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Venet T, Thomas A, Merlen L, Boucard S, Wathier L, Martin Remy A, Pouyatos B. Parameters influencing auditory fatigue among professionals working in the amplified music sector: noise exposure and individual factors. Int J Audiol 2024; 63:686-694. [PMID: 37622173 DOI: 10.1080/14992027.2023.2240012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 08/26/2023]
Abstract
OBJECTIVE Hearing disorders are common among music professionals, as they are frequently exposed to sound levels exceeding 100 dB(A). By assessing auditory fatigue, situations that are deleterious for hearing could be identified, allowing the deployment of preventive measures before permanent impairment occurs. However, little is known about the factors contributing to auditory fatigue. The objective is to determine the exposure parameters most influencing auditory fatigue during occupational exposure to amplified music. DESIGN Auditory fatigue was defined as variations of both pure tone auditory (ΔPTA) and efferent reflex thresholds (ΔER) during the workday. Noise exposure was monitored and information on the volunteers was gathered using a questionnaire. STUDY SAMPLE The population consisted of 43 adult volunteers exposed to amplified music (sound, light or stage technicians, security agents, barmen) and 24 unexposed administrative agents. RESULTS ΔPTA and ΔER were positively correlated with the energy of noise exposure and its stability over time, i.e a steady noise tends to create more auditory fatigue. CONCLUSION In addition to a global decrease of music levels and a systematic use of hearing protection, our results advocate for the provision of quiet periods within noise exposures as they reduce auditory fatigue accumulation and long-term risks for hearing.
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Affiliation(s)
- Thomas Venet
- Institut National de Recherche et de Sécurité, Vandœuvre-lès-Nancy, France
- DevAH EA 3450 - Développement, Adaptation et Handicap, Régulations cardio-respiratoires et de la motricité-Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Aurélie Thomas
- Institut National de Recherche et de Sécurité, Vandœuvre-lès-Nancy, France
| | - Lise Merlen
- Institut National de Recherche et de Sécurité, Vandœuvre-lès-Nancy, France
| | - Stéphane Boucard
- Institut National de Recherche et de Sécurité, Vandœuvre-lès-Nancy, France
| | - Ludivine Wathier
- Institut National de Recherche et de Sécurité, Vandœuvre-lès-Nancy, France
| | | | - Benoit Pouyatos
- Institut National de Recherche et de Sécurité, Vandœuvre-lès-Nancy, France
- DevAH EA 3450 - Développement, Adaptation et Handicap, Régulations cardio-respiratoires et de la motricité-Université de Lorraine, Vandœuvre-lès-Nancy, France
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2
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Ikäheimo K, Leinonen S, Lankinen T, Lindahl M, Saarma M, Pirvola U. Stereocilia fusion pathology in the cochlear outer hair cells at the nanoscale level. J Physiol 2024; 602:3995-4025. [PMID: 39037943 DOI: 10.1113/jp286318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 06/12/2024] [Indexed: 07/24/2024] Open
Abstract
The hair bundle of cochlear hair cells comprises specialized microvilli, the stereocilia, which fulfil the role of mechanotransduction. Genetic defects and environmental noise challenge the maintenance of hair bundle structure, critically contributing to age-related hearing loss. Stereocilia fusion is a major component of the hair bundle pathology in mature hair cells, but its role in hearing loss and its molecular basis are poorly understood. Here, we utilized super-resolution expansion microscopy to examine the molecular anatomy of outer hair cell stereocilia fusion in mouse models of age-related hearing loss, heightened endoplasmic reticulum stress and prolonged noise exposure. Prominent stereocilia fusion in our model of heightened endoplasmic reticulum stress, Manf (Mesencephalic astrocyte-derived neurotrophic factor)-inactivated mice in a background with Cadherin 23 missense mutation, impaired mechanotransduction and calcium balance in stereocilia. This was indicated by reduced FM1-43 dye uptake through the mechanotransduction channels, reduced neuroplastin/PMCA2 expression and increased expression of the calcium buffer oncomodulin inside stereocilia. Sparse BAIAP2L2 and myosin 7a expression was retained in the fused stereocilia but mislocalized away from their functional sites at the tips. These hair bundle abnormalities preceded cell soma degeneration, suggesting a sequela from stereociliary molecular perturbations to cell death signalling. In the age-related hearing loss and noise-exposure models, stereocilia fusion was more restricted within the bundles, yet both models exhibited oncomodulin upregulation at the fusion sites, implying perturbed calcium homeostasis. We conclude that stereocilia fusion is linked with the failure to maintain cellular proteostasis and with disturbances in stereociliary calcium balance. KEY POINTS: Stereocilia fusion is a hair cell pathology causing hearing loss. Inactivation of Manf, a component of the endoplasmic reticulum proteostasis machinery, has a cell-intrinsic mode of action in triggering outer hair cell stereocilia fusion and the death of these cells. The genetic background with Cadherin 23 missense mutation contributes to the high susceptibility of outer hair cells to stereocilia fusion, evidenced in Manf-inactivated mice and in the mouse models of early-onset hearing loss and noise exposure. Endoplasmic reticulum stress feeds to outer hair cell stereocilia bundle pathology and impairs the molecular anatomy of calcium regulation. The maintenance of the outer hair cell stereocilia bundle cohesion is challenged by intrinsic and extrinsic stressors, and understanding the underlying mechanisms will probably benefit the development of interventions to promote hearing health.
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Affiliation(s)
- Kuu Ikäheimo
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Saija Leinonen
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Tuuli Lankinen
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Maria Lindahl
- Institute of Biotechnology, HILIFE Unit, University of Helsinki, Helsinki, Finland
| | - Mart Saarma
- Institute of Biotechnology, HILIFE Unit, University of Helsinki, Helsinki, Finland
| | - Ulla Pirvola
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
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3
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Yeo XY, Kwon S, Rinai KR, Lee S, Jung S, Park R. A Consolidated Understanding of the Contribution of Redox Dysregulation in the Development of Hearing Impairment. Antioxidants (Basel) 2024; 13:598. [PMID: 38790703 PMCID: PMC11118506 DOI: 10.3390/antiox13050598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/26/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
The etiology of hearing impairment is multifactorial, with contributions from both genetic and environmental factors. Although genetic studies have yielded valuable insights into the development and function of the auditory system, the contribution of gene products and their interaction with alternate environmental factors for the maintenance and development of auditory function requires further elaboration. In this review, we provide an overview of the current knowledge on the role of redox dysregulation as the converging factor between genetic and environmental factor-dependent development of hearing loss, with a focus on understanding the interaction of oxidative stress with the physical components of the peripheral auditory system in auditory disfunction. The potential involvement of molecular factors linked to auditory function in driving redox imbalance is an important promoter of the development of hearing loss over time.
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Affiliation(s)
- Xin Yi Yeo
- Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore;
- Department of Medical Science, College of Medicine, CHA University, Seongnam 13488, Republic of Korea;
| | - Soohyun Kwon
- Department of Medical Science, College of Medicine, CHA University, Seongnam 13488, Republic of Korea;
- Department of BioNanotechnology, Gachon University, Seongnam 13120, Republic of Korea
| | - Kimberley R. Rinai
- Department of Life Science, College of Medicine, CHA University, Seongnam 13488, Republic of Korea;
| | - Sungsu Lee
- Department of Otolaryngology-Head and Neck Surgery, Chonnam National University Hospital and Medical School, Gwangju 61469, Republic of Korea;
| | - Sangyong Jung
- Department of Medical Science, College of Medicine, CHA University, Seongnam 13488, Republic of Korea;
| | - Raekil Park
- Department of Biomedical Science and Engineering, Gwangju Institute of Science & Technology (GIST), Gwangju 61005, Republic of Korea
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4
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Zhu G, Huang Y, Zhang L, Yan K, Qiu C, He Y, Liu Q, Zhu C, Morín M, Moreno‐Pelayo MÁ, Zhu M, Cao X, Zhou H, Qian X, Xu Z, Chen J, Gao X, Wan G. Cingulin regulates hair cell cuticular plate morphology and is required for hearing in human and mouse. EMBO Mol Med 2023; 15:e17611. [PMID: 37691516 PMCID: PMC10630877 DOI: 10.15252/emmm.202317611] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 09/12/2023] Open
Abstract
Cingulin (CGN) is a cytoskeleton-associated protein localized at the apical junctions of epithelial cells. CGN interacts with major cytoskeletal filaments and regulates RhoA activity. However, physiological roles of CGN in development and human diseases are currently unknown. Here, we report a multi-generation family presenting with autosomal dominant non-syndromic hearing loss (ADNSHL) that co-segregates with a CGN heterozygous truncating variant, c.3330delG (p.Leu1110Leufs*17). CGN is normally expressed at the apical cell junctions of the organ of Corti, with enriched localization at hair cell cuticular plates and circumferential belts. In mice, the putative disease-causing mutation results in reduced expression and abnormal subcellular localization of the CGN protein, abolishes its actin polymerization activity, and impairs the normal morphology of hair cell cuticular plates and hair bundles. Hair cell-specific Cgn knockout leads to high-frequency hearing loss. Importantly, Cgn mutation knockin mice display noise-sensitive, progressive hearing loss and outer hair cell degeneration. In summary, we identify CGN c.3330delG as a pathogenic variant for ADNSHL and reveal essential roles of CGN in the maintenance of cochlear hair cell structures and auditory function.
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Affiliation(s)
- Guang‐Jie Zhu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
| | - Yuhang Huang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
| | - Linqing Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
| | - Keji Yan
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology and Key Laboratory for Experimental Teratology of the Ministry of Education, School of Life SciencesShandong UniversityQingdaoChina
| | - Cui Qiu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
| | - Yihan He
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
| | - Qing Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
| | - Chengwen Zhu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
| | - Matías Morín
- Servicio de GenéticaHospital Universitario Ramón y Cajal, IRYCISMadridSpain
- Centro de Investigación Biomédica en Red de Enfermedades RarasInstituto de Salud Carlos III (CB06/07/0048; CIBERER‐ISCIII)MadridSpain
| | - Miguel Ángel Moreno‐Pelayo
- Servicio de GenéticaHospital Universitario Ramón y Cajal, IRYCISMadridSpain
- Centro de Investigación Biomédica en Red de Enfermedades RarasInstituto de Salud Carlos III (CB06/07/0048; CIBERER‐ISCIII)MadridSpain
| | - Min‐Sheng Zhu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
| | - Xin Cao
- Department of Medical Genetics, School of Basic Medical ScienceNanjing Medical UniversityNanjingChina
| | - Han Zhou
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
| | - Xiaoyun Qian
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
| | - Zhigang Xu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology and Key Laboratory for Experimental Teratology of the Ministry of Education, School of Life SciencesShandong UniversityQingdaoChina
| | - Jie Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
| | - Xia Gao
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
| | - Guoqiang Wan
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Otolaryngology Head and Neck Surgery, Jiangsu Provincial Key Medical Discipline (Laboratory), The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical SchoolNanjing UniversityNanjingChina
- MOE Key Laboratory of Model Animal for Disease Study, Jiangsu Key Laboratory of Molecular Medicine, National Resource Center for Mutant Mice of ChinaNanjing UniversityNanjingChina
- Research Institute of OtolaryngologyNanjingChina
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5
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Park J, Bird JE. The actin cytoskeleton in hair bundle development and hearing loss. Hear Res 2023; 436:108817. [PMID: 37300948 PMCID: PMC10408727 DOI: 10.1016/j.heares.2023.108817] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/18/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023]
Abstract
Inner ear hair cells assemble mechanosensitive hair bundles on their apical surface that transduce sounds and accelerations. Each hair bundle is comprised of ∼ 100 individual stereocilia that are arranged into rows of increasing height and width; their specific and precise architecture being necessary for mechanoelectrical transduction (MET). The actin cytoskeleton is fundamental to establishing this architecture, not only by forming the structural scaffold shaping each stereocilium, but also by composing rootlets and the cuticular plate that together provide a stable foundation supporting each stereocilium. In concert with the actin cytoskeleton, a large assortment of actin-binding proteins (ABPs) function to cross-link actin filaments into specific topologies, as well as control actin filament growth, severing, and capping. These processes are individually critical for sensory transduction and are all disrupted in hereditary forms of human hearing loss. In this review, we provide an overview of actin-based structures in the hair bundle and the molecules contributing to their assembly and functional properties. We also highlight recent advances in mechanisms driving stereocilia elongation and how these processes are tuned by MET.
