title: Keratinocyte growth factor can enhance alveolar epithelial repair by nonmitogenic mechanisms.
abstract: 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.
authors.affiliation: Department of Medicine, Cardiovascular Research Institute, University of California, San Francisco 94143-0130, USA. .
authors.forename: Kamran
authors.initials: K
authors.lastname: Atabai
authors.forename: Masanobu
authors.initials: M
authors.lastname: Ishigaki
authors.forename: Thomas
authors.initials: T
authors.lastname: Geiser
authors.forename: Iris
authors.initials: I
authors.lastname: Ueki
authors.forename: Michael A
authors.initials: MA
authors.lastname: Matthay
authors.forename: Lorraine B
authors.initials: LB
authors.lastname: Ware
mesh_terms: 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
chemical_list: D016326:Extracellular Matrix Proteins; C496455:Fgf7 protein, rat; D011137:Polystyrenes; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D066246:ErbB Receptors