Figure 2

Targeted deletion of RPT3 in AT2 cells leads to AT2 cell loss. (a) Sftpc^WT/CreER:RPT3^F/F and Sftpc^WT/CreER (Cre) mice were fed tamoxifen chow for 7 days, then switched to regular chow on day 7. (b) Representative maximum intensity projections of confocal z-stacks of lung sections stained for proSP-C and ABCA3. Insets show proSP-C⁺ ABCA3⁺ cell. Scale bars = 50 μm. (c) Frequency of AT2 cells assessed by morphometric analysis of b. Controls included both RPT3^F/F mice (Sftpc^WT/CreER:RPT3^F/F mice without tamoxifen treatment) and Cre mice that were fed tamoxifen chow for 7 days. DAPI counts remained unchanged across all groups (not shown). (d) Concentration of total phosphate (PO₄) in bronchoalveolar lavage fluid (BALF), normalized to body weight (BW). (e) Concentration of saturated phosphatidylcholine (SatPC) in BALF, normalized to BW. Total PO₄ and SatPC were measured in mice euthanized on day 11. *p < 0.05, ****p < 0.0001 by one-way ANOVA with Tukey’s multiple comparison test.