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Affiliation(s)
- Jinho Park
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, United States; Myology Institute, University of Florida, Gainesville, FL 32610, United States
| | - Jonathan E Bird
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, United States; Myology Institute, University of Florida, Gainesville, FL 32610, United States.
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6
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Wagner EL, Im JS, Sala S, Nakahata MI, Imbery TE, Li S, Chen D, Nimchuk K, Noy Y, Archer DW, Xu W, Hashisaki G, Avraham KB, Oakes PW, Shin JB. Repair of noise-induced damage to stereocilia F-actin cores is facilitated by XIRP2 and its novel mechanosensor domain. eLife 2023; 12:e72681. [PMID: 37294664 PMCID: PMC10259482 DOI: 10.7554/elife.72681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 05/17/2023] [Indexed: 06/11/2023] Open
Abstract
Prolonged exposure to loud noise has been shown to affect inner ear sensory hair cells in a variety of deleterious manners, including damaging the stereocilia core. The damaged sites can be visualized as 'gaps' in phalloidin staining of F-actin, and the enrichment of monomeric actin at these sites, along with an actin nucleator and crosslinker, suggests that localized remodeling occurs to repair the broken filaments. Herein, we show that gaps in mouse auditory hair cells are largely repaired within 1 week of traumatic noise exposure through the incorporation of newly synthesized actin. We provide evidence that Xin actin binding repeat containing 2 (XIRP2) is required for the repair process and facilitates the enrichment of monomeric γ-actin at gaps. Recruitment of XIRP2 to stereocilia gaps and stress fiber strain sites in fibroblasts is force-dependent, mediated by a novel mechanosensor domain located in the C-terminus of XIRP2. Our study describes a novel process by which hair cells can recover from sublethal hair bundle damage and which may contribute to recovery from temporary hearing threshold shifts and the prevention of age-related hearing loss.
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Affiliation(s)
- Elizabeth L Wagner
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
- Department of Biochemistry & Molecular Genetics, University of VirginiaCharlottesvilleUnited States
| | - Jun-Sub Im
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Stefano Sala
- Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University ChicagoChicagoUnited States
| | - Maura I Nakahata
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Terence E Imbery
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
- Department of Otolaryngology-Head & Neck Surgery, University of VirginiaCharlottesvilleUnited States
| | - Sihan Li
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
- Department of Biochemistry & Molecular Genetics, University of VirginiaCharlottesvilleUnited States
| | - Daniel Chen
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Katherine Nimchuk
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Yael Noy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv UniversityTel AvivIsrael
| | - David W Archer
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
| | - Wenhao Xu
- Genetically Engineered Murine Model (GEMM) Core, University of VirginiaCharlottesvilleUnited States
| | - George Hashisaki
- Department of Otolaryngology-Head & Neck Surgery, University of VirginiaCharlottesvilleUnited States
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv UniversityTel AvivIsrael
| | - Patrick W Oakes
- Department of Cell & Molecular Physiology, Stritch School of Medicine, Loyola University ChicagoChicagoUnited States
| | - Jung-Bum Shin
- Department of Neuroscience, University of VirginiaCharlottesvilleUnited States
- Department of Biochemistry & Molecular Genetics, University of VirginiaCharlottesvilleUnited States
- Department of Otolaryngology-Head & Neck Surgery, University of VirginiaCharlottesvilleUnited States
- Department of Cell Biology, University of VirginiaCharlottesvilleUnited States
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7
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Natarajan N, Batts S, Stankovic KM. Noise-Induced Hearing Loss. J Clin Med 2023; 12:2347. [PMID: 36983347 PMCID: PMC10059082 DOI: 10.3390/jcm12062347] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/22/2023] Open
Abstract
Noise-induced hearing loss (NIHL) is the second most common cause of sensorineural hearing loss, after age-related hearing loss, and affects approximately 5% of the world's population. NIHL is associated with substantial physical, mental, social, and economic impacts at the patient and societal levels. Stress and social isolation in patients' workplace and personal lives contribute to quality-of-life decrements which may often go undetected. The pathophysiology of NIHL is multifactorial and complex, encompassing genetic and environmental factors with substantial occupational contributions. The diagnosis and screening of NIHL are conducted by reviewing a patient's history of noise exposure, audiograms, speech-in-noise test results, and measurements of distortion product otoacoustic emissions and auditory brainstem response. Essential aspects of decreasing the burden of NIHL are prevention and early detection, such as implementation of educational and screening programs in routine primary care and specialty clinics. Additionally, current research on the pharmacological treatment of NIHL includes anti-inflammatory, antioxidant, anti-excitatory, and anti-apoptotic agents. Although there have been substantial advances in understanding the pathophysiology of NIHL, there remain low levels of evidence for effective pharmacotherapeutic interventions. Future directions should include personalized prevention and targeted treatment strategies based on a holistic view of an individual's occupation, genetics, and pathology.
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Affiliation(s)
- Nirvikalpa Natarajan
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Shelley Batts
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Konstantina M. Stankovic
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Wu Tsai Neuroscience Institute, Stanford University, Stanford, CA 94305, USA
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8
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Lysakowski A, Govindaraju AC, Raphael RM. Structural and functional diversity of mitochondria in vestibular/cochlear hair cells and vestibular calyx afferents. Hear Res 2022; 426:108612. [PMID: 36223702 DOI: 10.1016/j.heares.2022.108612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 07/21/2022] [Accepted: 09/19/2022] [Indexed: 11/30/2022]
Abstract
Mitochondria supply energy in the form of ATP to drive a plethora of cellular processes. In heart and liver cells, mitochondria occupy over 20% of the cellular volume and the major need for ATP is easily identifiable - i.e., to drive cross-bridge recycling in cardiac cells or biosynthetic machinery in liver cells. In vestibular and cochlear hair cells the overall cellular mitochondrial volume is much less, and mitochondria structure varies dramatically in different regions of the cell. The regional demands for ATP and cellular forces that govern mitochondrial structure and localization are not well understood. Below we review our current understanding of the heterogeneity of form and function in hair cell mitochondria. A particular focus of this review will be on regional specialization in vestibular hair cells, where large mitochondria are found beneath the cuticular plate in close association with the striated organelle. Recent findings on the role of mitochondria in hair cell death and aging are covered along with potential therapeutic approaches. Potential avenues for future research are discussed, including the need for integrated computational modeling of mitochondrial function in hair cells and the vestibular afferent calyx.
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Affiliation(s)
- Anna Lysakowski
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St., M/C 512, Chicago, IL 60605, USA.
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9
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Yu YC, Wang TC, Shih TC. A comprehensive finite-element human ear model to estimate noise-induced hearing loss associated with occupational noise exposure. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 226:107179. [PMID: 36306646 DOI: 10.1016/j.cmpb.2022.107179] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 09/17/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE Noise is a common occupational and environmental hazard; however, little is known about the use of computational tools to quantitively analyze data on basilar membrane (BM) damage in noise-induced hearing loss (NIHL). Here, we established a comprehensive three-dimensional finite-element human ear model to quantify the impact of noise exposure on BM and perilymph fluid. METHODS We used auditory risk units (ARUs) to evaluate the BM damage for subjects (3 men and 5 women; mean age, 32.75 ± 8.86 years; age range, 24-44 years). A 90-dB sound pressure level (SPL) was normally applied at the external auditory canal (EAC) entrance to simulate sound transmission from the EAC to the cochlea at frequencies of 0.2-10.0 kHz. RESULTS The pressure distribution of perilymph fluid is totally different on frequency responses under low and high sound-evoked (0.013-10.0 kHz). The highest ARUs were 18.479% at the distance of 1 mm from the base, and the second-highest to fourth-highest ARUs occurred at distances of 5-7 mm from the base, where their ARUs were 9.749%, 9.176%, and 11.231%. The total of the ARUs reached 81.956% at external frequencies' sounds of 3.2-5.0 kHz. Among these, the 3.8-kHz and 3.6-kHz frequencies yielded the highest and second-highest ARUs of 20.325% and 19.873%, respectively. CONCLUSIONS This study would inform our understanding of NIHL associated with occupational noise exposure. We present a FE modelling and describe how it might provide a unique way to unravel mechanisms that drive NIHL due to loud noises.
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Affiliation(s)
- You-Cheng Yu
- Department of Biomedical Imaging and Radiological Science, College of Medicine, China Medical University, Taichung 406040, Taiwan
| | - Tang-Chuan Wang
- School of Medicine, College of Medicine, China Medical University, Taichung 406040, Taiwan; Department of Public Health, College of Public Health, China Medical University, Taichung 406040, Taiwan; Department of Otolaryngology-Head and Neck Surgery, China Medical University Hsinchu Hospital, Zhubei City, Hsinchu County 302056, Taiwan
| | - Tzu-Ching Shih
- Department of Biomedical Imaging and Radiological Science, College of Medicine, China Medical University, Taichung 406040, Taiwan; The PhD Program for Medical Engineering and Rehabilitation Science, College of Biomedical Engineering, China Medical University, Taichung 406040, Taiwan.
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10
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Wu PZ, Liberman MC. Age-related stereocilia pathology in the human cochlea. Hear Res 2022; 422:108551. [PMID: 35716423 PMCID: PMC11170281 DOI: 10.1016/j.heares.2022.108551] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 05/13/2022] [Accepted: 06/08/2022] [Indexed: 11/16/2022]
Abstract
Age-related hearing loss in humans is characterized by progressive loss of threshold sensitivity, especially at high frequencies. A multivariable regression of histopathological metrics from normal-aging human cochleae (Wu et al., 2020) showed that hair cell loss better predicts the audiometric shifts than either neural loss or strial atrophy, however considerable variability in age-related threshold elevation remained unexplained. Here, we develop and apply an algorithm to quantify stereocilia pathology in high-power confocal images of inner and outer hair cells in normal aging human cochleae, aged 21 - 71 yrs. Microdissected epithelial wholemounts of the cochleae were immunostained for myosin VIIa and espin to show cuticular plates and stereocilia, respectively, and each cochlea was imaged at 10 log-spaced locations along the cochlear spiral. An approach based on Fourier transforms was used to quantify the regularity of each stereocilia bundle, and the outcome was compared to a parallel analysis by a human observer. Results show a significant age-related decline in stereocilia regularity and increase in stereocilia loss and fusion. Stereocilia pathology was especially severe on the outer hair cells and in the basal half of the cochlea, and may represent a key contributor to age-related threshold elevations. For the one case with an associated pre-mortem audiogram, the threshold shifts are better predicted from the pattern of stereocilia damage than from the pattern of hair cell loss alone.
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Affiliation(s)
- Pei-Zhe Wu
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA 02114, USA; Department of Otolaryngology-Head & Neck Surgery, Harvard Medical School, Boston, MA 02115, USA.
| | - M Charles Liberman
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles St., Boston, MA 02114, USA; Department of Otolaryngology-Head & Neck Surgery, Harvard Medical School, Boston, MA 02115, USA
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11
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Zhai X, Du H, Shen Y, Zhang X, Chen Z, Wang Y, Xu Z. FCHSD2 is required for stereocilia maintenance in mouse cochlear hair cells. J Cell Sci 2022; 135:jcs259912. [PMID: 35892293 DOI: 10.1242/jcs.259912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 07/15/2022] [Indexed: 11/20/2022] Open
Abstract
Stereocilia are F-actin-based protrusions on the apical surface of inner-ear hair cells and are indispensable for hearing and balance perception. The stereocilia of each hair cell are organized into rows of increasing heights, forming a staircase-like pattern. The development and maintenance of stereocilia are tightly regulated, and deficits in these processes lead to stereocilia disorganization and hearing loss. Previously, we showed that the F-BAR protein FCHSD2 is localized along the stereocilia of cochlear hair cells and cooperates with CDC42 to regulate F-actin polymerization and cell protrusion formation in cultured COS-7 cells. In the present work, Fchsd2 knockout mice were established to investigate the role of FCHSD2 in hearing. Our data show that stereocilia maintenance is severely affected in cochlear hair cells of Fchsd2 knockout mice, which leads to progressive hearing loss. Moreover, Fchsd2 knockout mice show increased acoustic vulnerability. Noise exposure causes robust stereocilia degeneration as well as enhanced hearing threshold elevation in Fchsd2 knockout mice. Lastly, Fchsd2/Cdc42 double knockout mice show more severe stereocilia deficits and hearing loss, suggesting that FCHSD2 and CDC42 cooperatively regulate stereocilia maintenance.
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Affiliation(s)
- Xiaoyan Zhai
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology and Key Laboratory for Experimental Teratology of the Ministry of Education , School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China
| | - Haibo Du
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology and Key Laboratory for Experimental Teratology of the Ministry of Education , School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China
| | - Yuxin Shen
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology and Key Laboratory for Experimental Teratology of the Ministry of Education , School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China
| | - Xiujuan Zhang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology and Key Laboratory for Experimental Teratology of the Ministry of Education , School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China
| | - Zhengjun Chen
- State Key Laboratory of Cell Biology , Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences (CAS), Shanghai 200031, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai 200031, China
| | - Yanfei Wang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology and Key Laboratory for Experimental Teratology of the Ministry of Education , School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China
| | - Zhigang Xu
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology and Key Laboratory for Experimental Teratology of the Ministry of Education , School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China
- Shandong Provincial Collaborative Innovation Center of Cell Biology , Shandong Normal University, Jinan, Shandong 250014, China
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12
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Krey JF, Liu C, Belyantseva IA, Bateschell M, Dumont RA, Goldsmith J, Chatterjee P, Morrill RS, Fedorov LM, Foster S, Kim J, Nuttall AL, Jones SM, Choi D, Friedman TB, Ricci AJ, Zhao B, Barr-Gillespie PG. ANKRD24 organizes TRIOBP to reinforce stereocilia insertion points. J Cell Biol 2022; 221:e202109134. [PMID: 35175278 PMCID: PMC8859912 DOI: 10.1083/jcb.202109134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/07/2022] [Accepted: 01/21/2022] [Indexed: 01/04/2023] Open
Abstract
The stereocilia rootlet is a key structure in vertebrate hair cells, anchoring stereocilia firmly into the cell's cuticular plate and protecting them from overstimulation. Using superresolution microscopy, we show that the ankyrin-repeat protein ANKRD24 concentrates at the stereocilia insertion point, forming a ring at the junction between the lower and upper rootlets. Annular ANKRD24 continues into the lower rootlet, where it surrounds and binds TRIOBP-5, which itself bundles rootlet F-actin. TRIOBP-5 is mislocalized in Ankrd24KO/KO hair cells, and ANKRD24 no longer localizes with rootlets in mice lacking TRIOBP-5; exogenous DsRed-TRIOBP-5 restores endogenous ANKRD24 to rootlets in these mice. Ankrd24KO/KO mice show progressive hearing loss and diminished recovery of auditory function after noise damage, as well as increased susceptibility to overstimulation of the hair bundle. We propose that ANKRD24 bridges the apical plasma membrane with the lower rootlet, maintaining a normal distribution of TRIOBP-5. Together with TRIOBP-5, ANKRD24 organizes rootlets to enable hearing with long-term resilience.
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Affiliation(s)
- Jocelyn F. Krey
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Chang Liu
- Department of Otolaryngology—Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN
| | - Inna A. Belyantseva
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD
| | - Michael Bateschell
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Rachel A. Dumont
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Jennifer Goldsmith
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Paroma Chatterjee
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Rachel S. Morrill
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Lev M. Fedorov
- Transgenic Mouse Models, University Shared Resources Program, Oregon Health & Science University, Portland, OR
| | - Sarah Foster
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
| | - Jinkyung Kim
- Department of Otolaryngology—Head & Neck Surgery, Stanford University, Stanford, CA
| | - Alfred L. Nuttall
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
| | - Sherri M. Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, NE
| | - Dongseok Choi
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, OR
| | - Thomas B. Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD
| | - Anthony J. Ricci
- Department of Otolaryngology—Head & Neck Surgery, Stanford University, Stanford, CA
| | - Bo Zhao
- Department of Otolaryngology—Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN
| | - Peter G. Barr-Gillespie
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR
- Vollum Institute, Oregon Health & Science University, Portland, OR
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13
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Vogl C, Neef J, Wichmann C. Methods for multiscale structural and functional analysis of the mammalian cochlea. Mol Cell Neurosci 2022; 120:103720. [DOI: 10.1016/j.mcn.2022.103720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 02/13/2022] [Accepted: 03/08/2022] [Indexed: 01/11/2023] Open
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14
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Ohata K, Kondo M, Ozono Y, Hanada Y, Sato T, Inohara H, Shimada S. Cochlear protection against noise exposure requires serotonin type 3A receptor via the medial olivocochlear system. FASEB J 2021; 35:e21486. [PMID: 33811700 DOI: 10.1096/fj.202002383r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/27/2021] [Accepted: 02/15/2021] [Indexed: 11/11/2022]
Abstract
The cochlear efferent feedback system plays important roles in auditory processing, including regulation of the dynamic range of hearing, and provides protection against acoustic trauma. These functions are performed through medial olivocochlear (MOC) neurons. However, the underlying cellular and molecular mechanisms are not fully understood. The serotonin type 3A (5-HT3A) receptor is widely expressed throughout the nervous system, which suggests important roles in various neural functions. However, involvement of the 5-HT3A receptor in the MOC system remains unclear. We used mice in this study and found that the 5-HT3A receptor was expressed in MOC neurons that innervated outer hair cells in the cochlea and was involved in the activation of MOC neurons by noise exposure. 5-HT3A receptor knockout impaired MOC functions, potentiated noise-induced hearing loss, and increased loss of ribbon synapses following noise exposure. Furthermore, 5-HT3 receptor agonist treatment alleviated the noise-induced hearing loss and loss of ribbon synapses, which enhanced cochlear protection provided by the MOC system. Our findings demonstrate that the 5-HT3A receptor plays fundamental roles in the MOC system and critically contributes to protection from noise-induced hearing impairment.
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Affiliation(s)
- Kazuya Ohata
- Department of Neuroscience and Cell Biology, Graduate School of Medicine, Osaka University, Suita, Japan.,Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Makoto Kondo
- Department of Neuroscience and Cell Biology, Graduate School of Medicine, Osaka University, Suita, Japan.,Addiction Research Unit, Osaka Psychiatric Research Center, Osaka Psychiatric Medical Center, Osaka, Japan
| | - Yoshiyuki Ozono
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Yukiko Hanada
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Takashi Sato
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Hidenori Inohara
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Shoichi Shimada
- Department of Neuroscience and Cell Biology, Graduate School of Medicine, Osaka University, Suita, Japan.,Addiction Research Unit, Osaka Psychiatric Research Center, Osaka Psychiatric Medical Center, Osaka, Japan
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15
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Sea Lice Are Sensitive to Low Frequency Sounds. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2021. [DOI: 10.3390/jmse9070765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The salmon louse Lepeophtheirus salmonis is a major disease problem in salmonids farming and there are indications that it also plays a role in the decline of wild salmon stocks. This study shows the first ultrastructural images of pathological changes in the sensory setae of the first antenna and in inner tissues in different stages of L. salmonis development after sound exposure in laboratory and sea conditions. Given the current ineffectiveness of traditional methods to eradicate this plague, and the strong impact on the environment these treatments often provoke, the described response to sounds and the associated injuries in the lice sensory organs could represent an interesting basis for developing a bioacoustics method to prevent lice infection and to treat affected salmons.
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16
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Stereocilia Rootlets: Actin-Based Structures That Are Essential for Structural Stability of the Hair Bundle. Int J Mol Sci 2020; 21:ijms21010324. [PMID: 31947734 PMCID: PMC6981779 DOI: 10.3390/ijms21010324] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 12/30/2019] [Accepted: 01/01/2020] [Indexed: 12/04/2022] Open
Abstract
Sensory hair cells of the inner ear rely on the hair bundle, a cluster of actin-filled stereocilia, to transduce auditory and vestibular stimuli into electrical impulses. Because they are long and thin projections, stereocilia are most prone to damage at the point where they insert into the hair cell’s soma. Moreover, this is the site of stereocilia pivoting, the mechanical movement that induces transduction, which additionally weakens this area mechanically. To bolster this fragile area, hair cells construct a dense core called the rootlet at the base of each stereocilium, which extends down into the actin meshwork of the cuticular plate and firmly anchors the stereocilium. Rootlets are constructed with tightly packed actin filaments that extend from stereocilia actin filaments which are wrapped with TRIOBP; in addition, many other proteins contribute to the rootlet and its associated structures. Rootlets allow stereocilia to sustain innumerable deflections over their lifetimes and exemplify the unique manner in which sensory hair cells exploit actin and its associated proteins to carry out the function of mechanotransduction.
