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Xu C, Zhang L, Zhou Y, Du H, Qi J, Tan F, Peng L, Gu X, Li N, Sun Q, Zhang Z, Lu Y, Qian X, Tong B, Sun J, Chai R, Shi Y. Pcolce2 overexpression promotes supporting cell reprogramming in the neonatal mouse cochlea. Cell Prolif 2024:e13633. [PMID: 38528645 DOI: 10.1111/cpr.13633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/30/2024] [Accepted: 03/06/2024] [Indexed: 03/27/2024] Open
Abstract
Hair cell (HC) damage is a leading cause of sensorineural hearing loss, and in mammals supporting cells (SCs) are unable to divide and regenerate HCs after birth spontaneously. Procollagen C-endopeptidase enhancer 2 (Pcolce2), which encodes a glycoprotein that acts as a functional procollagen C protease enhancer, was screened as a candidate regulator of SC plasticity in our previous study. In the current study, we used adeno-associated virus (AAV)-ie (a newly developed adeno-associated virus that targets SCs) to overexpress Pcolce2 in SCs. AAV-Pcolce2 facilitated SC re-entry into the cell cycle both in cultured cochlear organoids and in the postnatal cochlea. In the neomycin-damaged model, regenerated HCs were detected after overexpression of Pcolce2, and these were derived from SCs that had re-entered the cell cycle. These findings reveal that Pcolce2 may serve as a therapeutic target for the regeneration of HCs to treat hearing loss.
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Affiliation(s)
- Changling Xu
- Health Management Center, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, Sichuan, China
| | - Liyan Zhang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Yinyi Zhou
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Haoliang Du
- Department of Otolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline Laboratory, Nanjing, China
| | - Jieyu Qi
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Department of Neurology, Aerospace Center Hospital, School of Life Science, Beijing Institute of Technology, Beijing, China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Fangzhi Tan
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Li Peng
- Otovia Therapeutics Inc, Suzhou, China
| | - Xingliang Gu
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Nianci Li
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Qiuhan Sun
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Ziyu Zhang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Yicheng Lu
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Xiaoyun Qian
- Department of Otolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline Laboratory, Nanjing, China
| | - Busheng Tong
- Department of Otolaryngology-Head and Neck Surgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Jiaqiang Sun
- Department of Otolaryngology, Head and Neck Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Renjie Chai
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, School of Medicine, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Department of Neurology, Aerospace Center Hospital, School of Life Science, Beijing Institute of Technology, Beijing, China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Yi Shi
- Health Management Center, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences, Chengdu, Sichuan, China
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2
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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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Smith-Cortinez N, Tan AK, Stokroos RJ, Versnel H, Straatman LV. Regeneration of Hair Cells from Endogenous Otic Progenitors in the Adult Mammalian Cochlea: Understanding Its Origins and Future Directions. Int J Mol Sci 2023; 24:ijms24097840. [PMID: 37175547 PMCID: PMC10177935 DOI: 10.3390/ijms24097840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Sensorineural hearing loss is caused by damage to sensory hair cells and/or spiral ganglion neurons. In non-mammalian species, hair cell regeneration after damage is observed, even in adulthood. Although the neonatal mammalian cochlea carries regenerative potential, the adult cochlea cannot regenerate lost hair cells. The survival of supporting cells with regenerative potential after cochlear trauma in adults is promising for promoting hair cell regeneration through therapeutic approaches. Targeting these cells by manipulating key signaling pathways that control mammalian cochlear development and non-mammalian hair cell regeneration could lead to regeneration of hair cells in the mammalian cochlea. This review discusses the pathways involved in the development of the cochlea and the impact that trauma has on the regenerative capacity of the endogenous progenitor cells. Furthermore, it discusses the effects of manipulating key signaling pathways targeting supporting cells with progenitor potential to promote hair cell regeneration and translates these findings to the human situation. To improve hearing recovery after hearing loss in adults, we propose a combined approach targeting (1) the endogenous progenitor cells by manipulating signaling pathways (Wnt, Notch, Shh, FGF and BMP/TGFβ signaling pathways), (2) by manipulating epigenetic control, and (3) by applying neurotrophic treatments to promote reinnervation.
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Affiliation(s)
- Natalia Smith-Cortinez
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - A Katherine Tan
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Robert J Stokroos
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Louise V Straatman
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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4
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Effects of Mo-Rubbing abdomen manipulation on glucose metabolism and inflammatory factors in rats with type 2 diabetes mellitus. JOURNAL OF ACUPUNCTURE AND TUINA SCIENCE 2022. [DOI: 10.1007/s11726-022-1336-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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5
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Lin MJ, Lee CM, Hsu WL, Chen BC, Lee SJ. Macrophages Break Interneuromast Cell Quiescence by Intervening in the Inhibition of Schwann Cells in the Zebrafish Lateral Line. Front Cell Dev Biol 2022; 10:907863. [PMID: 35846366 PMCID: PMC9285731 DOI: 10.3389/fcell.2022.907863] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
In the zebrafish lateral line system, interneuromast cells (INCs) between neuromasts are kept quiescent by underlying Schwann cells (SWCs). Upon severe injuries that cause the complete loss of an entire neuromast, INCs can occasionally differentiate into neuromasts but how they escape from the inhibition by SWCs is still unclear. Using a genetic/chemical method to ablate a neuromast precisely, we found that a small portion of larvae can regenerate a new neuromast. However, the residual regeneration capacity was hindered by inhibiting macrophages. Using in toto imaging, we further discovered heterogeneities in macrophage behavior and distribution along the lateral line. We witnessed the crawling of macrophages between the injured lateral line and SWCs during regeneration and between the second primordium and the first mature lateral line during development. It implies that macrophages may physically alleviate the nerve inhibition to break the dormancy of INCs during regeneration and development in the zebrafish lateral line.
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Affiliation(s)
- Meng-Ju Lin
- Department of Life Science, National Taiwan University, Taipei, Taiwan, R.O.C.
| | - Chia-Ming Lee
- Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan, R.O.C.
| | - Wei-Lin Hsu
- Department of Life Science, National Taiwan University, Taipei, Taiwan, R.O.C.
| | - Bi-Chang Chen
- Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan, R.O.C.
| | - Shyh-Jye Lee
- Department of Life Science, National Taiwan University, Taipei, Taiwan, R.O.C.
- Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan, R.O.C.
- Center for Biotechnology, National Taiwan University, Taipei, Taiwan, R.O.C.
- *Correspondence: Shyh-Jye Lee,
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6
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Janesick AS, Scheibinger M, Benkafadar N, Kirti S, Heller S. Avian auditory hair cell regeneration is accompanied by JAK/STAT-dependent expression of immune-related genes in supporting cells. Development 2022; 149:dev200113. [PMID: 35420675 PMCID: PMC10656459 DOI: 10.1242/dev.200113] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 03/31/2022] [Indexed: 11/20/2023]
Abstract
The avian hearing organ is the basilar papilla that, in sharp contrast to the mammalian cochlea, can regenerate sensory hair cells and thereby recover from deafness within weeks. The mechanisms that trigger, sustain and terminate the regenerative response in vivo are largely unknown. Here, we profile the changes in gene expression in the chicken basilar papilla after aminoglycoside antibiotic-induced hair cell loss using RNA-sequencing. We identified changes in gene expression of a group of immune-related genes and confirmed with single-cell RNA-sequencing that these changes occur in supporting cells. In situ hybridization was used to further validate these findings. We determined that the JAK/STAT signaling pathway is essential for upregulation of the damage-response genes in supporting cells during the second day after induction of hair cell loss. Four days after ototoxic damage, we identified newly regenerated, nascent auditory hair cells that express genes linked to termination of the JAK/STAT signaling response. The robust, transient expression of immune-related genes in supporting cells suggests a potential functional involvement of JAK/STAT signaling in sensory hair cell regeneration.
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Affiliation(s)
- Amanda S. Janesick
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Mirko Scheibinger
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Nesrine Benkafadar
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Sakin Kirti
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Stefan Heller
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
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7
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Dock4 Is Required for the Maintenance of Cochlear Hair Cells and Hearing Function. FUNDAMENTAL RESEARCH 2022. [DOI: 10.1016/j.fmre.2022.04.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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8
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Holman HA, Wan Y, Rabbitt RD. Developmental GAD2 Expression Reveals Progenitor-like Cells with Calcium Waves in Mammalian Crista Ampullaris. iScience 2020; 23:101407. [PMID: 32771977 PMCID: PMC7415930 DOI: 10.1016/j.isci.2020.101407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/29/2020] [Accepted: 07/21/2020] [Indexed: 01/26/2023] Open
Abstract
Sense of motion, spatial orientation, and balance in vertebrates relies on sensory hair cells in the inner ear vestibular system. Vestibular supporting cells can regenerate hair cells that are lost from aging, ototoxicity, and trauma, although not all factors or specific cell types are known. Here we report a population of GAD2-positive cells in the mouse crista ampullaris and trace GAD2 progenitor-like cells that express pluripotent transcription factors SOX2, PROX1, and CTBP2. GAD2 progenitor-like cells organize into rosettes around a central branched structure in the eminentia cruciatum (EC) herein named the EC plexus. GCaMP5G calcium indicator shows spontaneous and acetylcholine-evoked whole-cell calcium waves in neonatal and adult mice. We present a hypothetical model that outlines the lineage and potential regenerative capacity of GAD2 cells in the mammalian vestibular neuroepithelium.
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Affiliation(s)
- Holly A Holman
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA.
