1
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Brooks PM, Lewis P, Million-Perez S, Yandulskaya AS, Khalil M, Janes M, Porco J, Walker E, Meyers JR. Pharmacological reprogramming of zebrafish lateral line supporting cells to a migratory progenitor state. Dev Biol 2024; 512:70-88. [PMID: 38729405 DOI: 10.1016/j.ydbio.2024.05.003] [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: 10/27/2023] [Revised: 04/17/2024] [Accepted: 05/07/2024] [Indexed: 05/12/2024]
Abstract
In the zebrafish lateral line, non-sensory supporting cells readily re-enter the cell cycle to generate new hair cells and supporting cells during homeostatic maintenance and following damage to hair cells. This contrasts with supporting cells from mammalian vestibular and auditory sensory epithelia which rarely re-enter the cell cycle, and hence loss of hair cells results in permanent sensory deficit. Lateral line supporting cells are derived from multipotent progenitor cells that migrate down the trunk midline as a primordium and are deposited to differentiate into a neuromast. We have found that we can revert zebrafish support cells back to a migratory progenitor state by pharmacologically altering the signaling environment to mimic that of the migratory primordium, with active Wnt signaling and repressed FGF signaling. The reverted supporting cells migrate anteriorly and posteriorly along the horizontal myoseptum and will re-epithelialize to form an increased number of neuromasts along the midline when the pharmacological agents are removed. These data demonstrate that supporting cells can be readily reprogrammed to a migratory multipotent progenitor state that can form new sensory neuromasts, which has important implications for our understanding of how the lateral line system matures and expands in fish and also suggest avenues for returning mammalian supporting cells back to a proliferative state.
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Affiliation(s)
- Paige M Brooks
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Parker Lewis
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Sara Million-Perez
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Anastasia S Yandulskaya
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Mahmoud Khalil
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Meredith Janes
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Joseph Porco
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Eleanor Walker
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA
| | - Jason R Meyers
- Dept. of Biology and Program in Neuroscience, Colgate University, 13 Oak Drive, Hamilton, NY, 13346, USA.
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2
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Lipovsek M. Comparative biology of the amniote vestibular utricle. Hear Res 2024; 448:109035. [PMID: 38763033 DOI: 10.1016/j.heares.2024.109035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/21/2024]
Abstract
The sensory epithelia of the auditory and vestibular systems of vertebrates have shared developmental and evolutionary histories. However, while the auditory epithelia show great variation across vertebrates, the vestibular sensory epithelia appear seemingly more conserved. An exploration of the current knowledge of the comparative biology of the amniote utricle, a vestibular sensory epithelium that senses linear acceleration, shows interesting instances of variability between birds and mammals. The distribution of sensory hair cell types, the position of the line of hair bundle polarity reversal and the properties of supporting cells show marked differences, likely impacting vestibular function and hair cell regeneration potential.
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Affiliation(s)
- Marcela Lipovsek
- Ear Institute, Faculty of Brain Sciences, University College London, London, UK.
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3
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Mendia C, Peineau T, Zamani M, Felgerolle C, Yahiaoui N, Christophersen N, Papal S, Maudoux A, Maroofian R, Patni P, Nouaille S, Bowl MR, Delmaghani S, Galehdari H, Vona B, Dulon D, Vitry S, El-Amraoui A. Clarin-2 gene supplementation durably preserves hearing in a model of progressive hearing loss. Mol Ther 2024; 32:800-817. [PMID: 38243601 PMCID: PMC10928142 DOI: 10.1016/j.ymthe.2024.01.021] [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: 10/20/2023] [Revised: 12/22/2023] [Accepted: 01/12/2024] [Indexed: 01/21/2024] Open
Abstract
Hearing loss is a major health concern affecting millions of people worldwide with currently limited treatment options. In clarin-2-deficient Clrn2-/- mice, used here as a model of progressive hearing loss, we report synaptic auditory abnormalities in addition to the previously demonstrated defects of hair bundle structure and mechanoelectrical transduction. We sought an in-depth evaluation of viral-mediated gene delivery as a therapy for these hearing-impaired mice. Supplementation with either the murine Clrn2 or human CLRN2 genes preserved normal hearing in treated Clrn2-/- mice. Conversely, mutated forms of CLRN2, identified in patients with post-lingual moderate to severe hearing loss, failed to prevent hearing loss. The ectopic expression of clarin-2 successfully prevented the loss of stereocilia, maintained normal mechanoelectrical transduction, preserved inner hair cell synaptic function, and ensured near-normal hearing thresholds over time. Maximal hearing preservation was observed when Clrn2 was delivered prior to the loss of transducing stereocilia. Our findings demonstrate that gene therapy is effective for the treatment of post-lingual hearing impairment and age-related deafness associated with CLRN2 patient mutations.
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Affiliation(s)
- Clara Mendia
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France; Sorbonne Université, Collège Doctoral, 75005 Paris, France
| | - Thibault Peineau
- Institut de l'Audition and Université de Bordeaux, Laboratoire de Neurophysiologie de la Synapse Auditive, Bordeaux Neurocampus, 33076 Bordeaux, France
| | - Mina Zamani
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz 6135783151, Iran
| | - Chloé Felgerolle
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France
| | - Nawal Yahiaoui
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France
| | - Nele Christophersen
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany; Institute of Human Genetics, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Samantha Papal
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France
| | - Audrey Maudoux
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France
| | - Reza Maroofian
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, WC1E 6BT London, UK
| | - Pranav Patni
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France
| | - Sylvie Nouaille
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France
| | - Michael R Bowl
- UCL Ear Institute, University College London, 332 Gray's Inn Road, WC1X 8EE London, UK
| | - Sedigheh Delmaghani
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France
| | - Hamid Galehdari
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz 6135783151, Iran
| | - Barbara Vona
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany; Institute of Human Genetics, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Didier Dulon
- Institut de l'Audition and Université de Bordeaux, Laboratoire de Neurophysiologie de la Synapse Auditive, Bordeaux Neurocampus, 33076 Bordeaux, France
| | - Sandrine Vitry
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France.
| | - Aziz El-Amraoui
- Institut Pasteur, Université Paris Cité, INSERM AO06, Institut de l'Audition, Unit Progressive Sensory Disorders, Pathophysiology and Therapy, 63 rue de Charenton, 75012 Paris, France.
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4
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Li Y, Tuttle MA, Liu Q, Pang Y. An NIR-emitting cyanine dye with pyridinium groups: the impact of regio-bond connection on the photophysical properties. Chem Commun (Camb) 2024; 60:2208-2211. [PMID: 38304975 PMCID: PMC10878061 DOI: 10.1039/d3cc06189b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 01/17/2024] [Indexed: 02/03/2024]
Abstract
Two ESIPT-based isomeric cyanines were synthesized with significant bathochromic shift in the optical absorption λabs and emission λem, along with a very large Stokes shift. Probe 2 exhibited a longer conjugation and better photostability. Both compounds exhibited good selectivity for labeling the plasma membrane of prokaryotic cells and the hair cells of zebrafish.
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Affiliation(s)
- Yonghao Li
- Department of Chemistry, University of Akron, Akron, Ohio 44325, USA.
| | - Matthew A Tuttle
- Department of Biology, University of Akron, Akron, Ohio 44325, USA
| | - Qin Liu
- Department of Biology, University of Akron, Akron, Ohio 44325, USA
| | - Yi Pang
- Department of Chemistry, University of Akron, Akron, Ohio 44325, USA.
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5
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Benkafadar N, Sato MP, Ling AH, Janesick A, Scheibinger M, Jan TA, Heller S. An essential signaling cascade for avian auditory hair cell regeneration. Dev Cell 2024; 59:280-291.e5. [PMID: 38128539 DOI: 10.1016/j.devcel.2023.11.028] [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: 04/24/2023] [Revised: 09/27/2023] [Accepted: 11/30/2023] [Indexed: 12/23/2023]
Abstract
Hearing loss is a chronic disease affecting millions of people worldwide, yet no restorative treatment options are available. Although non-mammalian species can regenerate their auditory sensory hair cells, mammals cannot. Birds retain facultative stem cells known as supporting cells that engage in proliferative regeneration when surrounding hair cells die. Here, we investigated gene expression changes in chicken supporting cells during auditory hair cell death. This identified a pathway involving the receptor F2RL1, HBEGF, EGFR, and ERK signaling. We propose a cascade starting with the proteolytic activation of F2RL1, followed by matrix-metalloprotease-mediated HBEGF shedding, and culminating in EGFR-mediated ERK signaling. Each component of this cascade is essential for supporting cell S-phase entry in vivo and is integral for hair cell regeneration. Furthermore, STAT3-phosphorylation converges with this signaling toward upregulation of transcription factors ATF3, FOSL2, and CREM. Our findings could provide a basis for designing treatments for hearing and balance disorders.
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Affiliation(s)
- Nesrine Benkafadar
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Mitsuo P Sato
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Angela H Ling
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Amanda Janesick
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mirko Scheibinger
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Taha A Jan
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Stefan Heller
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
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6
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Zhu K, Wang T, Li S, Liu Z, Zhan Y, Zhang Q. NcRNA: key and potential in hearing loss. Front Neurosci 2024; 17:1333131. [PMID: 38298898 PMCID: PMC10827912 DOI: 10.3389/fnins.2023.1333131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 12/18/2023] [Indexed: 02/02/2024] Open
Abstract
Hearing loss has an extremely high prevalence worldwide and brings incredible economic and social burdens. Mechanisms such as epigenetics are profoundly involved in the initiation and progression of hearing loss and potentially yield definite strategies for hearing loss treatment. Non-coding genes occupy 97% of the human genome, and their transcripts, non-coding RNAs (ncRNAs), are widely participated in regulating various physiological and pathological situations. NcRNAs, mainly including micro-RNAs (miRNAs), long-stranded non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are involved in the regulation of cell metabolism and cell death by modulating gene expression and protein-protein interactions, thus impacting the occurrence and prognosis of hearing loss. This review provides a detailed overview of ncRNAs, especially miRNAs and lncRNAs, in the pathogenesis of hearing loss. We also discuss the shortcomings and issues that need to be addressed in the study of hearing loss ncRNAs in the hope of providing viable therapeutic strategies for the precise treatment of hearing loss.
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Affiliation(s)
- Keyu Zhu
- Department of Plastic and Cosmetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ting Wang
- Department of Medical Ultrasound, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
| | - Sicheng Li
- Department of Plastic Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Zeming Liu
- Department of Plastic and Cosmetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuanyuan Zhan
- Department of Plastic and Cosmetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qi Zhang
- Department of Plastic and Cosmetic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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7
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Fettiplace R. Cochlear tonotopy from proteins to perception. Bioessays 2023:e2300058. [PMID: 37329318 DOI: 10.1002/bies.202300058] [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: 03/31/2023] [Accepted: 06/01/2023] [Indexed: 06/19/2023]
Abstract
A ubiquitous feature of the auditory organ in amniotes is the longitudinal mapping of neuronal characteristic frequencies (CFs), which increase exponentially with distance along the organ. The exponential tonotopic map reflects variation in hair cell properties according to cochlear location and is thought to stem from concentration gradients in diffusible morphogenic proteins during embryonic development. While in all amniotes the spatial gradient is initiated by sonic hedgehog (SHH), released from the notochord and floorplate, subsequent molecular pathways are not fully understood. In chickens, BMP7 is one such morphogen, secreted from the distal end of the cochlea. In mammals, the developmental mechanism differs from birds and may depend on cochlear location. A consequence of exponential maps is that each octave occupies an equal distance on the cochlea, a spacing preserved in the tonotopic maps in higher auditory brain regions. This may facilitate frequency analysis and recognition of acoustic sequences.
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Affiliation(s)
- Robert Fettiplace
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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8
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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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9
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Brown AD, Hayward T, Portfors CV, Coffin AB. On the value of diverse organisms in auditory research: From fish to flies to humans. Hear Res 2023; 432:108754. [PMID: 37054531 PMCID: PMC10424633 DOI: 10.1016/j.heares.2023.108754] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/28/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023]
Abstract
Historically, diverse organisms have contributed to our understanding of auditory function. In recent years, the laboratory mouse has become the prevailing non-human model in auditory research, particularly for biomedical studies. There are many questions in auditory research for which the mouse is the most appropriate (or the only) model system available. But mice cannot provide answers for all auditory problems of basic and applied importance, nor can any single model system provide a synthetic understanding of the diverse solutions that have evolved to facilitate effective detection and use of acoustic information. In this review, spurred by trends in funding and publishing and inspired by parallel observations in other domains of neuroscience, we highlight a few examples of the profound impact and lasting benefits of comparative and basic organismal research in the auditory system. We begin with the serendipitous discovery of hair cell regeneration in non-mammalian vertebrates, a finding that has fueled an ongoing search for pathways to hearing restoration in humans. We then turn to the problem of sound source localization - a fundamental task that most auditory systems have been compelled to solve despite large variation in the magnitudes and kinds of spatial acoustic cues available, begetting varied direction-detecting mechanisms. Finally, we consider the power of work in highly specialized organisms to reveal exceptional solutions to sensory problems - and the diverse returns of deep neuroethological inquiry - via the example of echolocating bats. Throughout, we consider how discoveries made possible by comparative and curiosity-driven organismal research have driven fundamental scientific, biomedical, and technological advances in the auditory field.
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Affiliation(s)
- Andrew D Brown
- Department of Speech and Hearing Sciences, University of Washington, 1417 NE 42nd St, Seattle, WA, 98105 USA; Virginia-Merrill Bloedel Hearing Research Center, University of Washington, 1701 NE Columbia Rd, Seattle, WA, 98195 USA.
| | - Tamasen Hayward
- College of Arts and Sciences, Washington State University, 14204 NE Salmon Creek Ave, Vancouver, WA 98686 USA
| | - Christine V Portfors
- School of Biological Sciences, Washington State University, 14204 NE Salmon Creek Ave, Vancouver, WA 98686 USA
| | - Allison B Coffin
- College of Arts and Sciences, Washington State University, 14204 NE Salmon Creek Ave, Vancouver, WA 98686 USA; School of Biological Sciences, Washington State University, 14204 NE Salmon Creek Ave, Vancouver, WA 98686 USA; Department of Integrative Physiology and Neuroscience, Washington State University, 14204 NE Salmon Creek Ave, Vancouver, WA 98686 USA.
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10
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Gill NB, Dowker-Key PD, Hubbard K, Voy BH, Whelan J, Hedrick M, Bettaieb A. Ginsenoside Rc from Panax Ginseng Ameliorates Palmitate-Induced UB/OC-2 Cochlear Cell Injury. Int J Mol Sci 2023; 24:7345. [PMID: 37108509 PMCID: PMC10139021 DOI: 10.3390/ijms24087345] [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: 02/28/2023] [Revised: 04/03/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
By 2050, at least 700 million people will require hearing therapy while 2.5 billion are projected to suffer from hearing loss. Sensorineural hearing loss (SNHL) arises from the inability of the inner ear to convert fluid waves into neural electric signals because of injury to cochlear hair cells that has resulted in their death. In addition, systemic chronic inflammation implicated in other pathologies may exacerbate cell death leading to SNHL. Phytochemicals have emerged as a possible solution because of the growing evidence of their anti-inflammatory, antioxidant, and anti-apoptotic properties. Ginseng and its bioactive molecules, ginsenosides, exhibit effects that suppress pro-inflammatory signaling and protect against apoptosis. In the current study, we investigated the effects of ginsenoside Rc (G-Rc) on UB/OC-2 primary murine sensory hair cell survival in response to palmitate-induced injury. G-Rc promoted UB/OC-2 cell survival and cell cycle progression. Additionally, G-Rc enhanced the differentiation of UB/OC-2 cells into functional sensory hair cells and alleviated palmitate-induced inflammation, endoplasmic reticulum stress, and apoptosis. The current study offers novel insights into the effects of G-Rc as a potential adjuvant for SNHL and warrants further studies elucidating the molecular mechanisms.
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Affiliation(s)
- Nicholas B. Gill
- Department of Nutrition, University of Tennessee Knoxville, Knoxville, TN 37996-1920, USA
| | - Presley D. Dowker-Key
- Department of Nutrition, University of Tennessee Knoxville, Knoxville, TN 37996-1920, USA
| | - Katelin Hubbard
- Department of Nutrition, University of Tennessee Knoxville, Knoxville, TN 37996-1920, USA
| | - Brynn H. Voy
- Department of Animal Science, University of Tennessee Institute of Agriculture, Knoxville, TN 37996-0840, USA
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996-0840, USA
| | - Jay Whelan
- Department of Nutrition, University of Tennessee Knoxville, Knoxville, TN 37996-1920, USA
| | - Mark Hedrick
- Department of Audiology and Speech Pathology, The University of Tennessee Health Science Center, Knoxville, TN 37996-0240, USA
| | - Ahmed Bettaieb
- Department of Nutrition, University of Tennessee Knoxville, Knoxville, TN 37996-1920, USA
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN 37996-0840, USA
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996-0840, USA
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11
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Future Pharmacotherapy for Sensorineural Hearing Loss by Protection and Regeneration of Auditory Hair Cells. Pharmaceutics 2023; 15:pharmaceutics15030777. [PMID: 36986638 PMCID: PMC10054686 DOI: 10.3390/pharmaceutics15030777] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/14/2023] [Accepted: 02/24/2023] [Indexed: 03/03/2023] Open
Abstract
Sensorineural hearing loss has been a global burden of diseases for decades. However, according to recent progress in experimental studies on hair cell regeneration and protection, clinical trials of pharmacotherapy for sensorineural hearing loss have rapidly progressed. In this review, we focus on recent clinical trials for hair cell protection and regeneration and outline mechanisms based on associated experimental studies. Outcomes of recent clinical trials provided valuable data regarding the safety and tolerability of intra-cochlear and intra-tympanic applications as drug delivery methods. Recent findings in molecular mechanisms of hair cell regeneration suggested the realization of regenerative medicine for sensorineural hearing loss in the near future.
