title: Tympanic membrane metalloproteinase inflammatory response.
abstract: 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.
authors.affiliation: Department of Otolaryngology, University of Florida, Gainesville, FL 32610-0264, USA.
authors.forename: Jason G
authors.initials: JG
authors.lastname: Wilmoth
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Schultz
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Antonelli
mesh_terms: 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*
chemical_list: D001427:Bacterial Toxins; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D020782:Matrix Metalloproteinases