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17
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Bielefeld EC, Harrison RT, Riley DeBacker J. Pharmaceutical otoprotection strategies to prevent impulse noise-induced hearing loss. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3790. [PMID: 31795721 DOI: 10.1121/1.5132285] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
One of the ongoing challenges for hearing researchers is successful protection of the ear from noise injury. For decades, the most effective methods have been based on modifying the acoustic properties of the noise, either by reducing noise output from various sources, interfering in the acoustic exposure path with environmental controls, or altering the noise dose for the individual with personal hearing protection devices. Because of the inefficiencies of some of the acoustic modification procedures, pharmaceutical otoprotection is targeted at making the cochlea less susceptible to injury. Short-duration, high-level impulse noises, typically caused by small-scale explosions, cause different sets of injuries in the ear than long-duration, low-variance noise exposures. Therefore, the expectation is that the ears exposed to impulse noise may need different pharmaceutical interventions, both in type of compounds used and the time course of administration of the compounds. The current review discusses four different classes of compounds that have been tested as impulse noise otoprotectants. In the process of describing those experiments, particular emphasis is placed on the acoustic properties of the impulses used, with the goal of providing context for evaluating the relevance of these different models to human impulse noise-induced hearing loss.
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Affiliation(s)
- Eric C Bielefeld
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, Ohio 43220, USA
| | - Ryan T Harrison
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, Ohio 43220, USA
| | - J Riley DeBacker
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, Ohio 43220, USA
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18
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Katsuno T, Belyantseva IA, Cartagena-Rivera AX, Ohta K, Crump SM, Petralia RS, Ono K, Tona R, Imtiaz A, Rehman A, Kiyonari H, Kaneko M, Wang YX, Abe T, Ikeya M, Fenollar-Ferrer C, Riordan GP, Wilson EA, Fitzgerald TS, Segawa K, Omori K, Ito J, Frolenkov GI, Friedman TB, Kitajiri SI. TRIOBP-5 sculpts stereocilia rootlets and stiffens supporting cells enabling hearing. JCI Insight 2019; 4:128561. [PMID: 31217345 DOI: 10.1172/jci.insight.128561] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/08/2019] [Indexed: 01/19/2023] Open
Abstract
TRIOBP remodels the cytoskeleton by forming unusually dense F-actin bundles and is implicated in human cancer, schizophrenia, and deafness. Mutations ablating human and mouse TRIOBP-4 and TRIOBP-5 isoforms are associated with profound deafness, as inner ear mechanosensory hair cells degenerate after stereocilia rootlets fail to develop. However, the mechanisms regulating formation of stereocilia rootlets by each TRIOBP isoform remain unknown. Using 3 new Triobp mouse models, we report that TRIOBP-5 is essential for thickening bundles of F-actin in rootlets, establishing their mature dimensions and for stiffening supporting cells of the auditory sensory epithelium. The coiled-coil domains of this isoform are required for reinforcement and maintenance of stereocilia rootlets. A loss of TRIOBP-5 in mouse results in dysmorphic rootlets that are abnormally thin in the cuticular plate but have increased widths and lengths within stereocilia cores, and causes progressive deafness recapitulating the human phenotype. Our study extends the current understanding of TRIOBP isoform-specific functions necessary for life-long hearing, with implications for insight into other TRIOBPopathies.
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Affiliation(s)
- Tatsuya Katsuno
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Inna A Belyantseva
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Alexander X Cartagena-Rivera
- Section on Auditory Mechanics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Keisuke Ohta
- Advanced Imaging Research Center, Kurume University School of Medicine, Kurume, Japan
| | - Shawn M Crump
- Department of Physiology, University of Kentucky, Lexington, Kentucky, USA
| | - Ronald S Petralia
- Advanced Imaging Core, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Kazuya Ono
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Risa Tona
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Ayesha Imtiaz
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Atteeq Rehman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Hiroshi Kiyonari
- Laboratory for Animal Resources and Genetic Engineering, Riken Center for Biosystems Dynamics Research, Kobe, Japan
| | - Mari Kaneko
- Laboratory for Animal Resources and Genetic Engineering, Riken Center for Biosystems Dynamics Research, Kobe, Japan
| | - Ya-Xian Wang
- Advanced Imaging Core, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Takaya Abe
- Laboratory for Animal Resources and Genetic Engineering, Riken Center for Biosystems Dynamics Research, Kobe, Japan
| | - Makoto Ikeya
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Kyoto, Japan
| | - Cristina Fenollar-Ferrer
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA.,Laboratory of Molecular and Cellular Neurobiology, National Institute of Mental Health, NIH, Bethesda, Maryland, USA
| | - Gavin P Riordan
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Elisabeth A Wilson
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Tracy S Fitzgerald
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Kohei Segawa
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Koichi Omori
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Juichi Ito
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | | | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, Maryland, USA
| | - Shin-Ichiro Kitajiri
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
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19
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Wagner EL, Shin JB. Mechanisms of Hair Cell Damage and Repair. Trends Neurosci 2019; 42:414-424. [PMID: 30992136 DOI: 10.1016/j.tins.2019.03.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/04/2019] [Accepted: 03/13/2019] [Indexed: 01/22/2023]
Abstract
Sensory hair cells of the inner ear are exposed to continuous mechanical stress, causing damage over time. The maintenance of hair cells is further challenged by damage from a variety of other ototoxic factors, including loud noise, aging, genetic defects, and ototoxic drugs. This damage can manifest in many forms, from dysfunction of the hair cell mechanotransduction complex to loss of specialized ribbon synapses, and may even result in hair cell death. Given that mammalian hair cells do not regenerate, the repair of hair cell damage is important for continued auditory function throughout life. Here, we discuss how several key hair cell structures can be damaged, and what is known about how they are repaired.
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Affiliation(s)
- Elizabeth L Wagner
- Department of Neuroscience, University of Virginia-School of Medicine, Charlottesville, VA 22908, USA; Department of Biochemistry and Molecular Genetics, University of Virginia-School of Medicine, Charlottesville, VA 22908, USA
| | - Jung-Bum Shin
- Department of Neuroscience, University of Virginia-School of Medicine, Charlottesville, VA 22908, USA.
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20
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Vélez-Ortega AC, Frolenkov GI. Building and repairing the stereocilia cytoskeleton in mammalian auditory hair cells. Hear Res 2019; 376:47-57. [PMID: 30638948 DOI: 10.1016/j.heares.2018.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/19/2018] [Accepted: 12/28/2018] [Indexed: 10/27/2022]
Abstract
Despite all recent achievements in identification of the molecules that are essential for the structure and mechanosensory function of stereocilia bundles in the auditory hair cells of mammalian species, we still have only a rudimentary understanding of the mechanisms of stereocilia formation, maintenance, and repair. Important molecular differences distinguishing mammalian auditory hair cells from hair cells of other types and species have been recently revealed. In addition, we are beginning to solve the puzzle of the apparent life-long stability of the stereocilia bundles in these cells. New data link the stability of the cytoskeleton in the mammalian auditory stereocilia with the normal activity of mechanotransduction channels. These data suggest new ideas on how a terminally-differentiated non-regenerating hair cell in the mammalian cochlea may repair and tune its stereocilia bundle throughout the life span of the organism.
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Affiliation(s)
- A Catalina Vélez-Ortega
- Department of Physiology, University of Kentucky, 800 Rose St., Lexington, KY, 40536-0298, USA.
| | - Gregory I Frolenkov
- Department of Physiology, University of Kentucky, 800 Rose St., Lexington, KY, 40536-0298, USA.
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21
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Coyat C, Cazevieille C, Baudoux V, Larroze-Chicot P, Caumes B, Gonzalez-Gonzalez S. Morphological consequences of acoustic trauma on cochlear hair cells and the auditory nerve. Int J Neurosci 2018; 129:580-587. [DOI: 10.1080/00207454.2018.1552693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Carolanne Coyat
- CILcare. 2214, Boulevard de la Lironde, Parc Scientifique Agropolis, Montpellier, France
| | - Chantal Cazevieille
- Correlative Microscopy and Electron Tomography Platform, Hopital Saint Eloi, Montpellier, France
| | - Véronique Baudoux
- CILcare. 2214, Boulevard de la Lironde, Parc Scientifique Agropolis, Montpellier, France
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22
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Mechanotransduction is required for establishing and maintaining mature inner hair cells and regulating efferent innervation. Nat Commun 2018; 9:4015. [PMID: 30275467 PMCID: PMC6167318 DOI: 10.1038/s41467-018-06307-w] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 08/21/2018] [Indexed: 12/13/2022] Open
Abstract
In the adult auditory organ, mechanoelectrical transducer (MET) channels are essential for transducing acoustic stimuli into electrical signals. In the absence of incoming sound, a fraction of the MET channels on top of the sensory hair cells are open, resulting in a sustained depolarizing current. By genetically manipulating the in vivo expression of molecular components of the MET apparatus, we show that during pre-hearing stages the MET current is essential for establishing the electrophysiological properties of mature inner hair cells (IHCs). If the MET current is abolished in adult IHCs, they revert into cells showing electrical and morphological features characteristic of pre-hearing IHCs, including the re-establishment of cholinergic efferent innervation. The MET current is thus critical for the maintenance of the functional properties of adult IHCs, implying a degree of plasticity in the mature auditory system in response to the absence of normal transduction of acoustic signals. Mechanoelectrical transducer (MET) channels on the tips of inner hair cells are essential for transducing auditory sensory information. Here, the authors show that disrupting MET channel function also prevents the preservation of normal inner hair cell identity in adult mice.
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23
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Vogl C, Butola T, Haag N, Hausrat TJ, Leitner MG, Moutschen M, Lefèbvre PP, Speckmann C, Garrett L, Becker L, Fuchs H, Hrabe de Angelis M, Nietzsche S, Kessels MM, Oliver D, Kneussel M, Kilimann MW, Strenzke N. The BEACH protein LRBA is required for hair bundle maintenance in cochlear hair cells and for hearing. EMBO Rep 2017; 18:2015-2029. [PMID: 28893864 DOI: 10.15252/embr.201643689] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 07/27/2017] [Accepted: 08/07/2017] [Indexed: 12/15/2022] Open
Abstract
Lipopolysaccharide-responsive beige-like anchor protein (LRBA) belongs to the enigmatic class of BEACH domain-containing proteins, which have been attributed various cellular functions, typically involving intracellular protein and membrane transport processes. Here, we show that LRBA deficiency in mice leads to progressive sensorineural hearing loss. In LRBA knockout mice, inner and outer hair cell stereociliary bundles initially develop normally, but then partially degenerate during the second postnatal week. LRBA deficiency is associated with a reduced abundance of radixin and Nherf2, two adaptor proteins, which are important for the mechanical stability of the basal taper region of stereocilia. Our data suggest that due to the loss of structural integrity of the central parts of the hair bundle, the hair cell receptor potential is reduced, resulting in a loss of cochlear sensitivity and functional loss of the fraction of spiral ganglion neurons with low spontaneous firing rates. Clinical data obtained from two human patients with protein-truncating nonsense or frameshift mutations suggest that LRBA deficiency may likewise cause syndromic sensorineural hearing impairment in humans, albeit less severe than in our mouse model.
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Affiliation(s)
- Christian Vogl
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Tanvi Butola
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Synaptic Nanophysiology Group, Max-Planck-Institute for Biophysical Chemistry Göttingen, Göttingen, Germany
| | - Natja Haag
- Institute for Biochemistry I, University Hospital Jena, Jena, Germany
| | - Torben J Hausrat
- Department for Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Michael G Leitner
- Department of Physiology, Philipps University Marburg, Marburg, Germany
| | - Michel Moutschen
- Department of Immunology and Infectious Diseases, University of Liège CHU Liège, Liège, Belgium
| | - Philippe P Lefèbvre
- Department of Otorhinolaryngology, University of Liège CHU Liège, Liège, Belgium
| | - Carsten Speckmann
- Division of Pediatric Hematology and Oncology, Center for Chronic Immunodeficiency and Department of Pediatrics and Adolescent Medicine, Medical Centre, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lillian Garrett
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Developmental Genetics, Helmholtz Zentrum München German Research Center for Environmental Health, Neuherberg, Germany
| | - Lore Becker
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München German Research Center for Environmental Health, Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München German Research Center for Environmental Health, Neuherberg, Germany
| | - Martin Hrabe de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München German Research Center for Environmental Health, Neuherberg, Germany.,Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, München, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | | | - Michael M Kessels
- Institute for Biochemistry I, University Hospital Jena, Jena, Germany
| | - Dominik Oliver
- Department of Physiology, Philipps University Marburg, Marburg, Germany
| | - Matthias Kneussel
- Department for Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Manfred W Kilimann
- Institute for Auditory Neuroscience, University Medical Center Göttingen, Göttingen, Germany.,Department of Molecular Neurobiology, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Nicola Strenzke
- Auditory Systems Physiology Group Department of Otolaryngology University Medical Center Göttingen, Göttingen, Germany
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Remodeling of the Inner Hair Cell Microtubule Meshwork in a Mouse Model of Auditory Neuropathy AUNA1. eNeuro 2016; 3:eN-NWR-0295-16. [PMID: 28058271 PMCID: PMC5197407 DOI: 10.1523/eneuro.0295-16.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/10/2016] [Accepted: 11/11/2016] [Indexed: 11/26/2022] Open
Abstract
Auditory neuropathy 1 (AUNA1) is a form of human deafness resulting from a point mutation in the 5′ untranslated region of the Diaphanous homolog 3 (DIAPH3) gene. Notably, the DIAPH3 mutation leads to the overexpression of the DIAPH3 protein, a formin family member involved in cytoskeleton dynamics. Through study of diap3-overexpressing transgenic (Tg) mice, we examine in further detail the anatomical, functional, and molecular mechanisms underlying AUNA1. We identify diap3 as a component of the hair cells apical pole in wild-type mice. In the diap3-overexpressing Tg mice, which show a progressive threshold shift associated with a defect in inner hair cells (IHCs), the neurotransmitter release and potassium conductances are not affected. Strikingly, the overexpression of diap3 results in a selective and early-onset alteration of the IHC cuticular plate. Molecular dissection of the apical components revealed that the microtubule meshwork first undergoes aberrant targeting into the cuticular plate of Tg IHCs, followed by collapse of the stereociliary bundle, with eventual loss of the IHC capacity to transmit incoming auditory stimuli.
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Pathophysiology of the inner ear after blast injury caused by laser-induced shock wave. Sci Rep 2016; 6:31754. [PMID: 27531021 PMCID: PMC4987642 DOI: 10.1038/srep31754] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/25/2016] [Indexed: 11/08/2022] Open
Abstract
The ear is the organ that is most sensitive to blast overpressure, and ear damage is most frequently seen after blast exposure. Blast overpressure to the ear results in sensorineural hearing loss, which is untreatable and is often associated with a decline in the quality of life. In this study, we used a rat model to demonstrate the pathophysiological and structural changes in the inner ear that replicate pure sensorineural hearing loss associated with blast injury using laser-induced shock wave (LISW) without any conductive hearing loss. Our results indicate that threshold elevation of the auditory brainstem response (ABR) after blast exposure was primarily caused by outer hair cell dysfunction induced by stereociliary bundle disruption. The bundle disruption pattern was unique; disturbed stereocilia were mostly observed in the outermost row, whereas those in the inner and middle rows stereocilia remained intact. In addition, the ABR examination showed a reduction in wave I amplitude without elevation of the threshold in the lower energy exposure group. This phenomenon was caused by loss of the synaptic ribbon. This type of hearing dysfunction has recently been described as hidden hearing loss caused by cochlear neuropathy, which is associated with tinnitus or hyperacusis.
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Pollock LM, McDermott BM. The cuticular plate: A riddle, wrapped in a mystery, inside a hair cell. ACTA ACUST UNITED AC 2015; 105:126-39. [DOI: 10.1002/bdrc.21098] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 05/31/2015] [Indexed: 01/11/2023]
Affiliation(s)
- Lana M. Pollock
- Department of Otolaryngology-Head and Neck Surgery; Case Western Reserve University; Cleveland Ohio
- Department of Genetics and Genome Sciences; Case Western Reserve University; Cleveland Ohio
| | - Brian M. McDermott
- Department of Otolaryngology-Head and Neck Surgery; Case Western Reserve University; Cleveland Ohio
- Department of Genetics and Genome Sciences; Case Western Reserve University; Cleveland Ohio
- Department of Biology; Case Western Reserve University; Cleveland Ohio
- Department of Neurosciences; Case Western Reserve University; Cleveland Ohio
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Abstract
OBJECTIVES To determine whether suprathreshold measures of auditory function, such as distortion-product otoacoustic emissions (DPOAEs) and auditory brainstem responses (ABRs), are correlated with noise exposure history in normal-hearing human ears. Recent data from animal studies have revealed significant deafferentation of auditory nerve fibers after full recovery from temporary noise-induced hearing loss. Furthermore, these data report smaller ABR wave I amplitudes in noise-exposed animal ears when compared with non-noise-exposed control animals or prenoise exposure amplitudes in the same animal. It is unknown whether a similar phenomenon exists in the normal-hearing, noise-exposed human ear. DESIGN Thirty normal-hearing human subjects with a range of noise exposure backgrounds (NEBs) participated in this study. NEB was quantified by the use of a noise exposure questionnaire that extensively queried loud sound exposure during the previous 12 months. DPOAEs were collected at three f2s (1, 2, and 4 kHz) over a range of L2s. DPOAE stimulus level began at 80 dB forward-pressure level and decreased in 10 dB steps. Two-channel ABRs were collected in response to click stimuli and 4 kHz tone bursts; one channel used an ipsilateral mastoid electrode and the other an ipsilateral tympanic membrane electrode. ABR stimulus level began at 90 dB nHL and was decreased in 10 dB steps. Amplitudes of waves I and V of the ABR were analyzed. RESULTS A statistically significant relationship between ABR wave I amplitude and NEB was found for clicked-evoked ABRs recorded at a stimulus level of 90 dB nHL using a mastoid recording electrode. For this condition, ABR wave I amplitudes decreased as a function of NEB. Similar systematic trends were present for ABRs collected in response to clicks and 4 kHz tone bursts at additional suprathreshold stimulation levels (≥70 dB nHL). The relationship weakened and disappeared with decreases in stimulation level (≤60 dB nHL). Similar patterns were present for ABRs collected using a tympanic membrane electrode. However, these relationships were not statistically significant and were weaker and more variable than those collected using a mastoid electrode. In contrast to the findings for ABR wave I, wave V amplitude was not significantly related to NEB. Furthermore, there was no evidence of a systematic relationship between suprathreshold DPOAEs and NEB. CONCLUSIONS A systematic trend of smaller ABR wave I amplitudes was found in normal-hearing human ears with greater amounts of voluntary NEB in response to suprathreshold clicks and 4 kHz tone bursts. These findings are consistent with the data from previous work completed in animals, where the reduction in suprathreshold responses was a result of deafferentation of high-threshold/low-spontaneous rate auditory nerve fibers. These data suggest that a similar mechanism might be operating in human ears after exposure to high sound levels. However, evidence of this damage is only apparent when examining suprathreshold wave I amplitude of the ABR. In contrast, suprathreshold DPOAE level was not significantly related to NEB. This was expected, given noise-induced auditory damage findings in animal ears did not extend to the outer hair cells, the generator for the DPOAE response.
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Piazza V, Weinhausen B, Diaz A, Dammann C, Maurer C, Reynolds M, Burghammer M, Köster S. Revealing the structure of stereociliary actin by X-ray nanoimaging. ACS NANO 2014; 8:12228-12237. [PMID: 25415362 DOI: 10.1021/nn5041526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Hair cell stereocilia are crucial for hearing and the sense of balance. They include an array of accurately packed, parallel actin filaments and act as levers, which transform mechanical deformation into neuronal signals. The length of vestibular stereocilia reaches several micrometers, whereas, for individual microfilaments, the diameter and therefore the characteristic length scale in the lateral direction is on the order of a few nanometers. These orders of magnitude render X-rays an ideal tool for investigating actin packing, and numerous studies on reconstituted in vitro systems have revealed important information. Here we report on the characterization of intact stereocilia using two nanoscale X-ray techniques. We use X-ray ptychography to image stereocilia with quantitative phase contrast and high dose efficiency, showing stereocilia with diameters and lengths in the expected range. We further employ X-ray nanodiffraction using a nanofocused X-ray beam on the same order of magnitude as the width of a stereocilium. Despite the small probe volume we can clearly visualize the stereocilia bundles. From the individual diffraction patterns we determine the local orientation of the actin structures and can clearly correlate them with the corresponding visible-light fluorescence images. Furthermore, azimuthal integration of individual diffraction patterns reveals distinct intensity curves, showing modulations of the signal, which reflect the relevant length scales and pronounced order in the biological system. The applied techniques are not limited to the studies on stereocilia but have the potential of being applied to many biological and soft-matter systems, in particular if a pronounced degree of order is present.