| | - Yong Wan
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Richard D Rabbitt
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA; Graduate Program in Neuroscience, University of Utah, Salt Lake City, UT 84112, USA; Department of Otolaryngology-Head & Neck Surgery, University of Utah, Salt Lake City, UT 84112, USA
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9
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Wu J, Dong X, Li W, Zhao L, Zhou L, Sun S, Li H. Dibenzazepine promotes cochlear supporting cell proliferation and hair cell regeneration in neonatal mice. Cell Prolif 2020; 53:e12872. [PMID: 32677724 PMCID: PMC7507434 DOI: 10.1111/cpr.12872] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/04/2020] [Accepted: 06/17/2020] [Indexed: 12/13/2022] Open
Abstract
Objectives To investigate the role of dibenzazepine (DBZ) in promoting supporting cell (SC) proliferation and hair cell (HC) regeneration in the inner ear. Materials and Methods Postnatal day 1 wild‐type or neomycin‐damaged mouse cochleae were cultured with DBZ. Immunohistochemistry and scanning electron microscopy were used to examine the morphology of cochlear cells, and high‐throughput RNA‐sequencing was used to measure gene expression levels. Results We found that DBZ promoted SC proliferation and HC regeneration in a dose‐dependent manner in both normal and damaged cochleae. In addition, most of the newly regenerated HCs induced by DBZ had visible and relatively mature stereocilia bundle structures. Finally, RNA sequencing detected the differentially expressed genes between DBZ treatment and controls, and interaction networks were constructed for the most highly differentially expressed genes. Conclusions Our study demonstrates that DBZ can significantly promote SC proliferation and increase the number of mitotically regenerated HCs with relatively mature stereocilia bundles in the neonatal mouse cochlea by inhibiting Notch signalling and activating Wnt signalling, suggesting the DBZ might be a new therapeutic target for stimulating HC regeneration.
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Affiliation(s)
- Jingfang Wu
- Otorhinolaryngology Department of Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, Fudan University School of Basic Medical Sciences, Shanghai, China
| | - Xinran Dong
- Molecular Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Wen Li
- Otorhinolaryngology Department of Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, Fudan University School of Basic Medical Sciences, Shanghai, China
| | - Liping Zhao
- Otorhinolaryngology Department of Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, Fudan University School of Basic Medical Sciences, Shanghai, China
| | - Li Zhou
- Shanghai High School, Shanghai, China
| | - Shan Sun
- Otorhinolaryngology Department of Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, Fudan University School of Basic Medical Sciences, Shanghai, China
| | - Huawei Li
- Otorhinolaryngology Department of Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, Fudan University School of Basic Medical Sciences, Shanghai, China.,The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
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Wan L, Lovett M, Warchol ME, Stone JS. Vascular endothelial growth factor is required for regeneration of auditory hair cells in the avian inner ear. Hear Res 2020; 385:107839. [PMID: 31760261 DOI: 10.1016/j.heares.2019.107839] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/30/2019] [Accepted: 11/01/2019] [Indexed: 12/12/2022]
Abstract
Hair cells in the auditory organ of the vertebrate inner ear are the sensory receptors that convert acoustic stimuli into electrical signals that are conveyed along the auditory nerve to the brainstem. Hair cells are highly susceptible to ototoxic drugs, infection, and acoustic trauma, which can cause cellular degeneration. In mammals, hair cells that are lost after damage are not replaced, leading to permanent hearing impairments. By contrast, supporting cells in birds and other non-mammalian vertebrates regenerate hair cells after damage, which restores hearing function. The cellular mechanisms that regulate hair cell regeneration are not well understood. We investigated the role of vascular endothelial growth factor (VEGF) during regeneration of auditory hair cells in chickens after ototoxic injury. Using RNA-Seq, immunolabeling, and in situ hybridization, we found that VEGFA, VEGFC, VEGFR1, VEGFR2, and VEGFR3 were expressed in the auditory epithelium, with VEGFA expressed in hair cells and VEGFR1 and VEGFR2 expressed in supporting cells. Using organotypic cultures of the chicken cochlear duct, we found that blocking VEGF receptor activity during hair cell injury reduced supporting cell proliferation as well as the numbers of regenerated hair cells. By contrast, addition of recombinant human VEGFA to organ cultures caused an increase in both supporting cell division and hair cell regeneration. VEGF's effects on supporting cells were preserved in isolated supporting cell cultures, indicating that VEGF can act directly upon supporting cells. These observations demonstrate a heretofore uncharacterized function for VEGF signaling as a critical positive regulator of hair cell regeneration in the avian inner ear.
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Affiliation(s)
- Liangcai Wan
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, WA, 98195, United States.
| | - Michael Lovett
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, 63110, United States.
| | - Mark E Warchol
- Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St. Louis, MO, 63110, United States.
| | - Jennifer S Stone
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, WA, 98195, United States.
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12
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Cheng C, Wang Y, Guo L, Lu X, Zhu W, Muhammad W, Zhang L, Lu L, Gao J, Tang M, Chen F, Gao X, Li H, Chai R. Age-related transcriptome changes in Sox2+ supporting cells in the mouse cochlea. Stem Cell Res Ther 2019; 10:365. [PMID: 31791390 PMCID: PMC6889721 DOI: 10.1186/s13287-019-1437-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/29/2019] [Accepted: 10/01/2019] [Indexed: 12/17/2022] Open
Abstract
Background Inner ear supporting cells (SCs) in the neonatal mouse cochlea are a potential source for hair cell (HC) regeneration, but several studies have shown that the regeneration ability of SCs decreases dramatically as mice age and that lost HCs cannot be regenerated in adult mice. To better understand how SCs might be better used to regenerate HCs, it is important to understand how the gene expression profile changes in SCs at different ages. Methods Here, we used Sox2GFP/+ mice to isolate the Sox2+ SCs at postnatal day (P)3, P7, P14, and P30 via flow cytometry. Next, we used RNA-seq to determine the transcriptome expression profiles of P3, P7, P14, and P30 SCs. To further analyze the relationships between these age-related and differentially expressed genes in Sox2+ SCs, we performed gene ontology (GO) analysis. Results Consistent with previous reports, we also found that the proliferation and HC regeneration ability of isolated Sox2+ SCs significantly decreased as mice aged. We identified numerous genes that are enriched and differentially expressed in Sox2+ SCs at four different postnatal ages, including cell cycle genes, signaling pathway genes, and transcription factors that might be involved in regulating the proliferation and HC differentiation ability of SCs. We thus present a set of genes that might regulate the proliferation and HC regeneration ability of SCs, and these might serve as potential new therapeutic targets for HC regeneration. Conclusions In our research, we found several genes that might play an important role in regulating the proliferation and HC regeneration ability of SCs. These datasets are expected to serve as a resource to provide potential new therapeutic targets for regulating the ability of SCs to regenerate HCs in postnatal mammals.