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12
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Kim KS, Koo HY, Bok J. Alternative splicing in shaping the molecular landscape of the cochlea. Front Cell Dev Biol 2023; 11:1143428. [PMID: 36936679 PMCID: PMC10018040 DOI: 10.3389/fcell.2023.1143428] [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: 01/13/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
The cochlea is a complex organ comprising diverse cell types with highly specialized morphology and function. Until now, the molecular underpinnings of its specializations have mostly been studied from a transcriptional perspective, but accumulating evidence points to post-transcriptional regulation as a major source of molecular diversity. Alternative splicing is one of the most prevalent and well-characterized post-transcriptional regulatory mechanisms. Many molecules important for hearing, such as cadherin 23 or harmonin, undergo alternative splicing to produce functionally distinct isoforms. Some isoforms are expressed specifically in the cochlea, while some show differential expression across the various cochlear cell types and anatomical regions. Clinical phenotypes that arise from mutations affecting specific splice variants testify to the functional relevance of these isoforms. All these clues point to an essential role for alternative splicing in shaping the unique molecular landscape of the cochlea. Although the regulatory mechanisms controlling alternative splicing in the cochlea are poorly characterized, there are animal models with defective splicing regulators that demonstrate the importance of RNA-binding proteins in maintaining cochlear function and cell survival. Recent technological breakthroughs offer exciting prospects for overcoming some of the long-standing hurdles that have complicated the analysis of alternative splicing in the cochlea. Efforts toward this end will help clarify how the remarkable diversity of the cochlear transcriptome is both established and maintained.
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Affiliation(s)
- Kwan Soo Kim
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
- Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hei Yeun Koo
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jinwoong Bok
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
- Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea
- *Correspondence: Jinwoong Bok,
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13
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Kelley MW. Cochlear Development; New Tools and Approaches. Front Cell Dev Biol 2022; 10:884240. [PMID: 35813214 PMCID: PMC9260282 DOI: 10.3389/fcell.2022.884240] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/19/2022] [Indexed: 12/21/2022] Open
Abstract
The sensory epithelium of the mammalian cochlea, the organ of Corti, is comprised of at least seven unique cell types including two functionally distinct types of mechanosensory hair cells. All of the cell types within the organ of Corti are believed to develop from a population of precursor cells referred to as prosensory cells. Results from previous studies have begun to identify the developmental processes, lineage restrictions and signaling networks that mediate the specification of many of these cell types, however, the small size of the organ and the limited number of each cell type has hampered progress. Recent technical advances, in particular relating to the ability to capture and characterize gene expression at the single cell level, have opened new avenues for understanding cellular specification in the organ of Corti. This review will cover our current understanding of cellular specification in the cochlea, discuss the most commonly used methods for single cell RNA sequencing and describe how results from a recent study using single cell sequencing provided new insights regarding cellular specification.
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14
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Rudolf MA, Andreeva A, Kim CE, DeNovio ACJ, Koshar AN, Baker W, Cartagena-Rivera AX, Corwin JT. Stiffening of Circumferential F-Actin Bands Correlates With Regenerative Failure and May Act as a Biomechanical Brake in the Mammalian Inner Ear. Front Cell Neurosci 2022; 16:859882. [PMID: 35602553 PMCID: PMC9114303 DOI: 10.3389/fncel.2022.859882] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
The loss of inner ear hair cells causes permanent hearing and balance deficits in humans and other mammals, but non-mammals recover after supporting cells (SCs) divide and replace hair cells. The proliferative capacity of mammalian SCs declines as exceptionally thick circumferential F-actin bands develop at their adherens junctions. We hypothesized that the reinforced junctions were limiting regenerative responses of mammalian SCs by impeding changes in cell shape and epithelial tension. Using micropipette aspiration and atomic force microscopy, we measured mechanical properties of utricles from mice and chickens. Our data show that the epithelial surface of the mouse utricle stiffens significantly during postnatal maturation. This stiffening correlates with and is dependent on the postnatal accumulation of F-actin and the cross-linker Alpha-Actinin-4 at SC-SC junctions. In chicken utricles, where SCs lack junctional reinforcement, the epithelial surface remains compliant. There, SCs undergo oriented cell divisions and their apical surfaces progressively elongate throughout development, consistent with anisotropic intraepithelial tension. In chicken utricles, inhibition of actomyosin contractility led to drastic SC shape change and epithelial buckling, but neither occurred in mouse utricles. These findings suggest that species differences in the capacity for hair cell regeneration may be attributable in part to the differences in the stiffness and contractility of the actin cytoskeletal elements that reinforce adherens junctions and participate in regulation of the cell cycle.
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Affiliation(s)
- Mark A. Rudolf
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Anna Andreeva
- School of Sciences and Humanities, Nazarbayev University, Nur-Sultan, Kazakhstan
| | - Christina E. Kim
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Anthony C.-J. DeNovio
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Antoan N. Koshar
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Wendy Baker
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Alexander X. Cartagena-Rivera
- Section on Mechanobiology, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, United States
| | - Jeffrey T. Corwin
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, VA, United States
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15
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Maudoux A, Vitry S, El-Amraoui A. Vestibular Deficits in Deafness: Clinical Presentation, Animal Modeling, and Treatment Solutions. Front Neurol 2022; 13:816534. [PMID: 35444606 PMCID: PMC9013928 DOI: 10.3389/fneur.2022.816534] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/23/2022] [Indexed: 11/13/2022] Open
Abstract
The inner ear is responsible for both hearing and balance. These functions are dependent on the correct functioning of mechanosensitive hair cells, which convert sound- and motion-induced stimuli into electrical signals conveyed to the brain. During evolution of the inner ear, the major changes occurred in the hearing organ, whereas the structure of the vestibular organs remained constant in all vertebrates over the same period. Vestibular deficits are highly prevalent in humans, due to multiple intersecting causes: genetics, environmental factors, ototoxic drugs, infections and aging. Studies of deafness genes associated with balance deficits and their corresponding animal models have shed light on the development and function of these two sensory systems. Bilateral vestibular deficits often impair individual postural control, gaze stabilization, locomotion and spatial orientation. The resulting dizziness, vertigo, and/or falls (frequent in elderly populations) greatly affect patient quality of life. In the absence of treatment, prosthetic devices, such as vestibular implants, providing information about the direction, amplitude and velocity of body movements, are being developed and have given promising results in animal models and humans. Novel methods and techniques have led to major progress in gene therapies targeting the inner ear (gene supplementation and gene editing), 3D inner ear organoids and reprograming protocols for generating hair cell-like cells. These rapid advances in multiscale approaches covering basic research, clinical diagnostics and therapies are fostering interdisciplinary research to develop personalized treatments for vestibular disorders.
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Affiliation(s)
- Audrey Maudoux
- Unit Progressive Sensory Disorders, Pathophysiology and Therapy, Institut Pasteur, Institut de l'Audition, Université de Paris, INSERM-UMRS1120, Paris, France.,Center for Balance Evaluation in Children (EFEE), Otolaryngology Department, Assistance Publique des Hôpitaux de Paris, Robert-Debré University Hospital, Paris, France
| | - Sandrine Vitry
- Unit Progressive Sensory Disorders, Pathophysiology and Therapy, Institut Pasteur, Institut de l'Audition, Université de Paris, INSERM-UMRS1120, Paris, France
| | - Aziz El-Amraoui
- Unit Progressive Sensory Disorders, Pathophysiology and Therapy, Institut Pasteur, Institut de l'Audition, Université de Paris, INSERM-UMRS1120, Paris, France
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16
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Wei G, Zhang X, Cai C, Sheng J, Xu M, Wang C, Gu Q, Guo C, Chen F, Liu D, Qian F. Dual-Specificity Phosphatase 14 Regulates Zebrafish Hair Cell Formation Through Activation of p38 Signaling Pathway. Front Cell Neurosci 2022; 16:840143. [PMID: 35401113 PMCID: PMC8984152 DOI: 10.3389/fncel.2022.840143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/14/2022] [Indexed: 11/13/2022] Open
Abstract
Most cases of acquired hearing loss are due to degeneration and subsequent loss of cochlear hair cells. Whereas mammalian hair cells are not replaced when lost, in zebrafish, they constantly renew and regenerate after injury. However, the molecular mechanism among this difference remains unknown. Dual-specificity phosphatase 14 (DUSP14) is an important negative modulator of mitogen-activated protein kinase (MAPK) signaling pathways. Our study was to investigate the effects of DUSP14 on supporting cell development and hair cell regeneration and explore the potential mechanism. Our results showed that dusp14 gene is highly expressed in zebrafish developing neuromasts and otic vesicles. Behavior analysis showed that dusp14 deficiency resulted in hearing defects in zebrafish larvae, which were reversed by dusp14 mRNA treatment. Moreover, knockdown of dusp14 gene caused a significant decrease in the number of neuromasts and hair cells in both neuromast and otic vesicle, mainly due to the inhibition of the proliferation of supporting cells, which results in a decrease in the number of supporting cells and ultimately in the regeneration of hair cells. We further found significant changes in a series of MAPK pathway genes through transcriptome sequencing analysis of dusp14-deficient zebrafish, especially mapk12b gene in p38 signaling. Additionally, inhibiting p38 signaling effectively rescued all phenotypes caused by dusp14 deficiency, including hair cell and supporting cell reduction. These results suggest that DUSP14 might be a key gene to regulate supporting cell development and hair cell regeneration and is a potential target for the treatment of hearing loss.
