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Rommelspacher H, Bera S, Brommer B, Ward R, Kwiatkowska M, Zygmunt T, Theden F, Üsekes B, Eren N, Nieratschker M, Arnoldner C, Plontke SK, Hellmann-Regen J, Schlingensiepen R. A single dose of AC102 restores hearing in a guinea pig model of noise-induced hearing loss to almost prenoise levels. Proc Natl Acad Sci U S A 2024; 121:e2314763121. [PMID: 38557194 PMCID: PMC11009624 DOI: 10.1073/pnas.2314763121] [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: 09/01/2023] [Accepted: 01/29/2024] [Indexed: 04/04/2024] Open
Abstract
Although sudden sensorineural hearing loss (SSNHL) is a serious condition, there are currently no approved drugs for its treatment. Nevertheless, there is a growing understanding that the cochlear pathologies that underlie SSNHL include apoptotic death of sensory outer hair cells (OHCs) as well as loss of ribbon synapses connecting sensory inner hair cells (IHCs) and neurites of the auditory nerve, designated synaptopathy. Noise-induced hearing loss (NIHL) is a common subtype of SSNHL and is widely used to model hearing loss preclinically. Here, we demonstrate that a single interventive application of a small pyridoindole molecule (AC102) into the middle ear restored auditory function almost to prenoise levels in a guinea pig model of NIHL. AC102 prevented noise-triggered loss of OHCs and reduced IHC synaptopathy suggesting a role of AC102 in reconnecting auditory neurons to their sensory target cells. Notably, AC102 exerted its therapeutic properties over a wide frequency range. Such strong improvements in hearing have not previously been demonstrated for other therapeutic agents. In vitro experiments of a neuronal damage model revealed that AC102 protected cells from apoptosis and promoted neurite growth. These effects may be explained by increased production of adenosine triphosphate, indicating improved mitochondrial function, and reduced levels of reactive-oxygen species which prevents the apoptotic processes responsible for OHC death. This action profile of AC102 might be causal for the observed hearing recovery in in vivo models.
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Affiliation(s)
| | - Sujoy Bera
- AudioCure Pharma GmbH, Berlin10115, Germany
| | | | | | | | | | | | - Berk Üsekes
- AudioCure Pharma GmbH, Berlin10115, Germany
- Department of Psychiatry and Psychotherapy, Section Clinical Neurobiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Campus Benjamin Franklin, Berlin12203, Germany
| | - Neriman Eren
- AudioCure Pharma GmbH, Berlin10115, Germany
- Department of Psychiatry and Psychotherapy, Section Clinical Neurobiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Campus Benjamin Franklin, Berlin12203, Germany
| | - Michael Nieratschker
- Department of Otorhinolaryngology, Head and Neck Surgery, Vienna General Hospital, Medical University of Vienna, Vienna1090, Austria
| | - Christoph Arnoldner
- Department of Otorhinolaryngology, Head and Neck Surgery, Vienna General Hospital, Medical University of Vienna, Vienna1090, Austria
| | - Stefan K. Plontke
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin Luther University Halle-Wittenberg, Halle06120, Germany
| | - Julian Hellmann-Regen
- Department of Psychiatry and Psychotherapy, Section Clinical Neurobiology, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Campus Benjamin Franklin, Berlin12203, Germany
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2
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Buswinka CJ, Osgood RT, Simikyan RG, Rosenberg DB, Indzhykulian AA. The hair cell analysis toolbox is a precise and fully automated pipeline for whole cochlea hair cell quantification. PLoS Biol 2023; 21:e3002041. [PMID: 36947567 PMCID: PMC10069775 DOI: 10.1371/journal.pbio.3002041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 04/03/2023] [Accepted: 02/17/2023] [Indexed: 03/23/2023] Open
Abstract
Our sense of hearing is mediated by sensory hair cells, precisely arranged and highly specialized cells subdivided into outer hair cells (OHCs) and inner hair cells (IHCs). Light microscopy tools allow for imaging of auditory hair cells along the full length of the cochlea, often yielding more data than feasible to manually analyze. Currently, there are no widely applicable tools for fast, unsupervised, unbiased, and comprehensive image analysis of auditory hair cells that work well either with imaging datasets containing an entire cochlea or smaller sampled regions. Here, we present a highly accurate machine learning-based hair cell analysis toolbox (HCAT) for the comprehensive analysis of whole cochleae (or smaller regions of interest) across light microscopy imaging modalities and species. The HCAT is a software that automates common image analysis tasks such as counting hair cells, classifying them by subtype (IHCs versus OHCs), determining their best frequency based on their location along the cochlea, and generating cochleograms. These automated tools remove a considerable barrier in cochlear image analysis, allowing for faster, unbiased, and more comprehensive data analysis practices. Furthermore, HCAT can serve as a template for deep learning-based detection tasks in other types of biological tissue: With some training data, HCAT's core codebase can be trained to develop a custom deep learning detection model for any object on an image.
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Affiliation(s)
- Christopher J Buswinka
- Mass Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
- Speech and Hearing Bioscience and Technology Program, Harvard University, Cambridge, Massachusetts, United States of America
| | - Richard T Osgood
- Mass Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Rubina G Simikyan
- Mass Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David B Rosenberg
- Mass Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Artur A Indzhykulian
- Mass Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States of America
- Speech and Hearing Bioscience and Technology Program, Harvard University, Cambridge, Massachusetts, United States of America
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3
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Pouyo R, Chung K, Delacroix L, Malgrange B. The ubiquitin-proteasome system in normal hearing and deafness. Hear Res 2022; 426:108366. [PMID: 34645583 DOI: 10.1016/j.heares.2021.108366] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/03/2021] [Accepted: 09/23/2021] [Indexed: 12/16/2022]
Abstract
Post-translational modifications of proteins are essential for the proper development and function of many tissues and organs, including the inner ear. Ubiquitination is a highly selective post-translational modification that involves the covalent conjugation of ubiquitin to a substrate protein. The most common outcome of protein ubiquitination is degradation by the ubiquitin-proteasome system (UPS), preventing the accumulation of misfolded, damaged, and excess proteins. In addition to proteasomal degradation, ubiquitination regulates other cellular processes, such as transcription, translation, endocytosis, receptor activity, and subcellular localization. All of these processes are essential for cochlear development and maintenance, as several studies link impairment of UPS with altered cochlear development and hearing loss. In this review, we provide insight into the well-oiled machinery of UPS with a focus on its confirmed role in normal hearing and deafness and potential therapeutic strategies to prevent and treat UPS-associated hearing loss.
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Affiliation(s)
- Ronald Pouyo
- GIGA-Stem Cells, Developmental Neurobiology Unit, University of Liege, Avenue hippocrate 15, B36 1st Floor B, Liege 4000, Belgium
| | - Keshi Chung
- GIGA-Stem Cells, Developmental Neurobiology Unit, University of Liege, Avenue hippocrate 15, B36 1st Floor B, Liege 4000, Belgium
| | - Laurence Delacroix
- GIGA-Stem Cells, Developmental Neurobiology Unit, University of Liege, Avenue hippocrate 15, B36 1st Floor B, Liege 4000, Belgium
| | - Brigitte Malgrange
- GIGA-Stem Cells, Developmental Neurobiology Unit, University of Liege, Avenue hippocrate 15, B36 1st Floor B, Liege 4000, Belgium.
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4
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Lee S, Song JJ, Beyer LA, Swiderski DL, Prieskorn DM, Acar M, Jen HI, Groves AK, Raphael Y. Combinatorial Atoh1 and Gfi1 induction enhances hair cell regeneration in the adult cochlea. Sci Rep 2020; 10:21397. [PMID: 33293609 PMCID: PMC7722738 DOI: 10.1038/s41598-020-78167-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/19/2020] [Indexed: 12/17/2022] Open
Abstract
Mature mammalian cochlear hair cells (HCs) do not spontaneously regenerate once lost, leading to life-long hearing deficits. Attempts to induce HC regeneration in adult mammals have used over-expression of the HC-specific transcription factor Atoh1, but to date this approach has yielded low and variable efficiency of HC production. Gfi1 is a transcription factor important for HC development and survival. We evaluated the combinatorial effects of Atoh1 and Gfi1 over-expression on HC regeneration using gene transfer methods in neonatal cochlear explants, and in vivo in adult mice. Adenoviral over-expression of Atoh1 and Gfi1 in cultured neonatal cochlear explants resulted in numerous ectopic HC-like cells (HCLCs), with significantly more cells in Atoh1 + Gfi1 cultures than Atoh1 alone. In vitro, ectopic HCLCs emerged in regions medial to inner HCs as well as in the stria vascularis. In vivo experiments were performed in mature Pou4f3DTR mice in which HCs were completely and specifically ablated by administration of diphtheria toxin. Adenoviral expression of Atoh1 or Atoh1 + Gfi1 in cochlear supporting cells induced appearance of HCLCs, with Atoh1 + Gfi1 expression leading to 6.2-fold increase of new HCLCs after 4 weeks compared to Atoh1 alone. New HCLCs were detected throughout the cochlea, exhibited immature stereocilia and survived for at least 8 weeks. Combinatorial Atoh1 and Gfi1 induction is thus a promising strategy to promote HC regeneration in the mature mammalian cochlea.
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Affiliation(s)
- Sungsu Lee
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
- Department of Otolaryngology - Head and Neck Surgery, Chonnam National University Hospital, Gwangju, South Korea
| | - Jae-Jun Song
- Department of Otolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, South Korea
| | - Lisa A Beyer
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Donald L Swiderski
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Diane M Prieskorn
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Melih Acar
- Department of Medical Biology, School of Medicine, Bahcesehir University, Istanbul, Turkey
| | - Hsin-I Jen
- Department of Neuroscience, Baylor College of Medicine, Houston, USA
| | - Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine, Houston, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, USA
| | - Yehoash Raphael
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA.
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5
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He L, Guo JY, Liu K, Wang GP, Gong SS. Research progress on flat epithelium of the inner ear. Physiol Res 2020; 69:775-785. [PMID: 32901490 DOI: 10.33549/physiolres.934447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sensorineural hearing loss and vertigo, resulting from lesions in the sensory epithelium of the inner ear, have a high incidence worldwide. The sensory epithelium of the inner ear may exhibit extreme degeneration and is transformed to flat epithelium (FE) in humans and mice with profound sensorineural hearing loss and/or vertigo. Various factors, including ototoxic drugs, noise exposure, aging, and genetic defects, can induce FE. Both hair cells and supporting cells are severely damaged in FE, and the normal cytoarchitecture of the sensory epithelium is replaced by a monolayer of very thin, flat cells of irregular contour. The pathophysiologic mechanism of FE is unclear but involves robust cell division. The cellular origin of flat cells in FE is heterogeneous; they may be transformed from supporting cells that have lost some features of supporting cells (dedifferentiation) or may have migrated from the flanking region. The epithelial-mesenchymal transition may play an important role in this process. The treatment of FE is challenging given the severe degeneration and loss of both hair cells and supporting cells. Cochlear implant or vestibular prosthesis implantation, gene therapy, and stem cell therapy show promise for the treatment of FE, although many challenges remain to be overcome.
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Affiliation(s)
- L He
- Department of Otolaryngology-Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China. ,
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6
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Yoshimura H, Shibata SB, Ranum PT, Moteki H, Smith RJH. Targeted Allele Suppression Prevents Progressive Hearing Loss in the Mature Murine Model of Human TMC1 Deafness. Mol Ther 2019; 27:681-690. [PMID: 30686588 DOI: 10.1016/j.ymthe.2018.12.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/20/2018] [Accepted: 12/27/2018] [Indexed: 12/19/2022] Open
Abstract
Hearing loss is the most common human sensory deficit. Its correction has been the goal of several gene-therapy based studies exploring a variety of interventions. Although these studies report varying degrees of success, all treatments have targeted developing inner ears in neonatal mice, a time point in the structural maturation of the cochlea prior to 26 weeks gestational age in humans. It is unclear whether cochlear gene therapy can salvage hearing in the mature organ of Corti. Herein, we report the first study to test gene therapy in an adult murine model of human deafness. Using a single intracochlear injection of an artificial microRNA carried in an AAV vector, we show that RNAi-mediated gene silencing can slow progression of hearing loss, improve inner hair cell survival, and prevent stereocilia bundle degeneration in the mature Beethoven mouse, a model of human TMC1 deafness. The ability to study gene therapy in mature murine ears constitutes a significant step toward its translation to human subjects.
