Presbycusis, age-related hearing loss, is a major reason for social isolation and loss of quality of life in the elderly but we have neither a clear understanding of the mechanisms involved nor of strategies to prevent it. This program project brings together laboratories with long-standing interests in the biochemistry and molecular biology of stress pathways in the inner ear and a group of scientists with expertise in genetic studies in mice, for a series of interrelated studies of the fundamental cell biology and genetics of presbycusis. Project 1 (Antioxidant and homeostatic pathways) will test the hypothesis that antioxidant defenses and redox-sensitive signaling pathways decline with age rendering the inner ear more prone to cell injury and death. Project 2 (Stress pathways in the aging cochlea) extends this hypothesis to age-related changes in the classic stress response (""""""""heat shock proteins""""""""), by analyzing induced responses to stress during aging, and will generate new mouse models to examine this pathway in the cochlea. Project 3 (Genetic analysis of stress resistance and loss of hearing) focuses on the genetic controls and physiological regulators that modulate hearing loss in a population of genetically heterogeneous mice. Genotyping will provide a genomic map of loci modulating hearing acuity, its change over age, and its resistance to noise-induced damage. Specifically, the project will test the hypothesis that modulation of stress-resistance will modulate presbycusis. The projects will be supported by three cores. Core A (Administration) will coordinate reporting and evaluation activities and facilitate interactions among the projects. Core B (Physiology) will evaluate auditory function, and Core C (Otopathology/Histology) will assess morphological changes and provide histological assays. The three projects are taking distinct but complementary approaches to delineate the molecular and genetic basis of age-related hearing loss. The results will answer questions on the relationships among two well-characterized stress pathways in the aging cochlea, and identify new genetic loci associated with age-related hearing loss.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Program Projects (P01)
Project #
5P01AG025164-05
Application #
7662403
Study Section
Special Emphasis Panel (ZAG1-ZIJ-4 (M2))
Program Officer
Chen, Wen G
Project Start
2005-09-01
Project End
2011-07-31
Budget Start
2009-08-01
Budget End
2011-07-31
Support Year
5
Fiscal Year
2009
Total Cost
$1,301,942
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Altschuler, R A; Dolan, D F; Halsey, K et al. (2015) Age-related changes in auditory nerve-inner hair cell connections, hair cell numbers, auditory brain stem response and gap detection in UM-HET4 mice. Neuroscience 292:22-33
Schacht, Jochen; Altschuler, Richard; Burke, David T et al. (2012) Alleles that modulate late life hearing in genetically heterogeneous mice. Neurobiol Aging 33:1842.e15-29
Gong, Tzy-Wen; Fairfield, Damon A; Fullarton, Lynne et al. (2012) Induction of heat shock proteins by hyperthermia and noise overstimulation in hsf1 -/- mice. J Assoc Res Otolaryngol 13:29-37
Sha, Su-Hua; Kanicki, Ariane; Halsey, Karin et al. (2012) Antioxidant-enriched diet does not delay the progression of age-related hearing loss. Neurobiol Aging 33:1010.e15-6
Miller, Richard A; Dolan, David; Han, Melissa et al. (2011) Resistance of skin fibroblasts to peroxide and UV damage predicts hearing loss in aging mice. Aging Cell 10:362-3
Leiser, Scott F; Miller, Richard A (2010) Nrf2 signaling, a mechanism for cellular stress resistance in long-lived mice. Mol Cell Biol 30:871-84
Sha, Su-Hua; Chen, Fu-Quan; Schacht, Jochen (2010) PTEN attenuates PIP3/Akt signaling in the cochlea of the aging CBA/J mouse. Hear Res 264:86-92
Sha, Su-Hua; Chen, Fu-Quan; Schacht, Jochen (2009) Activation of cell death pathways in the inner ear of the aging CBA/J mouse. Hear Res 254:92-9
Sha, Su-Hua; Kanicki, Ariane; Dootz, Gary et al. (2008) Age-related auditory pathology in the CBA/J mouse. Hear Res 243:87-94
Jiang, Hongyan; Talaska, Andra E; Schacht, Jochen et al. (2007) Oxidative imbalance in the aging inner ear. Neurobiol Aging 28:1605-12

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