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Affiliation(s)
- Guanyun Wei
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xu Zhang
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Translational Medical Research Center, Wuxi No. 2 People’s Hospital, Affiliated Wuxi Clinical College of Nantong University, Wuxi, China
| | - Chengyun Cai
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Jiajing Sheng
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Mengting Xu
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Cheng Wang
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Qiuxiang Gu
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Chao Guo
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
- Department of Biology, Brain Research Center, Southern University of Science and Technology, Shenzhen, China
- *Correspondence: Fangyi Chen,
| | - Dong Liu
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Dong Liu, ;
| | - Fuping Qian
- Key Laboratory of Neuroregeneration of MOE, Nantong Laboratory of Development and Diseases, School of Life Sciences, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Fuping Qian,
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17
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Wang Y, Urioste RT, Wei Y, Wilder DM, Arun P, Sajja V, Gist ID, Fitzgerald TS, Chang W, Kelley MW, Long JB. Blast-induced hearing impairment in rats is associated with structural and molecular changes of the inner ear. Sci Rep 2020; 10:10652. [PMID: 32606369 PMCID: PMC7327022 DOI: 10.1038/s41598-020-67389-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/29/2020] [Indexed: 02/08/2023] Open
Abstract
Auditory dysfunction is the most prevalent injury associated with blast overpressure exposure (BOP) in Warfighters and civilians, yet little is known about the underlying pathophysiological mechanisms. To gain insights into these injuries, an advanced blast simulator was used to expose rats to BOP and assessments were made to identify structural and molecular changes in the middle/inner ears utilizing otoscopy, RNA sequencing (RNA-seq), and histopathological analysis. Deficits persisting up to 1 month after blast exposure were observed in the distortion product otoacoustic emissions (DPOAEs) and the auditory brainstem responses (ABRs) across the entire range of tested frequencies (4–40 kHz). During the recovery phase at sub-acute time points, low frequency (e.g. 4–8 kHz) hearing improved relatively earlier than for high frequency (e.g. 32–40 kHz). Perforation of tympanic membranes and middle ear hemorrhage were observed at 1 and 7 days, and were restored by day 28 post-blast. A total of 1,158 differentially expressed genes (DEGs) were significantly altered in the cochlea on day 1 (40% up-regulated and 60% down-regulated), whereas only 49 DEGs were identified on day 28 (63% up-regulated and 37% down-regulated). Seven common DEGs were identified at both days 1 and 28 following blast, and are associated with inner ear mechanotransduction, cytoskeletal reorganization, myelin development and axon survival. Further studies on altered gene expression in the blast-injured rat cochlea may provide insights into new therapeutic targets and approaches to prevent or treat similar cases of blast-induced auditory damage in human subjects.
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Affiliation(s)
- Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA.
| | - Rodrigo T Urioste
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Yanling Wei
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Donna M Wilder
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Venkatasivasaisujith Sajja
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Irene D Gist
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | | | - Weise Chang
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders (NIDCD), Bethesda, MD, USA
| | - Matthew W Kelley
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders (NIDCD), Bethesda, MD, USA
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA.
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18
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Breitzler L, Lau IH, Fonseca PJ, Vasconcelos RO. Noise-induced hearing loss in zebrafish: investigating structural and functional inner ear damage and recovery. Hear Res 2020; 391:107952. [DOI: 10.1016/j.heares.2020.107952] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 02/19/2020] [Accepted: 03/16/2020] [Indexed: 12/20/2022]
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19
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EGF and a GSK3 Inhibitor Deplete Junctional E-cadherin and Stimulate Proliferation in the Mature Mammalian Ear. J Neurosci 2020; 40:2618-2632. [PMID: 32079647 DOI: 10.1523/jneurosci.2630-19.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/02/2020] [Accepted: 02/09/2020] [Indexed: 11/21/2022] Open
Abstract
Sensory hair cell losses underlie the vast majority of permanent hearing and balance deficits in humans, but many nonmammalian vertebrates can fully recover from hearing impairments and balance dysfunctions because supporting cells (SCs) in their ears retain lifelong regenerative capacities that depend on proliferation and differentiation as replacement hair cells. Most SCs in vertebrate ears stop dividing during embryogenesis; and soon after birth, vestibular SCs in mammals transition to lasting quiescence as they develop massively thickened circumferential F-actin bands at their E-cadherin-rich adherens junctions. Here, we report that treatment with EGF and a GSK3 inhibitor thinned the circumferential F-actin bands throughout the sensory epithelium of cultured utricles that were isolated from adult mice of either sex. That treatment also caused decreases in E-cadherin, β-catenin, and YAP in the striola, and stimulated robust proliferation of mature, normally quiescent striolar SCs. The findings suggest that E-cadherin-rich junctions, which are not present in the SCs of the fish, amphibians, and birds which readily regenerate hair cells, are responsible in part for the mammalian ear's vulnerability to permanent balance and hearing deficits.SIGNIFICANCE STATEMENT Millions of people are affected by hearing and balance deficits that arise when loud sounds, ototoxic drugs, infections, and aging cause hair cell losses. Such deficits are permanent for humans and other mammals, but nonmammals can recover hearing and balance after supporting cells regenerate replacement hair cells. Mammalian supporting cells lose the capacity to proliferate around the time they develop unique, exceptionally reinforced, E-cadherin-rich intercellular junctions. Here, we report the discovery of a pharmacological treatment that thins F-actin bands, depletes E-cadherin, and stimulates proliferation in long-quiescent supporting cells within a balance epithelium from adult mice. The findings suggest that high E-cadherin in those supporting cell junctions may be responsible, in part, for the permanence of hair cell loss in mammals.
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20
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Transcriptomic analysis of mouse cochleae suffering from gentamicin damage reveals the signalling pathways involved in hair cell regeneration. Sci Rep 2019; 9:10494. [PMID: 31324869 PMCID: PMC6642124 DOI: 10.1038/s41598-019-47051-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 07/05/2019] [Indexed: 01/13/2023] Open
Abstract
There is a strong capacity for hair cell regeneration after damage in the inner ear of non-mammals. However, mammalian hair cells are substantially unable to regenerate. To obtain insights into the mechanism of this difference, we analyzed the transcriptomic changes in the mouse cochleae suffered from gentamicin damage and compared them with those in the chick cochleae suffered from the same damage. The results indicated that 2,230 genes had significantly differential expression between the gentamicin- and saline-treated mouse cochleae. Some of the differentially expressed genes were grouped into 265 signaling pathways, including the Notch, Wnt (Wingless and INT-1), Bmp (bone morphogenetic protein), FGF (fibroblast growth factor) and Shh (sonic hedgehog) pathways. Using pharmacological inhibitors or agonists of these pathways, the effects of these pathways on hair cell regeneration were further studied. The results indicated that Bmp alone and its coregulation with the Notch or Wnt signaling pathways increased the numbers of generated cells from transdifferentiation or proliferation in the mouse cochlea after damage, in addition to the reported coregulation of Notch and Wnt. Thus, this work indicates a new signaling pathway (Bmp) and its synergetic coregulation in mammalian hair cell regeneration, providing potential therapeutic targets to increase mammalian hair cell regeneration.
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21
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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: 70] [Impact Index Per Article: 14.0] [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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22
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Liester MB, Sullivan EE. A review of epigenetics in human consciousness. COGENT PSYCHOLOGY 2019. [DOI: 10.1080/23311908.2019.1668222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Mitchell B. Liester
- Department of Psychiatry, University of Colorado School of Medicine, P.O. Box 302 153 N. Washington Street, Suite 103, Monument, CO 80132, USA
| | - Erin E. Sullivan
- Computer Science, University of Oklahoma, P.O. Box 302, Monument, CO 80132, USA
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23
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Mahmoodian-sani MR, Mehri-Ghahfarrokhi A. The potential of miR-183 family expression in inner ear for regeneration, treatment, diagnosis and prognosis of hearing loss. J Otol 2018; 12:55-61. [PMID: 29937838 PMCID: PMC5963458 DOI: 10.1016/j.joto.2017.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 03/22/2017] [Accepted: 03/29/2017] [Indexed: 12/04/2022] Open
Abstract
miRNA-183 family, in normal biology, is expressed in a harmonious and stable manner in the neurosensory organs and cells. Studies have also shown that miRNA-183 family, in different pathways, affects the neurosensory development, maintenance, survival and function. In addition, it has potential neuroprotective effects in response to neurosensory destructive stimulations. miRNA-96 mutation causes hereditary deafness in humans and mice, and therefore affects the inner ear activity and its maintenance. Certain roles have been identified for miR-96 in the maintenance and function of the inner ear. The comparison of the target genes of family-183 in transcriptomes of newborn and adult hair cells shows that hundreds of target genes in this family may affect development and maintenance of the ears. Identifying the genes that are regulated by miRNA-183 family provides researchers with important information about the complex development and environmental regulation of the inner ear, and can offer new approaches to the maintenance and regeneration of hair cells and auditory nerve.
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Affiliation(s)
- Mohammad-Reza Mahmoodian-sani
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Dept. of Genetics and Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Corresponding author. Fax: +98 381 3330709.
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24
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Jiang L, Xu J, Jin R, Bai H, Zhang M, Yang S, Zhang X, Zhang X, Han Z, Zeng S. Transcriptomic analysis of chicken cochleae after gentamicin damage and the involvement of four signaling pathways (Notch, FGF, Wnt and BMP) in hair cell regeneration. Hear Res 2018; 361:66-79. [DOI: 10.1016/j.heares.2018.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 06/22/2017] [Accepted: 01/06/2018] [Indexed: 10/18/2022]
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25
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Luo WW, Wang XW, Ma R, Chi FL, Chen P, Cong N, Gu YY, Ren DD, Yang JM. Junctional E-cadherin/p120-catenin Is Correlated with the Absence of Supporting Cells to Hair Cells Conversion in Postnatal Mice Cochleae. Front Mol Neurosci 2018. [PMID: 29515364 PMCID: PMC5826362 DOI: 10.3389/fnmol.2018.00020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Notch inhibition is known to generate supernumerary hair cells (HCs) at the expense of supporting cells (SCs) in the mammalian inner ear. However, inhibition of Notch activity becomes progressively less effective at inducing SC-to-HC conversion in the postnatal cochlea and balance organs as the animal ages. It has been suggested that the SC-to-HC conversion capacity is inversely correlated with E-cadherin accumulation in postnatal mammalian utricles. However, whether E-cadherin localization is linked to the SC-to-HC conversion capacity in the mammalian inner ear is poorly understood. In the present study, we treated cochleae from postnatal day 0 (P0) with the Notch signaling inhibitor DAPT and observed apparent SC-to-HC conversion along with E-cadherin/p120ctn disruption in the sensory region. In addition, the SC-to-HC conversion capacity and E-cadherin/p120ctn disorganization were robust in the apex but decreased toward the base. We further demonstrated that the ability to regenerate HCs and the disruption of E-cadherin/p120ctn concomitantly decreased with age and ceased at P7, even after extended DAPT treatments. This timing is consistent with E-cadherin/p120ctn accumulation in the postnatal cochleae. These results suggest that the decreasing capacity of SCs to transdifferentiate into HCs correlates with E-cadherin/p120ctn localization in the postnatal cochleae, which might account for the absence of SC-to-HC conversion in the mammalian cochlea.
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Affiliation(s)
- Wen-Wei Luo
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital of Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Xin-Wei Wang
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital of Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Rui Ma
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital of Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Fang-Lu Chi
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital of Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Ping Chen
- Department of Cell Biology, Emory University, Atlanta, GA, United States
| | - Ning Cong
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital of Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Yu-Yan Gu
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital of Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Dong-Dong Ren
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital of Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
| | - Juan-Mei Yang
- Department of Otology and Skull Base Surgery, Eye & ENT Hospital of Fudan University, Shanghai, China.,Key Laboratory of Hearing Medicine, Ministry of Health, Shanghai, China
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Scheibinger M, Ellwanger DC, Corrales CE, Stone JS, Heller S. Aminoglycoside Damage and Hair Cell Regeneration in the Chicken Utricle. J Assoc Res Otolaryngol 2017; 19:17-29. [PMID: 29134476 DOI: 10.1007/s10162-017-0646-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/30/2017] [Indexed: 12/30/2022] Open
Abstract
In this study, we present a systematic characterization of hair cell loss and regeneration in the chicken utricle in vivo. A single unilateral surgical delivery of streptomycin caused robust decline of hair cell numbers in striolar as well as extrastriolar regions, which in the striola was detected very early, 6 h post-insult. During the initial 12 h of damage response, we observed global repression of DNA replication, in contrast to the natural, mitotic hair cell production in undamaged control utricles. Regeneration of hair cells in striolar and extrastriolar regions occurred via high rates of asymmetric supporting cell divisions, accompanied by delayed replenishment by symmetric division. While asymmetric division of supporting cells is the main regenerative response to aminoglycoside damage, the detection of symmetric divisions supports the concept of direct transdifferentiation where supporting cells need to be replenished after their phenotypic conversion into new hair cells. Supporting cell divisions appear to be well coordinated because total supporting cell numbers throughout the regenerative process were invariant, despite the initial large-scale loss of hair cells. We conclude that a single ototoxic drug application provides an experimental framework to study the precise onset and timing of utricle hair cell regeneration in vivo. Our findings indicate that initial triggers and signaling events occur already within a few hours after aminoglycoside exposure. Direct transdifferentiation and asymmetric division of supporting cells to generate new hair cells subsequently happen largely in parallel and persist for several days.
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Affiliation(s)
- Mirko Scheibinger
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Daniel C Ellwanger
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - C Eduardo Corrales
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Department of Otology and Laryngology, Harvard Medical School and Brigham and Woman's Hospital, Boston, MA, 02115, USA
| | - Jennifer S Stone
- Department of Otolaryngology-Head and Neck Surgery, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA, 98195, USA
| | - Stefan Heller
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
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Weber LJ, Marcy HK, Shen YC, Tomkovich SE, Brooks KM, Hilk KE, Barald KF. The role of jab1, a putative downstream effector of the neurotrophic cytokine macrophage migration inhibitory factor (MIF) in zebrafish inner ear hair cell development. Exp Neurol 2017; 301:100-109. [PMID: 28928022 DOI: 10.1016/j.expneurol.2017.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 09/05/2017] [Accepted: 09/12/2017] [Indexed: 01/12/2023]
Abstract
Macrophage migration inhibitory factor (MIF) is a neurotrophic cytokine essential for inner ear hair cell (HC) development and statoacoustic ganglion (SAG) neurite outgrowth, and SAG survival in mouse, chick and zebrafish. Another neurotrophic cytokine, Monocyte chemoattractant protein 1 (MCP1) is known to synergize with MIF; but MCP1 alone is insufficient to support mouse/chick SAG neurite outgrowth or neuronal survival. Because of the relatively short time over which the zebrafish inner ear develops (~30hpf), the living zebrafish embryo is an ideal system to examine mif and mcp1 cytokine pathways and interactions. We used a novel technique: direct delivery of antisense oligonucleotide morpholinos (MOs) into the embryonic zebrafish otocyst to discover downstream effectors of mif as well as to clarify the relationship between mif and mcp1 in inner ear development. MOs for mif, mcp1 and the presumptive mif and mcp1 effector, c-Jun activation domain-binding protein-1 (jab1), were injected and then electroporated into the zebrafish otocyst 25-48hours post fertilization (hpf). We found that although mif is important at early stages (before 30hpf) for auditory macular HC development, jab1 is more critical for vestibular macular HC development before 30hpf. After 30hpf, mcp1 becomes important for HC development in both maculae.
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Affiliation(s)
- Loren J Weber
- Department of Cell and Developmental Biology, University of Michigan Medical School, 3728 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
| | - Hannah K Marcy
- Department of Cell and Developmental Biology, University of Michigan Medical School, 3728 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA; Undergraduate Research Opportunity Program, 1190 Undergraduate Science Building, 204 Washtenaw Avenue, Ann Arbor, MI 48109-2215, USA.
| | - Yu-Chi Shen
- Department of Cell and Developmental Biology, University of Michigan Medical School, 3728 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
| | - Sarah E Tomkovich
- Department of Cell and Developmental Biology, University of Michigan Medical School, 3728 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA; Undergraduate Research Opportunity Program, 1190 Undergraduate Science Building, 204 Washtenaw Avenue, Ann Arbor, MI 48109-2215, USA.
| | - Kristina M Brooks
- Department of Cell and Developmental Biology, University of Michigan Medical School, 3728 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
| | - Kelly E Hilk
- Department of Cell and Developmental Biology, University of Michigan Medical School, 3728 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA; Undergraduate Research Opportunity Program, 1190 Undergraduate Science Building, 204 Washtenaw Avenue, Ann Arbor, MI 48109-2215, USA.
| | - Kate F Barald
- Department of Cell and Developmental Biology, University of Michigan Medical School, 3728 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA; Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, MI 48109-0619, USA; Department of Biomedical Engineering, College of Engineering, 2200 Bonisteel Boulevard, University of Michigan, Ann Arbor, MI 48109-2099, USA.
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28
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Extensive Supporting Cell Proliferation and Mitotic Hair Cell Generation by In Vivo Genetic Reprogramming in the Neonatal Mouse Cochlea. J Neurosci 2017; 36:8734-45. [PMID: 27535918 DOI: 10.1523/jneurosci.0060-16.2016] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 07/05/2016] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED The generation of hair cells (HCs) from the differentiation of proliferating supporting cells (SCs) appears to be an ideal approach for replacing lost HCs in the cochlea and is promising for restoring hearing after damage to the organ of Corti. We show here that extensive proliferation of SCs followed by mitotic HC generation is achieved through a genetic reprogramming process involving the activation of β-catenin to upregulate Wnt signaling, the deletion of Notch1 to downregulate Notch signaling, and the overexpression of Atoh1 in Sox2(+) SCs in neonatal mouse cochleae. We used RNA sequencing to compare the transcripts of the cochleae from control mice and from mice with β-catenin activation, Notch1 deletion, and β-catenin activation combined with Notch1 deletion in Sox2(+) SCs. We identified the genes involved in the proliferation and transdifferentiation process that are either controlled by individual signaling pathways or by the combination of Wnt and Notch signaling. Moreover, the proliferation of SCs induced by Notch1 deletion disappears after deleting β-catenin in Notch1 knock-out Sox2(+) cells, which further demonstrates that Notch signaling is an upstream and negative regulator of Wnt signaling. SIGNIFICANCE STATEMENT We show here that the extensive proliferation of supporting cells (SCs) and the subsequent mitotic hair cell (HC) generation is achieved through a genetic reprogramming process involving activation of β-catenin to upregulate Wnt signaling, deletion of Notch1 to downregulate Notch signaling, and overexpression of Atoh1 in Sox2(+) SCs in neonatal mice cochleae. By comparing the transcripts of the cochleae among controls, β-catenin activation, Notch1 deletion, and β-catenin activation combined with Notch1 deletion group, we identified multiple genes involved in the proliferation and transdifferentiation process that are either controlled by individual signaling pathways or by the combination of Wnt and Notch signaling. This provides a better understanding of the mechanisms behind mitotic HC generation and might provide new approaches to stimulating mitotic HC regeneration.
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Ramamurthy P, White JB, Yull Park J, Hume RI, Ebisu F, Mendez F, Takayama S, Barald KF. Concomitant differentiation of a population of mouse embryonic stem cells into neuron-like cells and schwann cell-like cells in a slow-flow microfluidic device. Dev Dyn 2017; 246:7-27. [PMID: 27761977 PMCID: PMC5159187 DOI: 10.1002/dvdy.24466] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 09/16/2016] [Accepted: 09/30/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND To send meaningful information to the brain, an inner ear cochlear implant (CI) must become closely coupled to as large and healthy a population of remaining spiral ganglion neurons (SGN) as possible. Inner ear gangliogenesis depends on macrophage migration inhibitory factor (MIF), a directionally attractant neurotrophic cytokine made by both Schwann and supporting cells (Bank et al., 2012). MIF-induced mouse embryonic stem cell (mESC)-derived "neurons" could potentially substitute for lost or damaged SGN. mESC-derived "Schwann cells" produce MIF, as do all Schwann cells (Huang et al., a; Roth et al., 2007; Roth et al., 2008) and could attract SGN to a "cell-coated" implant. RESULTS Neuron- and Schwann cell-like cells were produced from a common population of mESCs in an ultra-slow-flow microfluidic device. As the populations interacted, "neurons" grew over the "Schwann cell" lawn, and early events in myelination were documented. Blocking MIF on the Schwann cell side greatly reduced directional neurite outgrowth. MIF-expressing "Schwann cells" were used to coat a CI: Mouse SGN and MIF-induced "neurons" grew directionally to the CI and to a wild-type but not MIF-knockout organ of Corti explant. CONCLUSIONS Two novel stem cell-based approaches for treating the problem of sensorineural hearing loss are described. Developmental Dynamics 246:7-27, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Poornapriya Ramamurthy
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, Michigan
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Joshua B White
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, Michigan
| | - Joong Yull Park
- School of Mechanical Engineering, College of Engineering, Chung-Ang University, Seoul, Republic of Korea
| | - Richard I Hume
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan
| | - Fumi Ebisu
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Flor Mendez
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Shuichi Takayama
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, Michigan
| | - Kate F Barald
- Department of Biomedical Engineering, College of Engineering, University of Michigan, Ann Arbor, Michigan
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan
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Abstract
Sensing and responding to our environment requires functional neurons that act in concert. Neuronal cell loss resulting from degenerative diseases cannot be replaced in humans, causing a functional impairment to integrate and/or respond to sensory cues. In contrast, zebrafish (Danio rerio) possess an endogenous capacity to regenerate lost neurons. Here, we will focus on the processes that lead to neuronal regeneration in the zebrafish retina. Dying retinal neurons release a damage signal, tumor necrosis factor α, which induces the resident radial glia, the Müller glia, to reprogram and re-enter the cell cycle. The Müller glia divide asymmetrically to produce a Müller glia that exits the cell cycle and a neuronal progenitor cell. The arising neuronal progenitor cells undergo several rounds of cell divisions before they migrate to the site of damage to differentiate into the neuronal cell types that were lost. Molecular and immunohistochemical studies have predominantly provided insight into the mechanisms that regulate retinal regeneration. However, many processes during retinal regeneration are dynamic and require live-cell imaging to fully discern the underlying mechanisms. Recently, a multiphoton imaging approach of adult zebrafish retinal cultures was developed. We will discuss the use of live-cell imaging, the currently available tools and those that need to be developed to advance our knowledge on major open questions in the field of retinal regeneration.
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Affiliation(s)
- Manuela Lahne
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - David R Hyde
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
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31
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Tang PC, Smith KM, Watson GM. Repair of traumatized mammalian hair cells via sea anemone repair proteins. ACTA ACUST UNITED AC 2016; 219:2265-70. [PMID: 27489215 DOI: 10.1242/jeb.135459] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 05/18/2016] [Indexed: 12/25/2022]
Abstract
Mammalian hair cells possess only a limited ability to repair damage after trauma. In contrast, sea anemones show a marked capability to repair damaged hair bundles by means of secreted repair proteins (RPs). Previously, it was found that recovery of traumatized hair cells in blind cavefish was enhanced by anemone-derived RPs; therefore, the ability of anemone RPs to assist recovery of damaged hair cells in mammals was tested here. After a 1 h incubation in RP-enriched culture media, uptake of FM1-43 by experimentally traumatized murine cochlear hair cells was restored to levels comparable to those exhibited by healthy controls. In addition, RP-treated explants had significantly more normally structured hair bundles than time-matched traumatized control explants. Collectively, these results indicate that anemone-derived RPs assist in restoring normal function and structure of experimentally traumatized hair cells of the mouse cochlea.
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Affiliation(s)
- Pei-Ciao Tang
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70503, USA
| | - Karen Müller Smith
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70503, USA
| | - Glen M Watson
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70503, USA
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32
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Jin Y, Ren N, Li S, Fu X, Sun X, Men Y, Xu Z, Zhang J, Xie Y, Xia M, Gao J. Deletion of Brg1 causes abnormal hair cell planer polarity, hair cell anchorage, and scar formation in mouse cochlea. Sci Rep 2016; 6:27124. [PMID: 27255603 PMCID: PMC4891731 DOI: 10.1038/srep27124] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 05/12/2016] [Indexed: 12/28/2022] Open
Abstract
Hair cells (HCs) are mechanosensors that play crucial roles in perceiving sound, acceleration, and fluid motion. The precise architecture of the auditory epithelium and its repair after HC loss is indispensable to the function of organ of Corti (OC). In this study, we showed that Brg1 was highly expressed in auditory HCs. Specific deletion of Brg1 in postnatal HCs resulted in rapid HC degeneration and profound deafness in mice. Further experiments showed that cell-intrinsic polarity of HCs was abolished, docking of outer hair cells (OHCs) by Deiter’s cells (DCs) failed, and scar formation in the reticular lamina was deficient. We demonstrated that Brg1 ablation disrupted the Gαi/Insc/LGN and aPKC asymmetric distributions, without overt effects on the core planer cell polarity (PCP) pathway. We also demonstrated that Brg1-deficient HCs underwent apoptosis, and that leakage in the reticular lamina caused by deficient scar formation shifted the mode of OHC death from apoptosis to necrosis. Together, these data demonstrated a requirement for Brg1 activity in HC development and suggested a role for Brg1 in the proper cellular structure formation of HCs.