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Affiliation(s)
- Hidekane Yoshimura
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano 390-8621, Japan
| | - Seiji B Shibata
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Otolaryngology-Head and Neck Surgery, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Paul T Ranum
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Hideaki Moteki
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano 390-8621, Japan
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Otolaryngology-Head and Neck Surgery, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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7
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Liu X, Li M, Smyth H, Zhang F. Otic drug delivery systems: formulation principles and recent developments. Drug Dev Ind Pharm 2018; 44:1395-1408. [PMID: 29659300 DOI: 10.1080/03639045.2018.1464022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Disorders of the ear severely impact the quality of life of millions of people, but the treatment of these disorders is an ongoing, but often overlooked challenge particularly in terms of formulation design and product development. The prevalence of ear disorders has spurred significant efforts to develop new therapeutic agents, but perhaps less innovation has been applied to new drug delivery systems to improve the efficacy of ear disease treatments. This review provides a brief overview of physiology, major diseases, and current therapies used via the otic route of administration. The primary focuses are on the various administration routes and their formulation principles. The article also presents recent advances in otic drug deliveries as well as potential limitations. Otic drug delivery technology will likely evolve in the next decade and more efficient or specific treatments for ear disease will arise from the development of less invasive drug delivery methods, safe and highly controlled drug delivery systems, and biotechnology targeting therapies.
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Affiliation(s)
- Xu Liu
- a College of Pharmacy , The University of Texas at Austin , Austin , TX , USA
| | - Mingshuang Li
- b Department of Communication Sciences and Disorders , The University of Texas at Austin , Austin , TX , USA
| | - Hugh Smyth
- a College of Pharmacy , The University of Texas at Austin , Austin , TX , USA
| | - Feng Zhang
- a College of Pharmacy , The University of Texas at Austin , Austin , TX , USA
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8
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Enhanced viral-mediated cochlear gene delivery in adult mice by combining canal fenestration with round window membrane inoculation. Sci Rep 2018; 8:2980. [PMID: 29445157 PMCID: PMC5812997 DOI: 10.1038/s41598-018-21233-z] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/31/2018] [Indexed: 12/22/2022] Open
Abstract
Cochlear gene therapy holds promise for the treatment of genetic deafness. Assessing its impact in adult murine models of hearing loss, however, has been hampered by technical challenges that have made it difficult to establish a robust method to deliver transgenes to the mature murine inner ear. Here in we demonstrate the feasibility of a combined round window membrane injection and semi-circular canal fenestration technique in the adult cochlea. Injection of both AAV2/9 and AAV2/Anc80L65 via this approach in P15–16 and P56–60 mice permits robust eGFP transduction of virtually all inner hair cells throughout the cochlea with variable transduction of vestibular hair cells. Auditory thresholds are not compromised. Transduction rate and cell tropism is primarily influenced by viral titer and AAV serotype but not age at injection. This approach is safe, versatile and efficient. Its use will facilitate studies using cochlear gene therapy in murine models of hearing loss over a wide range of time points.
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9
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Shibata SB, Yoshimura H, Ranum PT, Goodwin AT, Smith RJH. Intravenous rAAV2/9 injection for murine cochlear gene delivery. Sci Rep 2017; 7:9609. [PMID: 28852025 PMCID: PMC5575199 DOI: 10.1038/s41598-017-09805-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/28/2017] [Indexed: 01/08/2023] Open
Abstract
Gene therapy for genetic deafness is a promising approach by which to prevent hearing loss or to restore hearing after loss has occurred. Although a variety of direct approaches to introduce viral particles into the inner ear have been described, presumed physiological barriers have heretofore precluded investigation of systemic gene delivery to the cochlea. In this study, we sought to characterize systemic delivery of a rAAV2/9 vector as a non-invasive means of cochlear transduction. In wild-type neonatal mice (postnatal day 0-1), we show that intravenous injection of rAAV2/9 carrying an eGFP-reporter gene results in binaural transduction of inner hair cells, spiral ganglion neurons and vestibular hair cells. Transduction efficiency increases in a dose-dependent manner. Inner hair cells are transduced in an apex-to-base gradient, with transduction reaching 96% in the apical turn. Hearing acuity in treated animals is unaltered at postnatal day 30. Transduction is influenced by viral serotype and age at injection, with less efficient cochlear transduction observed with systemic delivery of rAAV2/1 and in juvenile mice with rAAV2/9. Collectively, these data validate intravenous delivery of rAAV2/9 as a novel and atraumatic technique for inner ear transgene delivery in early postnatal mice.
