. b Ashcroft scores by using the trichrome staining of the lung sections in the different conditions: Control PBS (Ctrl); Control AAV Bleomycin (Bleo); Ifi27l2a AAV PBS (Ifi27l2a PBS); Ifi27l2a AAV Bleomycin (Ifi27l2a Bleo); Dcn AAV PBS (Dcn PBS) and Mgp AAV PBS (Mgp PBS). N = 6 biological replicates (C57BL/6J WT mice) and three independent experiments. A two-sided independent T-test was used for the comparison of two groups. Data are presented as mean values ± SEM. Source data are provided as a Source Data file. c Daily body weight lost in the different groups. Data are presented as mean values ± SEM. Source data are provided as a Source Data file. d Experimental group survival rates. Source data are provided as a Source Data file. e Lung function impairment in the different conditions: Trichrome staining images of the control PBS, control bleomycin, Ifi27l2a PBS, Ifi27l2a bleomycin (from up to bottom) with arrows highlighting fibrotic clots (Ctrl and Bleo). On the right: confocal images of the lung stained with different staining: α-sma, Ki67 (both yellow) and mesothelial transfected cells (magenta). On the right-hand side, the quantification of the different immunostaining. N = 6 biological replicates (C57BL/6J WT mice) and three independent experiments. A two-sided independent T-test was used for the comparison of two groups. Data are presented as mean values ± SEM. Scale bar is 20 µm. Source data are provided as a Source Data file. f Lung function impairment in the different conditions: Trichrome staining images of the control PBS, Dcn PBS, control PBS, Mgp PBS (from up to bottom) with arrows highlighting fibrotic clots (Ctrl and Bleo). On the right: confocal images of the lung stained with different staining: extracellular matrix (NHS-FITC), Ctsb, α-sma (both yellow) and mesothelial transfected cells (magenta). On the right-hand side, the quantification of the different immunostaining. N = 6 biological replicates (C57BL/6J WT mice) and three independent experiments. A two-sided independent T-test was used for the comparison of two groups. Data are presented as mean values ± SEM. Scale bar is 20 µm. g Hydroxyproline measurements were performed for each group using the Enzymatic Hydroxyproline Assay. N = 6 biological replicates (C57BL/6J WT mice) and three independent experiments. A two-sided independent T-test was used for the comparison of two groups. Created in BioRender. Kadri, S. (2025) https://BioRender.com/s4fbbop.