Basement membranes in lung development, disease, and repair.

The primary function of the respiratory system is the exchange of oxygen and carbon dioxide across the alveolar-capillary barrier in the distal lung. This structure is composed of alveolar epithelial cells (type 1 and type 2) and capillary endothelial cells, separated by a thin, fused alveolar basement membrane. The developmental programming that creates this specialized niche is largely unexplored and the role of lung basement membranes in respiratory disease pathogenesis and repair remains an emerging field of study. Thus, in this review, we discuss the distribution, composition, and function of the alveolar basement membrane, as well as the other three lung basement membranes that support the airway epithelium, airway smooth muscles, and the endothelium of the macrovasculature in lung development and disease.