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Affiliation(s)
- Yecheng Jin
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Naixia Ren
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Shiwei Li
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Xiaolong Fu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Xiaoyang Sun
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Yuqin Men
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Zhigang Xu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Jian Zhang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Yue Xie
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
| | - Ming Xia
- Department of Otolaryngology-Head and Neck Surgery, The Second Hospital of Shandong University, Jinan 250033, China
| | - Jiangang Gao
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China
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Golden EJ, Benito-Gonzalez A, Doetzlhofer A. The RNA-binding protein LIN28B regulates developmental timing in the mammalian cochlea. Proc Natl Acad Sci U S A 2015; 112:E3864-73. [PMID: 26139524 PMCID: PMC4517247 DOI: 10.1073/pnas.1501077112] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Proper tissue development requires strict coordination of proliferation, growth, and differentiation. Strict coordination is particularly important for the auditory sensory epithelium, where deviations from the normal spatial and temporal pattern of auditory progenitor cell (prosensory cell) proliferation and differentiation result in abnormal cellular organization and, thus, auditory dysfunction. The molecular mechanisms involved in the timing and coordination of auditory prosensory proliferation and differentiation are poorly understood. Here we identify the RNA-binding protein LIN28B as a critical regulator of developmental timing in the murine cochlea. We show that Lin28b and its opposing let-7 miRNAs are differentially expressed in the auditory sensory lineage, with Lin28b being highly expressed in undifferentiated prosensory cells and let-7 miRNAs being highly expressed in their progeny-hair cells (HCs) and supporting cells (SCs). Using recently developed transgenic mouse models for LIN28B and let-7g, we demonstrate that prolonged LIN28B expression delays prosensory cell cycle withdrawal and differentiation, resulting in HC and SC patterning and maturation defects. Surprisingly, let-7g overexpression, although capable of inducing premature prosensory cell cycle exit, failed to induce premature HC differentiation, suggesting that LIN28B's functional role in the timing of differentiation uses let-7 independent mechanisms. Finally, we demonstrate that overexpression of LIN28B or let-7g can significantly alter the postnatal production of HCs in response to Notch inhibition; LIN28B has a positive effect on HC production, whereas let-7 antagonizes this process. Together, these results implicate a key role for the LIN28B/let-7 axis in regulating postnatal SC plasticity.
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Affiliation(s)
- Erin J Golden
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205; Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Ana Benito-Gonzalez
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205; Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Angelika Doetzlhofer
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205; Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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Pinto-Teixeira F, Viader-Llargués O, Torres-Mejía E, Turan M, González-Gualda E, Pola-Morell L, López-Schier H. Inexhaustible hair-cell regeneration in young and aged zebrafish. Biol Open 2015; 4:903-9. [PMID: 26002931 PMCID: PMC4571094 DOI: 10.1242/bio.012112] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Animals have evolved two general strategies to counter injury and maintain physiological function. The most prevalent is protection by isolating vital organs into body cavities. However, protection is not optimal for sensory systems because their external components need to be exposed to the environment to fulfill their receptive function. Thus, a common strategy to maintain sensory abilities against persistent environmental insult involves repair and regeneration. However, whether age or frequent injuries affect the regenerative capacity of sensory organs remains unknown. We have found that neuromasts of the zebrafish lateral line regenerate mechanosensory hair cells after recurrent severe injuries and in adulthood. Moreover, neuromasts can reverse transient imbalances of Notch signaling that result in defective organ proportions during repair. Our results reveal inextinguishable hair-cell regeneration in the lateral line, and suggest that the neuromast epithelium is formed by plastic territories that are maintained by continuous intercellular communication.
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Affiliation(s)
- Filipe Pinto-Teixeira
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Oriol Viader-Llargués
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Elen Torres-Mejía
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Melissa Turan
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Estela González-Gualda
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Laura Pola-Morell
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Hernán López-Schier
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
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35
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Monroe JD, Rajadinakaran G, Smith ME. Sensory hair cell death and regeneration in fishes. Front Cell Neurosci 2015; 9:131. [PMID: 25954154 PMCID: PMC4404912 DOI: 10.3389/fncel.2015.00131] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 03/21/2015] [Indexed: 01/31/2023] Open
Abstract
Sensory hair cells are specialized mechanotransductive receptors required for hearing and vestibular function. Loss of hair cells in humans and other mammals is permanent and causes reduced hearing and balance. In the early 1980’s, it was shown that hair cells continue to be added to the inner ear sensory epithelia in cartilaginous and bony fishes. Soon thereafter, hair cell regeneration was documented in the chick cochlea following acoustic trauma. Since then, research using chick and other avian models has led to great insights into hair cell death and regeneration. However, with the rise of the zebrafish as a model organism for studying disease and developmental processes, there has been an increased interest in studying sensory hair cell death and regeneration in its lateral line and inner ears. Advances derived from studies in zebrafish and other fish species include understanding the effect of ototoxins on hair cells and finding otoprotectants to mitigate ototoxin damage, the role of cellular proliferation vs. direct transdifferentiation during hair cell regeneration, and elucidating cellular pathways involved in the regeneration process. This review will summarize research on hair cell death and regeneration using fish models, indicate the potential strengths and weaknesses of these models, and discuss several emerging areas of future studies.
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Affiliation(s)
- Jerry D Monroe
- Department of Biology, Western Kentucky University Bowling Green, KY, USA
| | - Gopinath Rajadinakaran
- Department of Genetics and Genome Sciences, University of Connecticut Health Center Farmington, CT, USA
| | - Michael E Smith
- Department of Biology, Western Kentucky University Bowling Green, KY, USA
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36
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Abstract
Hearing loss is the most common form of sensory impairment in humans and affects more than 40 million people in the United States alone. No drug-based therapy has been approved by the Food and Drug Administration, and treatment mostly relies on devices such as hearing aids and cochlear implants. Over recent years, more than 100 genetic loci have been linked to hearing loss and many of the affected genes have been identified. This understanding of the genetic pathways that regulate auditory function has revealed new targets for pharmacological treatment of the disease. Moreover, approaches that are based on stem cells and gene therapy, which may have the potential to restore or maintain auditory function, are beginning to emerge.
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Affiliation(s)
- Ulrich Müller
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, San Diego, California 92037, USA
| | - Peter G Barr-Gillespie
- Oregon Hearing Research Center, Vollum Institute, Oregon Health &Science University, 3181 South West Sam Jackson Park Road, Portland, Oregon 97239, USA
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37
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Lush ME, Piotrowski T. Sensory hair cell regeneration in the zebrafish lateral line. Dev Dyn 2014; 243:1187-202. [PMID: 25045019 DOI: 10.1002/dvdy.24167] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/12/2014] [Accepted: 07/14/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Damage or destruction of sensory hair cells in the inner ear leads to hearing or balance deficits that can be debilitating, especially in older adults. Unfortunately, the damage is permanent, as regeneration of the inner ear sensory epithelia does not occur in mammals. RESULTS Zebrafish and other non-mammalian vertebrates have the remarkable ability to regenerate sensory hair cells and understanding the molecular and cellular basis for this regenerative ability will hopefully aid us in designing therapies to induce regeneration in mammals. Zebrafish not only possess hair cells in the ear but also in the sensory lateral line system. Hair cells in both organs are functionally analogous to hair cells in the inner ear of mammals. The lateral line is a mechanosensory system found in most aquatic vertebrates that detects water motion and aids in predator avoidance, prey capture, schooling, and mating. Although hair cell regeneration occurs in both the ear and lateral line, most research to date has focused on the lateral line due to its relatively simple structure and accessibility. CONCLUSIONS Here we review the recent discoveries made during the characterization of hair cell regeneration in zebrafish.
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Affiliation(s)
- Mark E Lush
- Stowers Institute for Medical Research, Kansas City, Missouri
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38
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Anttonen T, Belevich I, Kirjavainen A, Laos M, Brakebusch C, Jokitalo E, Pirvola U. How to bury the dead: elimination of apoptotic hair cells from the hearing organ of the mouse. J Assoc Res Otolaryngol 2014; 15:975-92. [PMID: 25074370 DOI: 10.1007/s10162-014-0480-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 07/01/2014] [Indexed: 12/20/2022] Open
Abstract
Hair cell death is a major cause of hearing impairment. Preservation of surface barrier upon hair cell loss is critical to prevent leakage of potassium-rich endolymph into the organ of Corti and to prevent expansion of cellular damage. Understanding of wound healing in this cytoarchitecturally complex organ requires ultrastructural 3D visualization. Powered by the serial block-face scanning electron microscopy, we penetrate into the cell biological mechanisms in the acute response of outer hair cells and glial-like Deiters' cells to ototoxic trauma in vivo. We show that Deiters' cells function as phagocytes. Upon trauma, their phalangeal processes swell and the resulting close cellular contacts allow engulfment of apoptotic cell debris. Apical domains of dying hair cells are eliminated from the inner ear sensory epithelia, an event thought to depend on supporting cells' actomyosin contractile activity. We show that in the case of apoptotic outer hair cells of the organ of Corti, elimination of their apices is preceded by strong cell body shrinkage, emphasizing the role of the dying cell itself in the cleavage. Our data reveal that the resealing of epithelial surface by junctional extensions of Deiters' cells is dynamically reinforced by newly polymerized F-actin belts. By analyzing Cdc42-inactivated Deiters' cells with defects in actin dynamics and surface closure, we show that compromised barrier integrity shifts hair cell death from apoptosis to necrosis and leads to expanded hair cell and nerve fiber damage. Our results have implications concerning therapeutic protective and regenerative interventions, because both interventions should maintain barrier integrity.