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Affiliation(s)
- Seiji B Shibata
- Department of Otolaryngology - Head and Neck Surgery, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.,Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Hidekane Yoshimura
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.,Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Nagano, 390-8621, Japan
| | - Paul T Ranum
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.,Interdisciplinary Graduate Program in Molecular & Cellular Biology, The University of Iowa Graduate College, University of Iowa, Iowa City, IA, 52242, USA
| | - Alexander T Goodwin
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Richard J H Smith
- Department of Otolaryngology - Head and Neck Surgery, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA. .,Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA. .,Interdisciplinary Graduate Program in Molecular & Cellular Biology, The University of Iowa Graduate College, University of Iowa, Iowa City, IA, 52242, USA. .,Iowa Institute of Human Genetics, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
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10
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Korver AMH, Smith RJH, Van Camp G, Schleiss MR, Bitner-Glindzicz MAK, Lustig LR, Usami SI, Boudewyns AN. Congenital hearing loss. Nat Rev Dis Primers 2017; 3:16094. [PMID: 28079113 PMCID: PMC5675031 DOI: 10.1038/nrdp.2016.94] [Citation(s) in RCA: 268] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Congenital hearing loss (hearing loss that is present at birth) is one of the most prevalent chronic conditions in children. In the majority of developed countries, neonatal hearing screening programmes enable early detection; early intervention will prevent delays in speech and language development and has long-lasting beneficial effects on social and emotional development and quality of life. A diagnosis of hearing loss is usually followed by a search for an underlying aetiology. Congenital hearing loss might be attributed to environmental and prenatal factors, which prevail in low-income settings; congenital infections, particularly cytomegalovirus infection, are also a common risk factor for hearing loss. Genetic causes probably account for the majority of cases in developed countries; mutations can affect any component of the hearing pathway, in particular, inner ear homeostasis (endolymph production and maintenance) and mechano-electrical transduction (the conversion of a mechanical stimulus into electrochemical activity). Once the underlying cause of hearing loss is established, it might direct therapeutic decision making and guide prevention and (genetic) counselling. Management options include specific antimicrobial therapies, surgical treatment of craniofacial abnormalities and implantable or non-implantable hearing devices. An improved understanding of the pathophysiology and molecular mechanisms that underlie hearing loss and increased awareness of recent advances in genetic testing will promote the development of new treatment and screening strategies.
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Affiliation(s)
- Anna M H Korver
- Department of Pediatrics, St Antonius Hospital, PO BOX 2500, 3430 EM Nieuwegein, The Netherlands
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories and the Genetics PhD Program, University of Iowa, Iowa City, Iowa, USA
| | - Guy Van Camp
- Department of Medical Genetics, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Mark R Schleiss
- Division of Pediatric Infectious Diseases and Immunology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Maria A K Bitner-Glindzicz
- Genetics and Genomic Medicine Programme, University College London Great Ormond Street Institute of Child Health, London, UK
| | - Lawrence R Lustig
- Department of Otolaryngology-Head and Neck Surgery, Columbia University Medical Center, New York, New York, USA
| | - Shin-Ichi Usami
- Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan
| | - An N Boudewyns
- Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
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11
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Vorasubin N, Hosokawa S, Hosokawa K, Ishiyama G, Ishiyama A, Lopez IA. Neuroglobin immunoreactivity in the human cochlea. Brain Res 2015; 1630:56-63. [PMID: 26556771 DOI: 10.1016/j.brainres.2015.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 10/29/2015] [Accepted: 11/02/2015] [Indexed: 10/22/2022]
Abstract
Neuroglobin (Ngb) is an oxygen-binding protein with a demonstrated role in endogenous neuroprotective mechanisms. It has been shown to function as a scavenger for reactive oxidizing species thereby assisting in cellular defense against oxidative stress. In the present study, we characterized the presence of Ngb in the human cochlea. Immunohistochemical staining was performed on formalin fixed celloidin human cochlea sections obtained from human temporal bones, using affinity purified polyclonal antibodies against Ngb. Thirty-six temporal bones were analyzed, 15 with normal otologic histories and 21 diagnosed with different inner ear pathologies. Ngb immunoreactivity (Ngb-IR) was consistently expressed in the neurons of spiral ganglia (SG) and supporting cells of the organ of Corti. There was a significant decrease of Ngb-IR in SGNs from specimens with inner ear pathologies when compared to normal specimens. In contrast, Ngb-IR in the organ of Corti did not show significant changes between pathological and normal specimens. The differential pattern of Ngb expression in these cochlear structures suggests that Ngb may participate in defense mechanisms in inner ear pathologies where oxidative stress is involved.
