Expression of c-erbB receptors and ligands in human nasal epithelium.
BACKGROUND
The epidermal growth factor (EGF) family of growth factors plays an important role in maintenance and repair in a variety of epithelial tissues. However, very little is known about coexpression of these factors and their receptors, the c-erbB family of receptor tyrosine kinases, in human nasal epithelium.


OBJECTIVE
We sought to investigate the expression of these molecules in cultured nasal epithelial cells and nasal mucosa from healthy individuals.


METHODS
Identification of c-erbB receptors and their ligands was sought by using reverse transcription PCR, Western blotting, and immunohistochemistry.


RESULTS
Messenger RNA encoding the EGF receptors (EGFR) c-erbB2 and c-erbB3, but not c-erbB4, was detected in primary cultures of human nasal epithelial cells. Transcripts encoding EGF, heparin-binding EGF, transforming growth factor (TGF) alpha, and amphiregulin were also detected. Receptor and ligand expression was confirmed by using immunocytochemical staining of the cells and Western blotting of the cell lysates. Immunohistochemical analysis of tissue sections obtained from biopsy specimens of nasal mucosa revealed intense membrane staining for the EGFR within the respiratory nasal epithelium, which was predominantly localized at the level of the columnar epithelial layers. Similar staining patterns were observed for c-erbB2 and c-erbB3 in the respiratory nasal epithelium. Evidence for EGF, transforming growth factor alpha, heparin-binding EGF, amphiregulin, and betacellulin immunostaining in the nasal epithelium was also obtained; their staining patterns paralleled that of EGFR immunostaining.


CONCLUSIONS
Colocalization of c-erbB receptors and ligands establishes a basis on which to investigate c-erbB receptor- mediated effects in human nasal epithelium.
Polosa
R
R
Division of Respiratory, Cell & Molecular Biology, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom.
Prosperini
G
G
Tomaselli
V
V
Howarth
P H
PH
Holgate
S T
ST
Davies
D E
DE
D002478:Cells, Cultured; D004727:Endothelium / Q000737:chemistry / Q000378:metabolism; D066246:ErbB Receptors / Q000032:analysis; D006801:Humans; D009297:Nasal Mucosa / Q000737:chemistry / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*
D066246:ErbB Receptors; D018719:Erb-b2 Receptor Tyrosine Kinases