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Affiliation(s)
- Tommi Anttonen
- Department of Biosciences, University of Helsinki, P.O. Box 56 (Viikinkaari 1), 00014, Helsinki, Finland
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Steiner AB, Kim T, Cabot V, Hudspeth AJ. Dynamic gene expression by putative hair-cell progenitors during regeneration in the zebrafish lateral line. Proc Natl Acad Sci U S A 2014; 111:E1393-401. [PMID: 24706895 PMCID: PMC3986164 DOI: 10.1073/pnas.1318692111] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hearing loss is most commonly caused by the destruction of mechanosensory hair cells in the ear. This condition is usually permanent: Despite the presence of putative hair-cell progenitors in the cochlea, hair cells are not naturally replenished in adult mammals. Unlike those of the mammalian ear, the progenitor cells of nonmammalian vertebrates can regenerate hair cells throughout life. The basis of this difference remains largely unexplored but may lie in molecular dissimilarities that affect how progenitors respond to hair-cell death. To approach this issue, we analyzed gene expression in hair-cell progenitors of the lateral-line system. We developed a transgenic line of zebrafish that expresses a red fluorescent protein in the presumptive hair-cell progenitors known as mantle cells. Fluorescence-activated cell sorting from the skins of transgenic larvae, followed by microarray-based expression analysis, revealed a constellation of transcripts that are specifically enriched in these cells. Gene expression analysis after hair-cell ablation uncovered a cohort of genes that are differentially regulated early in regeneration, suggesting possible roles in the response of progenitors to hair-cell death. These results provide a resource for studying hair-cell regeneration and the biology of sensory progenitor cells.
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Affiliation(s)
- Aaron B Steiner
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065
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Responses to cell loss become restricted as the supporting cells in mammalian vestibular organs grow thick junctional actin bands that develop high stability. J Neurosci 2014; 34:1998-2011. [PMID: 24478379 DOI: 10.1523/jneurosci.4355-13.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Sensory hair cell (HC) loss is a major cause of permanent hearing and balance impairments for humans and other mammals. Yet, fish, amphibians, reptiles, and birds readily replace HCs and recover from such sensory deficits. It is unknown what prevents replacement in mammals, but cell replacement capacity declines contemporaneously with massive postnatal thickening of F-actin bands at the junctions between vestibular supporting cells (SCs). In non-mammals, SCs can give rise to regenerated HCs, and the bands remain thin even in adults. Here we investigated the stability of the F-actin bands between SCs in ears from chickens and mice and Madin-Darby canine kidney cells. Pharmacological experiments and fluorescence recovery after photobleaching (FRAP) of SC junctions in utricles from mice that express a γ-actin-GFP fusion protein showed that the thickening F-actin bands develop increased resistance to depolymerization and exceptional stability that parallels a sharp decline in the cell replacement capacity of the maturing mammalian ear. The FRAP recovery rate and the mobile fraction of γ-actin-GFP both decreased as the bands thickened with age and became highly stabilized. In utricles from neonatal mice, time-lapse recordings in the vicinity of dying HCs showed that numerous SCs change shape and organize multicellular actin purse strings that reseal the epithelium. In contrast, adult SCs appeared resistant to deformation, with resealing responses limited to just a few neighboring SCs that did not form purse strings. The exceptional stability of the uniquely thick F-actin bands at the junctions of mature SCs may play an important role in restricting dynamic repair responses in mammalian vestibular epithelia.
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Gene-expression analysis of hair cell regeneration in the zebrafish lateral line. Proc Natl Acad Sci U S A 2014; 111:E1383-92. [PMID: 24706903 DOI: 10.1073/pnas.1402898111] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Deafness caused by the terminal loss of inner ear hair cells is one of the most common sensory diseases. However, nonmammalian animals (e.g., birds, amphibians, and fish) regenerate damaged hair cells. To understand better the reasons underpinning such disparities in regeneration among vertebrates, we set out to define at high resolution the changes in gene expression associated with the regeneration of hair cells in the zebrafish lateral line. We performed RNA-Seq analyses on regenerating support cells purified by FACS. The resulting expression data were subjected to pathway enrichment analyses, and the differentially expressed genes were validated in vivo via whole-mount in situ hybridizations. We discovered that cell cycle regulators are expressed hours before the activation of Wnt/β-catenin signaling following hair cell death. We propose that Wnt/β-catenin signaling is not involved in regulating the onset of proliferation but governs proliferation at later stages of regeneration. In addition, and in marked contrast to mammals, our data clearly indicate that the Notch pathway is significantly down-regulated shortly after injury, thus uncovering a key difference between the zebrafish and mammalian responses to hair cell injury. Taken together, our findings lay the foundation for identifying differences in signaling pathway regulation that could be exploited as potential therapeutic targets to promote either sensory epithelium or hair cell regeneration in mammals.
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Sensational placodes: neurogenesis in the otic and olfactory systems. Dev Biol 2014; 389:50-67. [PMID: 24508480 PMCID: PMC3988839 DOI: 10.1016/j.ydbio.2014.01.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 01/27/2014] [Accepted: 01/28/2014] [Indexed: 11/22/2022]
Abstract
For both the intricate morphogenetic layout of the sensory cells in the ear and the elegantly radial arrangement of the sensory neurons in the nose, numerous signaling molecules and genetic determinants are required in concert to generate these specialized neuronal populations that help connect us to our environment. In this review, we outline many of the proteins and pathways that play essential roles in the differentiation of otic and olfactory neurons and their integration into their non-neuronal support structures. In both cases, well-known signaling pathways together with region-specific factors transform thickened ectodermal placodes into complex sense organs containing numerous, diverse neuronal subtypes. Olfactory and otic placodes, in combination with migratory neural crest stem cells, generate highly specialized subtypes of neuronal cells that sense sound, position and movement in space, odors and pheromones throughout our lives.
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Locher H, Frijns JHM, van Iperen L, de Groot JCMJ, Huisman MA, Chuva de Sousa Lopes SM. Neurosensory development and cell fate determination in the human cochlea. Neural Dev 2013; 8:20. [PMID: 24131517 PMCID: PMC3854452 DOI: 10.1186/1749-8104-8-20] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 09/20/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hearing depends on correct functioning of the cochlear hair cells, and their innervation by spiral ganglion neurons. Most of the insight into the embryological and molecular development of this sensory system has been derived from animal studies. In contrast, little is known about the molecular expression patterns and dynamics of signaling molecules during normal fetal development of the human cochlea. In this study, we investigated the onset of hair cell differentiation and innervation in the human fetal cochlea at various stages of development. RESULTS At 10 weeks of gestation, we observed a prosensory domain expressing SOX2 and SOX9/SOX10 within the cochlear duct epithelium. In this domain, hair cell differentiation was consistently present from 12 weeks, coinciding with downregulation of SOX9/SOX10, to be followed several weeks later by downregulation of SOX2. Outgrowing neurites from spiral ganglion neurons were found penetrating into the cochlear duct epithelium prior to hair cell differentiation, and directly targeted the hair cells as they developed. Ubiquitous Peripherin expression by spiral ganglion neurons gradually diminished and became restricted to the type II spiral ganglion neurons by 18 weeks. At 20 weeks, when the onset of human hearing is thought to take place, the expression profiles in hair cells and spiral ganglion neurons matched the expression patterns of the adult mammalian cochleae. CONCLUSIONS Our study provides new insights into the fetal development of the human cochlea, contributing to our understanding of deafness and to the development of new therapeutic strategies to restore hearing.
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Affiliation(s)
| | | | | | | | | | - Susana M Chuva de Sousa Lopes
- Department of Anatomy and Embryology, Leiden University Medical Center, T-01-032, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
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Gabrielli L, Bonasoni MP, Santini D, Piccirilli G, Chiereghin A, Guerra B, Landini MP, Capretti MG, Lanari M, Lazzarotto T. Human fetal inner ear involvement in congenital cytomegalovirus infection. Acta Neuropathol Commun 2013; 1:63. [PMID: 24252374 PMCID: PMC3893406 DOI: 10.1186/2051-5960-1-63] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 09/23/2013] [Indexed: 01/12/2023] Open
Abstract
Background Congenital cytomegalovirus (CMV) infection is a leading cause of sensorineural hearing loss (SNHL). The mechanisms of pathogenesis of CMV-related SNHL are still unclear. The aim is to study congenital CMV-related damage in the fetal inner ear, in order to better understand the underlying pathophysiology behind CMV-SNHL. Results We studied inner ears and brains of 20 human fetuses, all at 21 week gestational age, with a high viral load in the amniotic fluid, with and without ultrasound (US) brain abnormalities. We evaluated histological brain damage, inner ear infection, local inflammatory response and tissue viral load. Immunohistochemistry revealed that CMV was positive in 14/20 brains (70%) and in the inner ears of 9/20 fetuses (45%). In the cases with inner ear infection, the marginal cell layer of the stria vascularis was always infected, followed by infection in the Reissner’s membrane. The highest tissue viral load was observed in the inner ear with infected Organ of Corti. Vestibular labyrinth showed CMV infection of sensory cells in the utricle and in the crista ampullaris. US cerebral anomalies were detected in 6 cases, and in all those cases, the inner ear was always involved. In the other 14 cases with normal brain scan, histological brain damage was present in 8 fetuses and 3 of them presented inner ear infection. Conclusions CMV-infection of the marginal cell layer of the stria vascularis may alter potassium and ion circulation, dissipating the endocochlear potential with consequent SNHL. Although abnormal cerebral US is highly predictive of brain and inner ear damage, normal US findings cannot exclude them either.
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