Keratinocyte growth factor can enhance alveolar epithelial repair by nonmitogenic mechanisms.
Pretreatment with keratinocyte growth factor (KGF) ameliorates experimentally induced acute lung injury in rats. Although alveolar epithelial type II cell hyperplasia probably contributes, the mechanisms underlying KGF's protective effect remain incompletely described. Therefore, we tested the hypothesis that KGF given to rats in vivo would enhance alveolar epithelial repair in vitro by nonproliferative mechanisms. After intratracheal instillation (48 h) of KGF (5 mg/kg), alveolar epithelial type II cells were isolated for in vitro alveolar epithelial repair studies. KGF-treated cells had markedly increased epithelial repair (96 +/- 22%) compared with control cells (P < 0.001). KGF-treated cells had increased cell spreading and migration at the wound edge but no increase in in vitro proliferation compared with control cells. KGF-treated cells were more adherent to extracellular matrix proteins and polystyrene. Inhibition of the epidermal growth factor (EGF) receptor with tyrosine kinase inhibitors abolished the KGF effect on epithelial repair. In conclusion, in vivo administration of KGF augments the epithelial repair rate of alveolar epithelial cells by altering cell adherence, spreading, and migration and through stimulation of the EGF receptor.
Atabai
Kamran
K
Department of Medicine, Cardiovascular Research Institute, University of California, San Francisco 94143-0130, USA. .
Ishigaki
Masanobu
M
Geiser
Thomas
T
Ueki
Iris
I
Matthay
Michael A
MA
Ware
Lorraine B
LB
D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000378:metabolism / Q000494:pharmacology; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D008938:Mitosis / Q000187:drug effects / Q000502:physiology; D011137:Polystyrenes / Q000378:metabolism / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000166:cytology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020545:Respiratory Mucosa / Q000166:cytology*; D013047:Specific Pathogen-Free Organisms; D014945:Wound Healing / Q000187:drug effects* / Q000502:physiology
D016326:Extracellular Matrix Proteins; C496455:Fgf7 protein, rat; D011137:Polystyrenes; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D066246:ErbB Receptors