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Affiliation(s)
- Cheng Cheng
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing, 210008, China.,Research Institute of Otolaryngology, No. 321 Zhongshan Road, Nanjing, 210008, China
| | - Yunfeng Wang
- Shanghai Fenyang Vision & Audition Center, Shanghai, China.,ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University, Room 611, Building 9, No. 83, Fenyang Road, Xuhui District, Shanghai, 200031, China
| | - Luo Guo
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University, Room 611, Building 9, No. 83, Fenyang Road, Xuhui District, Shanghai, 200031, China
| | - Xiaoling Lu
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University, Room 611, Building 9, No. 83, Fenyang Road, Xuhui District, Shanghai, 200031, China
| | - Weijie Zhu
- MOE Key Laboratory for Developmental Genes and Human Disease, State Key Laboratory of Bioelectronics, Co-Innovation Center of Neuroregeneration, Institute of Life Sciences, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Waqas Muhammad
- MOE Key Laboratory for Developmental Genes and Human Disease, State Key Laboratory of Bioelectronics, Co-Innovation Center of Neuroregeneration, Institute of Life Sciences, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China.,Department of Biotechnology, Federal Urdu University of Arts, Science and Technology, Gulshan-e-Iqbal Campus, Karachi, Pakistan
| | - Liyan Zhang
- MOE Key Laboratory for Developmental Genes and Human Disease, State Key Laboratory of Bioelectronics, Co-Innovation Center of Neuroregeneration, Institute of Life Sciences, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Ling Lu
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing, 210008, China
| | - Junyan Gao
- Jiangsu Rehabilitation Research Center for Hearing and Speech Impairment, Nanjing, 210004, Jiangsu, China
| | - Mingliang Tang
- MOE Key Laboratory for Developmental Genes and Human Disease, State Key Laboratory of Bioelectronics, Co-Innovation Center of Neuroregeneration, Institute of Life Sciences, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Xia Gao
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing, 210008, China.
| | - Huawei Li
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University, Room 611, Building 9, No. 83, Fenyang Road, Xuhui District, Shanghai, 200031, China.
| | - Renjie Chai
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University, Room 611, Building 9, No. 83, Fenyang Road, Xuhui District, Shanghai, 200031, China. .,MOE Key Laboratory for Developmental Genes and Human Disease, State Key Laboratory of Bioelectronics, Co-Innovation Center of Neuroregeneration, Institute of Life Sciences, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China. .,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China. .,Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, China. .,Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, 100069, China.
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13
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Zhang X, Yu J. Baicalin attenuates gentamicin-induced cochlear hair cell ototoxicity. J Appl Toxicol 2019; 39:1208-1214. [PMID: 31021006 DOI: 10.1002/jat.3806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/18/2018] [Accepted: 11/29/2018] [Indexed: 01/13/2023]
Abstract
Gentamicin can lead to cochlear hair cells associated ototoxicity by inducing apoptosis and oxidative stress, which can be alleviated by baicalin, one flavonoid extracted from the root of Scutellaria baicalensis. The role of baicalin in protecting gentamicin-induced hearing loss is unclear. Interference with oxidative stress was investigated in this study using House Ear Institute-Organ of Corti1 (HEI-OC1) cells, which were simultaneously treated with baicalin (0-400 μm) and gentamicin (0.2 or 1 mm). MTT was used to assay cell viability and apoptosis was detected with Annexin V-fluorescein isothiocyanate staining. The production of reactive oxygen species was indicated by 2,7-dichlorofluorescein diacetate fluorescence intensity and mitochondrial depolarization was assayed by JC1-mitochondrial membrane potential assay. Poly(ADP-ribose) polymerase (PARP), cleaved-caspase 3 and cleaved-PARP expression were analyzed with western blot. Baicalin improved the viability of HEI-OC1 cells and significantly reduced the oxidative stress and mitochondrial depolarization compared with the gentamicin treatment group. Gentamicin treatment increased the activation of PARP and caspase-3, while such an increase could be downregulated by baicalin. Baicalin attenuates gentamicin-induced cochlear hair cells ototoxicity, and such inhibition may be mediated by the regulation of reactive oxygen species production, mitochondrial depolarization, and caspase-3 and PARP activation.
