Keratinocyte growth factor and autocrine repair in airway epithelium.
BACKGROUND
Delayed or nonreepithelialization of the large conducting airway (ie, trachea and bronchus) is a clinically recognized but poorly understood result of airway trauma. This delay results in granulation tissue formation and scarring, which impairs mucocilliary transport and can critically compromise gas exchange. Keratinocyte growth factor (KGF) is a known epithelial cell mitogen that is derived from mesenchymal cells. We previously observed its expression in injured tracheal explants, and in the present study we investigated its origin.


METHODS
Freshly isolated porcine tracheal epithelial cells were cytospun onto glass slides for immunohistochemical identification and localization of KGF and for in situ hybridization localization of its messenger RNA. Polymerase chain reaction analysis for KGF was also performed.


RESULTS
Freshly isolated respiratory epithelial cells were identified as being of epithelial origin and uncontaminated by fibroblasts, as evidenced by stains that were positive for AE3 and negative for vimentin. Immunohistochemical analysis and in situ hybridization revealed a subset of cells that were positive for both the protein and the message for KGF.


CONCLUSIONS
This subset of KGF-expressing respiratory epithelial cells may participate in a hitherto undescribed autocrine loop for stimulating KGF production in response to injury.
Hicks
Wesley L
WL
Department of Head and Neck Surgery, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
Hall
Leon A
LA
Hard
Robert
R
Gardella
Joseph
J
Bright
Frank
F
Parashurama
Natesh
N
Parasharama
Natesh
N
Lwebuga-Mukasa
Jamson
J
Sigurdson
Lynn
L
D000818:Animals; D019898:Autocrine Communication / Q000235:genetics*; D002478:Cells, Cultured; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors / Q000235:genetics*; D015870:Gene Expression / Q000502:physiology; D006097:Granulation Tissue / Q000378:metabolism; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D012038:Regeneration / Q000235:genetics*; D020545:Respiratory Mucosa / Q000378:metabolism*; D013552:Swine; D014132:Trachea / Q000378:metabolism*
D012333:RNA, Messenger; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors