Tympanic membrane metalloproteinase inflammatory response.
OBJECTIVE
The goal of this study was to determine whether expression of matrix metalloproteinases (MMP) in tympanic membranes (TM) is stimulated by host tumor necrosis factor-alpha (TNF-alpha) and bacterial toxin (lipopolysaccharide, LPS), which may play a role in the pathogenesis of cholesteatoma.


METHODS
Gerbil TMs (n = 48) were cultured in the presence of either TNF-alpha or LPS. Quantitative analysis of TNF-alpha and MMPs was performed on both the homogenized TMs and the culture media supernatant.


RESULTS
Levels of TNF-alpha and MMPs did not increase significantly in TMs with exposure to inflammatory mediators. TNF-alpha levels in supernatant were elevated (P < 0.007) with more concentrated LPS exposure. Supernatant levels of MMP2 were increased (P < 0.007) at most concentrations of LPS and TNF-alpha.


CONCLUSIONS
Cultured TMs expressed MMPs in response to bacterial and host inflammatory mediators. These findings support a link between inflammation and the secretion of potentially destructive MMPs in the TM, which may contribute to the pathogenesis of cholesteatoma.
Wilmoth
Jason G
JG
Department of Otolaryngology, University of Florida, Gainesville, FL 32610-0264, USA.
Schultz
Gregory S
GS
Antonelli
Patrick J
PJ
D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D018424:Cholesteatoma, Middle Ear / Q000503:physiopathology; D046508:Culture Techniques; D005849:Gerbillinae; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D010033:Otitis Media / Q000503:physiopathology; D012486:Salmonella typhimurium / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014432:Tympanic Membrane / Q000187:drug effects / Q000378:metabolism*
D001427:Bacterial Toxins; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D020782:Matrix Metalloproteinases