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Affiliation(s)
- Xianfen Zhang
- Department of Otolaryngology, Yantaishan Hospital, Shandong, China
| | - Jun Yu
- Department of Otolaryngology, Yantai YEDA Hospital, Shandong, China
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14
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Kathpalia P, Nag TC, Chattopadhyay P, Sharma A, Bhat MA, Roy TS, Wadhwa S. In ovo Sound Stimulation Mediated Regulation of BDNF in the Auditory Cortex and Hippocampus of Neonatal Chicks. Neuroscience 2019; 408:293-307. [PMID: 31026564 DOI: 10.1016/j.neuroscience.2019.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/15/2019] [Accepted: 04/07/2019] [Indexed: 12/22/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is known to mediate activity-dependent changes in the developing auditory system. Its expression in the brainstem auditory nuclei, auditory cortex and hippocampus of neonatal chicks (Gallus gallus domesticus) in response to in ovo high intensity sound exposure at 110 dB (arrhythmic sound: recorded traffic noise, 30-3000 Hz with peak at 2700 Hz, rhythmic sound: sitar music, 100-4000 Hz) was examined to understand the previously reported altered volume and neuronal number in these regions. In the brainstem auditory nuclei, no mature BDNF, but proBDNF at the protein level was detected, and no change in its levels was observed after in ovo sound stimulation (music and noise). Increased ProBDNF protein levels were found in the auditory cortex in response to arrhythmic sound, along with decreased levels of one of the BDNF mRNA transcripts, in response to both rhythmic and arrhythmic sound stimulation. In the hippocampus, increased levels of mature BDNF were found in response to music. Expression microarray analysis was performed to understand changes in gene expression in the hippocampus in response to music and noise, followed by gene ontology analysis showing enrichment of probable signaling pathways. Differentially expressed genes like CAMK1 and STAT1 were found to be involved in downstream signaling on comparing music versus noise-exposed chicks. In conclusion, we report that BDNF is differentially regulated in the auditory cortex at the transcriptional and post-translational level, and in the hippocampus at the post-translational level in response to in ovo sound stimulation.
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Affiliation(s)
- Poorti Kathpalia
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Tapas Chandra Nag
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India.
| | | | - Arundhati Sharma
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Muzaffer Ahmed Bhat
- Department of Physiology, All India Institute of Medical Sciences, New Delhi, India
| | - Tara Sankar Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Shashi Wadhwa
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India; Department of Anatomy, North Delhi Municipal Medical College, New Delhi, India
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15
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Lush ME, Diaz DC, Koenecke N, Baek S, Boldt H, St Peter MK, Gaitan-Escudero T, Romero-Carvajal A, Busch-Nentwich EM, Perera AG, Hall KE, Peak A, Haug JS, Piotrowski T. scRNA-Seq reveals distinct stem cell populations that drive hair cell regeneration after loss of Fgf and Notch signaling. eLife 2019; 8:44431. [PMID: 30681411 PMCID: PMC6363392 DOI: 10.7554/elife.44431] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 01/24/2019] [Indexed: 12/25/2022] Open
Abstract
Loss of sensory hair cells leads to deafness and balance deficiencies. In contrast to mammalian hair cells, zebrafish ear and lateral line hair cells regenerate from poorly characterized support cells. Equally ill-defined is the gene regulatory network underlying the progression of support cells to differentiated hair cells. scRNA-Seq of lateral line organs uncovered five different support cell types, including quiescent and activated stem cells. Ordering of support cells along a developmental trajectory identified self-renewing cells and genes required for hair cell differentiation. scRNA-Seq analyses of fgf3 mutants, in which hair cell regeneration is increased, demonstrates that Fgf and Notch signaling inhibit proliferation of support cells in parallel by inhibiting Wnt signaling. Our scRNA-Seq analyses set the foundation for mechanistic studies of sensory organ regeneration and is crucial for identifying factors to trigger hair cell production in mammals. The data is searchable and publicly accessible via a web-based interface.
