1
|
Trevino M, Lobarinas E, Maulden AC, Heinz MG. The chinchilla animal model for hearing science and noise-induced hearing loss. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3710. [PMID: 31795699 PMCID: PMC6881193 DOI: 10.1121/1.5132950] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 05/07/2023]
Abstract
The chinchilla animal model for noise-induced hearing loss has an extensive history spanning more than 50 years. Many behavioral, anatomical, and physiological characteristics of the chinchilla make it a valuable animal model for hearing science. These include similarities with human hearing frequency and intensity sensitivity, the ability to be trained behaviorally with acoustic stimuli relevant to human hearing, a docile nature that allows many physiological measures to be made in an awake state, physiological robustness that allows for data to be collected from all levels of the auditory system, and the ability to model various types of conductive and sensorineural hearing losses that mimic pathologies observed in humans. Given these attributes, chinchillas have been used repeatedly to study anatomical, physiological, and behavioral effects of continuous and impulse noise exposures that produce either temporary or permanent threshold shifts. Based on the mechanistic insights from noise-exposure studies, chinchillas have also been used in pre-clinical drug studies for the prevention and rescue of noise-induced hearing loss. This review paper highlights the role of the chinchilla model in hearing science, its important contributions, and its advantages and limitations.
Collapse
Affiliation(s)
- Monica Trevino
- School of Behavioral and Brain Sciences, Callier Center, The University of Texas at Dallas, 1966 Inwood Road, Dallas, Texas 75235, USA
| | - Edward Lobarinas
- School of Behavioral and Brain Sciences, Callier Center, The University of Texas at Dallas, 1966 Inwood Road, Dallas, Texas 75235, USA
| | - Amanda C Maulden
- Department of Speech, Language, and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, Indiana 47907, USA
| | - Michael G Heinz
- Weldon School of Biomedical Engineering, Purdue University, 715 Clinic Drive, West Lafayette, Indiana 47907, USA
| |
Collapse
|
2
|
Bielefeld EC, Harrison RT, Riley DeBacker J. Pharmaceutical otoprotection strategies to prevent impulse noise-induced hearing loss. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3790. [PMID: 31795721 DOI: 10.1121/1.5132285] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
One of the ongoing challenges for hearing researchers is successful protection of the ear from noise injury. For decades, the most effective methods have been based on modifying the acoustic properties of the noise, either by reducing noise output from various sources, interfering in the acoustic exposure path with environmental controls, or altering the noise dose for the individual with personal hearing protection devices. Because of the inefficiencies of some of the acoustic modification procedures, pharmaceutical otoprotection is targeted at making the cochlea less susceptible to injury. Short-duration, high-level impulse noises, typically caused by small-scale explosions, cause different sets of injuries in the ear than long-duration, low-variance noise exposures. Therefore, the expectation is that the ears exposed to impulse noise may need different pharmaceutical interventions, both in type of compounds used and the time course of administration of the compounds. The current review discusses four different classes of compounds that have been tested as impulse noise otoprotectants. In the process of describing those experiments, particular emphasis is placed on the acoustic properties of the impulses used, with the goal of providing context for evaluating the relevance of these different models to human impulse noise-induced hearing loss.
Collapse
Affiliation(s)
- Eric C Bielefeld
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, Ohio 43220, USA
| | - Ryan T Harrison
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, Ohio 43220, USA
| | - J Riley DeBacker
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, Ohio 43220, USA
| |
Collapse
|
3
|
Le Prell CG, Hammill TL, Murphy WJ. Noise-induced hearing loss and its prevention: Integration of data from animal models and human clinical trials. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:4051. [PMID: 31795668 PMCID: PMC7195863 DOI: 10.1121/1.5132951] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Animal models have been used to gain insight into the risk of noise-induced hearing loss (NIHL) and its potential prevention using investigational new drug agents. A number of compounds have yielded benefit in pre-clinical (animal) models. However, the acute traumatic injury models commonly used in pre-clinical testing are fundamentally different from the chronic and repeated exposures experienced by many human populations. Diverse populations that are potentially at risk and could be considered for enrollment in clinical studies include service members, workers exposed to occupational noise, musicians and other performing artists, and children and young adults exposed to non-occupational (including recreational) noise. Both animal models and clinical populations were discussed in this special issue, followed by discussion of individual variation in vulnerability to NIHL. In this final contribution, study design considerations for NIHL otoprotection in pre-clinical and clinical testing are integrated and broadly discussed with evidence-based guidance offered where possible, drawing on the contributions to this special issue as well as other existing literature. The overarching goals of this final paper are to (1) review and summarize key information across contributions and (2) synthesize information to facilitate successful translation of otoprotective drugs from animal models into human application.
Collapse
Affiliation(s)
- Colleen G Le Prell
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
| | - Tanisha L Hammill
- Department of Defense, Defense Health Agency, Falls Church, Virginia 22042, USA
| | - William J Murphy
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Cincinanati, Ohio 45226-1998, USA
| |
Collapse
|
4
|
Gittleman SN, Le Prell CG, Hammill TL. Octave band noise exposure: Laboratory models and otoprotection efforts. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3800. [PMID: 31795706 PMCID: PMC7195864 DOI: 10.1121/1.5133393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/21/2019] [Indexed: 05/05/2023]
Abstract
With advances in the understanding of mechanisms of noise injury, the past 30 years have brought numerous efforts to identify drugs that prevent noise-induced hearing loss (NIHL). The diverse protocols used across investigations have made comparisons across drugs difficult. A systematic review of the literature by Hammill [(2017). Doctoral thesis, The University of Texas at Austin] identified original reports of chemical interventions to prevent or treat hearing loss caused by noise exposure. An initial search returned 3492 articles. After excluding duplicate articles and articles that did not meet the systematic review inclusion criteria, a total of 213 studies published between 1977 and 2016 remained. Reference information, noise exposure parameters, species, sex, method of NIHL assessment, and pharmaceutical intervention details for these 213 studies were entered into a database. Frequency-specific threshold shifts in control animals (i.e., in the absence of pharmaceutical intervention) are reported here. Specific patterns of hearing loss as a function of species and noise exposure parameters are provided to facilitate the selection of appropriate pre-clinical models. The emphasis of this report is octave band noise exposure, as this is one of the most common exposure protocols across pharmacological otoprotection studies.
