Although clinical use of aminoglycoside antibiotics is essential against life-threatening bacterial infections, there are serious ototoxic and nephrotoxic side-effects in 4-14 percent of all aminoglycoside prescriptions (4 million annually). Ototoxicity causes sensory hair cell death, hearing loss, and vestibular disorders, leading to physical, mental, educational, and language difficulties in patients. The overall aim of our studies is to identify, and then prevent the cellular mechanisms that initiate ototoxic drug-induced hair cell death. The long- term goal of this project is to develop interventional strategies that will allow future clinicians to use aminoglycosides without serious side effects. Gentamicin and forskolin are two unrelated ototoxic drugs that depolarize mitochondria, and increase production of reactive oxygen species and calcium levels in hair cells. Each of these toxic sequelae is a powerful trigger for inducing hair cell death. These common cellular responses to toxicity suggest that unrelated ototoxic drugs trigger a common pathway that lead to hair cell death. Therefore, we will use explants of bullfrog saccular hair cells to: (1) Identify the acute effects of gentamicin and forskolin in hair cells, and determine if they trigger these toxic sequelae by similar or differing mechanisms (2) Determine if inhibitors of drug-uptake can prevent toxic sequelae in hair cells (3) Determine if effective inhibitors of drug-uptake and toxic sequelae enhance hair cell survival during ototoxic drug treatment These studies provide a direct link between the molecular and biochemical studies of ototoxic drugs and the morphological analysis of fixed tissues after drug treatment. This knowledge will advance development of clinical strategies to prevent drug- induced hair cell death, and preserve inner ear function during this critical pharmaceutical therapy.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC004555-03
Application #
6618078
Study Section
Special Emphasis Panel (ZRG1-IFCN-6 (01))
Program Officer
Freeman, Nancy
Project Start
2001-09-01
Project End
2006-07-31
Budget Start
2003-08-01
Budget End
2004-07-31
Support Year
3
Fiscal Year
2003
Total Cost
$315,456
Indirect Cost
Name
Oregon Health and Science University
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Steyger, Peter S; Cunningham, Lisa L; Esquivel, Carlos R et al. (2018) Editorial: Cellular Mechanisms of Ototoxicity. Front Cell Neurosci 12:75
Kros, Corné J; Steyger, Peter S (2018) Aminoglycoside- and Cisplatin-Induced Ototoxicity: Mechanisms and Otoprotective Strategies. Cold Spring Harb Perspect Med :
Kachelmeier, Allan; Shola, Tsering; Meier, William B et al. (2018) Simplified, automated methods for assessing pixel intensities of fluorescently-tagged drugs in cells. PLoS One 13:e0206628
Garinis, Angela C; Kemph, Alison; Tharpe, Anne Marie et al. (2018) Monitoring neonates for ototoxicity. Int J Audiol 57:S41-S48
Jiang, Meiyan; Taghizadeh, Farshid; Steyger, Peter S (2017) Potential Mechanisms Underlying Inflammation-Enhanced Aminoglycoside-Induced Cochleotoxicity. Front Cell Neurosci 11:362
Jiang, Meiyan; Karasawa, Takatoshi; Steyger, Peter S (2017) Aminoglycoside-Induced Cochleotoxicity: A Review. Front Cell Neurosci 11:308
Garinis, Angela C; Liao, Selena; Cross, Campbell P et al. (2017) Effect of gentamicin and levels of ambient sound on hearing screening outcomes in the neonatal intensive care unit: A pilot study. Int J Pediatr Otorhinolaryngol 97:42-50
Adler, Henry J; Anbuhl, Kelsey L; Atcherson, Samuel R et al. (2017) Community network for deaf scientists. Science 356:386-387
Garinis, Angela C; Cross, Campbell P; Srikanth, Priya et al. (2017) The cumulative effects of intravenous antibiotic treatments on hearing in patients with cystic fibrosis. J Cyst Fibros 16:401-409
Chu, Yu-Hsuan; Escobedo, Jorge O; Jiang, Meiyan et al. (2016) Rhodamine analogues for molecular ruler applications. Dyes Pigm 126:46-53

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