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Affiliation(s)
- Mark E Lush
- Stowers Institute for Medical Research, Kansas City, United States
| | - Daniel C Diaz
- Stowers Institute for Medical Research, Kansas City, United States
| | - Nina Koenecke
- Stowers Institute for Medical Research, Kansas City, United States
| | - Sungmin Baek
- Stowers Institute for Medical Research, Kansas City, United States
| | - Helena Boldt
- Stowers Institute for Medical Research, Kansas City, United States
| | | | | | - Andres Romero-Carvajal
- Stowers Institute for Medical Research, Kansas City, United States.,Pontificia Universidad Catolica del Ecuador, Ciencias Biologicas, Quito, Ecuador
| | - Elisabeth M Busch-Nentwich
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom.,Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Anoja G Perera
- Stowers Institute for Medical Research, Kansas City, United States
| | - Kathryn E Hall
- Stowers Institute for Medical Research, Kansas City, United States
| | - Allison Peak
- Stowers Institute for Medical Research, Kansas City, United States
| | - Jeffrey S Haug
- Stowers Institute for Medical Research, Kansas City, United States
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17
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McGovern MM, Zhou L, Randle MR, Cox BC. Spontaneous Hair Cell Regeneration Is Prevented by Increased Notch Signaling in Supporting Cells. Front Cell Neurosci 2018; 12:120. [PMID: 29780306 PMCID: PMC5945818 DOI: 10.3389/fncel.2018.00120] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/13/2018] [Indexed: 11/13/2022] Open
Abstract
During embryonic development, differentiation of cochlear progenitor cells into hair cells (HCs) or supporting cells (SCs) is partially controlled through Notch signaling. Many studies have shown that inhibition of Notch signaling allows SCs to convert into HCs in both normal and drug damaged neonatal mouse cochleae. This mechanism is also implicated during HC regeneration in non-mammalian vertebrates; however, the mechanism of spontaneous HC regeneration in the neonatal mouse cochlea is less understood. While inhibition of Notch signaling can force SCs to convert into HCs and increase the number of regenerated HCs, it is currently unknown whether this pathway is involved in spontaneous HC regeneration observed in vivo. Therefore, we investigated the role of Notch signaling during the spontaneous HC regeneration process using Atoh1-CreERTM::Rosa26loxP-stop-loxP-DTA/+ mice injected with tamoxifen at postnatal day (P) 0 and P1 to ablate HCs and stimulate spontaneous HC regeneration. Expression changes of genes in the Notch pathway were measured using immunostaining and in situ hybridization, with most changes observed in the apical one-third of the cochlea where the majority of HC regeneration occurs. Expression of the Notch target genes Hes1, Hes5, Hey1, HeyL, and Jagged1 were decreased. To investigate whether reduction of Notch signaling is involved in the spontaneous HC regeneration process, we overexpressed the Notch1 intracellular fragment (N1ICD) in cochlear SCs and other non-sensory epithelial cells in the context of HC damage. Specifically, Atoh1-CreERTM::Rosa26loxP-stop-loxP-DTA/+::Sox10rtTA::TetO-LacZ::TetO-N1ICD mice were injected with tamoxifen at P0/P1 to stimulate spontaneous HC regeneration and given doxycycline from P0-P7 to induce expression of N1ICD as well as LacZ for fate-mapping. We observed a 92% reduction in the number of fate-mapped regenerated HCs in mice with N1ICD overexpression compared to controls with HC damage but no manipulation of Notch signaling. Therefore, we conclude that increased Notch signaling prevents spontaneous HC regeneration from occurring in the neonatal mouse cochlea. Understanding which components of the Notch pathway regulates regenerative plasticity in the neonatal mouse cochlea will inform investigations focused on stimulating HC regeneration in mature cochlea and eventually in humans to treat hearing loss.
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Affiliation(s)
- Melissa M. McGovern
- Department of Pharmacology, School of Medicine, Southern Illinois University, Springfield, IL, United States
| | - Luyi Zhou
- Department of Pharmacology, School of Medicine, Southern Illinois University, Springfield, IL, United States
| | - Michelle R. Randle
- Department of Pharmacology, School of Medicine, Southern Illinois University, Springfield, IL, United States
| | - Brandon C. Cox
- Department of Pharmacology, School of Medicine, Southern Illinois University, Springfield, IL, United States
- Department of Surgery, Division of Otolaryngology, School of Medicine, Southern Illinois University, Springfield, IL, United States
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18
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Lewis RM, Keller JJ, Wan L, Stone JS. Bone morphogenetic protein 4 antagonizes hair cell regeneration in the avian auditory epithelium. Hear Res 2018; 364:1-11. [PMID: 29754876 DOI: 10.1016/j.heares.2018.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 03/11/2018] [Accepted: 04/16/2018] [Indexed: 02/01/2023]
Abstract
Permanent hearing loss is often a result of damage to cochlear hair cells, which mammals are unable to regenerate. Non-mammalian vertebrates such as birds replace damaged hair cells and restore hearing function, but mechanisms controlling regeneration are not understood. The secreted protein bone morphogenetic protein 4 (BMP4) regulates inner ear morphogenesis and hair cell development. To investigate mechanisms controlling hair cell regeneration in birds, we examined expression and function of BMP4 in the auditory epithelia (basilar papillae) of chickens of either sex after hair cell destruction by ototoxic antibiotics. In mature basilar papillae, BMP4 mRNA is highly expressed in hair cells, but not in hair cell progenitors (supporting cells). Supporting cells transcribe genes encoding receptors for BMP4 (BMPR1A, BMPR1B, and BMPR2) and effectors of BMP4 signaling (ID transcription factors). Following hair cell destruction, BMP4 transcripts are lost from the sensory epithelium. Using organotypic cultures, we demonstrate that treatments with BMP4 during hair cell destruction prevent supporting cells from upregulating expression of the pro-hair cell transcription factor ATOH1, entering the cell cycle, and fully transdifferentiating into hair cells, but they do not induce cell death. By contrast, noggin, a BMP4 inhibitor, increases numbers of regenerated hair cells. These findings demonstrate that BMP4 antagonizes hair cell regeneration in the chicken basilar papilla, at least in part by preventing accumulation of ATOH1 in hair cell precursors.
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Affiliation(s)
- Rebecca M Lewis
- University of Washington School of Medicine and the Virginia Merrill Bloedel Hearing Research Center, Seattle, WA, United States; Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, United States
| | - Jesse J Keller
- University of Washington School of Medicine and the Virginia Merrill Bloedel Hearing Research Center, Seattle, WA, United States; Oregon Health Sciences University, Portland, OR, United States
| | - Liangcai Wan
- University of Washington School of Medicine and the Virginia Merrill Bloedel Hearing Research Center, Seattle, WA, United States; Department of Otolaryngology-Head and Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jennifer S Stone
- University of Washington School of Medicine and the Virginia Merrill Bloedel Hearing Research Center, Seattle, WA, United States.
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Cao H, Shi J, Du J, Chen K, Dong C, Jiang D, Jiang H. MicroRNA-194 Regulates the Development and Differentiation of Sensory Patches and Statoacoustic Ganglion of Inner Ear by Fgf4. Med Sci Monit 2018; 24:1712-1723. [PMID: 29570699 PMCID: PMC5880017 DOI: 10.12659/msm.906277] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Background MicroRNA 194 is involved in the differentiation of various types of cells, such as adipose derived stem cells, human embryonic stem cells, and bone marrow mesenchymal stem cells. Previously, we found that miR-194 was highly expressed in the inner ear sensory patch and neurons in mice embryos. However, the role of miR-194 in the development of the inner ear and its underlying mechanism have not been elucidated yet. Material/Methods The expression level of miR-194 has been altered by using antisense morpholino oligonucleotides (MO) and synthesized miRNAs in zebrafish. Results We found that miR-194 was vastly expressed in the inner ear and central nervous system (CNS) in zebrafish. Loss of function of miR-194 could strongly affected the development of zebrafish embryos, including delayed embryonic development, edema of the pericardium, small head, axial deviation, delayed development of inner ear, closer location of two otoliths, delayed fusion of the semicircular canals, and abnormal otolith number in some cases. In addition, the behavior of zebrafish was also adversely affected with impaired balance and biased swimming route. Misexpression of miR-194 could strongly affected the development and differentiation of spiral ganglion neuron (SGN) in inner ear through Fgf4 in vitro. Similar results have also been observed that the overexpression and knockdown of miR-194 strongly disturbed the development and differentiation of the sensory patches and Statoacoustic ganglion (SAG) through Fgf4 in zebrafish in vivo. Our results indicated that miR-194 may regulate the development and differentiation of sensory patches and SAG through Fgf4. Conclusions Our data revealed a vital role of miR-194 in regulating the development and differentiation of the inner ear.
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Affiliation(s)
- Hui Cao
- Department of Otolaryngology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).,Department of Otolaryngology, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Jianbo Shi
- Department of Otolaryngology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China (mainland)
| | - Jintao Du
- Department of Otolaryngology, West China hospital of Sichuan University, Chengdu, Sichuan, China (mainland)
| | - Kaitian Chen
- Department of Otolaryngology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China (mainland)
| | - Chang Dong
- Department of Otolaryngology, People's Hospital of Hainan Province, Haikou, Hainan, China (mainland)
| | - Di Jiang
- Department of Otolaryngology, People's Hospital of Dongguan, Dongguan, Guangdong, China (mainland)
| | - Hongyan Jiang
- Department of Otolaryngology, People's Hospital of Hainan Province, Haikou, Hainan, China (mainland)
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20
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Regeneration of Cochlear Hair Cells and Hearing Recovery through Hes1 Modulation with siRNA Nanoparticles in Adult Guinea Pigs. Mol Ther 2018; 26:1313-1326. [PMID: 29680697 DOI: 10.1016/j.ymthe.2018.03.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 03/06/2018] [Accepted: 03/06/2018] [Indexed: 12/17/2022] Open
Abstract
Deafness is commonly caused by the irreversible loss of mammalian cochlear hair cells (HCs) due to noise trauma, toxins, or infections. We previously demonstrated that small interfering RNAs (siRNAs) directed against the Notch pathway gene, hairy and enhancer of split 1 (Hes1), encapsulated within biocompatible poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) could regenerate HCs within ototoxin-ablated murine organotypic cultures. In the present study, we delivered this sustained-release formulation of Hes1 siRNA (siHes1) into the cochleae of noise-injured adult guinea pigs. Auditory functional recovery was measured by serial auditory brainstem responses over a nine-week follow-up period, and HC regeneration was evaluated by immunohistological evaluations and scanning electron microscopy. Significant HC restoration and hearing recovery were observed across a broad tonotopic range in ears treated with siHes1 NPs, beginning at three weeks and extending out to nine weeks post-treatment. Moreover, both ectopic and immature HCs were uniquely observed in noise-injured cochleae treated with siHes1 NPs, consistent with de novo HC production. Our results indicate that durable cochlear HCs were regenerated and promoted significant hearing recovery in adult guinea pigs through reversible modulation of Hes1 expression. Therefore, PLGA-NP-mediated delivery of siHes1 to the cochlea represents a promising pharmacologic approach to regenerate functional and sustainable mammalian HCs in vivo.
