Loss of Dab1 Alters Expression Patterns of Endocytic and Signaling Molecules During Embryonic Lung Development in Mice.

Lung development is governed by tightly regulated signaling mechanisms, including endocytosis-mediated pathways critical for epithelial-mesenchymal communication and tissue remodeling. This study investigated the effects of Dab1 deficiency on the expression of endocytic and signaling-related proteins, Megalin, Cubilin, Caveolin-1, GIPC1, and Dab2IP, during embryonic lung development in yotari mice. Using immunofluorescence and quantitative image analysis, protein expressions were compared between yotari and wild-type embryos at gestational days E13.5 and E15.5. Results showed significantly reduced expression of Caveolin-1 in the yotari epithelium across both stages, along with diminished mesenchymal levels of Megalin and GIPC1 at E13.5. Cubilin and Dab2IP expression patterns showed no statistically significant differences, although developmental and compartmental shifts were observed. These findings suggest that Dab1 deficiency selectively disrupts endocytic and signaling scaffolds crucial for branching morphogenesis and alveolar maturation. The altered spatiotemporal expression of these proteins underscores the essential role of Dab1 in regulating lung epithelial-mesenchymal dynamics and maintaining developmental homeostasis during critical stages of organogenesis.