Collapse
Affiliation(s)
- Sarah N Gittleman
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
| | - Colleen G Le Prell
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, Texas 75080, USA
| | - Tanisha L Hammill
- Department of Defense, Defense Health Agency, Falls Church, Virginia 22042, USA
| |
Collapse
|
5
|
Heinrich UR, Schmidtmann I, Meuser R, Ernst BP, Wünsch D, Siemer S, Gribko A, Stauber RH, Strieth S. Early Alterations of Endothelial Nitric Oxide Synthase Expression Patterns in the Guinea Pig Cochlea After Noise Exposure. J Histochem Cytochem 2019; 67:845-855. [PMID: 31510846 DOI: 10.1369/0022155419876644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Constitutively expressed endothelial nitric oxide synthase (eNOS) is supposed to play a role in noise-induced nitric oxide (NO)-production. It is commonly known that intense noise exposure results in inducible NOS (iNOS) expression and increased NO-production, but knowledge about a contribution of the eNOS isoform is still lacking. Effects of noise exposure on eNOS immunolabeling were determined in male guinea pigs (n=24). For light microscopic analysis, 11 animals were exposed to 90 dB for 1 hr and 6 animals were used as controls. After exposure, eNOS immunostaining was performed on paraffin sections, and the staining intensities were quantified for 4 cochlear regions. For electron microscopic analysis, 2 animals were exposed for 2 hr to 90 dB and 5 animals were used as controls. The intensity of eNOS immunolabeling was found to be already comprehensively increased 1 hr after noise exposure to 90 dB. At the ultrastructural level, a clear increase in eNOS immunolabeling was found in microtubules-rich areas of cochlear cuticular structures. Hence, our findings indicate that the reticular lamina forming the endolymph-perilymph barrier at the apical side of the organ of Corti is involved in a fast intrinsic otoprotective mechanism of the cochlea.
Collapse
Affiliation(s)
- Ulf R Heinrich
- Department of Otorhinolaryngology, University Medical Center Mainz, Mainz, Germany
| | - Irene Schmidtmann
- Institute for Medical Biostatistics, Epidemiology and Informatics (IMBEI), University Medical Center Mainz, Mainz, Germany
| | - Regina Meuser
- Institute for Medical Biostatistics, Epidemiology and Informatics (IMBEI), University Medical Center Mainz, Mainz, Germany
| | - Benjamin P Ernst
- Department of Otorhinolaryngology, University Medical Center Mainz, Mainz, Germany
| | - Desiree Wünsch
- Department of Otorhinolaryngology, University Medical Center Mainz, Mainz, Germany
| | - Svenja Siemer
- Department of Otorhinolaryngology, University Medical Center Mainz, Mainz, Germany
| | - Alena Gribko
- Department of Otorhinolaryngology, University Medical Center Mainz, Mainz, Germany
| | - Roland H Stauber
- Department of Otorhinolaryngology, University Medical Center Mainz, Mainz, Germany
| | - Sebastian Strieth
- Department of Otorhinolaryngology, University Medical Center Mainz, Mainz, Germany
| |
Collapse
|
6
|
Harrison RT, Bielefeld EC. Little evidence for a chronotolerance effect for impulse noise exposure in the C57BL/6J mouse. Neurosci Lett 2018; 684:127-131. [DOI: 10.1016/j.neulet.2018.07.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 06/27/2018] [Accepted: 07/18/2018] [Indexed: 12/20/2022]
|
7
|
Ryals M, Pak K, Jalota R, Kurabi A, Ryan AF. A kinase inhibitor library screen identifies novel enzymes involved in ototoxic damage to the murine organ of Corti. PLoS One 2017; 12:e0186001. [PMID: 29049311 PMCID: PMC5648133 DOI: 10.1371/journal.pone.0186001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 09/22/2017] [Indexed: 11/25/2022] Open
Abstract
Ototoxicity is a significant side effect of a number of drugs, including the aminoglycoside antibiotics and platinum-based chemotherapeutic agents that are used to treat life-threatening illnesses. Although much progress has been made, the mechanisms that lead to ototoxic loss of inner ear sensory hair cells (HCs) remains incompletely understood. Given the critical role of protein phosphorylation in intracellular processes, including both damage and survival signaling, we screened a library of kinase inhibitors targeting members of all the major families in the kinome. Micro-explants from the organ of Corti of mice in which only the sensory cells express GFP were exposed to 200 μM of the ototoxic aminoglycoside gentamicin with or without three dosages of each kinase inhibitor. The loss of sensory cells was compared to that seen with gentamicin alone, or without treatment. Of the 160 inhibitors, 15 exhibited a statistically significant protective effect, while 3 significantly enhanced HC loss. The results confirm some previous studies of kinase involvement in HC damage and survival, and also highlight several novel potential kinase pathway contributions to ototoxicity.
Collapse
Affiliation(s)
- Matthew Ryals
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Kwang Pak
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Rahul Jalota
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Arwa Kurabi
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Allen F. Ryan
- Department of Surgery/Otolaryngology, University of California, San Diego, School of Medicine, La Jolla, California, United States of America
- Research Service, Veterans Administration Medical Center, San Diego, California, United States of America
- * E-mail:
| |
Collapse
|
8
|
Pharmacological agents used for treatment and prevention in noise-induced hearing loss. Eur Arch Otorhinolaryngol 2016; 273:4089-4101. [DOI: 10.1007/s00405-016-3936-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/10/2016] [Indexed: 12/20/2022]
|
9
|
de Iriarte Rodríguez R, Magariños M, Pfeiffer V, Rapp UR, Varela-Nieto I. C-Raf deficiency leads to hearing loss and increased noise susceptibility. Cell Mol Life Sci 2015; 72:3983-98. [PMID: 25975225 PMCID: PMC4575698 DOI: 10.1007/s00018-015-1919-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 04/21/2015] [Accepted: 04/27/2015] [Indexed: 12/20/2022]
Abstract
The family of RAF kinases transduces extracellular information to the nucleus, and their activation is crucial for cellular regulation on many levels, ranging from embryonic development to carcinogenesis. B-RAF and C-RAF modulate neurogenesis and neuritogenesis during chicken inner ear development. C-RAF deficiency in humans is associated with deafness in the rare genetic insulin-like growth factor 1 (IGF-1), Noonan and Leopard syndromes. In this study, we show that RAF kinases are expressed in the developing inner ear and in adult mouse cochlea. A homozygous C-Raf deletion in mice caused profound deafness with no evident cellular aberrations except for a remarkable reduction of the K+ channel Kir4.1 expression, a trait that suffices as a cause of deafness. To explore the role of C-Raf in cellular protection and repair, heterozygous C-Raf+/− mice were exposed to noise. A reduced C-RAF level negatively affected hearing preservation in response to noise through mechanisms involving the activation of JNK and an exacerbated apoptotic response. Taken together, these results strongly support a role for C-RAF in hearing protection.