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Affiliation(s)
- Nopawan Vorasubin
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1624, USA
| | - Seiji Hosokawa
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1624, USA; Department of Otorhinolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Kumiko Hosokawa
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1624, USA; Department of Otorhinolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Gail Ishiyama
- Department of Neurology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1624, USA
| | - Akira Ishiyama
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1624, USA
| | - Ivan A Lopez
- Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1624, USA.
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12
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Plontke SK. Otology Jubilee: 150 years of the Archiv für Ohrenheilkunde "Where do we come from?--Where are we?--Where are we going?". Eur Arch Otorhinolaryngol 2015; 272:1301-3. [PMID: 25690605 DOI: 10.1007/s00405-015-3538-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 02/02/2015] [Indexed: 10/24/2022]
Affiliation(s)
- Stefan K Plontke
- Department of Otorhinolaryngology, Head and Neck Surgery, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle (Saale), Germany,
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13
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Oesterle EC. Changes in the adult vertebrate auditory sensory epithelium after trauma. Hear Res 2013; 297:91-8. [PMID: 23178236 PMCID: PMC3637947 DOI: 10.1016/j.heares.2012.11.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 10/30/2012] [Accepted: 11/06/2012] [Indexed: 01/12/2023]
Abstract
Auditory hair cells transduce sound vibrations into membrane potential changes, ultimately leading to changes in neuronal firing and sound perception. This review provides an overview of the characteristics and repair capabilities of traumatized auditory sensory epithelium in the adult vertebrate ear. Injured mammalian auditory epithelium repairs itself by forming permanent scars but is unable to regenerate replacement hair cells. In contrast, injured non-mammalian vertebrate ear generates replacement hair cells to restore hearing functions. Non-sensory support cells within the auditory epithelium play key roles in the repair processes.
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Affiliation(s)
- Elizabeth C Oesterle
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, CHDD CD176, Box 357923, Univ. of Washington, Seattle, WA 98195-7923, USA.
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Gunewardene N, Dottori M, Nayagam BA. The convergence of cochlear implantation with induced pluripotent stem cell therapy. Stem Cell Rev Rep 2012; 8:741-54. [PMID: 21956409 DOI: 10.1007/s12015-011-9320-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
According to 2010 estimates from The National Institute on Deafness and other Communication Disorders, approximately 17% (36 million) American adults have reported some degree of hearing loss. Currently, the only clinical treatment available for those with severe-to-profound hearing loss is a cochlear implant, which is designed to electrically stimulate the auditory nerve in the absence of hair cells. Whilst the cochlear implant has been revolutionary in terms of providing hearing to the severe-to-profoundly deaf, there are variations in cochlear implant performance which may be related to the degree of degeneration of auditory neurons following hearing loss. Hence, numerous experimental studies have focused on enhancing the efficacy of cochlear implants by using neurotrophins to preserve the auditory neurons, and more recently, attempting to replace these dying cells with new neurons derived from stem cells. As a result, several groups are now investigating the potential for both embryonic and adult stem cells to replace the degenerating sensory elements in the deaf cochlea. Recent advances in our knowledge of stem cells and the development of induced pluripotency by Takahashi and Yamanaka in 2006, have opened a new realm of science focused on the use of induced pluripotent stem (iPS) cells for therapeutic purposes. This review will provide a broad overview of the potential benefits and challenges of using iPS cells in combination with a cochlear implant for the treatment of hearing loss, including differentiation of iPS cells into an auditory neural lineage and clinically relevant transplantation approaches.
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Affiliation(s)
- Niliksha Gunewardene
- Department of Otolaryngology, University of Melbourne, Melbourne, Victoria, Australia
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15
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Atoh1 directs the formation of sensory mosaics and induces cell proliferation in the postnatal mammalian cochlea in vivo. J Neurosci 2012; 32:6699-710. [PMID: 22573692 DOI: 10.1523/jneurosci.5420-11.2012] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hearing impairment due to the loss of sensory hair cells is permanent in humans. Considerable interest targets the hair cell differentiation factor Atoh1 as a potential tool with which to promote hair cell regeneration. We generated a novel mouse model to direct the expression of Atoh1 in a spatially and temporally specific manner in the postnatal mammalian cochlea to determine the competency of various types of cochlear epithelial cells for hair cell differentiation. Atoh1 can generate cells in young animals with morphological, molecular, and physiological properties reminiscent of hair cells. This competency is cell type specific and progressively restricted with age. Significantly, Atoh1 induces ectopic sensory patches through Notch signaling to form a cellular mosaic similar to the endogenous sensory epithelia and expansion of the sensory mosaic through the conversion of supporting cells and nonautonomous supporting cell production. Furthermore, Atoh1 also activates proliferation within the normally postmitotic cochlear epithelium. These results provide insight into the potential and limitations of Atoh1-mediated hair cell regeneration.
