Fig 1: Overexpression of ATF3 or THRA promotes lung repair after injury(A) Schematic showing the experimental design for AAV6 instillation and time points of sample collections. i.n.: intranasally; i.t.: intratracheally; i.p.: intraperitoneally.(B) Confocal images of immunostaining of Pro-SPC (red) and EdU (green) on lung sections from mice treated with AAV6-GFP or AAV6-ATF3 or AAV6-THRA at 8 days after SpT4 infection (8 dpi). Cell nuclear was stained with DAPI (blue). Arrows point to regions double-positive for Pro-SPC and EdU. Graph on the right showing a fold change in the percentage of Pro-SPC + EdU+ of total Pro-SPC + cells analyzed.(C) Compliance and forced expiration extension (FEV) in the first 0.05 s of forced vital capacity (FVC) were recorded using flexiVent in mice treated with AAV6-GFP or AAV6-ATF3 or AAV6-THRA at 14 dpi.(D) Experimental design for studies performed in (E) using SftpcCreERT2; Rosa26tdTomato adult mice.(E) Confocal images of lung sections at 14 dpi with immunostaining with antibodies to RFP (green) and T1α (red), an AT1 cell marker, to detect the differentiation of lineage-labeled AT2 cells into AT1 cells. Arrows point to regions double-positive for RFP and T1α. Graph on the right showing fold change in the percentage of RFP + T1α+ area of total RFP + area per field using ImageJ. Scale bars: 20 μm in (B, E). Data are presented in (B, C, E) as mean ± SEM ∗p < 0.05; ∗∗p < 0.01. p values were calculated using one-way ANOVA.