Collapse
Affiliation(s)
- Rocío de Iriarte Rodríguez
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain.,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain
| | - Marta Magariños
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain. .,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain. .,Departamento de Biología, Universidad Autónoma de Madrid, Darwin 2, 28049, Madrid, Spain.
| | - Verena Pfeiffer
- Institute for Medical Radiation and Cell Research (MSZ), University of Würzburg, Versbacher Strasse 5, 97078, Würzburg, Germany.,Institute for Anatomy and Cell Biology, University of Würzburg, Koellikerstraße 6, 97070, Würzburg, Germany
| | - Ulf R Rapp
- Institute for Medical Radiation and Cell Research (MSZ), University of Würzburg, Versbacher Strasse 5, 97078, Würzburg, Germany.,Molecular Mechanisms of Lung Cancer, Max Planck Institute for Heart and Lung Research, Parkstr. 1, 61231, Bad Nauheim, Germany
| | - Isabel Varela-Nieto
- Instituto de Investigaciones Biomédicas "Alberto Sols", CSIC-UAM, Arturo Duperier 4, 28029, Madrid, Spain.,Centre for Biomedical Network Research (CIBERER), Institute of Health Carlos III (ISCIII), Madrid, Spain.,Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| |
Collapse
|
10
|
Bielefeld EC. Protection from noise-induced hearing loss with Src inhibitors. Drug Discov Today 2015; 20:760-5. [PMID: 25637168 DOI: 10.1016/j.drudis.2015.01.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/09/2014] [Accepted: 01/20/2015] [Indexed: 01/23/2023]
Abstract
Noise-induced hearing loss is a major cause of acquired hearing loss around the world and pharmacological approaches to protecting the ear from noise are under investigation. Noise results in a combination of mechanical and metabolic damage pathways in the cochlea. The Src family of protein tyrosine kinases could be active in both pathways and Src inhibitors have successfully prevented noise-induced cochlear damage and hearing loss in animal models. The long-term goal is to optimize delivery methods into the cochlea to reduce invasiveness and limit side-effects before human clinical testing can be considered. At their current early stage of research investigation, Src inhibitors represent an exciting class of compounds for inclusion in a multifaceted pharmacological approach to protecting the ear from noise.
Collapse
Affiliation(s)
- Eric C Bielefeld
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, OH 43210, USA.
| |
Collapse
|
11
|
A putative role of p53 pathway against impulse noise induced damage as demonstrated by protection with pifithrin-alpha and a Src inhibitor. Neurosci Res 2014; 81-82:30-7. [DOI: 10.1016/j.neures.2014.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 12/16/2013] [Accepted: 01/17/2014] [Indexed: 11/22/2022]
|
12
|
Effect of intratympanic dimethyl sulphoxide (DMSO) in an in vivo model of cisplatin-related ototoxicity. Eur Arch Otorhinolaryngol 2014; 271:3121-6. [DOI: 10.1007/s00405-014-2957-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 02/17/2014] [Indexed: 12/14/2022]
|
13
|
An Src-protein tyrosine kinase inhibitor to reduce cisplatin ototoxicity while preserving its antitumor effect. Anticancer Drugs 2013; 24:43-51. [DOI: 10.1097/cad.0b013e32835739fd] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
14
|
Bas E, Dinh CT, Garnham C, Polak M, Van de Water TR. Conservation of hearing and protection of hair cells in cochlear implant patients' with residual hearing. Anat Rec (Hoboken) 2012; 295:1909-27. [DOI: 10.1002/ar.22574] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 07/24/2012] [Indexed: 12/13/2022]
|
15
|
Feng S, Pflueger M, Lin SX, Groveman BR, Su J, Yu XM. Regulation of voltage-gated sodium current by endogenous Src family kinases in cochlear spiral ganglion neurons in culture. Pflugers Arch 2012; 463:571-84. [PMID: 22297656 DOI: 10.1007/s00424-012-1072-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 12/09/2011] [Accepted: 01/02/2012] [Indexed: 01/28/2023]
Abstract
Voltage-gated sodium (Na+) and potassium (K+)channels have been found to be regulated by Src family kinases(SFKs).However, how these channels are regulated by SFKs in cochlear spiral ganglion neurons (SGNs) remains unknown.Here, we report that altering the activity of endogenous SFKs modulated voltage-gated Na+, but not K+, currents recorded in embryonic SGNs in culture. Voltage-gated Na+ current was suppressed by inhibition of endogenous SFKs or just Src and potentiated by the activation of these enzymes. Detailed investigations showed that under basal conditions, SFK inhibitor application did not significantly affect the voltage-dependent activation, but shifted the steady-state inactivation curves of Na+ currents and delayed the recovery of Na+ currents from inactivation. Application of Src specific inhibitor, Src40–58,not only shifted the inactivation curve but also delayed the recovery of Na+ currents and moved the voltage-dependent activation curve towards the left. The pre-inhibition of SFKs occluded all the effects induced by Src40–58 application, except the left shift of the activation curve. The activation of SFKs did not change either steady-state inactivation or recovery of Na+ currents, but caused the left shift of the activation curve.SFK inhibitor application effectively prevented all the effects induced by SFK activation, suggesting that both the voltage-dependent activation and steady-state inactivation of Na+ current are subjects of SFK regulation. The different effects induced by activation versus inhibition of SFKs implied that under basal conditions, endogenously active and inactive SFKs might be differentially involved in the regulation of voltage-gated Na+ channels in SGNs.
Collapse
Affiliation(s)
- Shuang Feng
- Department of Otolaryngology—Head and Neck Surgery, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi, People’s Republic of China
| | | | | | | | | | | |
Collapse
|
16
|
Zheng G, Hu BH. Cell-cell junctions: a target of acoustic overstimulation in the sensory epithelium of the cochlea. BMC Neurosci 2012; 13:71. [PMID: 22712683 PMCID: PMC3407512 DOI: 10.1186/1471-2202-13-71] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 06/19/2012] [Indexed: 12/20/2022] Open
Abstract
Background Exposure to intense noise causes the excessive movement of the organ of Corti, stretching the organ and compromising sensory cell functions. We recently revealed changes in the transcriptional expression of multiple adhesion-related genes during the acute phases of cochlear damage, suggesting that the disruption of cell-cell junctions is an early event in the process of cochlear pathogenesis. However, the functional state of cell junctions in the sensory epithelium is not clear. Here, we employed graded dextran-FITC, a macromolecule tracer that is impermeable to the organ of Corti under physiological conditions, to evaluate the barrier function of cell junctions in normal and noise-traumatized cochlear sensory epithelia. Results Exposure to an impulse noise of 155 dB (peak sound pressure level) caused a site-specific disruption in the intercellular junctions within the sensory epithelium of the chinchilla cochlea. The most vulnerable sites were the junctions among the Hensen cells and between the Hensen and Deiters cells within the outer zone of the sensory epithelium. The junction clefts that formed in the reticular lamina were permeable to 40 and 500 but not 2,000 kDa dextran-FITC macromolecules. Moreover, this study showed that the interruption of junction integrity occurred in the reticular lamina and also in the basilar membrane, a site that had been considered to be resistant to acoustic injury. Finally, our study revealed a general spatial correlation between the site of sensory cell damage and the site of junction disruption. However, the two events lacked a strict one-to-one correlation, suggesting that the disruption of cell-cell junctions is a contributing, but not the sole, factor for initiating acute sensory cell death. Conclusions Impulse noise causes the functional disruption of intercellular junctions in the sensory epithelium of the chinchilla cochlea. This disruption occurs at an early phase of cochlear damage. Understanding the role of this disruption in cochlear pathogenesis will require future study.
Collapse
Affiliation(s)
- Guiliang Zheng
- Center for Hearing and Deafness, State University of New York at Buffalo, Buffalo, USA
| | | |
Collapse
|
17
|
Groveman BR, Feng S, Fang XQ, Pflueger M, Lin SX, Bienkiewicz EA, Yu X. The regulation of N-methyl-D-aspartate receptors by Src kinase. FEBS J 2011; 279:20-8. [PMID: 22060915 DOI: 10.1111/j.1742-4658.2011.08413.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Src family kinases (SFKs) play critical roles in the regulation of many cellular functions by growth factors, G-protein-coupled receptors and ligand-gated ion channels. Recent data have shown that SFKs serve as a convergent point of multiple signaling pathways regulating N-methyl-d-aspartate (NMDA) receptors in the central nervous system. Multiple SFK molecules, such as Src and Fyn, closely associate with their substrate, NMDA receptors, via indirect and direct binding mechanisms. The NMDA receptor is associated with an SFK signaling complex consisting of SFKs; the SFK-activating phosphatase, protein tyrosine phosphatase α; and the SFK-inactivating kinase, C-terminal Src kinase. Early studies have demonstrated that intramolecular interactions with the SH2 or SH3 domain lock SFKs in a closed conformation. Disruption of the interdomain interactions can induce the activation of SFKs with multiple signaling pathways involved in regulation of this process. The enzyme activity of SFKs appears 'graded', exhibiting different levels coinciding with activation states. It has also been proposed that the SH2 and SH3 domains may stimulate catalytic activity of protein tyrosine kinases, such as Abl. Recently, it has been found that the enzyme activity of neuronal Src protein is associated with its stability, and that the SH2 and SH3 domain interactions may act not only to constrain the activation of neuronal Src, but also to regulate the enzyme activity of active neuronal Src. Collectively, these findings demonstrate novel mechanisms underlying the regulation of SFKs.
Collapse
Affiliation(s)
- Bradley R Groveman
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, USA.
| | | | | | | | | | | | | |
Collapse
|
18
|
Bielefeld EC, Hangauer D, Henderson D. Protection from impulse noise-induced hearing loss with novel Src-protein tyrosine kinase inhibitors. Neurosci Res 2011; 71:348-54. [PMID: 21840347 PMCID: PMC3210387 DOI: 10.1016/j.neures.2011.07.1836] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 07/28/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
Apoptosis is a significant mechanism of cochlear hair cell loss from noise. Molecules that inhibit apoptotic intracellular signaling reduce cochlear damage and hearing loss from noise. The current study is an extension of a previous study of the protective value of Src-protein tyrosine kinase inhibitors against noise (Harris et al., 2005). The current study tested three Src-inhibitors: the indole-based KX1-141, the biaryl-based KX2-329, and the ATP-competitive KX2-328. Each of the three drugs was delivered into the chinchillas' cochleae by allowing the solutions to diffuse across the round window membrane thirty minutes prior to exposure to impulse noise. Hearing thresholds were measured using auditory evoked responses from electrodes in the inferior colliculi. Ears treated with KX2-329 showed significantly lower threshold shifts and outer hair cell losses than the control group. The cochleae treated with KX1-141 and KX2-328 did not show statistically significant protection from the impulse noise. The finding of protection with KX2-329 demonstrates that a biaryl-based Src inhibitor has protective capacity against noise-induced hearing loss that is as good as that demonstrated by KX1-004, a Src inhibitor drug that has been studied extensively as an otoprotectant against noise, and suggests that KX2-329 could be useful for protection against noise.
Collapse
Affiliation(s)
- Eric C. Bielefeld
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, OH 43220, USA
| | - David Hangauer
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Donald Henderson
- Center for Hearing and Deafness, Department of Communicative Disorders and Sciences, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
| |
Collapse
|
19
|
Jamesdaniel S, Hu B, Kermany MH, Jiang H, Ding D, Coling D, Salvi R. Noise induced changes in the expression of p38/MAPK signaling proteins in the sensory epithelium of the inner ear. J Proteomics 2011; 75:410-24. [PMID: 21871588 DOI: 10.1016/j.jprot.2011.08.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 08/04/2011] [Accepted: 08/08/2011] [Indexed: 12/20/2022]
Abstract
Noise exposure is a major cause of hearing loss. Classical methods of studying protein involvement have provided a basis for understanding signaling pathways that mediate hearing loss and damage repair but do not lend themselves to studying large networks of proteins that are likely to increase or decrease during noise trauma. To address this issue, antibody microarrays were used to quantify the very early changes in protein expression in three distinct regions of the chinchilla cochlea 2h after exposure to a 0.5-8 kHz band of noise for 2h at 112 dB SPL. The noise exposure caused significant functional impairment 2h post-exposure which only partially recovered. Distortion product otoacoustic emissions were abolished 2h after the exposure, but at 4 weeks post-exposure, otoacoustic emissions were present, but still greatly depressed. Cochleograms obtained 4 weeks post-exposure demonstrated significant loss of outer hair cells in the basal 60% of the cochlea corresponding to frequencies in the noise spectrum. A comparative analysis of the very early (2h post-exposure) noise-induced proteomic changes indicated that the sensory epithelium, lateral wall and modiolus differ in their biological response to noise. Bioinformatic analysis of the cochlear protein profile using "The Database for Annotation, Visualization and Integrated Discovery 2008" (DAVID - http://david.abcc. ncifcrf.gov) revealed the initiation of the cell death process in sensory epithelium and modiolus. An increase in Fas and phosphorylation of FAK and p38/MAPK in the sensory epithelium suggest that noise-induced stress signals at the cell membrane are transmitted to the nucleus by Fas and focal adhesion signaling through the p38/MAPK signaling pathway. Up-regulation of downstream nuclear proteins E2F3 and WSTF in immunoblots and microarrays along with their immunolocalization in the outer hair cells supported the pivotal role of p38/MAPK signaling in the mechanism underlying noise-induced hearing loss.
Collapse
Affiliation(s)
- Samson Jamesdaniel
- Center for Hearing and Deafness, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA
| | | | | | | | | | | | | |
Collapse
|
20
|
Ding X, Xu L, Gerald F, Gao X. The assessment of hearing impairment among healthy children in rural and urban areas in China. Int J Pediatr Otorhinolaryngol 2011; 75:330-6. [PMID: 21185089 DOI: 10.1016/j.ijporl.2010.11.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 11/22/2010] [Accepted: 11/24/2010] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To investigate the auditory function of healthy children and provide experimental data to protect children's hearing in China. METHODS Total of 191 normally growing children (6-12 years old) in Qinling mountain area, the pasturing area around Qinghai Lake and Nanjing city were randomly included in this study. The whole-frequency auditory thresholds of these children were examined. RESULTS There was significant difference between the boys' and girls' auditory thresholds at nearly the whole frequencies in the Qinling area. Significant difference was also found between the boys' and girls' auditory thresholds at high frequencies and super high frequencies in the pasturing area around Qinghai Lake. Overall, the girls' auditory function was much better than the boys'. In contrast, there was no significant difference between the boys' and girls' auditory thresholds in Nanjing city. The auditory thresholds in high frequencies and super high frequencies of the boys in Nanjing city were lower than those of the boys in mountain and plateau pasturing areas, while there was no significant difference of the girls' auditory thresholds between city and rural areas except for a few low frequencies. CONCLUSIONS Hearing impairment was found in Chinese children of rural areas, especially among the boys. Since the children in rural areas should have no chance to be exposed to the modern industrial noises, it is most likely that the impulse noises from firecrackers caused the partial loss of hearings.
