Otitis media (OM) is a common disease of the pediatric age group considered to be multifactorial in etiology. While most cases of symptomatic OM with acute onset resolve within one month of presentation, a significant percentage persists for months to years as OM with effusion (OME), and many children present with OME evidenced by middle ear (ME) mucosal inflammation and effusion without recent signs and symptoms. OME is a persistent inflammation that most often fails to respond to conventional medical therapies. Recent studies conducted by us show that hydrops ex vacuo is a valid explanation for the development and persistence of OME under certain conditions. Disrupting Eustachian tube (ET) function in animals causes middle ear (ME) pressure dysregulation reflected as underpressures, which in turn causes increased permeability of the mucosal vasculature and results in ME effusion. However, the mechanism(s) responsible for transducing the biological signals associated with the underpressure that result in ME mucosal inflammation are not known. We hypothesize that transduction of the signal associated with middle ear underpressure initiates and sustains an inflammatory process that contributes to persistence of OME and to adverse changes in ME physiology.
Three Specific Aims are proposed to test this hypothesis: 1) To determine the role of inflammatory signaling in the production and persistence of ME effusion after ET obstruction, 2) To utilize tissue culture model systems for the elucidation of specific cellular mechanisms involved in disease pathogenesis, and 3) To use biochemical, pharmacologic and genetic manipulation to assess the role of key inflammatory mediators and pathways in provoking or sustaining the mucosal changes induced in the animal OME model systems. To achieve these aims, experiments are proposed using rodent models of OME and tissue cultures of ME epithelial cells and fibroblasts already established by the investigators. With these studies the investigators hope to elucidate the role of specific inflammatory signals and pathways in promoting disease persistence, and thus to identify potential targets for future therapeutic interventions.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC007197-03
Application #
7386554
Study Section
Auditory System Study Section (AUD)
Program Officer
Watson, Bracie
Project Start
2006-04-01
Project End
2009-03-31
Budget Start
2008-04-01
Budget End
2009-03-31
Support Year
3
Fiscal Year
2008
Total Cost
$263,021
Indirect Cost
Name
Children's Hosp Pittsburgh/Upmc Health Sys
Department
Type
DUNS #
044304145
City
Pittsburgh
State
PA
Country
United States
Zip Code
15224
Silva, Rodrigo C; Dohar, Joseph E; Hebda, Patricia A (2012) Novel rat model of tympanostomy tube otorrhea. Int J Pediatr Otorhinolaryngol 76:179-82