Growth factors influence growth and differentiation of the middle ear mucosa.
OBJECTIVE
Otitis media is a major cause of morbidity in pediatric and adult patients. This inflammatory condition is characterized by mucosal hyperplasia that is thought to be mediated by the complex actions of growth factors and their respective receptors. It was the purpose of this study to determine which growth factors might be responsible for the growth and differentiation of the middle ear epithelium during otitis media.


METHODS
The effect of several growth factors on the expansion and differentiation of normal middle ear mucosa was evaluated in tissue culture.


METHODS
Explants of normal rat middle ear mucosa were exposed in vitro to six different growth factors known to influence epithelial cells in other tissues: epidermal growth factor, amphiregulin, betacellulin, heregulin-alpha, keratinocyte growth factor, and hepatocyte growth factor.


RESULTS
After 12 days, the growth and level of cytokeratin expression were analyzed for each of the explant outgrowths. Each factor appeared to have a significant, concentration-dependent effect on either the growth or differentiation of the cultured middle ear epithelial cells.


CONCLUSIONS
The results suggest that several of the tested growth factors may play a significant role in controlling hyperplasia of the middle ear mucosa during otitis media.
Palacios
S D
SD
Department of Head and Neck Surgery, University of California-San Diego, School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093, USA.
Oehl
H J
HJ
Rivkin
A Z
AZ
Aletsee
C
C
Pak
K
K
Ryan
A F
AF
D066258:Amphiregulin; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D066259:Betacellulin; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D066255:EGF Family of Proteins; D004432:Ear, Middle / Q000187:drug effects*; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D006023:Glycoproteins / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D017228:Hepatocyte Growth Factor / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins; D015603:Keratinocytes; D008297:Male; D009092:Mucous Membrane / Q000187:drug effects; D020890:Neuregulin-1 / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D066258:Amphiregulin; D000970:Antineoplastic Agents; C587850:Areg protein, rat; D066259:Betacellulin; C587853:Btc protein, rat; D066255:EGF Family of Proteins; C496455:Fgf7 protein, rat; D006023:Glycoproteins; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D020890:Neuregulin-1; C117463:heregulin alpha; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D004815:Epidermal Growth Factor; D017228:Hepatocyte Growth Factor