[Proliferation of alveolar epithelial cells and gene expression of surfactant proteins in adult respiratory distress syndrome (ARDS)].

Regeneration of alveolar epithelial cells is one of the important repair processes in many types of lung injury, including the adult respiratory distress syndrome (ARDS). We have examined the effects of growth factors and cytokines on alveolar epithelial cells in vitro, and also examined histopathology and surfactant protein gene expressions in alveolar epithelial cells in rats with endotoxin-induced lung injury. Keratinocyte growth factor only induced a marked increase in levels of mRNAs for SP-A and SP-B, accompanied by an increase in SP-A protein. Intratracheal administration of endotoxin induced the marked proliferation of alveolar type II cells in association with the increased surfactant protein mRNAs, and SP-A production. Proliferation and differentiation of alveolar epithelial cells, and KGF may play important roles of repair process of the damaged alveoli after acute lung injury.