Figure 2.

Phosphorylated Y489 β-catenin (p–β-catenin^Y489) and phosphorylated Y654 β-catenin (p–β-catenin^Y654) localization in epithelial cells in human bronchopulmonary dysplasia (BPD) and in hyperoxia mouse model. A: Immunofluorescence (IF) for p–β-catenin^Y489 (red) and p–β-catenin^Y654 (red) in human infant lungs with BPD at term corrected gestational age, with epithelial cell adhesion molecule (Ep-CAM; green counterstain). Some Ep-CAM (green)–positive cells are also positive for p–β-catenin^Y489, and p–β-catenin^Y654 is exclusively present in Ep-CAM–positive cells. B: Frequency of distribution curves of histocytometry data demonstrates overlap between BPD and 18-week fetal lung, with these two populations of nuclei distinct from the nuclei in term infants when sorted for nuclear intensity of p–β-catenin^Y489 staining (P < 0.0001). C: IF for p–β-catenin^Y489 (red) and p–β-catenin^Y654 (red) in neonatal mouse lungs exposed to hyperoxia from postnatal day 1 (PN1) to PN14. D: Frequency of distribution curves for quantitative IF for nuclear staining for p–β-catenin^Y489. Boxed areas in left panels are shown in higher magnification in right panels (A and C). Two-tailed t-test significant for differences between normoxia and hyperoxia exposed neonatal mice (P < 0.0001). Scale bar = 20 μm (A and C). Original magnification, ×60 (A and C).