Figure 2

Comparison of loss and recovery of club cells, AT1s and AT2s between aged and young mice following influenza pneumonia. A-C. Club cell coverage index (A), AT1 coverage index (B), and AT2 density (number per mm² tissue area) (C) in aged (square) and young (triangular) mice following influenza infection. All error bars represent standard errors. *p < 0.05, **p < 0.01 by Student t-test. D-W. Representative immunofluorescence staining of lung sections for SCGB1A1 (green) and pro-SPC (red) in D-O (DAPI stain is shown in blue in E and H), and PDPN (red) and DAPI (blue) in P-W at the indicated time-points following influenza infection. The boxed areas in D, G, P and T are shown in higher magnification in E, H, Q and U, respectively. The arrows point to loss of SCGB1A1-expressing club cells; in D-O the dotted lines circle the regions with loss of pro-SPC-expressing AT2s; in P-W the dotted lines circle the regions with loss of PDPN-expressing AT1s . Scale bars are 500 μm for the low magnification images, and 50 μm for the high magnification images. Ten aged and 10 young mice were used for each time-point.