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Affiliation(s)
- Valeria Piazza
- Institute for X-ray Physics, Georg-August-University Göttingen , Göttingen, Germany
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Chen L, Dean C, Gandolfi M, Nahm E, Mattiace L, Kim AH. Dexamethasone's effect in the retrocochlear auditory centers of a noise-induced hearing loss mouse model. Otolaryngol Head Neck Surg 2014; 151:667-74. [PMID: 25113508 DOI: 10.1177/0194599814545771] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Examine prophylactic effects of dexamethasone (Dex) in retrocochlear auditory centers in a noise-induced hearing loss (NIHL) mouse model. STUDY DESIGN Prospective animal study. SETTING Academic research center. SUBJECTS AND METHODS Thirty-two mice were divided into control, untreated, saline (2 and 10 µL), and Dex (2 and 10 µL) groups. Dex was applied intratympanically (IT) prior to 110 to 120 dB noise over 6 hours. Auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) were performed at 1 day, 1 week, 1 month, and 2 months. Retrocochlear neuronal cells were labeled with FluoroGold and counted. Hair cells of the organ of Corti were labeled with fluorescein isothiocyanate-conjugated phalloidin and counted. RESULTS Auditory brainstem response thresholds of untreated NIHL, 2 and 10 µL IT saline, and 2 and 10 µL IT Dex were 21.7 ± 2.9 dB, 20 ± 0 dB, 20 ± 5 dB, 18.3 ± 2.9 dB, and 18.3 ± 2.9 dB, respectively. At 1-day post NIHL, all groups demonstrated profound hearing loss. At 2 weeks, 2 and 10 µL Dex thresholds improved to 47.5 ± 3.5 dB and 48.8 ± 18.9 dB, respectively, whereas the untreated and saline groups remained unchanged. Mean cell counts in the cochlear nucleus (CN), superior olivary complex (SOC), and lateral lemniscus (LL) of control mice were 1483 ± 190, 2807 ± 67, and 112 ± 20, respectively. After acoustic trauma, the untreated, saline, and 2 µL Dex groups yielded decreased neuronal counts in the SOC. In contrast, the 10 µL Dex group had 1883 ± 186 (CN), 2774 ± 182 (SOC), and 166 ± 18 (LL). There was sporadic hair cell loss for all traumatized groups. CONCLUSION Our NIHL mouse model demonstrated dose-dependent Dex pretreatment otoprotection against NIHL with preservation of retrocochlear auditory neurons.
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Affiliation(s)
- Leon Chen
- Department of Otolaryngology-Head and Neck Surgery, New York Eye and Ear Infirmary, New York, New York, USA
| | - Clare Dean
- Department of Otolaryngology-Head and Neck Surgery, New York Eye and Ear Infirmary, New York, New York, USA
| | - Michele Gandolfi
- Department of Otolaryngology-Head and Neck Surgery, New York Eye and Ear Infirmary, New York, New York, USA
| | - Edmund Nahm
- Department of Otolaryngology-Head and Neck Surgery, New York Eye and Ear Infirmary, New York, New York, USA
| | - Linda Mattiace
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA
| | - Ana H Kim
- Department of Otolaryngology-Head and Neck Surgery, New York Eye and Ear Infirmary, New York, New York, USA Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA
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31
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The prevention of noise induced hearing loss in children. Int J Pediatr 2012; 2012:473541. [PMID: 23304173 PMCID: PMC3530863 DOI: 10.1155/2012/473541] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 11/14/2012] [Accepted: 11/16/2012] [Indexed: 11/17/2022] Open
Abstract
Increasingly, our acoustic environment is filled with amplified sound sources (e.g., MP3 players, video game stations, and sports/entertainment venues). There is serious concern and also some controversy about the risks of acoustic trauma in children. This overview provides some basic information on the physiological mechanisms that lead to noise induced hearing loss, a survey of various studies that, on balance, indicates that there is cause for concern, and finally a discussion on measures that can help to prevent noise induced hearing loss in children. This paper is designed for public health and other healthcare professions (ENT, audiologists, family doctors, and pediatricians) who should understand the risks of noise induced hearing loss and its prevention.
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Striated organelle, a cytoskeletal structure positioned to modulate hair-cell transduction. Proc Natl Acad Sci U S A 2012; 109:4473-8. [PMID: 22396594 DOI: 10.1073/pnas.1101003109] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The striated organelle (SO), a cytoskeletal structure located in the apical region of cochlear and vestibular hair cells, consists of alternating, cross-linked, thick and thin filamentous bundles. In the vestibular periphery, the SO is well developed in both type I and type II hair cells. We studied the 3D structure of the SO with intermediate-voltage electron microscopy and electron microscope tomography. We also used antibodies to α-2 spectrin, one protein component, to trace development of the SO in vestibular hair cells over the first postnatal week. In type I cells, the SO forms an inverted open-ended cone attached to the cell membrane along both its upper and lower circumferences and separated from the cuticular plate by a dense cluster of exceptionally large mitochondria. In addition to contacts with the membrane and adjacent mitochondria, the SO is connected both directly and indirectly, via microtubules, to some stereociliary rootlets. The overall architecture of the apical region in type I hair cells--a striated structure restricting a cluster of large mitochondria between its filaments, the cuticular plate, and plasma membrane--suggests that the SO might serve two functions: to maintain hair-cell shape and to alter transduction by changing the geometry and mechanical properties of hair bundles.
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Effects of cigarette smoking on hearing recovery from noise-induced temporary hearing threshold shifts in mice. Otol Neurotol 2011; 32:926-32. [PMID: 21725268 DOI: 10.1097/mao.0b013e318225575a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
HYPOTHESIS Cigarette smoking may potentiate noise-induced hearing loss. BACKGROUND Many epidemiological studies have shown that cigarette smoking is a major risk factor for noise-induced hearing loss. METHODS BALB/c mice were exposed to passive smoking for 2 h/d for 2 weeks before exposure to 110-dB sound pressure level white noise for 3 hours once. Hearing was assessed via the auditory brainstem response with tone-burst stimulation and distortion product otoacoustic emissions before and at 1, 3, 5, 7, 14, 21, and 28 days after noise exposure. Oxidative stress and hypoxia were assessed by immunostaining with 8-oxoG and hypoxia-inducible factor 1α, respectively. RESULTS Control mice unexposed to both smoking and noise and mice exposed to smoking only showed no shift in hearing threshold. In contrast, mice exposed to noise only or smoking plus noise showed abrupt increases in hearing threshold. In mice exposed to noise only, hearing threshold returned to prenoise levels after 2 weeks. However, in mice exposed to smoking plus noise, the loss of hearing was significantly higher, and hearing threshold did not return to the pre-exposure levels until 4 weeks later. Positive staining with 8-oxoG and hypoxia-inducible factor 1α were observed in the inner ear of the smoking-only and smoking-plus-noise group similar to noise-only mice, whereas no positive staining was observed in control group. CONCLUSION These results indicate that cigarette smoking may potentiate the harmful effects of noise on hearing and disturb the recovery mechanism in the cochlea.
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Nowotny M, Gummer AW. Vibration responses of the organ of Corti and the tectorial membrane to electrical stimulation. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 130:3852-3872. [PMID: 22225042 DOI: 10.1121/1.3651822] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Coupling of somatic electromechanical force from the outer hair cells (OHCs) into the organ of Corti is investigated by measuring transverse vibration patterns of the organ of Cori and tectorial membrane (TM) in response to intracochlear electrical stimulation. Measurement places at the organ of Corti extend from the inner sulcus cells to Hensen's cells and at the lower (and upper) surface of the TM from the inner sulcus to the OHC region. These locations are in the neighborhood of where electromechanical force is coupled into (1) the mechanoelectrical transducers of the stereocilia and (2) fluids of the organ of Corti. Experiments are conducted in the first, second, and third cochlear turns of an in vitro preparation of the adult guinea pig cochlea. Vibration measurements are made at functionally relevant stimulus frequencies (0.48-68 kHz) and response amplitudes (<15 nm). The experiments provide phase relations between the different structures, which, dependent on frequency range and longitudinal cochlear position, include in-phase transverse motions of the TM, counterphasic transverse motions between the inner hair cell and OHCs, as well as traveling-wave motion of Hensen's cells in the radial direction. Mechanics of sound processing in the cochlea are discussed based on these phase relationships.
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Affiliation(s)
- Manuela Nowotny
- Faculty of Medicine, Section of Physiological Acoustics and Communication, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Strasse 5, 72076 Tübingen, Germany
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Bielefeld EC, Hangauer D, Henderson D. Protection from impulse noise-induced hearing loss with novel Src-protein tyrosine kinase inhibitors. Neurosci Res 2011; 71:348-54. [PMID: 21840347 PMCID: PMC3210387 DOI: 10.1016/j.neures.2011.07.1836] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 07/28/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
Apoptosis is a significant mechanism of cochlear hair cell loss from noise. Molecules that inhibit apoptotic intracellular signaling reduce cochlear damage and hearing loss from noise. The current study is an extension of a previous study of the protective value of Src-protein tyrosine kinase inhibitors against noise (Harris et al., 2005). The current study tested three Src-inhibitors: the indole-based KX1-141, the biaryl-based KX2-329, and the ATP-competitive KX2-328. Each of the three drugs was delivered into the chinchillas' cochleae by allowing the solutions to diffuse across the round window membrane thirty minutes prior to exposure to impulse noise. Hearing thresholds were measured using auditory evoked responses from electrodes in the inferior colliculi. Ears treated with KX2-329 showed significantly lower threshold shifts and outer hair cell losses than the control group. The cochleae treated with KX1-141 and KX2-328 did not show statistically significant protection from the impulse noise. The finding of protection with KX2-329 demonstrates that a biaryl-based Src inhibitor has protective capacity against noise-induced hearing loss that is as good as that demonstrated by KX1-004, a Src inhibitor drug that has been studied extensively as an otoprotectant against noise, and suggests that KX2-329 could be useful for protection against noise.
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Affiliation(s)
- Eric C. Bielefeld
- Department of Speech and Hearing Science, The Ohio State University, 110 Pressey Hall, 1070 Carmack Road, Columbus, OH 43220, USA
| | - David Hangauer
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Donald Henderson
- Center for Hearing and Deafness, Department of Communicative Disorders and Sciences, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA
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Acoustic overstimulation-induced apoptosis in fibrocytes of the cochlear spiral limbus of mice. Eur Arch Otorhinolaryngol 2011; 268:973-8. [DOI: 10.1007/s00405-011-1484-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Accepted: 01/06/2011] [Indexed: 10/18/2022]
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Chrostowski M, Yang L, Wilson HR, Bruce IC, Becker S. Can homeostatic plasticity in deafferented primary auditory cortex lead to travelling waves of excitation? J Comput Neurosci 2010; 30:279-99. [PMID: 20623168 DOI: 10.1007/s10827-010-0256-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 06/06/2010] [Accepted: 06/18/2010] [Indexed: 12/19/2022]
Abstract
Travelling waves of activity in neural circuits have been proposed as a mechanism underlying a variety of neurological disorders, including epileptic seizures, migraine auras and brain injury. The highly influential Wilson-Cowan cortical model describes the dynamics of a network of excitatory and inhibitory neurons. The Wilson-Cowan equations predict travelling waves of activity in rate-based models that have sufficiently reduced levels of lateral inhibition. Travelling waves of excitation may play a role in functional changes in the auditory cortex after hearing loss. We propose that down-regulation of lateral inhibition may be induced in deafferented cortex via homeostatic plasticity mechanisms. We use the Wilson-Cowan equations to construct a spiking model of the primary auditory cortex that includes a novel, mathematically formalized description of homeostatic plasticity. In our model, the homeostatic mechanisms respond to hearing loss by reducing inhibition and increasing excitation, producing conditions under which travelling waves of excitation can emerge. However, our model predicts that the presence of spontaneous activity prevents the development of long-range travelling waves of excitation. Rather, our simulations show short-duration excitatory waves that cancel each other out. We also describe changes in spontaneous firing, synchrony and tuning after simulated hearing loss. With the exception of shifts in characteristic frequency, changes after hearing loss were qualitatively the same as empirical findings. Finally, we discuss possible applications to tinnitus, the perception of sound without an external stimulus.
