Abstract
β1 integrins are known to regulate lung development and homeostasis, however their role in lung epithelial repair is unclear. In this study, we challenged mice with a type 2 alveolar epithelial cell deletion of β1 integrin with a single dose of intratracheal lipopolysaccharide. These mice developed persistent inflammation, severe lung injury, and emphysema. The β1 integrin-deficient alveolus repaired by repopulating with overabundant large, round type 2 alveolar epithelial cells and reduced numbers of alveolar type 1 cells. These abnormal β1 integrin deficient type 2 cells had significant actin cytoskeletal defects resulting in their inability to attain a flattened type 1 cell shape. In addition, terminal differentiation into type 1 and 2 alveolar epithelial cells was impaired as they expressed both type 2 and intermediate cell markers. Thus, β1 integrin plays a key role in alveolar repair by regulating the cell-shape change required for type 2 to type 1 epithelial differentiation.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
The authors have declared that no conflict of interest exists.