Mouse tracheal BSCs are less sensitive than alveolar cells to DNA damage-induced cell death.

<p>(A) Barcode plots showing strong correlation of mouse and human expression signatures. The upper panel correlates the mouse tracheal BSC signature with that of human lung BSCs; the lower panel correlates the mouse alveolar cell signature with that of human AT2 cells. For each plot, genes are ordered left to right from most up-regulated to most down-regulated in human BSCs or AT2 cells, relative to all other cell populations. Positive mouse signature genes are marked with red vertical bars, and negative mouse signature genes with blue. Variable-height vertical bars show log-fold changes for the mouse signature genes. Worms show relative enrichment of mouse genes in the human ranked list. Rotation gene set tests give <i>p</i> = 0.0001 for each plot. (B) Immunofluorescence staining of γH2AX and T1α in alveoli or trachea of wild-type (WT) mice that are either nonirradiated or 1, 4, 8, 24, or 96 h post irradiation (6 Gy, top panel) or saline injected or 1, 4, 8, 24 or 96 h post bleomycin injection (40 mg/kg intravenously, bottom panel). T1α marks alveolar type 1 cells in the lung and BSCs in the trachea. Representative images of <i>n</i> = 3 mice at each time point. Scale bar = 20 μm. (C) FACS detection of dead cells in lung alveolar (EpCAM⁺) or tracheal BSCs (T1α⁺) isolated from WT mice 24 h post irradiation (6 Gy). <i>n</i> = 4–6 mice per group. Student’s <i>t</i> test. (D) Immunohistochemistry staining of Ki67 in alveoli or trachea of WT mice control or 4 h, 8 h, or 24 h post irradiation (6 Gy). Representative images for one of <i>n</i> = 3 mice at each time point. Scale bar = 20 μm. The underlying data for panel C can be found in the <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.2000731#pbio.2000731.s009" target="_blank">S1 Data</a> file.