Activities of matrix metalloproteinases and tissue inhibitor of metalloproteinase-2 in idiopathic hemotympanum and otitis media with effusion.
CONCLUSIONS
The expression profile of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-2 (TIMP-2) was specific to the type of middle ear effusion. Further studies are necessary for elucidating its correlation with the sequelae of otitis media with effusion (OME) and idiopathic hemotympanum.


OBJECTIVE
We aimed to investigate the relative activities of gelatinases (MMP-2 and -9), stromelysin-1 (MMP-3), and matrilysin-1 (MMP-7), as well as measuring TIMP-2 levels in the serous and mucous effusions of OME and hemorrhagic effusion of the idiopathic hemotympanum.


METHODS
Middle ear effusions were collected from patients with OME and idiopathic hemotympanum, and were classified as mucoid, serous, or hemorrhagic. MMP activity in the effusion samples was examined by gelatin and casein zymography. Levels of TIMP-2 were measured by ELISA. Human temporal bone sections, with and without otitis media (OM), were examined histologically.


RESULTS
One case showed tympanic membrane thinning in the OM group, but none in the control group. While MMP-2 was present in all effusions, the active form of MMP-2 was found only in mucous effusions. MMP-3 and MMP-7 activity was detected only in the mucous effusions. MMP-9 exhibited activity in all effusions, with the highest levels in mucous effusions. TIMP-2 levels were markedly elevated in serous effusions.
Moon
Sung K
SK
Gonda Department of Cell and Molecular Biology, House Ear Institute, Los Angeles, CA, USA. smoon@hei.org
Linthicum
Fred H
FH
Yang
Hae Dong
HD
Lee
Seung Joo
SJ
Park
Keehyun
K
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004427:Ear Diseases / Q000473:pathology* / Q000601:surgery; D004432:Ear, Middle / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006470:Hemorrhage / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D020783:Matrix Metalloproteinase 7 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008876:Middle Ear Ventilation; D010034:Otitis Media with Effusion / Q000473:pathology* / Q000601:surgery; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism*
D019716:Tissue Inhibitor of Metalloproteinase-2; D020782:Matrix Metalloproteinases; C511768:MMP3 protein, human; D019278:Matrix Metalloproteinase 3; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9