Altered Lung Morphogenesis, Epithelial Cell Differentiation and Mechanics in Mice Deficient in the Wnt/β-Catenin Antagonist Chibby
Figure 6
Defective differentiation and morphology of alveolar epithelial cells in Cby−/− mice.
(A) Peripheral lung sections were co-immunostained with antibodies against the type II pneumocyte marker proSP-C (red) and type I pneumocyte marker Aqp5 (green). Nuclei were detected with DAPI. The immunostained area was quantified by counting the number of pixels present. Values represent means ± SE. Student's t-test; *P<0.05, **P<0.001. (B–E) TEM was performed on adult distal lungs from Cby+/+ (B, D) and Cby−/− (C, E) mice. In the alveolar epithelium of Cby+/+ mice, squamous type I pneumocytes and cuboidal type II pneumocytes containing lamellar bodies were observed. In Cby−/− lungs, the thickening of the cytoplasmic extension of type I cells was noted. Type II cells also exhibited morphological defects and frequently contained an increased number of lamellar bodies. Lipid-laden interstitial fibroblasts were often found in Cby−/− lungs (C). Black arrowheads point to microvilli (D and E). P1, type I pneumocytes; P2, type II pneumocytes; LB, lamellar bodies; C, capillaries; R, red blood cells; Av, alveolar airspace; M, mitochondria; asterisks, lipid droplets. Scale bars: (A) 50 µm; (B, C) 10 µm; (D, E) 5 µm.