Hearing loss affects millions of people worldwide and often results from death of the sensory hair cells in the inner ear. Hair cells are lost due to noise exposure, drug damage, and progressively during the aging process. The overall goal of the proposed research is to further understand the intracellular signaling pathways responsible for hair cell death due to drug damage, specifically damage caused by the aminoglycoside antibiotics. This research will use the zebrafish lateral line, a powerful in vivo model system for real-time hair cell death and protection studies. Our previous research has demonstrated that the closely related aminoglycosides neomycin and gentamicin damage hair cells via at least two distinct and partially overlapping cell death processes. The specific goal of the proposed research is to understand the intracellular events that differentiate these cell death processes with a focus on the multifaceted role of the tumor suppressor protein p53 during hair cell death in this system. This research will test the hypothesis that aminoglycoside-induced hair cell death in the zebrafish lateral line is dependent on diverse p53 functions, with the acute damage caused by neomycin or short-term gentamicin exposure requiring direct activity of p53 at the mitochondria, and the slower phase of gentamicin-induced damage dependent on p53 transcriptional activity in the nucleus. Specifically, the proposed project will 1) test the requirement for p53 in aminoglycoside-induced hair cell death, 2) characterize the involvement of direct p53 mitochondrial activity during aminoglycoside exposure, and 3) test the requirement for p53 nuclear activity during aminoglycoside-induced hair cell damage. A more thorough understanding of the specific cell death pathways activated by different hair cell toxins will allow us to more directly target potential protective therapies, allowing for hearing preservation in patients treated with ototoxic drugs.

Public Health Relevance

The goal of this proposed research is to better understand hearing loss so that we may prevent it. This research uses zebrafish, which have sensory cells that are similar to the cells that allow us to hear, in order to study how these cells are damaged due to drugs. Understanding how these sensory cells are damaged will help us design strategies to protect them, hopefully preventing hearing loss.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Small Research Grants (R03)
Project #
5R03DC011344-04
Application #
8374110
Study Section
Special Emphasis Panel (ZDC1-SRB-Y (56))
Program Officer
Freeman, Nancy
Project Start
2010-12-01
Project End
2014-11-30
Budget Start
2012-12-01
Budget End
2014-11-30
Support Year
4
Fiscal Year
2013
Total Cost
$143,450
Indirect Cost
$48,450
Name
Washington State University
Department
Veterinary Sciences
Type
Schools of Veterinary Medicine
DUNS #
041485301
City
Pullman
State
WA
Country
United States
Zip Code
99164
Coffin, Allison B; Rubel, Edwin W; Raible, David W (2013) Bax, Bcl2, and p53 differentially regulate neomycin- and gentamicin-induced hair cell death in the zebrafish lateral line. J Assoc Res Otolaryngol 14:645-59
Esterberg, Robert; Coffin, Allison B; Ou, Henry et al. (2013) Fish in a Dish: Drug Discovery for Hearing Habilitation. Drug Discov Today Dis Models 10: