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Pisani A, Paciello F, Montuoro R, Rolesi R, Galli J, Fetoni AR. Antioxidant Therapy as an Effective Strategy against Noise-Induced Hearing Loss: From Experimental Models to Clinic. Life (Basel) 2023; 13:life13041035. [PMID: 37109564 PMCID: PMC10144536 DOI: 10.3390/life13041035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Cochlear redox unbalance is the main mechanism of damage involved in the pathogenesis of noise-induced-hearing loss. Indeed, the increased free radical production, in conjunction with a reduced efficacy of the endogenous antioxidant system, plays a key role in cochlear damage induced by noise exposure. For this reason, several studies focused on the possibility to use exogenous antioxidant to prevent or attenuate noise-induce injury. Thus, several antioxidant molecules, alone or in combination with other compounds, have been tested in both experimental and clinical settings. In our findings, we tested the protective effects of several antioxidant enzymes, spanning from organic compounds to natural compounds, such as nutraceuticals of polyphenols. In this review, we summarize and discuss the strengths and weaknesses of antioxidant supplementation focusing on polyphenols, Q-Ter, the soluble form of CoQ10, Vitamin E and N-acetil-cysteine, which showed great otoprotective effects in different animal models of noise induced hearing loss and which has been proposed in clinical trials.
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Affiliation(s)
- Anna Pisani
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Raffaele Montuoro
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Rolando Rolesi
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Jacopo Galli
- Department of Otolaryngology Head and Neck Surgery, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Anna Rita Fetoni
- Department of Neuroscience, Reproductive Sciences and Dentistry-Audiology Section, University of Naples Federico II, 80131 Naples, Italy
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Paciello F, Ripoli C, Fetoni AR, Grassi C. Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline. Antioxidants (Basel) 2023; 12:antiox12020332. [PMID: 36829891 PMCID: PMC9952092 DOI: 10.3390/antiox12020332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
Abstract
Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.
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Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
- Correspondence: ; Tel.: +39-0630154966
| | - Anna Rita Fetoni
- Unit of Audiology, Department of Neuroscience, Università degli Studi di Napoli Federico II, 80138 Naples, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
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3
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Ertugrul S, Soylemez E, Gurel T. Effectiveness of hearing protection apparatus in preventing noise induced vestibular loss. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2022; 32:2708-2717. [PMID: 34629003 DOI: 10.1080/09603123.2021.1987395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
Hearing protection apparatus (HPAs) are frequently used to prevent the detrimental effect of noise on the hearing system. However, it is not known exactly whether wearing HPAs in workers protects the vestibular system. This study aims to investigate the effectiveness of wearing HPAs in preventing vestibular loss caused by noise. Eighty-one workers exposed to chronic noise were divided into three groups according to their HPAs wearing status. Pure-tone audiometry test was used to evaluate the hearing. Caloric test and visual analogue scale were used to evaluate their vestibular systems. The pure-tone average of the workers who constantly wore HPAs was better than that of the other groups (p< 0.05). There was no difference between the groups in the vestibular tests (p > 0.05). This study demonstrated that HPAs do not protect the vestibular system but protect the hearing system in the inner ear from the harmful effects of noise.
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Affiliation(s)
- Süha Ertugrul
- Department of Otorhinolaryngology, Faculty of Medicine, Karabuk University, Karabuk, Turkey
| | - Emre Soylemez
- Department of Audiology, Karabuk University, Vocational School of Health Services, Karabuk, Turkey
| | - Tuğçe Gurel
- Gaziosmanpaşa Training and Research Hospital, İstanbul, Turkey
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4
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Protective Effects of Curcumin and N-Acetyl Cysteine Against Noise-Induced Sensorineural Hearing Loss: An Experimental Study. Indian J Otolaryngol Head Neck Surg 2022; 74:467-471. [PMID: 36032833 PMCID: PMC9411444 DOI: 10.1007/s12070-020-02269-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/03/2020] [Indexed: 11/26/2022] Open
Abstract
We investigated the effectiveness of N-acetyl cysteine (NAC) and curcumin, which have known antioxidant and anti-inflammatory effects, in reducing acoustic trauma. We randomly divided 40 adult male rats into four groups: a control group (group 1), a curcumin group (group 2), a NAC group (group 3), and an ethyl alcohol group (group 4). The rats were exposed to 110 dB sound at a frequency of 4 kHz for 2 h to simulate acoustic trauma. Group 1, group 2, group 3, and group 4 received 1 ml saline, 200 mg/kg curcumin, 350 mg/kg NAC, or 1 ml ethyl alcohol, respectively, intraperitoneally 30 min before and 24 and 48 h after acoustic trauma. Distortion product otoacoustic emissions (DPOAEs) were recorded before and after the acoustic trauma, and 72 h after drug administration. In group 2, signal-to-noise ratio (SNR) values in frequencies of 1000 Hz, 1500 Hz, and 4000 Hz decreased in the second measurements when compared to the first, and showed improvements in the third measurements in comparison to the second ones. In group 3, SNR values decreased in the second measurements, but only the values at 6000 Hz were found to be statistically significant (p = 0.007). The values in the third measurements were statistically significant when compared to the second ones. There was a statistically significant difference in the third measurements in both groups 2 and 3, possibly due to curcumin and NAC treatment. This study showed that curcumin and NAC may be effective against noise-induced hearing loss.
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5
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Reid MB. Redox Implications of Extreme Task Performance: The Case in Driver Athletes. Cells 2022; 11:cells11050899. [PMID: 35269521 PMCID: PMC8909750 DOI: 10.3390/cells11050899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/26/2022] [Accepted: 03/03/2022] [Indexed: 02/04/2023] Open
Abstract
Redox homeostasis and redox-mediated signaling mechanisms are fundamental elements of human biology. Physiological levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) modulate a range of functional processes at the cellular, tissue, and systemic levels in healthy humans. Conversely, excess ROS or RNS activity can disrupt function, impairing the performance of daily activities. This article analyzes the impact of redox mechanisms on extreme task performance. Such activities (a) require complex motor skills, (b) are physically demanding, (c) are performed in an extreme environment, (d) require high-level executive function, and (e) pose an imminent risk of injury or death. The current analysis utilizes race car driving as a representative example. The physiological challenges of this extreme task include physical exertion, g loading, vibration, heat exposure, dehydration, noise, mental demands, and emotional factors. Each of these challenges stimulates ROS signaling, RNS signaling, or both, alters redox homeostasis, and exerts pro-oxidant effects at either the tissue or systemic levels. These redox mechanisms appear to promote physiological stress during race car driving and impair the performance of driver athletes.
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Affiliation(s)
- Michael B Reid
- College of Health and Human Performance, University of Florida, Gainesville, FL 32611, USA
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Kaliyappan K, Nakuci J, Preda M, Schweser F, Muldoon S, Krishnan Muthaiah VP. Correlation of Histomorphometric Changes with Diffusion Tensor Imaging for Evaluation of Blast-Induced Auditory Neurodegeneration in Chinchilla. J Neurotrauma 2021; 38:3248-3259. [PMID: 34605670 DOI: 10.1089/neu.2020.7556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In the present study, we have evaluated the blast-induced auditory neurodegeneration in chinchilla by correlating the histomorphometric changes with diffusion tensor imaging. The chinchillas were exposed to single unilateral blast-overpressure (BOP) at ∼172dB peak sound pressure level (SPL) and the pathological changes were compared at 1 week and 1 month after BOP. The functional integrity of the auditory system was assessed by auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE). The axonal integrity was assessed using diffusion tensor imaging at regions of interests (ROIs) of the central auditory neuraxis (CAN) including the cochlear nucleus (CN), inferior colliculus (IC), and auditory cortex (AC). Post-BOP, cyto-architecture metrics such as viable cells, degenerating neurons, and apoptotic cells were quantified at the CAN ROIs using light microscopic studies using cresyl fast violet, hematoxylin and eosin, and modified Crossmon's trichrome stains. We observed mean ABR threshold shifts of 30- and 10-dB SPL at 1 week and 1 month after BOP, respectively. A similar pattern was observed in DPAOE amplitudes shift. In the CAN ROIs, diffusion tensor imaging studies showed a decreased axial diffusivity in CN 1 month after BOP and a decreased mean diffusivity and radial diffusivity at 1 week after BOP. However, morphometric measures such as decreased viable cells and increased degenerating neurons and apoptotic cells were observed at CN, IC, and AC. Specifically, increased degenerating neurons and reduced viable cells were high on the ipsilateral side when compared with the contralateral side. These results indicate that a single blast significantly damages structural and functional integrity at all levels of CAN ROIs.
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Affiliation(s)
- Kathiravan Kaliyappan
- Department of Rehabilitation Sciences, School of Public Health and Health Professions, College of Arts and Sciences, University at Buffalo, Buffalo, New York, USA
| | - Johan Nakuci
- Neuroscience Program, College of Arts and Sciences, University at Buffalo, Buffalo, New York, USA
| | - Marilena Preda
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, College of Arts and Sciences, University at Buffalo, Buffalo, New York, USA.,Center for Biomedical Imaging, Clinical and Translational Science Institute, College of Arts and Sciences, University at Buffalo, Buffalo, New York, USA
| | - Ferdinand Schweser
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, College of Arts and Sciences, University at Buffalo, Buffalo, New York, USA.,Center for Biomedical Imaging, Clinical and Translational Science Institute, College of Arts and Sciences, University at Buffalo, Buffalo, New York, USA
| | - Sarah Muldoon
- Department of Mathematics, College of Arts and Sciences, University at Buffalo, Buffalo, New York, USA
| | - Vijaya Prakash Krishnan Muthaiah
- Department of Rehabilitation Sciences, School of Public Health and Health Professions, College of Arts and Sciences, University at Buffalo, Buffalo, New York, USA
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Varela-Nieto I, Murillo-Cuesta S, Rodríguez-de la Rosa L, Oset-Gasque MJ, Marco-Contelles J. Use of Radical Oxygen Species Scavenger Nitrones to Treat Oxidative Stress-Mediated Hearing Loss: State of the Art and Challenges. Front Cell Neurosci 2021; 15:711269. [PMID: 34539349 PMCID: PMC8440819 DOI: 10.3389/fncel.2021.711269] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/11/2021] [Indexed: 12/20/2022] Open
Abstract
Nitrones are potent antioxidant molecules able to reduce oxidative stress by trapping reactive oxygen and nitrogen species. The antioxidant potential of nitrones has been extensively tested in multiple models of human diseases. Sensorineural hearing loss has a heterogeneous etiology, genetic alterations, aging, toxins or exposure to noise can cause damage to hair cells at the organ of Corti, the hearing receptor. Noxious stimuli share a battery of common mechanisms by which they cause hair cell injury, including oxidative stress, the generation of free radicals and redox imbalance. Therefore, targeting oxidative stress-mediated hearing loss has been the subject of much attention. Here we review the chemistry of nitrones, the existing literature on their use as antioxidants and the general state of the art of antioxidant treatments for hearing loss.
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Affiliation(s)
- Isabel Varela-Nieto
- Institute for Biomedical Research “Alberto Sols,” Spanish National Research Council (CSIC)-Autonomous University of Madrid, Madrid, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain
- Hospital La Paz Institute for Health Research, Madrid, Spain
| | - Silvia Murillo-Cuesta
- Institute for Biomedical Research “Alberto Sols,” Spanish National Research Council (CSIC)-Autonomous University of Madrid, Madrid, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain
- Hospital La Paz Institute for Health Research, Madrid, Spain
| | - Lourdes Rodríguez-de la Rosa
- Institute for Biomedical Research “Alberto Sols,” Spanish National Research Council (CSIC)-Autonomous University of Madrid, Madrid, Spain
- Biomedical Research Networking Center on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain
- Hospital La Paz Institute for Health Research, Madrid, Spain
| | - María Jesús Oset-Gasque
- Department of Biochemistry and Molecular Biology, School of Pharmacy, Complutense University of Madrid, Madrid, Spain
- Institute of Neurochemistry Research, Complutense University of Madrid, Madrid, Spain
| | - José Marco-Contelles
- Laboratory of Medicinal Chemistry, Institute of General Organic Chemistry, CSIC, Madrid, Spain
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8
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Sekulic-Jablanovic M, Voronkova K, Bodmer D, Petkovic V. Combination of antioxidants and NFAT (nuclear factor of activated T cells) inhibitor protects auditory hair cells from ototoxic insult. J Neurochem 2019; 154:519-529. [PMID: 31755556 DOI: 10.1111/jnc.14921] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 02/06/2023]
Abstract
Hair cell (HC) degeneration causes hearing loss in millions of people worldwide. Aminoglycoside exposure is one major cause of sensory HC damage. Aminoglycosides generate free radicals within the inner ear, permanently damaging sensory cells, and thus causing hearing loss. Hearing protection requires strategies to overcome the apparently irreversible loss of HCs in mammals. The nuclear factor of activated T cells (NFAT) inhibitor 11R-VIVIT reportedly protects HCs from gentamicin toxicity. Here we investigated whether the combination of 11R-VIVIT with the antioxidant L-carnitine or N-acetylcysteine could protect mouse cochlear HCs from gentamicin damage. Compared to single-component treatment, combined treatment with 11R-VIVIT plus L-carnitine yielded significant protection from gentamicin, and 11R-VIVIT plus N-acetylcysteine provided almost complete protection of HCs from gentamicin. Caspase activity in organ of Corti was significantly reduced by combined treatment with 11R-VIVIT + N-acetylcysteine + gentamicin, compared to 11R-VIVIT + gentamicin or gentamicin alone. Analysis of relative gene expression by qPCR revealed down-regulation of the pro-apoptotic genes Fasl and Casp9, and up-regulation of the antioxidant genes Hmox1 and Nrf2 after treatment with 11R-VIVIT + N-acetylcysteine + gentamicin, compared to single-compound treatment or gentamicin alone in cultures. Selective NFAT inhibition by 11R-VIVIT may be a good strategy for preventing gentamicin-induced HC damage. L-carnitine and N-acetylcysteine, with their ROS-reducing properties, contribute to the synergistic effectiveness with 11R-VIVIT by decreasing ROS-induced NFAT translocation. Our data suggest that a combined approach of NFAT inhibition together with an antioxidant, like N-acetylcysteine, could be useful for hearing loss treatment and/or prevention. Cover Image for this issue: https://doi.org/10.1111/jnc.14759.
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Affiliation(s)
| | | | - Daniel Bodmer
- Department of Biomedicine, University of Basel, Basel, Switzerland.,Clinic for Otolaryngology, Head and Neck Surgery, University Hospital Basel, Basel, Switzerland
| | - Vesna Petkovic
- Department of Biomedicine, University of Basel, Basel, Switzerland
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9
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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.
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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
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10
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Fetoni AR, Paciello F, Rolesi R, Paludetti G, Troiani D. Targeting dysregulation of redox homeostasis in noise-induced hearing loss: Oxidative stress and ROS signaling. Free Radic Biol Med 2019; 135:46-59. [PMID: 30802489 DOI: 10.1016/j.freeradbiomed.2019.02.022] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/04/2019] [Accepted: 02/18/2019] [Indexed: 12/20/2022]
Abstract
Hearing loss caused by exposure to recreational and occupational noise remains a worldwide disabling condition and dysregulation of redox homeostasis is the hallmark of cochlear damage induced by noise exposure. In this review we discuss the dual function of ROS to both promote cell damage (oxidative stress) and cell adaptive responses (ROS signaling) in the cochlea undergoing a stressful condition such as noise exposure. We focus on animal models of noise-induced hearing loss (NIHL) and on the function of exogenous antioxidants to maintaining a physiological role of ROS signaling by distinguishing the effect of exogenous "direct" antioxidants (i.e. CoQ10, NAC), that react with ROS to decrease oxidative stress, from the exogenous "indirect" antioxidants (i.e. nutraceutics and phenolic compounds) that can activate cellular redox enzymes through the Keap1-Nrf2-ARE pathway. The anti-inflammatory properties of Nrf2 signaling are discussed in relation to the ROS/inflammation interplay in noise exposure. Unveiling the mechanisms of ROS regulating redox-associated signaling pathways is essential in providing relevant targets for innovative and effective therapeutic strategies against NIHL.
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Affiliation(s)
- Anna Rita Fetoni
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy; CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Fabiola Paciello
- Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy; CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | - Rolando Rolesi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Gaetano Paludetti
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Diana Troiani
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy.
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Fujimoto C, Yamasoba T. Mitochondria-Targeted Antioxidants for Treatment of Hearing Loss: A Systematic Review. Antioxidants (Basel) 2019; 8:antiox8040109. [PMID: 31022870 PMCID: PMC6523236 DOI: 10.3390/antiox8040109] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 01/22/2023] Open
Abstract
Mitochondrial dysfunction is associated with the etiologies of sensorineural hearing loss, such as age-related hearing loss, noise- and ototoxic drug-induced hearing loss, as well as hearing loss due to mitochondrial gene mutation. Mitochondria are the main sources of reactive oxygen species (ROS) and ROS-induced oxidative stress is involved in cochlear damage. Moreover, the release of ROS causes further damage to mitochondrial components. Antioxidants are thought to counteract the deleterious effects of ROS and thus, may be effective for the treatment of oxidative stress-related diseases. The administration of mitochondria-targeted antioxidants is one of the drug delivery systems targeted to mitochondria. Mitochondria-targeted antioxidants are expected to help in the prevention and/or treatment of diseases associated with mitochondrial dysfunction. Of the various mitochondria-targeted antioxidants, the protective effects of MitoQ and SkQR1 against ototoxicity have been previously evaluated in animal models and/or mouse auditory cell lines. MitoQ protects against both gentamicin- and cisplatin-induced ototoxicity. SkQR1 also provides auditory protective effects against gentamicin-induced ototoxicity. On the other hand, decreasing effect of MitoQ on gentamicin-induced cell apoptosis in auditory cell lines has been controversial. No clinical studies have been reported for otoprotection using mitochondrial-targeted antioxidants. High-quality clinical trials are required to reveal the therapeutic effect of mitochondria-targeted antioxidants in terms of otoprotection in patients.
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Affiliation(s)
- Chisato Fujimoto
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
- Department of Otolaryngology, Tokyo Teishin Hospital, 2-14-23, Fujimi, Chiyoda-ku, Tokyo 102-8798, Japan.
| | - Tatsuya Yamasoba
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
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12
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Morioka S, Sakaguchi H, Yamaguchi T, Ninoyu Y, Mohri H, Nakamura T, Hisa Y, Ogita K, Saito N, Ueyama T. Hearing vulnerability after noise exposure in a mouse model of reactive oxygen species overproduction. J Neurochem 2018; 146:459-473. [PMID: 29675997 DOI: 10.1111/jnc.14451] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/09/2018] [Accepted: 04/10/2018] [Indexed: 12/20/2022]
Abstract
Previous studies have convincingly argued that reactive oxygen species (ROS) contribute to the development of several major types of sensorineural hearing loss, such as noise-induced hearing loss (NIHL), drug-induced hearing loss, and age-related hearing loss. However, the underlying molecular mechanisms induced by ROS in these pathologies remain unclear. To resolve this issue, we established an in vivo model of ROS overproduction by generating a transgenic (TG) mouse line expressing the human NADPH oxidase 4 (NOX4, NOX4-TG mice), which is a constitutively active ROS-producing enzyme that does not require stimulation or an activator. Overproduction of ROS was detected at the cochlea of the inner ear in NOX4-TG mice, but they showed normal hearing function under baseline conditions. However, they demonstrated hearing function vulnerability, especially at high-frequency sounds, upon exposure to intense noise, which was accompanied by loss of cochlear outer hair cells (OHCs). The vulnerability to loss of hearing function and OHCs was rescued by treatment with the antioxidant Tempol. Additionally, we found increased protein levels of the heat-shock protein 47 (HSP47) in models using HEK293 cells, including H2 O2 treatment and cells with stable and transient expression of NOX4. Furthermore, the up-regulated levels of Hsp47 were observed in both the cochlea and heart of NOX4-TG mice. Thus, antioxidant therapy is a promising approach for the treatment of NIHL. Hsp47 may be an endogenous antioxidant factor, compensating for the chronic ROS overexposure in vivo, and counteracting ROS-related hearing loss.
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Affiliation(s)
- Shigefumi Morioka
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan.,Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hirofumi Sakaguchi
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Taro Yamaguchi
- Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Yuzuru Ninoyu
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | - Hiroaki Mohri
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | - Takashi Nakamura
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | - Yasuo Hisa
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan.,Faculty of Health and Medical Sciences, Kyoto Gakuen University, Kyoto, Japan
| | - Kiyokazu Ogita
- Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan
| | - Naoaki Saito
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | - Takehiko Ueyama
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
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Ghezzi P, Floridi L, Boraschi D, Cuadrado A, Manda G, Levic S, D'Acquisto F, Hamilton A, Athersuch TJ, Selley L. Oxidative Stress and Inflammation Induced by Environmental and Psychological Stressors: A Biomarker Perspective. Antioxid Redox Signal 2018; 28:852-872. [PMID: 28494612 DOI: 10.1089/ars.2017.7147] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SIGNIFICANCE The environment can elicit biological responses such as oxidative stress (OS) and inflammation as a consequence of chemical, physical, or psychological changes. As population studies are essential for establishing these environment-organism interactions, biomarkers of OS or inflammation are critical in formulating mechanistic hypotheses. Recent Advances: By using examples of stress induced by various mechanisms, we focus on the biomarkers that have been used to assess OS and inflammation in these conditions. We discuss the difference between biomarkers that are the result of a chemical reaction (such as lipid peroxides or oxidized proteins that are a result of the reaction of molecules with reactive oxygen species) and those that represent the biological response to stress, such as the transcription factor NRF2 or inflammation and inflammatory cytokines. CRITICAL ISSUES The high-throughput and holistic approaches to biomarker discovery used extensively in large-scale molecular epidemiological exposome are also discussed in the context of human exposure to environmental stressors. FUTURE DIRECTIONS We propose to consider the role of biomarkers as signs and to distinguish between signs that are just indicators of biological processes and proxies that one can interact with and modify the disease process. Antioxid. Redox Signal. 28, 852-872.
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Affiliation(s)
- Pietro Ghezzi
- 1 Brighton & Sussex Medical School , Brighton, United Kingdom
| | - Luciano Floridi
- 2 Oxford Internet Institute, University of Oxford , Oxford, United Kingdom .,3 Alan Turing Institute , London, United Kingdom
| | - Diana Boraschi
- 4 Institute of Protein Biochemistry , National Research Council, Napoli, Italy
| | - Antonio Cuadrado
- 5 Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Investigación Sanitaria La Paz (IdiPaz), Instituto de Investigaciones Biomédicas Alberto Sols UAM-CSIC , Madrid, Spain .,6 Department of Biochemistry, Faculty of Medicine, Autonomous University of Madrid , Madrid, Spain
| | - Gina Manda
- 7 "Victor Babes" National Institute of Pathology , Bucharest, Romania
| | - Snezana Levic
- 1 Brighton & Sussex Medical School , Brighton, United Kingdom
| | - Fulvio D'Acquisto
- 8 William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London , London, United Kingdom
| | - Alice Hamilton
- 8 William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London , London, United Kingdom
| | - Toby J Athersuch
- 9 Department of Surgery and Cancer, Faculty of Medicine, and MRC-PHE Centre for Environment and Health, School of Public Health, Imperial College London , London, United Kingdom
| | - Liza Selley
- 9 Department of Surgery and Cancer, Faculty of Medicine, and MRC-PHE Centre for Environment and Health, School of Public Health, Imperial College London , London, United Kingdom
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HPN-07, a free radical spin trapping agent, protects against functional, cellular and electrophysiological changes in the cochlea induced by acute acoustic trauma. PLoS One 2017; 12:e0183089. [PMID: 28832600 PMCID: PMC5568441 DOI: 10.1371/journal.pone.0183089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 07/28/2017] [Indexed: 11/29/2022] Open
Abstract
Oxidative stress is considered a major cause of the structural and functional changes associated with auditory pathologies induced by exposure to acute acoustic trauma AAT). In the present study, we examined the otoprotective effects of 2,4-disulfophenyl-N-tert-butylnitrone (HPN-07), a nitrone-based free radical trap, on the physiological and cellular changes in the auditory system of chinchilla following a six-hour exposure to 4 kHz octave band noise at 105 dB SPL. HPN-07 has been shown to suppress oxidative stress in biological models of a variety of disorders. Our results show that administration of HPN-07 beginning four hours after acoustic trauma accelerated and enhanced auditory/cochlear functional recovery, as measured by auditory brainstem responses (ABR), distortion product otoacoustic emissions (DPOAE), compound action potentials (CAP), and cochlear microphonics (CM). The normally tight correlation between the endocochlear potential (EP) and evoked potentials of CAP and CM were persistently disrupted after noise trauma in untreated animals but returned to homeostatic conditions in HPN-07 treated animals. Histological analyses revealed several therapeutic advantages associated with HPN-07 treatment following AAT, including reductions in inner and outer hair cell loss; reductions in AAT-induced loss of calretinin-positive afferent nerve fibers in the spiral lamina; and reductions in fibrocyte loss within the spiral ligament. These findings support the conclusion that early intervention with HPN-07 following an AAT efficiently blocks the propagative ototoxic effects of oxidative stress, thereby preserving the homeostatic and functional integrity of the cochlea.
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Le TN, Straatman LV, Lea J, Westerberg B. Current insights in noise-induced hearing loss: a literature review of the underlying mechanism, pathophysiology, asymmetry, and management options. J Otolaryngol Head Neck Surg 2017; 46:41. [PMID: 28535812 PMCID: PMC5442866 DOI: 10.1186/s40463-017-0219-x] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/15/2017] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Noise-induced hearing loss is one of the most common forms of sensorineural hearing loss, is a major health problem, is largely preventable and is probably more widespread than revealed by conventional pure tone threshold testing. Noise-induced damage to the cochlea is traditionally considered to be associated with symmetrical mild to moderate hearing loss with associated tinnitus; however, there is a significant number of patients with asymmetrical thresholds and, depending on the exposure, severe to profound hearing loss as well. MAIN BODY Recent epidemiology and animal studies have provided further insight into the pathophysiology, clinical findings, social and economic impacts of noise-induced hearing loss. Furthermore, it is recently shown that acoustic trauma is associated with vestibular dysfunction, with associated dizziness that is not always measurable with current techniques. Deliberation of the prevalence, treatment and prevention of noise-induced hearing loss is important and timely. Currently, prevention and protection are the first lines of defence, although promising protective effects are emerging from multiple different pharmaceutical agents, such as steroids, antioxidants and neurotrophins. CONCLUSION This review provides a comprehensive update on the pathophysiology, investigations, prevalence of asymmetry, associated symptoms, and current strategies on the prevention and treatment of noise-induced hearing loss.
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Affiliation(s)
- Trung N. Le
- Division of Otolaryngology - Head & Neck Surgery, Department of Surgery, University of British Columbia, Vancouver, BC Canada
| | - Louise V. Straatman
- Division of Otolaryngology - Head & Neck Surgery, Department of Surgery, University of British Columbia, Vancouver, BC Canada
| | - Jane Lea
- Division of Otolaryngology - Head & Neck Surgery, Department of Surgery, University of British Columbia, Vancouver, BC Canada
| | - Brian Westerberg
- Division of Otolaryngology - Head & Neck Surgery, Department of Surgery, University of British Columbia, Vancouver, BC Canada
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Lasri J, Eltayeb NE, Haukka M, Alghamdi Y. Crystal and molecular structure studies of (Z)-N-methyl-C-4-substituted phenyl nitrones by XRD, DFT, FTIR and NMR methods. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.08.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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Eshraghi AA, Roell J, Shaikh N, Telischi FF, Bauer B, Guardiola M, Bas E, Van De Water T, Rivera I, Mittal J. A novel combination of drug therapy to protect residual hearing post cochlear implant surgery. Acta Otolaryngol 2016; 136:420-4. [PMID: 26854005 DOI: 10.3109/00016489.2015.1134809] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
UNLABELLED Conclusions A cocktail combining NAC, Mannitol, and Dexamethasone may be used to prevent loss of residual hearing post-implantation. There is a window of opportunity to treat the cochlea before the onset of cell death in HCs. Objective Inner ear trauma caused by cochlear implant electrode insertion trauma (EIT) initiates multiple molecular mechanisms in hair cells (HCs) or support cells (SCs), resulting in initiation of programmed cell death within the damaged tissues of the cochlea, which leads to loss of residual hearing. In earlier studies L-N-acetylcysteine (L-NAC), Mannitol, and dexamethasone have been shown independently to protect the HCs loss against different types of inner ear trauma. These three molecules have different otoprotective effects. The goal of this preliminary study is to test the efficacy of a combination of these molecules to enhance the otoprotection of HCs against EIT. Methods OC explants were dissected from P-3 rats and placed in serum-free media. Explants were divided into control and experimental groups. CONTROL GROUP (1) untreated controls; (2) EIT. Experimental group: (1) EIT + L-NAC (5, 2, or 1 mM); (2) EIT + Mannitol (100, 50, or 10 mM); (3) EIT + Dex (20, 10, or 5 μg/mL); (4) EIT + L-NAC + Mannitol + Dex. After EIT was caused in an in-vitro model of CI, explants were cultured in media containing L-NAC alone, Mannitol alone, or Dex alone at decreasing concentrations. Concentrations of L-NAC, Mannitol, and Dex that showed 50% protection of hair cell loss individually were used as a combination in experimental group 4. Results There was an increase of total hair cell (THC) loss in the EIT OC explants when compared with control group HC counts or the tri-therapy cochlea. This study defined the dosage of L-NAC, Mannitol, and Dex for the survival of 50% protection of hair cells in vitro. Their combination provided close to 96% protection, demonstrating an additive effect.
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Affiliation(s)
- Adrien A Eshraghi
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Jonathan Roell
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Noah Shaikh
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Fred F Telischi
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Blake Bauer
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Mateo Guardiola
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Esperanza Bas
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Thomas Van De Water
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Ileana Rivera
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
| | - Jeenu Mittal
- a Department of Otolaryngology , University of Miami Miller School of Medicine , Miami , FL , USA
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Stiles M, Moiseyev GP, Budda ML, Linens A, Brush RS, Qi H, White GL, Wolf RF, Ma JX, Floyd R, Anderson RE, Mandal NA. PBN (Phenyl-N-Tert-Butylnitrone)-Derivatives Are Effective in Slowing the Visual Cycle and Rhodopsin Regeneration and in Protecting the Retina from Light-Induced Damage. PLoS One 2015; 10:e0145305. [PMID: 26694648 PMCID: PMC4687940 DOI: 10.1371/journal.pone.0145305] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 12/02/2015] [Indexed: 11/18/2022] Open
Abstract
A2E and related toxic molecules are part of lipofuscin found in the retinal pigment epithelial (RPE) cells in eyes affected by Stargardt's disease, age-related macular degeneration (AMD), and other retinal degenerations. A novel therapeutic approach for treating such degenerations involves slowing down the visual cycle, which could reduce the amount of A2E in the RPE. This can be accomplished by inhibiting RPE65, which produces 11-cis-retinol from all-trans-retinyl esters. We recently showed that phenyl-N-tert-butylnitrone (PBN) inhibits RPE65 enzyme activity in RPE cells. In this study we show that like PBN, certain PBN-derivatives (PBNDs) such as 4-F-PBN, 4-CF3-PBN, 3,4-di-F-PBN, and 4-CH3-PBN can inhibit RPE65 and synthesis of 11-cis-retinol in in vitro assays using bovine RPE microsomes. We further demonstrate that systemic (intraperitoneal, IP) administration of these PBNDs protect the rat retina from light damage. Electroretinography (ERG) and histological analysis showed that rats treated with PBNDs retained ~90% of their photoreceptor cells compared to a complete loss of function and 90% loss of photoreceptors in the central retina in rats treated with vehicle/control injections. Topically applied PBN and PBNDs also significantly slowed the rate of the visual cycle in mouse and baboon eyes. One hour dark adaptation resulted in 75-80% recovery of bleachable rhodopsin in control/vehicle treated mice. Eye drops of 5% 4-CH3-PBN were most effective, inhibiting the regeneration of bleachable rhodopsin significantly (60% compared to vehicle control). In addition, a 10% concentration of PBN and 5% concentration of 4-CH3-PBN in baboon eyes inhibited the visual cycle by 60% and by 30%, respectively. We have identified a group of PBN related nitrones that can reach the target tissue (RPE) by systemic and topical application and slow the rate of rhodopsin regeneration and therefore the visual cycle in mouse and baboon eyes. PBNDs can also protect the rat retina from light damage. There is potential in developing these compounds as preventative therapeutics for the treatment of human retinal degenerations in which the accumulation of lipofuscin may be pathogenic.
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Affiliation(s)
- Megan Stiles
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Gennadiy P. Moiseyev
- Department of Physiology, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Madeline L. Budda
- Department of Cell Biology, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Annette Linens
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Richard S. Brush
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Hui Qi
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Gary L. White
- Department of Pathology, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Roman F. Wolf
- Department of Pathology, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Jian-xing Ma
- Department of Physiology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Department of Endocrinology and Diabetes, OUHSC, Oklahoma City, Oklahoma, United States of America
| | - Robert Floyd
- Experimental Therapeutics, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Robert E. Anderson
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Department of Pathology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Nawajes A. Mandal
- Department of Ophthalmology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Department of Cell Biology, OUHSC, Oklahoma City, Oklahoma, United States of America
- Department of Endocrinology and Diabetes, OUHSC, Oklahoma City, Oklahoma, United States of America
- Oklahoma Center for Neuroscience, OUHSC, Oklahoma City, Oklahoma, United States of America
- Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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19
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Choi SH, Choi CH. Noise-Induced Neural Degeneration and Therapeutic Effect of Antioxidant Drugs. J Audiol Otol 2015; 19:111-9. [PMID: 26771008 PMCID: PMC4704551 DOI: 10.7874/jao.2015.19.3.111] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 10/18/2015] [Accepted: 10/24/2015] [Indexed: 02/04/2023] Open
Abstract
The primary site of lesion induced by noise exposure is the hair cells in the organ of Corti and the primary neural degeneration occurs in synaptic terminals of cochlear nerve fibers and spiral ganglion cells. The cellular basis of noise-induced hearing loss is oxidative stress, which refers to a severe disruption in the balance between the production of free radicals and antioxidant defense system in the cochlea by excessive production of free radicals induced by noise exposure. Oxidative stress has been identified by a variety of biomarkers to label free radical activity which include four-hydroxy-2-nonenal, nitrotyrosine, and malondialdehyde, and inducible nitric oxide synthase, cytochrome-C, and cascade-3, 8, 9. Furthermore, oxidative stress is contributing to the necrotic and apoptotic cell deaths in the cochlea. To counteract the known mechanisms of pathogenesis and oxidative stress induced by noise exposure, a variety of antioxidant drugs including oxygen-based antioxidants such as N-acetyl-L-cystein and acetyl-L-carnitine and nitrone-based antioxidants such as phenyl-N-tert-butylnitrone (PBN), disufenton sodium, 4-hydroxy PBN, and 2, 4-disulfonyl PBN have been used in our laboratory. These antioxidant drugs were effective in preventing or treating noise-induced hearing loss. In combination with other antioxidants, antioxidant drugs showed a strong synergistic effect. Furthermore, successful use of antioxidant drugs depends on the optimal timing of treatment and the duration of treatment, which are highly related to the time window of free radical formation induced by noise exposure.
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Affiliation(s)
- Seong Hee Choi
- Department of Audiology & Speech Language Pathology, Research Institute of Biomimetic Sensory Control, and Catholic Hearing Voice Speech Center, Catholic University of Daegu, Gyeongsan, Korea
| | - Chul-Hee Choi
- Department of Audiology & Speech Language Pathology, Research Institute of Biomimetic Sensory Control, and Catholic Hearing Voice Speech Center, Catholic University of Daegu, Gyeongsan, Korea
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20
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Kopke R, Slade MD, Jackson R, Hammill T, Fausti S, Lonsbury-Martin B, Sanderson A, Dreisbach L, Rabinowitz P, Torre P, Balough B. Efficacy and safety of N-acetylcysteine in prevention of noise induced hearing loss: A randomized clinical trial. Hear Res 2015; 323:40-50. [DOI: 10.1016/j.heares.2015.01.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 12/31/2014] [Accepted: 01/07/2015] [Indexed: 01/12/2023]
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21
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Lasri J, Ismail AI, Haukka M, Soliman SM. Synthesis, molecular structure, spectroscopic properties and stability of (Z)-N-methyl-C-2,4,6-trimethylphenylnitrone. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 136 Pt C:1857-1868. [PMID: 25467680 DOI: 10.1016/j.saa.2014.10.096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 10/23/2014] [Indexed: 06/04/2023]
Abstract
New N-methyl-C-2,4,6-trimethylphenylnitrone 1 has been synthesized starting from N-methylhydroxylamine and mesitaldehyde. The product was fully characterized using different spectroscopic techniques; FTIR, NMR, UV-Vis, high resolution mass spectrometry and X-ray diffraction. The relative stability and percent of population of its two possible isomers (E and Z) were calculated using the B3LYP/6-311++G(d,p) method in gas phase and in solution. In agreement with the X-ray results, it was found that Z-isomer is the most stable one in both gas phase and solution. The molecular geometry, vibrational frequencies, gauge-including atomic orbital (GIAO), and chemical shift values were also calculated using the same level of theory. The TD-DFT results of the studied nitrone predicted a π-π(∗) transition band at 285.1nm (fosc=0.3543) in the gas phase. The rest of the spectral bands undergo either hyperchromic or hypsochromic shifts in the presence of solvent. Polarizability and HOMO-LUMO gap values were used to predict the nonlinear optical properties (NLO) of the studied compound. NBO analysis has been used to determine the most accurate Lewis structure of the studied molecule.
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Affiliation(s)
- Jamal Lasri
- Department of Chemistry, Rabigh College of Science and Arts, King Abdulaziz University, P.O. Box 344, Rabigh 21911, Saudi Arabia.
| | - Ali I Ismail
- Department of Chemistry, Rabigh College of Science and Arts, King Abdulaziz University, P.O. Box 344, Rabigh 21911, Saudi Arabia
| | - Matti Haukka
- University of Jyväskylä, Department of Chemistry, P.O. Box 35, FI-40014 University of Jyväskylä, Finland
| | - Saied M Soliman
- Department of Chemistry, Rabigh College of Science and Arts, King Abdulaziz University, P.O. Box 344, Rabigh 21911, Saudi Arabia; Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321, Egypt.
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22
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Tornari C, Towers ER, Gale JE, Dawson SJ. Regulation of the orphan nuclear receptor Nr2f2 by the DFNA15 deafness gene Pou4f3. PLoS One 2014; 9:e112247. [PMID: 25372459 PMCID: PMC4221282 DOI: 10.1371/journal.pone.0112247] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 10/08/2014] [Indexed: 12/23/2022] Open
Abstract
Hair cells are the mechanotransducing cells of the inner ear that are essential for hearing and balance. POU4F3--a POU-domain transcription factor selectively expressed by these cells--has been shown to be essential for hair cell differentiation and survival in mice and its mutation in humans underlies late-onset progressive hearing loss (DFNA15). The downstream targets of POU4F3 are required for hair cell differentiation and survival. We aimed to identify such targets in order to elucidate the molecular pathways involved in hair cell production and maintenance. The orphan thyroid nuclear receptor Nr2f2 was identified as a POU4F3 target using a subtractive hybridization strategy and EMSA analysis showed that POU4F3 binds to two sites in the Nr2f2 5' flanking region. These sites were shown to be required for POU4F3 activation as their mutation leads to a reduction in the response of an Nr2f2 5' flanking region reporter construct to POU4F3. Immunocytochemistry was carried out in the developing and adult inner ear in order to investigate the relevance of this interaction in hearing. NR2F2 expression in the postnatal mouse organ of Corti was shown to be detectable in all sensory epithelia examined and characterised. These data demonstrate that Nr2f2 is a direct target of POU4F3 in vitro and that this regulatory relationship may be relevant to hair cell development and survival.
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Affiliation(s)
| | - Emily R. Towers
- UCL Ear Institute, University College London, London, United Kingdom
| | - Jonathan E. Gale
- UCL Ear Institute, University College London, London, United Kingdom
| | - Sally J. Dawson
- UCL Ear Institute, University College London, London, United Kingdom
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Lu J, Li W, Du X, Ewert DL, West MB, Stewart C, Floyd RA, Kopke RD. Antioxidants reduce cellular and functional changes induced by intense noise in the inner ear and cochlear nucleus. J Assoc Res Otolaryngol 2014; 15:353-72. [PMID: 24497307 PMCID: PMC4010594 DOI: 10.1007/s10162-014-0441-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 01/06/2014] [Indexed: 10/25/2022] Open
Abstract
The present study marks the first evaluation of combined application of the antioxidant N-acetylcysteine (NAC) and the free radical spin trap reagent, disodium 2,4-disulfophenyl-N-tert-butylnitrone (HPN-07), as a therapeutic approach for noise-induced hearing loss (NIHL). Pharmacokinetic studies and C-14 tracer experiments demonstrated that both compounds achieve high blood levels within 30 min after i.p injection, with sustained levels of radiolabeled cysteine (released from NAC) in the cochlea, brainstem, and auditory cortex for up to 48 h. Rats exposed to 115 dB octave-band noise (10-20 kHz) for 1 h were treated with combined NAC/HPN-07 beginning 1 h after noise exposure and for two consecutive days. Auditory brainstem responses (ABR) showed that treatment substantially reduced the degree of threshold shift across all test frequencies (2-16 kHz), beginning at 24 h after noise exposure and continuing for up to 21 days. Reduced distortion product otoacoustic emission (DPOAE) level shifts were also detected at 7 and 21 days following noise exposure in treated animals. Noise-induced hair cell (HC) loss, which was localized to the basal half of the cochlea, was reduced in treated animals by 85 and 64% in the outer and inner HC regions, respectively. Treatment also significantly reduced an increase in c-fos-positive neuronal cells in the cochlear nucleus following noise exposure. However, no detectable spiral ganglion neuron loss was observed after noise exposure. The results reported herein demonstrate that the NAC/HPN-07 combination is a promising pharmacological treatment of NIHL that reduces both temporary and permanent threshold shifts after intense noise exposure and acts to protect cochlear sensory cells, and potentially afferent neurites, from the damaging effects of acoustic trauma. In addition, the drugs were shown to reduce aberrant activation of neurons in the central auditory regions of the brain following noise exposure. It is likely that the protective mechanisms are related to preservation of structural components of the cochlea and blocking the activation of immediate early genes in the auditory centers of the brain.
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Affiliation(s)
- Jianzhong Lu
- />Hough Ear Institute, 3400 N.W. 56th Street, Oklahoma City, OK 73112 USA
| | - Wei Li
- />Hough Ear Institute, 3400 N.W. 56th Street, Oklahoma City, OK 73112 USA
| | - Xiaoping Du
- />Hough Ear Institute, 3400 N.W. 56th Street, Oklahoma City, OK 73112 USA
| | - Donald L. Ewert
- />Hough Ear Institute, 3400 N.W. 56th Street, Oklahoma City, OK 73112 USA
| | - Matthew B. West
- />Hough Ear Institute, 3400 N.W. 56th Street, Oklahoma City, OK 73112 USA
| | - Charles Stewart
- />Oklahoma Medical Research Foundation, Oklahoma City, OK 73104 USA
| | - Robert A. Floyd
- />Oklahoma Medical Research Foundation, Oklahoma City, OK 73104 USA
| | - Richard D Kopke
- />Hough Ear Institute, 3400 N.W. 56th Street, Oklahoma City, OK 73112 USA
- />Oklahoma Medical Research Foundation, Oklahoma City, OK 73104 USA
- />Departments of Physiology and Otolaryngology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 USA
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Choi CH, Du X, Floyd RA, Kopke RD. Therapeutic effects of orally administrated antioxidant drugs on acute noise-induced hearing loss. Free Radic Res 2013; 48:264-72. [PMID: 24182331 DOI: 10.3109/10715762.2013.861599] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The objective of this study was to investigate the dose-dependent therapeutic effect of the orally administrated antioxidant drugs [4-hydroxy alpha-phenyl-tert-butylnitrone (4-OHPBN) and N-acetyl-L-cysteine (NAC)] on acute noise-induced hearing loss because oral administration is the most commonly used method of drug administration due to its convenience, safety, and economical efficiency. METHODS Thirty chinchilla were exposed to a 105 dB octave band noise centered at 4 kHz for 6 h and randomly assigned to a control group (saline only) and three experimental groups [4-OHPBN (10 mg/kg) plus NAC (20 mg/kg), 4-OHPBN (20 mg/kg) plus NAC (50 mg/kg), and 4-OHPBN (50 mg/kg) plus NAC (100 mg/kg)]. The drugs were orally administrated beginning 4 h after noise exposure and then administered twice daily for the next 2 days. Permanent auditory brainstem response threshold shifts, distortion product otoacoustic emission threshold shifts, and the percentage of missing outer hair cell were determined. RESULTS The oral administration significantly reduced permanent hearing threshold shift, distortion product otoacoustic emission threshold shift, and the percentage of missing outer hair cell in a dose-dependent manner. DISCUSSION This result demonstrates that orally administered drugs can treat acute noise-induced hearing loss in a dose-dependent manner. This suggests that oral administration was effective in treating acute noise-induced hearing loss as in intraperitoneal administration.
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Affiliation(s)
- C-H Choi
- Catholic University of Daegu, Audiology & Speech Language Pathology, Research Institute of Biomimetic Sensory Control, and Catholic Hearing Voice Speech Center , Kyungsansi, Kyungsanbukdo , Republic of Korea
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Floyd RA, Castro Faria Neto HC, Zimmerman GA, Hensley K, Towner RA. Nitrone-based therapeutics for neurodegenerative diseases: their use alone or in combination with lanthionines. Free Radic Biol Med 2013; 62:145-156. [PMID: 23419732 PMCID: PMC3715559 DOI: 10.1016/j.freeradbiomed.2013.01.033] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 01/25/2013] [Accepted: 01/29/2013] [Indexed: 01/12/2023]
Abstract
The possibility of free radical reactions occurring in biological processes led to the development and employment of novel methods and techniques focused on determining their existence and importance in normal and pathological conditions. For this reason the use of nitrones for spin trapping free radicals became widespread in the 1970s and 1980s, when surprisingly the first evidence of their potent biological properties was noted. Since then widespread exploration and demonstration of the potent biological properties of phenyl-tert-butylnitrone (PBN) and its derivatives took place in preclinical models of septic shock and then in experimental stroke. The most extensive commercial effort made to capitalize on the potent properties of the PBN-nitrones was for acute ischemic stroke. This occurred during 1993-2006, when the 2,4-disulfonylphenyl PBN derivative, called NXY-059 in the stroke studies, was shown to be safe in humans and was taken all the way through clinical phase 3 trials and then was deemed to be ineffective. As summarized in this review, because of its excellent human safety profile, 2,4-disulfonylphenyl PBN, now called OKN-007 in the cancer studies, was tested as an anti-cancer agent in several preclinical glioma models and shown to be very effective. Based on these studies this compound is now scheduled to enter into early clinical trials for astrocytoma/glioblastoma multiforme this year. The potential use of OKN-007 in combination with neurotropic compounds such as the lanthionine ketamine esters is discussed for glioblastoma multiforme as well as for various other indications leading to dementia, such as aging, septic shock, and malaria infections. There is much more research and development activity ongoing for various indications with the nitrones, alone or in combination with other active compounds, as briefly noted in this review.
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Affiliation(s)
- Robert A Floyd
- Experimental Therapeutics, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
| | | | - Guy A Zimmerman
- Laboratorio de Immunofarmacologia, Instituto Oswaldo Cruz, IOC, Fiocruz, Rio de Janeiro, Brazil; Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Kenneth Hensley
- Department of Pathology and Department of Neurosciences, University of Toledo Medical Center, Toledo, OH
| | - Rheal A Towner
- Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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Sheela NR, Sampathkrishnan S, Thirumalai Kumar M, Muthu S. Synthesis, spectroscopic (FT-IR, FT-Raman, 13C, 1H, UV) study, first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis of 2(2-Hydroxyphenyl)-N-(4-Methylphenyl) Nitrone. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 109:272-281. [PMID: 23542518 DOI: 10.1016/j.saa.2013.03.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 02/25/2013] [Accepted: 03/03/2013] [Indexed: 06/02/2023]
Abstract
The title compound, 2(2-Hydroxyphenyl)-N-(4-Methylphenyl) Nitrone (2HPN4MPN) was synthesized and characterized by FT-IR, FT-Raman, UV-Vis and (1)HNMR, (13)CNMR spectral analysis. The molecular geometry, harmonic vibrational frequencies and bonding features of the title compound in the ground state are computed at three parameter hybrid functional Lee-Yang-Parr/6-311++G(d,p) levels of theory. The most stable conformer of 2HPN4MPN is identified from the computational results. The assignments of the vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMF). The UV-Vis spectrum was recorded in chloroform solution. The energy and oscillator strength calculated by time-dependent density functional theory (TD-DFT) complements the experimental findings. The calculated HOMO and LUMO energies confirm that charge transfer occurs within the molecule. In addition, DFT calculations of the compound, Molecular Electrostatic Potential (MEP), Natural Bond Orbital analysis (NBO) and non-linear optical (NLO) properties are performed at B3LYP/6-311++G(d,p) level of theory. Finally, the calculations are applied to simulated FT-IR and FT-Raman spectra of the title compound which show good agreement with observed spectra.
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Affiliation(s)
- N R Sheela
- Department of Applied Physics, Sri Venkateswara College of Engineering, Sriperumbudur 602 105, India
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Choi CH. Mechanisms and treatment of blast induced hearing loss. KOREAN JOURNAL OF AUDIOLOGY 2012; 16:103-7. [PMID: 24653882 PMCID: PMC3936657 DOI: 10.7874/kja.2012.16.3.103] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 11/11/2012] [Accepted: 11/15/2012] [Indexed: 01/21/2023]
Abstract
The main objective of this study is to provide an overview of the basic mechanisms of blast induced hearing loss and review pharmacological treatments or interventions that can reduce or inhibit blast induced hearing loss. The mechanisms of blast induced hearing loss have been studied in experimental animal models mimicking features of damage or injury seen in human. Blast induced hearing loss is characterized by perforation and rupture of the tympanic membrane, ossicular damage, basilar membrane damage, inner and outer hair cell loss, rupture of round window, changes in chemical components of cochlear fluid, vasospasm, ischemia, oxidative stress, excitotoxicity, hematoma, and hemorrhage in both animals and humans. These histopathological consequences of blast exposure can induce hearing loss, tinnitus, dizziness, and headache. The pharmacological approaches to block or inhibit some of the auditory pathological consequences caused by blast exposure have been developed with antioxidant drugs such as 2,4-disulfonyl α-phenyl tertiary butyl nitrone (HXY-059, now called HPN-07) and N-acetylcysteine (NAC). A combination of antioxidant drugs (HPN-07 and NAC) was administered to reduce blast induced cochlear damage and hearing loss. The combination of the antioxidant drugs can prevent or treat blast induced hearing loss by reducing damage to the mechanical and neural component of the auditory system. Although information of the underlying mechanisms and treatment of blast induced hearing loss are provided, further and deep research should be achieved due to the limited and controversial knowledge.
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Affiliation(s)
- Chul-Hee Choi
- Department of Audiology and Speech-Language Pathology, Research Institute of Biomimetic Sensory Control, and Catholic Hearing Voice Speech Center, Catholic University of Daegu, Gyeongsan, Korea
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28
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Potential implication of the chemical properties and bioactivity of nitrone spin traps for therapeutics. Future Med Chem 2012; 4:1171-207. [PMID: 22709256 DOI: 10.4155/fmc.12.74] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nitrone therapeutics has been employed in the treatment of oxidative stress-related diseases such as neurodegeneration, cardiovascular disease and cancer. The nitrone-based compound NXY-059, which is the first drug to reach clinical trials for the treatment of acute ischemic stroke, has provided promise for the development of more robust pharmacological agents. However, the specific mechanism of nitrone bioactivity remains unclear. In this review, we present a variety of nitrone chemistry and biological activity that could be implicated for the nitrone's pharmacological activity. The chemistries of spin trapping and spin adduct reveal insights on the possible roles of nitrones for altering cellular redox status through radical scavenging or nitric oxide donation, and their biological effects are presented. An interdisciplinary approach towards the development of novel synthetic antioxidants with improved pharmacological properties encompassing theoretical, synthetic, biochemical and in vitro/in vivo studies is covered.
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Ewert DL, Lu J, Li W, Du X, Floyd R, Kopke R. Antioxidant treatment reduces blast-induced cochlear damage and hearing loss. Hear Res 2012; 285:29-39. [PMID: 22326291 DOI: 10.1016/j.heares.2012.01.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 01/23/2012] [Accepted: 01/27/2012] [Indexed: 01/16/2023]
Abstract
Exposure to blast overpressure has become one of the hazards of both military and civilian life in many parts of the world due to war and terrorist activity. Auditory damage is one of the primary sequela of blast trauma, affecting immediate situational awareness and causing permanent hearing loss. Protecting against blast exposure is limited by the inability to anticipate the timing of these exposures, particularly those caused by terrorists. Therefore a therapeutic regimen is desirable that is able to ameliorate auditory damage when administered after a blast exposure has occurred. The purpose of this study was to determine if administration of a combination of antioxidants 2,4-disulfonyl α-phenyl tertiary butyl nitrone (HPN-07) and N-acetylcysteine (NAC) beginning 1 h after blast exposure could reduce both temporary and permanent hearing loss. To this end, a blast simulator was developed and the operational conditions established for exposing rats to blast overpressures comparable to those encountered in an open-field blast of 14 pounds per square inch (psi). This blast model produced reproducible blast overpressures that resulted in physiological and physical damage to the auditory system that was proportional to the number and amplitude of the blasts. After exposure to 3 consecutive 14 psi blasts 100% of anesthetized rats had permanent hearing loss as determined at 21 days post exposure by auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) testing. Animals treated with HPN-07 and NAC after blast exposure showed a significant reduction in ABR threshold shifts and DPOAE level shifts at 2-16 kHz with significant reduction in inner hair cell (IHC) and outer hair cell (OHC) loss across the 5-36 kHz region of the cochlea compared with control animals. The time course of changes in the auditory system was documented at 3 h, 24 h, 7 day and 21 day after blast exposure. At 3 h after blast exposure the auditory brainstem response (ABR) threshold shifts were elevated by 60 dB in both treated and control groups. A partial recovery of to 35 dB was observed at 24 h in the controls, indicative of a temporary threshold shift (TTS) and there was essentially no further recovery by 21 days representing a permanent threshold shift (PTS) of about 30 dB. Antioxidant treatment increased the amount of both TTS and PTS recovery relative to controls by 10 and 20 dB respectively. Distortion product otoacoustic emission (DPOAE) reached a maximum level shift of 25-30 dB measured in both control and treated groups at 3 h after blast exposure. These levels did not change by day 21 in the control group but in the treatment group the level shifts began to decline at 24 h until by day 21 they were 10-20 dB below that of the controls. Loss of cochlear hair cells measured at 21 day after blast exposure was mostly in the outer hair cells (OHC) and broadly distributed across the basilar membrane, consistent with the distribution of loss of frequency responses as measured by ABR and DPOAE analysis and typical of blast-induced damage. OHC loss progressively increased after blast exposure reaching an average loss of 32% in the control group and 10% in the treated group at 21 days. These findings provide the first evidence that a combination of antioxidants, HPN-07 and NAC, can both enhance TTS recovery and prevent PTS by reducing damage to the mechanical and neural components of the auditory system when administered shortly after blast exposure.
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Affiliation(s)
- Donald L Ewert
- Hough Ear Institute, 3400 N.W. 56th Street, Oklahoma City, OK 73112, USA.
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Du X, Chen K, Choi CH, Li W, Cheng W, Stewart C, Hu N, Floyd RA, Kopke RD. Selective degeneration of synapses in the dorsal cochlear nucleus of chinchilla following acoustic trauma and effects of antioxidant treatment. Hear Res 2011; 283:1-13. [PMID: 22178982 DOI: 10.1016/j.heares.2011.11.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 11/18/2011] [Accepted: 11/30/2011] [Indexed: 12/20/2022]
Abstract
The purpose of this study was to reveal synaptic plasticity within the dorsal cochlear nucleus (DCN) as a result of noise trauma and to determine whether effective antioxidant protection to the cochlea can also impact plasticity changes in the DCN. Expression of synapse activity markers (synaptophysin and precerebellin) and ultrastructure of synapses were examined in the DCN of chinchilla 10 days after a 105 dB SPL octave-band noise (centered at 4 kHz, 6 h) exposure. One group of chinchilla was treated with a combination of antioxidants (4-hydroxy phenyl N-tert-butylnitrone, N-acetyl-l-cysteine and acetyl-l-carnitine) beginning 4 h after noise exposure. Down-regulated synaptophysin and precerebellin expression, as well as selective degeneration of nerve terminals surrounding cartwheel cells and their primary dendrites were found in the fusiform soma layer in the middle region of the DCN of the noise exposure group. Antioxidant treatment significantly reduced synaptic plasticity changes surrounding cartwheel cells. Results of this study provide further evidence of acoustic trauma-induced neural plasticity in the DCN and suggest that loss of input to cartwheel cells may be an important factor contributing to the emergence of hyperactivity in the DCN after noise exposure. Results further suggest that early antioxidant treatment for acoustic trauma not only rescues cochlear hair cells, but also has impact on central auditory structures.
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Affiliation(s)
- Xiaoping Du
- Hough Ear Institute, Oklahoma, OK 73112, USA
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31
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Reduced formation of oxidative stress biomarkers and migration of mononuclear phagocytes in the cochleae of chinchilla after antioxidant treatment in acute acoustic trauma. Int J Otolaryngol 2011; 2011:612690. [PMID: 21961007 PMCID: PMC3179894 DOI: 10.1155/2011/612690] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 07/19/2011] [Indexed: 02/01/2023] Open
Abstract
Objective. Inhibition of inflammation and free radical formation in the cochlea may be involved in antioxidant treatment in acute acoustic trauma. Procedure. Chinchilla were exposed to 105 dB sound pressure level octave band noise for 6 hours. One group of chinchilla was treated with antioxidants after noise exposure. Auditory brainstem responses, outer hair cell counts, and immunohistochemical analyses of biomarkers in the cochlea were conducted. Results. The antioxidant treatment significantly reduced hearing threshold shifts, outer hair cell loss, numbers of CD45+ cells, as well as 4-hydroxy-2-nonenal and nitrotyrosine formation in the cochlea. Conclusion. Antioxidant treatment may provide protection to sensory cells by inhibiting formation of reactive oxygen and nitrogen products and migration of mononuclear phagocytes in the cochlea. The present study provides further evidence of effectiveness of antioxidant treatment in reducing permanent hearing loss.
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Floyd RA, Towner RA, He T, Hensley K, Maples KR. Translational research involving oxidative stress and diseases of aging. Free Radic Biol Med 2011; 51:931-41. [PMID: 21549833 PMCID: PMC3156308 DOI: 10.1016/j.freeradbiomed.2011.04.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 02/28/2011] [Accepted: 04/07/2011] [Indexed: 01/01/2023]
Abstract
There is ample mounting evidence that reactive oxidant species are exacerbated in inflammatory processes, many pathological conditions, and underlying processes of chronic age-related diseases. Therefore there is increased expectation that therapeutics can be developed that act in some fashion to suppress reactive oxidant species and ameliorate the condition. This has turned out to be more difficult than at first expected. Developing therapeutics for indications in which reactive oxidant species are an important consideration presents some unique challenges. We discuss important questions including whether reactive oxidant species should be a therapeutic target, the need to recognize the fact that an antioxidant in a defined chemical system may be a poor antioxidant operationally in a biological system, and the importance of considering that reactive oxidant species may accompany the disease or pathological system rather than being a causative factor. We also discuss the value of having preclinical models to determine if the processes that are important in causing the disease under study are critically dependent on reactive oxidant species events and if the therapeutic under consideration quells these processes. In addition we discuss measures of success that must be met in commercial research and development and in preclinical and clinical trials and discuss as examples our translational research effort in developing nitrones for the treatment of acute ischemic stroke and as anti-cancer agents.
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Affiliation(s)
- Robert A Floyd
- Experimental Therapeutics, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
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Choi CH, Chen K, Du X, Floyd RA, Kopke RD. Effects of delayed and extended antioxidant treatment on acute acoustic trauma. Free Radic Res 2011; 45:1162-72. [DOI: 10.3109/10715762.2011.605360] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Le Prell CG, Gagnon PM, Bennett DC, Ohlemiller KK. Nutrient-enhanced diet reduces noise-induced damage to the inner ear and hearing loss. Transl Res 2011; 158:38-53. [PMID: 21708355 PMCID: PMC3132794 DOI: 10.1016/j.trsl.2011.02.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 02/15/2011] [Accepted: 02/15/2011] [Indexed: 01/13/2023]
Abstract
Oxidative stress has been implicated broadly as a cause of cell death and neural degeneration in multiple disease conditions; however, the evidence for successful intervention with dietary antioxidant manipulations has been mixed. In this study, we investigated the potential for protection of cells in the inner ear using a dietary supplement with multiple antioxidant components, which were selected for their potential interactive effectiveness. Protection against permanent threshold shift (PTS) was observed in CBA/J mice maintained on a diet supplemented with a combination of β-carotene, vitamins C and E, and magnesium when compared with PTS in control mice maintained on a nutritionally complete control diet. Although hair cell survival was not enhanced, noise-induced loss of type II fibrocytes in the lateral wall was significantly reduced (P < 0.05), and there was a trend toward less noise-induced loss in strial cell density in animals maintained on the supplemented diet. Taken together, our data suggest that prenoise oral treatment with the high-nutrient diet can protect cells in the inner ear and reduce PTS in mice. The demonstration of functional and morphologic preservation of cells in the inner ear with oral administration of this antioxidant supplemented diet supports the possibility of translation to human patients and suggests an opportunity to evaluate antioxidant protection in mouse models of oxidative stress-related disease and pathology.
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Affiliation(s)
- Colleen G Le Prell
- Department of Speech, Language, and Hearing Sciences, University of Florida, Box 100174, Gainesville, FL 32610, USA.
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35
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Haase GM, Prasad KN, Cole WC, Baggett-Strehlau JM, Wyatt SE. Antioxidant micronutrient impact on hearing disorders: concept, rationale, and evidence. Am J Otolaryngol 2011; 32:55-61. [PMID: 20015808 DOI: 10.1016/j.amjoto.2009.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 09/03/2009] [Accepted: 09/06/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE Although auditory disorders are complex conditions, device-related modalities dominate current treatment. However, dysfunction from the central cortex to the inner ear apparatus is increasingly thought to be related to biochemical pathway abnormalities and to free radical-induced oxidative damage and chronic inflammation. Therefore, considering appropriate biologic therapy as an adjunct to standard care against these damaging factors may provide rational expansion of treatment options for otolaryngologists and audiologists. METHODS This review outlines the biologic concepts related to some auditory and vestibular conditions and details the current rationale for utilizing antioxidants for a spectrum of hearing disorders. The strategy is based on the authors' collective experience in antioxidant science and supported with published research, pilot animal data and preliminary clinical observations. RESULTS A comprehensive micronutrient approach was developed to exploit these pathways, and demonstrated safety and efficacy against oxidative damage and inflammation and clinically relevant neuroprotection. Cooperative research with Department of Defense institutions used prospective, randomized designs to show (1) reduction in oxidative damage measured in plasma and urine over six months, (2) protection against oxidative damage during 12 weeks of intense military training, (3) protection against inflammation after total body blast exposure (rodents), (4) strong neuroprotection against chemically-induced Parkinson's disease (rodents), (5) nerve VIII function improvement after concussive head injury in military personnel, and (6) tinnitus improvement in majority of patients after 90-day evaluation. CONCLUSION This systematic review of biologic strategies against hearing disorders combined with new animal and human observations may provide a rational basis for expanding current practice paradigms.
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Sakata T, Ueno T, Takase H, Shiraishi K, Nakagawa T. Acute idiopathic sensorineural hearing impairment at frequency exceeding 8 kHz. Acta Otolaryngol 2010; 130:1141-6. [PMID: 20297929 DOI: 10.3109/00016481003664793] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSIONS Acute idiopathic sensorineural hearing impairment at a frequency exceeding 8 kHz (high-frequency range) was recognized in patients suffering from acute tinnitus without hearing loss. The cases in this study may contribute to clarifying the pathogenesis of tinnitus without hearing loss and evaluating its response to steroid therapy. OBJECTIVES The aim of this study was to demonstrate the existence of acute idiopathic sensorineural hearing impairment only in the high-frequency range and to investigate its relation to tinnitus without hearing loss. METHODS Five patients aged 29 years or younger who consulted a hospital within a few days after the onset of unilateral tinnitus without hearing loss were studied. We conducted audiometry involving the high-frequency range on first medical examination and on improvement in tinnitus, and investigated the association between the hearing findings in the high-frequency range and a tinnitus prognosis. RESULTS All five patients showed abnormalities in the threshold in the high-frequency range on the affected side. In the three cases given prednisolone, tinnitus and the threshold abnormalities were reduced within 20 days. In contrast, tinnitus and the threshold abnormalities showed little change in two patients who were not treated.
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Floyd RA. Serendipitous findings while researching oxygen free radicals. Free Radic Biol Med 2009; 46:1004-13. [PMID: 19439210 PMCID: PMC2683184 DOI: 10.1016/j.freeradbiomed.2009.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 02/05/2009] [Accepted: 02/05/2009] [Indexed: 11/13/2022]
Abstract
This review is based on the honor of receiving the Discovery Award from the Society of Free Radical Biology and Medicine. The review is reflective and presents our thinking that led to experiments that yielded novel observations. Critical questioning of our understanding of oxygen free radicals in biomedical problems led us to use and develop more direct and extremely sensitive methods. This included nitrone free radical spin trapping and HPLC-electrochemical detection. This technology led to the pioneering use of salicylate to trap hydroxyl free radicals and show increased flux in ischemia/reperfused brain regions and also to first sensitively detect 8-hydroxyl-2-deoxyguanosine in oxidatively damaged DNA and help assess its role in cancer development. We demonstrated that methylene blue (MB) photoinduces formation of 8-hydroxyguanine in DNA and RNA and discovered that MB sensitively photoinactivates RNA viruses, including HIV and the West Nile virus. Studies in experimental stroke led us serendipitously to discover that alpha-phenyl-tert-butylnitrone (PBN) was neuroprotective if given after the stroke. This led to extensive commercial development of NXY-059, a PBN derivative, for the treatment of stroke. More recently we discovered that PBN nitrones have potent anti-cancer activity and are active in preventing hearing loss caused by acute acoustical trauma.
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Affiliation(s)
- Robert A Floyd
- Experimental Therapeutics Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73170, USA.
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Floyd RA, Kopke RD, Choi CH, Foster SB, Doblas S, Towner RA. Nitrones as therapeutics. Free Radic Biol Med 2008; 45:1361-74. [PMID: 18793715 PMCID: PMC2796547 DOI: 10.1016/j.freeradbiomed.2008.08.017] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 08/08/2008] [Accepted: 08/08/2008] [Indexed: 01/20/2023]
Abstract
Nitrones have the general chemical formula X-CH=NO-Y. They were first used to trap free radicals in chemical systems and then subsequently in biochemical systems. More recently several nitrones, including alpha-phenyl-tert-butylnitrone (PBN), have been shown to have potent biological activity in many experimental animal models. Many diseases of aging, including stroke, cancer development, Parkinson disease, and Alzheimer disease, are known to have enhanced levels of free radicals and oxidative stress. Some derivatives of PBN are significantly more potent than PBN and have undergone extensive commercial development for stroke. Recent research has shown that PBN-related nitrones also have anti-cancer activity in several experimental cancer models and have potential as therapeutics in some cancers. Also, in recent observations nitrones have been shown to act synergistically in combination with antioxidants in the prevention of acute acoustic-noise-induced hearing loss. The mechanistic basis of the potent biological activity of PBN-related nitrones is not known. Even though PBN-related nitrones do decrease oxidative stress and oxidative damage, their potent biological anti-inflammatory activity and their ability to alter cellular signaling processes cannot readily be explained by conventional notions of free radical trapping biochemistry. This review is focused on our studies and others in which the use of selected nitrones as novel therapeutics has been evaluated in experimental models in the context of free radical biochemical and cellular processes considered important in pathologic conditions and age-related diseases.
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Affiliation(s)
- Robert A Floyd
- Experimental Therapeutics Research Program, Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
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40
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Ohlemiller KK. Recent findings and emerging questions in cochlear noise injury. Hear Res 2008; 245:5-17. [PMID: 18790034 PMCID: PMC2610263 DOI: 10.1016/j.heares.2008.08.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 08/12/2008] [Accepted: 08/19/2008] [Indexed: 12/11/2022]
Affiliation(s)
- Kevin K Ohlemiller
- Fay and Carl Simons Center for the Biology of Hearing and Deafness, Central Institute for the Deaf at Washington University, Department of Otolaryngology, Washington University Medical School, St. Louis, MO 63110, USA.
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