Fig. 5

Mfn1/2^iΔAEC2 mice develop spontaneous lung fibrosis. a Schema demonstrating the generation of mice with AEC2 cell-specific tamoxifen-inducible deletion of Mfn1/2. Sftpc^CreERT2+/+ or Sftpc^CreERT2+/− mice were used as controls. b Genotyping of CD45(-)EpCAM(+) cells isolated from Mfn1/2^iΔAEC2 mice (n = 3 mice; lane 1 to lane 3 serves as the positive control). c Representative immunoblots of AEC2 cell lysates obtained 6 weeks after tamoxifen-induced deletion, showing decreased protein levels of both MFN1 and MFN2 in the Mfn1/2^−/− AEC2 cells (n = 3 mice per group). d Representative TEM images (upper row, ×12,000; lower row, ×50,000) show mitochondrial ultrastructural changes in Sftpc^CreERT2+/− and Mfn1/2^−/− AEC2 cells (n = 3 mice per group) with disrupted cristae marked with white arrowheads (scale bar, upper row 2 μm, lower row 500 nm. e Kaplan–Meier survival curves of Mfn1/2^iΔAEC2 (n = 22) and Sftpc^CreERT2+/+ (n = 23) mice (p < 0.01 by log-rank test). f Representative Masson’s trichrome-stained lung sections (upper panel, ×100 magnification; lower panel, ×200 magnification) 17 weeks post tamoxifen-induced deletion (Sftpc^CreERT2+/+ mice n = 6; Mfn1/2^iΔAEC2 mice n = 11; scale bar, upper panel 4 mm, lower panel 200 μm). g Representative IHC staining of vimentin, alpha-smooth muscle actin (α-SMA), and collagen III (Col-III) (×200 magnification; n = 3 mice per group; scale bar 200 μm). h Representative immunofluorescent staining of 5x5 tiled confocal images (using ×40 objective) of frozen murine lung sections stained for podoplanin (green), surfactant protein-C (SP-C) (yellow), ER-TR7 (magenta), and Hoechst 33342 stain (blue) (n = 3 mice per group; scale bar 50 μm). i Representative immunofluorescence staining confocal images of podoplanin (green), SP-C (yellow), ER-TR7 (magenta) and Hoechst 33342 nuclear stain (blue) using lung sections of Sftpc^CreERT2+/−, Mfn1^iΔAEC2 and Mfn2^iΔAEC2 mice (n = 2 mice per group; scale bar 20 μm). Source data (c, e) are provided as a Source Data file