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Affiliation(s)
- Michael Chrostowski
- McMaster Integrative Neuroscience Discovery & Study, McMaster University, 1280 Main Street West, Hamilton, ON, Canada.
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Yoshioka M, Uchida Y, Sugiura S, Ando F, Shimokata H, Nomura H, Nakashima T. The impact of arterial sclerosis on hearing with and without occupational noise exposure: a population-based aging study in males. Auris Nasus Larynx 2010; 37:558-64. [PMID: 20430548 DOI: 10.1016/j.anl.2010.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Revised: 02/01/2010] [Accepted: 02/23/2010] [Indexed: 11/13/2022]
Abstract
OBJECTIVES Arterial sclerosis contributes to inadequate blood supply to multiple organs, suggesting that general atherosclerosis may play an important role in the inner ear. Since noise is a major etiology for hearing loss, the aim of this study was to evaluate both the respective and the combined effects of arterial sclerosis and occupational noise exposure on hearing after accounting for age in middle-aged and elderly men. METHODS The evaluation was conducted using 773 subjects from a population-based sample of 1189 men, aged 40-83 years. The impact of carotid atherosclerosis (CA) or retinal arteriolosclerosis (RA) on hearing was assessed according to history of occupational noise exposure (Noise) obtained in a questionnaire. Differences in the mean pure-tone thresholds at each frequency, between the CA (+) and CA (-) groups or between the RA (+) and RA (-) groups, based on noise exposure were compared using the general linear model (GLM) Procedure in SAS, with adjustments for age. Then, the main effect of CA or RA, and the interactive effect of noise and either CA or RA on pure-tone threshold at seven frequencies were analyzed using an analysis of covariance (ANCOVA), after adjusting for age. RESULTS In the Noise (+) group, a statistically significant deterioration in hearing was found in the CA (+) group compared with the CA (-) group at 500 and 1000 Hz. The results in RA were significant at even lower frequencies than in CA. In the results from ANCOVA, the significant main effect of CA was shown in the pure-tone threshold at 8000 Hz, but not in the analysis of RA. A significant interactive effect of either CA or RA and Noise was observed in hearing at the range from 125 to 1000 Hz. CONCLUSIONS The present study suggests that the impact of arterial sclerosis on hearing is limited but significantly hazardous in middle-aged and elderly men, and that arterial sclerosis exacerbates the deleterious effects of noise on hearing. Early recognition of arterial sclerosis might be contributory to the hearing prognosis after middle age, especially for noise-exposed men.
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Affiliation(s)
- Mayumi Yoshioka
- Department of Otorhinolaryngology Cognitive and Speech Medicine, Nagoya University School of Medicine, 65 Tsuruma-Cho, Showa Ward, Nagoya City, Aichi Prefecture 466-8550, Japan
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40
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Kopke RD. Pharmacological approaches to the prevention and treatment of cochlear injury due to noise. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/16513860601181046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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41
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Schuck JB, Smith ME. Cell proliferation follows acoustically-induced hair cell bundle loss in the zebrafish saccule. Hear Res 2009; 253:67-76. [PMID: 19327392 DOI: 10.1016/j.heares.2009.03.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 03/11/2009] [Accepted: 03/16/2009] [Indexed: 10/21/2022]
Abstract
Fishes are capable of regenerating sensory hair cells in the inner ear after acoustic trauma. However, a time course of auditory hair cell regeneration has not been established for zebrafish. Adult zebrafish (Danio rerio) were exposed to a 100 Hz pure tone at 179 dB re 1 microPa RMS for 36 h and then allowed to recover for 0-14 days before morphological analysis. Hair cell bundle loss and recovery were determined using phalloidin to visualize hair bundles. Cell proliferation was quantified through bromodeoxyuridine (BrdU) labeling. Immediately following sound exposure, zebrafish saccules exhibited significant hair bundle damage (e.g., splayed, broken, and missing stereocilia) and loss (i.e., missing bundles and lesions in the epithelia) in the caudal region. Hair bundle counts increased over the course of the experiment, reaching pre-treatment levels at 14 days post-sound exposure (dpse). Low levels of proliferation were observed in untreated controls, indicating that some cells of the zebrafish saccule are mitotically active in the absence of a damaging event. In sound-exposed fish, cell proliferation peaked two dpse in the caudal region, and to a lesser extent in the rostral region. This proliferation was followed by an increase in numbers of cuticular plates with rudimentary stereocilia and immature-like hair bundles at 7 and 14 dpse, suggesting that at least some of the saccular cell proliferation resulted in newly formed hair cells. This study establishes a time course of hair cell bundle regeneration in the zebrafish inner ear and demonstrates that cell proliferation is associated with the regenerative process.
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Affiliation(s)
- Julie B Schuck
- Department of Biology and Biotechnology Center, Western Kentucky University, 1906 College Heights Blvd. #11080, Bowling Green, KY 42104-1080, USA
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Kikkawa YS, Pawlowski KS, Wright CG, Alagramam KN. Development of Outer Hair Cells in Ames Waltzer Mice: Mutation in Protocadherin 15 Affects Development of Cuticular Plate and Associated Structures. Anat Rec (Hoboken) 2008; 291:224-32. [DOI: 10.1002/ar.20632] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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43
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Kitsunai Y, Yoshida N, Murakoshi M, Iida K, Kumano S, Kobayashi T, Wada H. Effects of heat stress on filamentous actin and prestin of outer hair cells in mice. Brain Res 2007; 1177:47-58. [PMID: 17884025 DOI: 10.1016/j.brainres.2007.08.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 08/08/2007] [Accepted: 08/08/2007] [Indexed: 12/16/2022]
Abstract
When the ear is exposed to traumatic loud noise, outer hair cells (OHCs) are damaged and thus permanent hearing loss occurs. Recently, prior conditioning with heat stress has been reported to protect OHCs from traumatic noise exposure by increasing the stiffness of the OHC soma and has also been reported to enhance distortion product otoacoustic emissions [DPOAEs; Murakoshi, M., Yoshida, N., Kitsunai, Y., Iida, K., Kumano, S., Suzuki, T., Kobayashi, T., Wada, H., 2006. Effects of heat stress on Young's modulus of outer hair cells in mice. Brain Res. 1107, 121-130]. In the present study, to further investigate the heat stress-induced protective mechanism of hearing and such stress-induced DPOAE enhancement mechanism, the amount of filamentous actin (F-actin), which is concerned with cell stiffness, and the amount of prestin, which is concerned with the generation of DPOAEs, were examined in OHCs, with and without heat stress. Heat stress was found to increase the amount of F-actin 6-24 h after heat stress. The greatest increase in the amount of F-actin was observed at the cuticular plate where F-actin anchors the roots of the stereocilia to the cell body. Based on this result, the part of the stereocilia most reinforced and protected by heat stress was concluded to be the roots of the stereocilia. In contrast with F-actin, heat stress did not affect the amount of prestin.
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Affiliation(s)
- Yoko Kitsunai
- Department of Bioengineering and Robotics, Tohoku University, 6-6-01 Aoba-yama, Sendai 980-8579, Japan
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44
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Saunders JC. The role of central nervous system plasticity in tinnitus. JOURNAL OF COMMUNICATION DISORDERS 2007; 40:313-34. [PMID: 17418230 PMCID: PMC2083119 DOI: 10.1016/j.jcomdis.2007.03.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Accepted: 03/01/2007] [Indexed: 05/14/2023]
Abstract
UNLABELLED Tinnitus is a vexing disorder of hearing characterized by sound sensations originating in the head without any external stimulation. The specific etiology of these sensations is uncertain but frequently associated with hearing loss. The "neurophysiogical" model of tinnitus has enhanced appreciation of central nervous system (CNS) contributions. The model assumes that plastic changes in the primary and non-primary auditory pathways contribute to tinnitus with the former perhaps sustaining them, and the latter contributing to perceived severity and emotionality. These plastic changes are triggered by peripheral injury, which results in new patterns of brain activity due to anatomic alterations in the connectivity of CNS neurons. These alterations may change the balance between excitatory and inhibitory brain processes, perhaps producing cascades of new neural activity flowing between brainstem and cortex in a self-sustaining manner that produces persistent perceptions of tinnitus. The bases of this model are explored with an attempt to distinguish phenomenological from mechanistic explanations. LEARNING OUTCOMES (1) Readers will learn that the variables associated with the behavioral experience of tinnitus are as complex as the biological variables. (2) Readers will understand what the concept of neuroplastic brain change means, and how it is associated with tinnitus. (3) Readers will learn that there may be no one brain location associated with tinnitus, and it may result from interactions between multiple brain areas. (4) Readers will learn how disinhibition, spontaneous activity, neural synchronization, and tonotopic reorganization may contribute to tinnitus.
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Affiliation(s)
- James C Saunders
- Department of Otorhinolaryngololgy, Head and Neck Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
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45
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Lechene C, Hillion F, McMahon G, Benson D, Kleinfeld AM, Kampf JP, Distel D, Luyten Y, Bonventre J, Hentschel D, Park KM, Ito S, Schwartz M, Benichou G, Slodzian G. High-resolution quantitative imaging of mammalian and bacterial cells using stable isotope mass spectrometry. J Biol 2007; 5:20. [PMID: 17010211 PMCID: PMC1781526 DOI: 10.1186/jbiol42] [Citation(s) in RCA: 226] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 04/21/2006] [Accepted: 05/11/2006] [Indexed: 11/28/2022] Open
Abstract
Background Secondary-ion mass spectrometry (SIMS) is an important tool for investigating isotopic composition in the chemical and materials sciences, but its use in biology has been limited by technical considerations. Multi-isotope imaging mass spectrometry (MIMS), which combines a new generation of SIMS instrument with sophisticated ion optics, labeling with stable isotopes, and quantitative image-analysis software, was developed to study biological materials. Results The new instrument allows the production of mass images of high lateral resolution (down to 33 nm), as well as the counting or imaging of several isotopes simultaneously. As MIMS can distinguish between ions of very similar mass, such as 12C15N- and 13C14N-, it enables the precise and reproducible measurement of isotope ratios, and thus of the levels of enrichment in specific isotopic labels, within volumes of less than a cubic micrometer. The sensitivity of MIMS is at least 1,000 times that of 14C autoradiography. The depth resolution can be smaller than 1 nm because only a few atomic layers are needed to create an atomic mass image. We illustrate the use of MIMS to image unlabeled mammalian cultured cells and tissue sections; to analyze fatty-acid transport in adipocyte lipid droplets using 13C-oleic acid; to examine nitrogen fixation in bacteria using 15N gaseous nitrogen; to measure levels of protein renewal in the cochlea and in post-ischemic kidney cells using 15N-leucine; to study DNA and RNA co-distribution and uridine incorporation in the nucleolus using 15N-uridine and 81Br of bromodeoxyuridine or 14C-thymidine; to reveal domains in cultured endothelial cells using the native isotopes 12C, 16O, 14N and 31P; and to track a few 15N-labeled donor spleen cells in the lymph nodes of the host mouse. Conclusion MIMS makes it possible for the first time to both image and quantify molecules labeled with stable or radioactive isotopes within subcellular compartments.