Collapse
Affiliation(s)
- Xiaoqiong Ding
- Department of Otolaryngology, Nanjing University Medical School, Nanjing 210008, China
| | | | | | | |
Collapse
|
21
|
Wang J, Tymczyszyn N, Yu Z, Yin S, Bance M, Robertson GS. Overexpression of X-linked inhibitor of apoptosis protein protects against noise-induced hearing loss in mice. Gene Ther 2011; 18:560-8. [PMID: 21228883 DOI: 10.1038/gt.2010.172] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Apoptosis is responsible for cochlear cell death induced by noise. Here, we show that transgenic (TG) mice that overexpress X-linked inhibitor of apoptosis protein (XIAP) under control of the ubiquitin promoter display reduced hearing loss and cochlear damage induced by acoustic overstimulation (125 dB sound pressure level, 6 h) compared with wild-type (WT) littermates. Hearing status was evaluated using the auditory brainstem response (ABR), whereas cochlear damage was assessed by counts of surviving hair cells (HCs) and spiral ganglion neurons (SGNs) as well as their fibers to HCs. Significantly smaller threshold shifts were found for TG mice than WT littermates. Correspondingly, the TG mice also showed a reduced loss of HCs, SGNs and their fibers to HCs. HC loss was limited to the basal end of the cochlea that detects high frequency sound. In contrast, the ABRs demonstrated a loss of hearing sensitivity across the entire frequency range tested (2-32 kHz) indicating that the hearing loss could not be fully attributed to HC loss alone. The TG mice displayed superior hearing sensitivity over this whole range, suggesting that XIAP overexpression reduces noise-induced hearing loss not only by protecting HCs but also other components of the cochlea.
Collapse
Affiliation(s)
- J Wang
- School of Human Communication Disorder, Dalhousie University, Halifax, Nova Scotia, Canada.
| | | | | | | | | | | |
Collapse
|
22
|
Kopke RD. Pharmacological approaches to the prevention and treatment of cochlear injury due to noise. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/16513860601181046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
23
|
|
24
|
Swan EEL, Mescher MJ, Sewell WF, Tao SL, Borenstein JT. Inner ear drug delivery for auditory applications. Adv Drug Deliv Rev 2008; 60:1583-99. [PMID: 18848590 PMCID: PMC2657604 DOI: 10.1016/j.addr.2008.08.001] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 08/21/2008] [Indexed: 02/07/2023]
Abstract
Many inner ear disorders cannot be adequately treated by systemic drug delivery. A blood-cochlear barrier exists, similar physiologically to the blood-brain barrier, which limits the concentration and size of molecules able to leave the circulation and gain access to the cells of the inner ear. However, research in novel therapeutics and delivery systems has led to significant progress in the development of local methods of drug delivery to the inner ear. Intratympanic approaches, which deliver therapeutics to the middle ear, rely on permeation through tissue for access to the structures of the inner ear, whereas intracochlear methods are able to directly insert drugs into the inner ear. Innovative drug delivery systems to treat various inner ear ailments such as ototoxicity, sudden sensorineural hearing loss, autoimmune inner ear disease, and for preserving neurons and regenerating sensory cells are being explored.
Collapse
Affiliation(s)
- Erin E Leary Swan
- Charles Stark Draper Laboratory, 555 Technology Square, Cambridge, MA 02139, USA.
| | | | | | | | | |
Collapse
|
25
|
Hu BH, Zheng GL. Membrane disruption: an early event of hair cell apoptosis induced by exposure to intense noise. Brain Res 2008; 1239:107-18. [PMID: 18778691 DOI: 10.1016/j.brainres.2008.08.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 08/12/2008] [Accepted: 08/12/2008] [Indexed: 10/21/2022]
Abstract
Membrane leakage has been found in hair cells undergoing apoptosis following exposure to intense noise. However, it is not known whether this membrane damage is the consequence of apoptotic degeneration or direct mechanical stress. The current study was designed to investigate whether membrane damage occurred before the onset of apoptosis and to determine the level of the membrane damage. Chinchillas were exposed to an impulse noise at 155 dB peak SPL. The noise-induced membrane damage was assessed functionally, using membrane tracers with graded molecular sizes (propidium iodide and FITC-dextrans with molecular sizes of 3, 40, 500, and 2000 kDa), and morphologically, using DiO staining and semithin sections. The study revealed two major findings. First, exposure to intense noise caused a rapid increase in membrane permeability, and the onset of membrane leakage preceded the manifestation of nuclear condensation. This indicates that the early membrane damage observed in apoptosis is the direct consequence of mechanical stress. Second, the level of membrane damage was severe, allowing the entry of 3 kDa and 40 kDa FITC-dextrans, but the membrane was not completely broken down, as evidenced by the preservation of the ability to exclude 500 kDa and 2000 kDa FITC-dextran molecules and the maintenance of the cell boundary. Notably, despite the membrane damage, hair cells continue to undergo the apoptotic process, leading to the generation of a type of apoptosis with early membrane damage.
Collapse
Affiliation(s)
- Bo Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
| | | |
Collapse
|
26
|
Qi W, Ding D, Salvi RJ. Cytotoxic effects of dimethyl sulphoxide (DMSO) on cochlear organotypic cultures. Hear Res 2007; 236:52-60. [PMID: 18207679 DOI: 10.1016/j.heares.2007.12.002] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 11/03/2007] [Accepted: 12/06/2007] [Indexed: 10/22/2022]
Abstract
The amphipathic molecule dimethyl sulphoxide (DMSO) is a solvent often used to dissolve compounds applied to the inner ear; however, little is known about its potential cytotoxic side effects. To address this question, we applied 0.1-6% DMSO for 24h to cochlear organotypic cultures from postnatal day 3 rats and examined its cytotoxic effects. DMSO concentrations of 0.1% and 0.25% caused little or no damage. However, concentrations between 0.5% and 6% resulted in stereocilia damage, hair cell swelling and a dose-dependent loss of hair cells. Hair cell damage began in the basal turn of the cochlea and spread towards the apex with increasing concentration. Surprisingly, DMSO-induced damage was greater for inner hair cells than outer hair cell whereas nearby supporting cells were largely unaffected. Most hair cell death was associated with nuclear shrinkage and fragmentation, morphological features consistent with apoptosis. DMSO treatment induced TUNEL-positive staining in many hair cells and activated both initiator caspase-9 and caspase-8 and executioner caspase-3; this suggests that apoptosis is initiated by both intrinsic mitochondrial and extrinsic membrane cell death signaling pathways.
Collapse
Affiliation(s)
- Weidong Qi
- Center for Hearing and Deafness, State University of New York at Buffalo, 137Cary Hall, Buffalo, NY 14214, USA
| | | | | |
Collapse
|
27
|
Hu BH, Henderson D, Yang WP. The impact of mitochondrial energetic dysfunction on apoptosis in outer hair cells of the cochlea following exposure to intense noise. Hear Res 2007; 236:11-21. [PMID: 18082984 DOI: 10.1016/j.heares.2007.11.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 10/11/2007] [Accepted: 11/08/2007] [Indexed: 01/11/2023]
Abstract
Previous studies have shown that exposure to intense noise causes outer hair cells (OHCs) to die, primarily through the process of apoptotic degeneration. The current study was designed to examine the regulatory role of mitochondrial bioenergetic function in controlling the initiation and execution of the apoptotic process of OHCs. Chinchilla cochleae were treated with 3-nitropropionic acid (3-NP, 20 or 50mM), an irreversible inhibitor of succinate dehydrogenase (SDH), to inhibit the mitochondrial energy production before and after exposure to 75 pairs of impulses at 155dB pSPL. Comparison of the noise-exposed cochleae treated with and without 3-NP revealed that the inhibition of SDH activity delayed nuclear degradation in apoptotic OHCs. However, the initiation of apoptosis appeared to be undeterred. There was no major shift of cell death pathways from apoptosis to necrosis, although a small portion of OHCs showed signs of secondary necrosis. Collectively, the results of the study suggest that, while the mitochondrial energetic function plays an important role in regulating the apoptotic process, its dysfunction has a limited influence on the suppression of apoptotic induction in OHCs following exposure to intense noise.
Collapse
Affiliation(s)
- Bo Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo NY 14214, USA.
| | | | | |
Collapse
|
28
|
Hu BH. Delayed mitochondrial dysfunction in apoptotic hair cells in chinchilla cochleae following exposure to impulse noise. Apoptosis 2007; 12:1025-36. [PMID: 17268771 DOI: 10.1007/s10495-006-0027-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Apoptotic death of hair cells (HCs) in the cochlea has been found following exposure to intense noise. The current study was designed to examine the mitochondrial energetic function of HCs during the course of noise-induced apoptosis. Two aspects of the mitochondrial energetic function, succinate dehydrogenase (SDH) activity and mitochondrial membrane potential (MMP), were examined in HCs of chinchilla cochleae following exposure to a series of 75 pairs of impulse noises at 155 dB pSPL. The results showed that nuclear condensation and uptake of propidium iodide or trypan blue appeared at 10 min after the noise exposure, indicating a rapid progression of HC apoptosis. However, SDH activity was preserved at this time point. As the time elapsed (1 hr or 24 hrs) after the noise exposure, all newly-generated apoptotic HCs showed strong SDH activity, indicating the preservation of SDH activity during the course of apoptosis. Examination of MMP with rhodamine 123 staining revealed that MMP was sustained in the apoptotic HCs having mild nuclear condensation, even after the occurrence of cell membrane leakage. MMP was reduced with further progression of nuclear condensation. These results suggest the presence of a delayed mitochondrial dysfunction in apoptotic HCs following exposure to intense noise.
Collapse
Affiliation(s)
- Bo Hua Hu
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
| |
Collapse
|
29
|
Le Prell CG, Hughes LF, Miller JM. Free radical scavengers vitamins A, C, and E plus magnesium reduce noise trauma. Free Radic Biol Med 2007; 42:1454-63. [PMID: 17395018 PMCID: PMC1950331 DOI: 10.1016/j.freeradbiomed.2007.02.008] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Revised: 01/05/2007] [Accepted: 02/06/2007] [Indexed: 12/20/2022]
Abstract
Free radical formation in the cochlea plays a key role in the development of noise-induced hearing loss (NIHL). The amount, distribution, and time course of free radical formation have been defined, including a clinically significant formation of both reactive oxygen species and reactive nitrogen species 7-10 days after noise exposure. Reduction in cochlear blood flow as a result of free radical formation has also been described. Here we report that the antioxidant agents vitamins A, C, and E act in synergy with magnesium to effectively prevent noise-induced trauma. Neither the antioxidant agents nor the magnesium reliably reduced NIHL or sensory cell death with the doses we used when these agents were delivered alone. In combination, however, they were highly effective in reducing both hearing loss and cell death even with treatment initiated just 1 h before noise exposure. This study supports roles for both free radical formation and noise-induced vasoconstriction in the onset and progression of NIHL. Identification of this safe and effective antioxidant intervention that attenuates NIHL provides a compelling rationale for human trials in which free radical scavengers are used to eliminate this single major cause of acquired hearing loss.
Collapse
Affiliation(s)
- Colleen G Le Prell
- Kresge Hearing Research Institute, University of Michigan, 1301 East Ann Street, Ann Arbor, MI 48109-0506, USA.
| | | | | |
Collapse
|
30
|
Coleman JKM, Littlesunday C, Jackson R, Meyer T. AM-111 protects against permanent hearing loss from impulse noise trauma. Hear Res 2007; 226:70-8. [PMID: 16839720 DOI: 10.1016/j.heares.2006.05.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 05/04/2006] [Accepted: 05/18/2006] [Indexed: 11/24/2022]
Abstract
The otoprotective peptide AM-111, a cell-permeable inhibitor of JNK mediated apoptosis, was tested for its efficacy as a rescue agent following impulse noise trauma. Single dose administrations of AM-111 at 1h or 4h post-impulse noise exposure (155 dB peak SPL) via systemic or local routes were evaluated with a total of 48 chinchillas. The animals received the compound either by IP injection or locally onto the round window membrane (hyaluronic acid gel formulation or osmotic mini-pump). Efficacy was determined by auditory brainstem responses (ABR) as well as cytocochleograms. Three weeks after impulse noise exposure, permanent threshold shifts (PTS) were significantly lower for AM-111 treated ears compared to controls, regardless of the drug administration route and the time point of drug delivery. Even the treatments which started 4h post-noise exposure, reduced hearing loss in the 2-8 kHz range compared to controls by up to 16-25 dB to a PTS as low as 6-17 dB, demonstrating significant protection against permanent hearing loss from impulse noise trauma. These findings suggest a key role for JNK mediated cochlear sensory cell death from oxidative stress.
