Matrix metalloproteinase-8/collagenase-2 in childhood otitis media with effusion.
BACKGROUND
Matrix metalloproteinases (MMPs), gelatinases, have been associated with otitis media with effusion (OME), but the role of collagenase-2/matrix metalloproteinase-8 (MMP-8) in OME has not been studied previously. We studied the levels, isoenzyme distribution, and activation of MMP-8 in childhood OME, and also the levels of pro- and active forms of MMP-2 and -9 as well as 120 kDa gelatinase complexes were assessed.


METHODS
Seventy middle ear fluid (MEF) samples were collected from 54 children with OME and classified to mucoid (n = 39) or serous (n = 31). MMPs were studied from MEF samples by time-resolved immunofluorometric assay, Western immunoblotting, and gelatin-zymography.


RESULTS
MMP-8 was found in its active form in MEF of children with OME. MMP-8 levels were significantly higher in mucous relative to serous OME. The pro- or active MMP-2 and -9 were found in MEF, but no MEF type-specific differences were found.


CONCLUSIONS
Our results suggest that MMP-8 may play a role in the pathogenesis of childhood OME. New therapeutic strategies with MMP inhibitors targeting MMP-8, but allowing MMP-8 to carry out the protective action, may play a role in the future treatment of otitis media and OME. However, further studies of this topic are needed.
Division of Infectious Diseases, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland.
Anneli
A
Lauhio
Szilard
S
Rezes
Taina
T
Tervahartiala
Istvan
I
Sziklai
Anne
A
Pitkäranta
Timo
T
Sorsa
D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D005260:Female; D015200:Fluoroimmunoassay; D018093:Gelatinases / Q000737:chemistry*; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020784:Matrix Metalloproteinase 8 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D010034:Otitis Media with Effusion / Q000201:enzymology* / Q000209:etiology
D018093:Gelatinases; D020778:Matrix Metalloproteinase 2; D020784:Matrix Metalloproteinase 8; D020780:Matrix Metalloproteinase 9