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16
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Lenz DR, Avraham KB. Hereditary hearing loss: from human mutation to mechanism. Hear Res 2011; 281:3-10. [PMID: 21664957 DOI: 10.1016/j.heares.2011.05.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 05/26/2011] [Accepted: 05/27/2011] [Indexed: 11/17/2022]
Abstract
The genetic heterogeneity of hereditary hearing loss is thus far represented by hundreds of genes encoding a large variety of proteins. Mutations in these genes have been discovered for patients with different modes of inheritance and types of hearing loss, ranging from syndromic to non-syndromic and mild to profound. In many cases, the mechanisms whereby the mutations lead to hearing loss have been partly elucidated using cell culture systems and mouse and other animal models. The discovery of the genes has completely changed the practice of genetic counseling in this area, providing potential diagnosis in many cases that can be coupled with clinical phenotypes and offer predictive information for families. In this review we provide three examples of gene discovery in families with hereditary hearing loss, all associated with elucidation of some of the mechanisms leading to hair cell degeneration and pathology of deafness.
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Affiliation(s)
- Danielle R Lenz
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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17
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El-Amraoui A, Petit C. [Stem cell therapy in the inner ear: recent achievements and prospects]. Med Sci (Paris) 2011; 26:981-5. [PMID: 21106181 DOI: 10.1051/medsci/20102611981] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Because of its high prevalence and social impact, hearing impairment is a major public health problem. Whatever the cause--heredity, acoustic trauma, aminoglycoside antibiotics, noise exposure or aging--the hearing impairment is often caused by an irreversible loss of sensory hair cells. So far, hearing aids and cochlear implants are the only possibility to "treat" profound deafness. With the advent of regenerative medicine, extensive studies aimed to repair, regenerate or replace lost hair cells have been initiated. Recently, Stefan Heller and colleagues described a guidance protocol to induce mouse embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC) to differentiate into mechanosensitive hair cells. The resulting hair cells hold promise as a tool for hair cell molecular physiology and physiopathology, drug discovery, and possibly also hair cell replacement. The next challenges, alternative strategies, their limitations and prospects are also discussed.
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Affiliation(s)
- Aziz El-Amraoui
- Institut Pasteur, Unité de génétique et physiologie de l'audition, INSERM UMRS587, UPMC Paris 06, 25 rue du Docteur Roux, Paris, France.
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Raviv D, Dror AA, Avraham KB. Hearing loss: a common disorder caused by many rare alleles. Ann N Y Acad Sci 2011; 1214:168-79. [PMID: 21175685 DOI: 10.1111/j.1749-6632.2010.05868.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Perception of sound is a fundamental role of the auditory system. Traveling with the force of their mechanical energy, sound waves are captured by the ear and activate the sensory pathway of this complex organ. The hair cells, specialized sensory cells within the inner ear, transmit the mechanical energy into electrical nerve stimuli that reach the brain. A large number of proteins are responsible for the overarching tasks required to maintain the complex mechanism of sound sensation. Many hearing disorders are due to single gene defects inherited in a Mendelian fashion, thus enabling clinical diagnostics. However, at the same time, hearing impairment is genetically heterogeneous, with both common and rare forms occurring due to mutations in over 100 genes. The crosstalk between human and mouse genetics has enabled comprehensive studies on gene identification and protein function, taking advantage of the tools animal models have to offer. The aim of the following review is to provide background and examples of human deafness genes and the discovery of their function in the auditory system.
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Affiliation(s)
- Dorith Raviv
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Dror AA, Avraham KB. Hearing Impairment: A Panoply of Genes and Functions. Neuron 2010; 68:293-308. [DOI: 10.1016/j.neuron.2010.10.011] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2010] [Indexed: 12/13/2022]
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