Collapse
MESH Headings
- Animals
- Apoptosis/drug effects
- Chinchilla
- Enzyme Inhibitors/administration & dosage
- Enzyme Inhibitors/pharmacology
- Evoked Potentials, Auditory, Brain Stem/drug effects
- Female
- Gels
- Hair Cells, Auditory/drug effects
- Hair Cells, Auditory/pathology
- Hearing Loss, Noise-Induced/enzymology
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Hearing Loss, Noise-Induced/prevention & control
- Infusion Pumps, Implantable
- Injections, Intraperitoneal
- JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors
- Peptides/administration & dosage
- Peptides/pharmacology
Collapse
Affiliation(s)
- John K M Coleman
- Naval Medical Center Spatial Orientation Center, 34800 Bob Wilson Dr. Suite 200, Naval Medical Center San Diego, San Diego, CA 92134-5000, USA
| | | | | | | |
Collapse
|
31
|
Coling DE, Ding D, Young R, Lis M, Stofko E, Blumenthal KM, Salvi RJ. Proteomic analysis of cisplatin-induced cochlear damage: Methods and early changes in protein expression. Hear Res 2007; 226:140-56. [PMID: 17321087 DOI: 10.1016/j.heares.2006.12.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Revised: 12/06/2006] [Accepted: 12/23/2006] [Indexed: 11/30/2022]
Abstract
To identify early changes in protein expression associated with cisplatin ototoxicity, we used two dimensional-difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption-time-of-flight (MALDI-TOF) mass spectrometry to analyze proteins from P3 rat cochleae that were cultured for 3h with or without 1mM cisplatin. Replicate analysis of fluorescent images from six gels revealed significant (p<0.01) cisplatin-induced changes (greater than 1.5-fold) in expression of 22 cochlear proteins. These include increases in the expression of five proteins, four of which were identified as nucleobindin 1, a nuclear calcium signaling and homeostasis protein (2.1-fold), heterogeneous nuclear ribonucleoprotein C, an RNA processing protein (1.8-fold), a 55 kDa protein that is either endothelial differentiation-related factor 1 or alpha-6 tubulin (1.7-fold), and calreticulin, a calcium binding chaperone of the endoplasmic reticulum (ER, 1.6-fold). The expression of 17 proteins was significantly (p<0.01) decreased by greater than 1.5-fold. These include ribonuclease/angiogenin inhibitor 1 (1.6-fold), RAS-like, family 12 (predicted), ras association (RalGDS/AF-6) domain family 5 (4.5-fold), homologous the RAS family of GTPase signaling proteins (2.4-fold), and Protein tyrosine phosphatase domain containing 1 (predicted, 6.1-fold). We identified seven cochlear proteins with either smaller (1.2-1.5-fold) or less significant (p<0.05) cisplatin-induced changes in expression. Notably, heat shock 70 kDa protein 5 (Hspa5, Grp78, and BiP), an ER chaperone protein involved in stress response, decreased 1.7-fold. We observed changes consistent with phosphorylation in the level of isoforms of another ER stress-induced protein, glucose-regulated protein Grp58. Changes in cisplatin-induced protein expression are discussed with respect to known or hypothesized functions of the identified proteins.
Collapse
Affiliation(s)
- Donald E Coling
- Center for Hearing and Deafness, 137 Cary Hall, University at Buffalo, Buffalo, NY 14214, USA.
| | | | | | | | | | | | | |
Collapse
|
32
|
Le Prell CG, Yamashita D, Minami SB, Yamasoba T, Miller JM. Mechanisms of noise-induced hearing loss indicate multiple methods of prevention. Hear Res 2007; 226:22-43. [PMID: 17141991 PMCID: PMC1995566 DOI: 10.1016/j.heares.2006.10.006] [Citation(s) in RCA: 230] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2006] [Revised: 10/05/2006] [Accepted: 10/24/2006] [Indexed: 12/20/2022]
Abstract
Recent research has shown the essential role of reduced blood flow and free radical formation in the cochlea in noise-induced hearing loss (NIHL). The amount, distribution, and time course of free radical formation have been defined, including a clinically significant late formation 7-10 days following noise exposure, and one mechanism underlying noise-induced reduction in cochlear blood flow has finally been identified. These new insights have led to the formulation of new hypotheses regarding the molecular mechanisms of NIHL; and, from these, we have identified interventions that prevent NIHL, even with treatment onset delayed up to 3 days post-noise. It is essential to now assess the additive effects of agents intervening at different points in the cell death pathway to optimize treatment efficacy. Finding safe and effective interventions that attenuate NIHL will provide a compelling scientific rationale to justify human trials to eliminate this single major cause of acquired hearing loss.
Collapse
Affiliation(s)
- Colleen G Le Prell
- Kresge Hearing Research Institute, University of Michigan, 1301 East Ann Street, Ann Arbor, MI 48109-0506, USA.
| | | | | | | | | |
Collapse
|
33
|
Bielefeld EC, Henderson D. Influence of sympathetic fibers on noise-induced hearing loss in the chinchilla. Hear Res 2007; 223:11-9. [PMID: 17092669 DOI: 10.1016/j.heares.2006.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Revised: 09/25/2006] [Accepted: 09/26/2006] [Indexed: 11/16/2022]
Abstract
The influence of the sympathetic efferent fibers on cochlear susceptibility to noise-induced hearing loss is still an open question. In the current study, we explore the effects of unilateral and bilateral Superior Cervical Ganglion (SCG) ablation in the chinchilla on hearing loss from noise exposure, as measured with inferior colliculus (IC) evoked potentials, distortion product otoacoustic emissions (DPOAE), and outer hair cell (OHC) loss. The SCG was isolated at the level of the bifurcation of the carotid artery and removed unilaterally in 15 chinchillas. Another eight chinchillas underwent bilateral ablation. Twelve animals were employed as sham controls. Noise exposure was a 4kHz octave band noise for 1h at 110dB SPL. Results showed improved recovery of DPOAE amplitudes after noise exposure in ears that underwent SCGectomy, as well as lower evoked potential threshold shifts relative to sham controls. Effects of SCGectomy on OHC loss were small. Results of the study suggest that sympathetic fibers do exert some influence on susceptibility to noise, but the influence may not be a major one.
Collapse
Affiliation(s)
- Eric C Bielefeld
- Center for Hearing and Deafness, Department of Communicative Disorders and Sciences, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, United States.
| | | |
Collapse
|
34
|
Kopke RD, Jackson RL, Coleman JKM, Liu J, Bielefeld EC, Balough BJ. NAC for noise: from the bench top to the clinic. Hear Res 2006; 226:114-25. [PMID: 17184943 DOI: 10.1016/j.heares.2006.10.008] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 10/30/2006] [Accepted: 10/31/2006] [Indexed: 02/07/2023]
Abstract
Noise-induced hearing loss (NIHL) is an important etiology of deafness worldwide. Hearing conservation programs are in place and have reduced the prevalence of NIHL, but this disorder is still far too common. Occupational and recreational pursuits expose people to loud noise and ten million persons in the US have some degree of noise-induced hearing impairment. It is estimated that 50 million in the US and 600 million people worldwide are exposed to noise hazards occupationally. Noise deafness is still an important and frequent cause of battlefield injury in the US military. A mainstay of hearing conservation programs is personal mechanical hearing protection devices which are helpful but have inherent limitations. Research has shown that oxidative stress plays an important role in noise-induced cochlear injury resulting in the discovery that a number of antioxidant and cell death inhibiting compounds can ameliorate deafness associated with acoustic trauma. This article reviews one such compound, N-acetylcysteine (NAC), in terms of its efficacy in reducing hearing loss in a variety of animal models of acute acoustic trauma and hypothesizes what its therapeutic mechanisms of action might be based on the known actions of NAC. Early clinical trials with NAC are mentioned.
Collapse
Affiliation(s)
- Richard D Kopke
- Hough Ear Institute, 3400 N.W. 56th Street, Oklahoma City, OK 73112, USA.
| | | | | | | | | | | |
Collapse
|
35
|
Chung WH, Pak K, Lin B, Webster N, Ryan AF. A PI3K pathway mediates hair cell survival and opposes gentamicin toxicity in neonatal rat organ of Corti. J Assoc Res Otolaryngol 2006; 7:373-82. [PMID: 17053865 PMCID: PMC2504631 DOI: 10.1007/s10162-006-0050-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Accepted: 07/27/2006] [Indexed: 01/13/2023] Open
Abstract
Gentamicin is well known to promote hair cell death in inner ear, but it also appears to activate opposing pathways that promote hair cell survival. In combination with others, our previous work has indicated that a K-Ras/Rac/JNK pathway is important for hair cell death and an H-Ras/Raf/MEK/Erk pathway is involved in promoting hair cell survival (Battaglia et al., Neuroscience 122(4):1025-1035, 2003). However, these data also suggested that a Ras-independent survival pathway for activation of MEK might be stimulated by gentamicin. To investigate alternatives to the Ras/Raf/MEK/Erk pathway in promoting hair cell survival, cochlear explants were exposed to gentamicin combined with several inhibitors of alternative pathways (LY294002, calphostin C, SH-6, U73122). When exposed to gentamicin with the PI3K inhibitor LY294002 (10, 50 microM), the protein kinase C (PKC) inhibitor calphostin C (50, 100 nM) or the PKB/Akt inhibitor SH-6 (5, 10 microM), hair cell damage was significantly increased compared to gentamicin alone. By Western blotting, strong PKB/Akt activation was observed in the organ of Corti following exposure to 50 microM gentamicin for 6 h. In addition, PKC activation by 12-O-tetradecanoylphorbol-13-acetate protected outer hair cells from gentamicin induced cell death. In contrast, the phospholipase C-gamma (PLCgamma) inhibitor U73122 (2, 5 microM) did not affect hair cell damage when combined with gentamicin. Also, phosphorylation of PLCgamma was not increased in the organ of Corti following gentamicin treatment, as evaluated by Western blot. The results indicate that PI3K promotes hair cell survival via its downstream targets, PKC and PKB/Akt. This suggests that both Ras-dependent and Ras-independent survival pathways are involved during gentamicin exposure. In contrast, PLCgamma activation of PKC does not appear to play a role.
Collapse
Affiliation(s)
- Won-Ho Chung
- Department of Surgery Otolaryngology, UCSD School of Medicine and VA Medical Center, 9500 Gilman Drive #0666, La Jolla, CA USA
- Department of Otolaryngology and Head & Neck Surgery, Samsung Medical Center Sungkyunkwan University School of Medicine, 50 Ilwon Dong Kangnam Ku, Seoul, 135-710 South Korea
| | - Kwang Pak
- Department of Surgery Otolaryngology, UCSD School of Medicine and VA Medical Center, 9500 Gilman Drive #0666, La Jolla, CA USA
| | - Bo Lin
- Department of Medicine, UCSD School of Medicine and VA Medical Center, 9500 Gilman Drive, La Jolla, CA 92093-0666 USA
| | - Nicholas Webster
- Department of Medicine, UCSD School of Medicine and VA Medical Center, 9500 Gilman Drive, La Jolla, CA 92093-0666 USA
| | - Allen F. Ryan
- Department of Surgery Otolaryngology, UCSD School of Medicine and VA Medical Center, 9500 Gilman Drive #0666, La Jolla, CA USA
- Department of Neurosciences, UCSD School of Medicine and VA Medical Center, 9500 Gilman Drive #0666, La Jolla, USA
| |
Collapse
|
36
|
Kirkegaard M, Murai N, Risling M, Suneson A, Järlebark L, Ulfendahl M. Differential gene expression in the rat cochlea after exposure to impulse noise. Neuroscience 2006; 142:425-35. [PMID: 16887274 DOI: 10.1016/j.neuroscience.2006.06.037] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 06/21/2006] [Accepted: 06/22/2006] [Indexed: 12/20/2022]
Abstract
Understanding the molecular biology of noise trauma is vital to developing effective and timely interventions. In a model of explosion-mediated impulse noise injury, differential gene expression was studied in whole rat cochlea preparations at 3 and 24 h following the exposure. We developed a technique using mRNA from a single cochlea on each oligonucleotide microarray to avoid pooling of mRNA samples. Application of a conservative statistical analysis approach resulted in the identification of 61 differentially expressed genes. Within 3 h after the exposure, there was an up-regulation of immediate early genes, mainly transcription factors and genes involved in the tissue's response to oxidative stress. No genes were found to be significantly down-regulated. At 24 h following the exposure, up-regulated genes included members of inflammatory and antioxidant pathways and one gene involved in glutathione metabolism was down-regulated. A subset of genes was confirmed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The present study demonstrates the power of the microarray technique in providing a global view of the gene regulation following noise exposure, and in identifying genes that may be mechanistically important in hearing loss, and thereby serve as a basis for the development of therapeutic interventions.
Collapse
Affiliation(s)
- M Kirkegaard
- Center for Hearing and Communication Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | | | | | | | | | | |
Collapse
|
37
|
Abstract
Modern research has provided new insights into the biological mechanisms of noise-induced hearing loss, and with these new insights comes hope for possible prevention or treatment. Underlying the classic set of cochlear pathologies that occur as a result of noise exposure are increased levels of reactive oxygen species (ROS) that play a significant role in noise-induced hair cell death. Both necrotic and apoptotic cell death have been identified in the cochlea. Included in the current review is a brief review of ROS, along with a description of sources of cochlear ROS generation and how ROS can damage cochlear tissue. The pathways of necrotic and apoptotic cell death are also reviewed. Interventions are discussed that target the prevention of noise-induced hair cell death: the use of antioxidants to scavenge and eliminate the damaging ROS, pharmacological interventions to limit the damage resulting from ROS, and new techniques aimed at interrupting the apoptotic biochemical cascade that results in the death of irreplaceable hair cells.
Collapse
Affiliation(s)
- Donald Henderson
- Center for Hearing and Deafness, Department of Communicative Disorders and Sciences, State University of New York at Buffalo, Buffalo, New York 14214, USA.
| | | | | | | |
Collapse
|