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Affiliation(s)
- Claude Lechene
- National Resource for Imaging Mass Spectrometry, Harvard Medical School and Department of Medicine, Brigham and Women's Hospital, Cambridge, MA 02139, USA
| | - Francois Hillion
- Cameca, 29 Quai des Gresillons, 92622 Gennevilliers Cedex, France
| | - Greg McMahon
- National Resource for Imaging Mass Spectrometry, Harvard Medical School and Department of Medicine, Brigham and Women's Hospital, Cambridge, MA 02139, USA
| | | | - Alan M Kleinfeld
- Torrey Pines Institute for Molecular Studies, San Diego, CA 92121, USA
| | - J Patrick Kampf
- Torrey Pines Institute for Molecular Studies, San Diego, CA 92121, USA
| | - Daniel Distel
- Ocean Genome Legacy Foundation, Ipswich, MA 01938, USA
| | - Yvette Luyten
- Ocean Genome Legacy Foundation, Ipswich, MA 01938, USA
| | - Joseph Bonventre
- Harvard Medical School and Renal Division, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Dirk Hentschel
- Harvard Medical School and Renal Division, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Kwon Moo Park
- Harvard Medical School and Renal Division, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Susumu Ito
- Harvard Medical School, Boston, MA 02115, USA
| | - Martin Schwartz
- Department of Microbiology, University of Virginia, Charlottesville, VA 22908, USA
| | - Gilles Benichou
- Harvard Medical School and Department of Surgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Georges Slodzian
- Universite Paris-Sud, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, 91406 Orsay, France
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Murakoshi M, Yoshida N, Kitsunai Y, Iida K, Kumano S, Suzuki T, Kobayashi T, Wada H. Effects of heat stress on Young's modulus of outer hair cells in mice. Brain Res 2006; 1107:121-30. [PMID: 16822487 DOI: 10.1016/j.brainres.2006.05.095] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Revised: 05/26/2006] [Accepted: 05/30/2006] [Indexed: 11/20/2022]
Abstract
Intense sound exposure causes permanent hearing loss due to hair cell and cochlear damage. Prior conditioning with sublethal stressors, such as nontraumatic sound, heat stress and restraint protects the ear from acoustic injury. However, the mechanisms underlying conditioning-related cochlear protection remain unknown. In this paper, Young's modulus and the amount of filamentous actin (F-actin) of outer hair cells (OHCs) with/without heat stress were investigated by atomic force microscopy and confocal laser scanning microscopy, respectively. Conditioning with heat stress resulted in a statistically significant increase in Young's modulus of OHCs at 3-6 h after application, and such modulus then began to decrease by 12 h and returned to pre-conditioning level at 48 h after heat stress. The amount of F-actin began to increase by 3 h after heat stress and peaked at 12 h. It then began to decrease by 24 h and returned to the pre-conditioning level by 48-96 h after heat stress. These time courses are consistent with a previous report in which heat stress was shown to suppress permanent threshold shift (PTS). In addition, distortion product otoacoustic emissions (DPOAEs) were confirmed to be enhanced by heat stress. These results suggest that conditioning with heat stress structurally modifies OHCs so that they become stiffer due to an increase in the amount of F-actin. As a consequence, OHCs possibly experience less strain when they are exposed to loud noise, resulting in protection of mammalian hearing from traumatic noise exposure.
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MESH Headings
- Acoustic Stimulation/methods
- Actins/metabolism
- Animals
- Animals, Newborn
- Auditory Threshold/physiology
- Cell Size
- Hair Cells, Auditory, Outer/metabolism
- Hair Cells, Auditory, Outer/pathology
- Hair Cells, Auditory, Outer/physiopathology
- Hot Temperature/adverse effects
- Male
- Mice
- Mice, Inbred CBA
- Microscopy, Atomic Force/methods
- Microscopy, Confocal/methods
- Models, Biological
- Otoacoustic Emissions, Spontaneous/physiology
- Stress, Physiological/etiology
- Stress, Physiological/pathology
- Stress, Physiological/physiopathology
- Time Factors
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Affiliation(s)
- Michio Murakoshi
- Department of Bioengineering and Robotics, Tohoku University, 6-6-01 Aoba-yama, Sendai 980-8579, Japan
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Abstract
Modern research has provided new insights into the biological mechanisms of noise-induced hearing loss, and with these new insights comes hope for possible prevention or treatment. Underlying the classic set of cochlear pathologies that occur as a result of noise exposure are increased levels of reactive oxygen species (ROS) that play a significant role in noise-induced hair cell death. Both necrotic and apoptotic cell death have been identified in the cochlea. Included in the current review is a brief review of ROS, along with a description of sources of cochlear ROS generation and how ROS can damage cochlear tissue. The pathways of necrotic and apoptotic cell death are also reviewed. Interventions are discussed that target the prevention of noise-induced hair cell death: the use of antioxidants to scavenge and eliminate the damaging ROS, pharmacological interventions to limit the damage resulting from ROS, and new techniques aimed at interrupting the apoptotic biochemical cascade that results in the death of irreplaceable hair cells.
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Affiliation(s)
- Donald Henderson
- Center for Hearing and Deafness, Department of Communicative Disorders and Sciences, State University of New York at Buffalo, Buffalo, New York 14214, USA.
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48
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Śliwińska‐Kowalska M, Jedlińska U. Prolonged Exposure to Industrial Noise: Cochlear Pathology does not Correlate with the Degree of Permanent Threshold Shift, but is Related to Duration of Exposure. J Occup Health 2006. [DOI: 10.1539/joh.40.123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
| | - Urszula Jedlińska
- Department of PathomorphologyThe Nofer Institute of Occupational Medicine
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Noreña AJ, Eggermont JJ. Enriched acoustic environment after noise trauma reduces hearing loss and prevents cortical map reorganization. J Neurosci 2005; 25:699-705. [PMID: 15659607 PMCID: PMC6725313 DOI: 10.1523/jneurosci.2226-04.2005] [Citation(s) in RCA: 216] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Exposure to sound of sufficient duration and level causes permanent damage to the peripheral auditory system, which results in the reorganization of the cortical tonotopic map. The changes are such that neurons with pre-exposure tuning to frequencies in the hearing loss range now become tuned to frequencies near the near-normal lower boundary of the hearing loss range, which thus becomes over represented. However, cats exposed to a traumatizing noise and immediately thereafter placed for a few weeks in an enriched acoustic environment presented a much-restricted hearing loss compared with similarly exposed cats that were placed for the same time in a quiet environment. The enriched environment spectrally matched the expected hearing loss range and was approximately 40 dB above the level of the expected hearing loss. The hearing loss in the quiet environment-reared cats ranged from 6 to 32 kHz with the largest loss (on average, 40 dB) ranging from 24 to 32 kHz. In contrast, the hearing loss in the enriched-environment cats was restricted to 6-8 kHz at a level of, on average, 35 dB and with 16-32 kHz having normal thresholds. Despite the remaining hearing loss for the enriched-environment cats in the 6-8 kHz range, plastic tonotopic map changes in primary auditory cortex could no longer be demonstrated, suggesting that the enriched acoustic environment prevents this reorganization. This finding has implications for the treatment of hearing disorders, such as tinnitus, that have been linked to cortical tonotopic map reorganization.
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Affiliation(s)
- Arnaud J Noreña
- Neurosciences and Sensory Systems Laboratory, Unité Mixte de Recherche Centre National de la Recherche Scientifique 5020, Université Claude Bernard, 69366 Lyon, cedex 7, France
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50
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Cho Y, Gong TWL, Kanicki A, Altschuler RA, Lomax MI. Noise overstimulation induces immediate early genes in the rat cochlea. ACTA ACUST UNITED AC 2005; 130:134-48. [PMID: 15519684 DOI: 10.1016/j.molbrainres.2004.07.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2004] [Indexed: 11/16/2022]
Abstract
In mammals, exposure to intense noise produces a permanent hearing loss called permanent threshold shift (PTS), whereas a moderate noise produces only a temporary threshold shift (TTS). Little is known about the molecular responses to such high intensity noise exposures. In this study we used gene arrays to examine the early response to acoustic overstimulation in the rat cochlea. We compared cochlear RNA from noise-exposed rats with RNA from unexposed controls. The intense PTS noise induced several immediate early genes encoding both transcription factors (c-FOS, EGR1, NUR77/TR3) and cytokines (PC3/BTG2, LIF and IP10). In contrast, the TTS noise down-regulated the gene for growth hormone. The response of these genes to different noise intensities was examined by quantitative RT-PCR 2.5 h after the 90-min noise exposure. For most genes, the extent of induction correlates with the intensity of the noise exposure. Three proteins (EGR1, NUR77/TR3, and IP10) were detected in many regions of the unexposed cochlea. After exposure to 120 dB noise, these proteins were present at higher levels or showed extended expression in additional regions of the cochlea. LIF was undetectable in the cochlea of unexposed rats, but could be seen in the organ of Corti and spiral ganglion neurons following noise. NUR77/TR3 was a nuclear protein before noise, but following noise translocated to the cytoplasm. These studies provide new insights into the molecular response to noise overstimulation in the mammalian cochlea.
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MESH Headings
- Acoustic Stimulation
- Animals
- Autoradiography/methods
- Cochlea/anatomy & histology
- Cochlea/radiation effects
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- ERG1 Potassium Channel
- Ether-A-Go-Go Potassium Channels
- Gene Expression/radiation effects
- Gene Expression Profiling/methods
- Gene Expression Regulation/radiation effects
- Genes, Immediate-Early/physiology
- Immediate-Early Proteins/genetics
- Immediate-Early Proteins/metabolism
- Immunohistochemistry/methods
- Leukemia Inhibitory Factor Receptor alpha Subunit
- Male
- Noise
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Oligonucleotide Array Sequence Analysis/methods
- Potassium Channels/metabolism
- Potassium Channels, Voltage-Gated
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Cytokine/genetics
- Receptors, Cytokine/metabolism
- Receptors, Cytoplasmic and Nuclear
- Receptors, OSM-LIF
- Receptors, Steroid
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Transcription Factors/genetics
- Transcription Factors/metabolism
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Affiliation(s)
- Younsook Cho
- Department of Cell and Developmental Biology, The University of Michigan Medical School, Ann Arbor, MI 48109, USA
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