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21
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Diphtheria Toxin-Induced Cell Death Triggers Wnt-Dependent Hair Cell Regeneration in Neonatal Mice. J Neurosci 2017; 36:9479-89. [PMID: 27605621 DOI: 10.1523/jneurosci.2447-15.2016] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 07/20/2016] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED Cochlear hair cells (HCs), the sensory cells that respond to sound, do not regenerate after damage in adult mammals, and their loss is a major cause of deafness. Here we show that HC regeneration in newborn mouse ears occurred spontaneously when the original cells were ablated by treatment with diphtheria toxin (DT) in ears that had been engineered to overexpress the DT receptor, but was not detectable when HCs were ablated in vivo by the aminoglycoside antibiotic neomycin. A variety of Wnts (Wnt1, Wnt2, Wnt2b, Wnt4, Wnt5a, Wnt7b, Wnt9a, Wnt9b, and Wnt11) and Wnt pathway component Krm2 were upregulated after DT damage. Nuclear β-catenin was upregulated in HCs and supporting cells of the DT-damaged cochlea. Pharmacological inhibition of Wnt decreased spontaneous regeneration, confirming a role of Wnt signaling in HC regeneration. Inhibition of Notch signaling further potentiated supporting cell proliferation and HC differentiation that occurred spontaneously. The absence of new HCs in the neomycin ears was correlated to less robust Wnt pathway activation, but the ears subjected to neomycin treatment nonetheless showed increased cell division and HC differentiation after subsequent forced upregulation of β-catenin. These studies suggest, first, that Wnt signaling plays a key role in regeneration, and, second, that the outcome of a regenerative response to damage in the newborn cochlea is determined by reaching a threshold level of Wnt signaling rather than its complete absence or presence. SIGNIFICANCE STATEMENT Sensory HCs of the inner ear do not regenerate in the adult, and their loss is a major cause of deafness. We found that HCs regenerated spontaneously in the newborn mouse after diphtheria toxin (DT)-induced, but not neomycin-induced, HC death. Regeneration depended on activation of Wnt signaling, and regeneration in DT-treated ears correlated to a higher level of Wnt activation than occurred in nonregenerating neomycin-treated ears. This is significant because insufficient regeneration caused by a failure to reach a threshold level of signaling, if true in the adult, has the potential to be exploited for development of clinical approaches for the treatment of deafness caused by HC loss.
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22
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Kelley MW, Stone JS. Development and Regeneration of Sensory Hair Cells. AUDITORY DEVELOPMENT AND PLASTICITY 2017. [DOI: 10.1007/978-3-319-21530-3_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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23
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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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Nguyen K, Kempfle JS, Jung DH, McKenna CE. Recent advances in therapeutics and drug delivery for the treatment of inner ear diseases: a patent review (2011-2015). Expert Opin Ther Pat 2016; 27:191-202. [PMID: 27855527 DOI: 10.1080/13543776.2017.1252751] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Kim Nguyen
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Judith S. Kempfle
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
- Eaton Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
| | - David H. Jung
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
- Eaton Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
| | - Charles E. McKenna
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
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25
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Wang T, Chai R, Kim GS, Pham N, Jansson L, Nguyen DH, Kuo B, May L, Zuo J, Cunningham LL, Cheng AG. Lgr5+ cells regenerate hair cells via proliferation and direct transdifferentiation in damaged neonatal mouse utricle. Nat Commun 2015; 6:6613. [PMID: 25849379 PMCID: PMC4391285 DOI: 10.1038/ncomms7613] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 02/11/2015] [Indexed: 01/10/2023] Open
Abstract
Recruitment of endogenous progenitors is critical during tissue repair. The inner ear utricle requires mechanosensory hair cells (HCs) to detect linear acceleration. After damage, non-mammalian utricles regenerate HCs via both proliferation and direct transdifferentiation. In adult mammals, limited transdifferentiation from unidentified progenitors occurs to regenerate extrastriolar Type II HCs. Here we show that HC damage in neonatal mouse utricle activates the Wnt target gene Lgr5 in striolar supporting cells. Lineage tracing and time-lapse microscopy reveal that Lgr5+ cells transdifferentiate into HC-like cells in vitro. In contrast to adults, HC ablation in neonatal utricles in vivo recruits Lgr5+ cells to regenerate striolar HCs through mitotic and transdifferentiation pathways. Both Type I and II HCs are regenerated, and regenerated HCs display stereocilia and synapses. Lastly, stabilized ß-catenin in Lgr5+ cells enhances mitotic activity and HC regeneration. Thus Lgr5 marks Wnt-regulated, damage-activated HC progenitors and may help uncover factors driving mammalian HC regeneration.
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Affiliation(s)
- Tian Wang
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Renjie Chai
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210096, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Grace S. Kim
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Nicole Pham
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Lina Jansson
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Duc-Huy Nguyen
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Bryan Kuo
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN, 38103, USA
| | - Lindsey May
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jian Zuo
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN, 38103, USA
| | - Lisa L. Cunningham
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Alan G. Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Corresponding author: Alan G. Cheng, M.D., 801 Welch Road, Department of Otolaryngology-HNS, Stanford, CA 94305, Phone: (650) 725-6500, Fax: (650) 721-2163,
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Lin J, Zhang X, Wu F, Lin W. Hair cell damage recruited Lgr5-expressing cells are hair cell progenitors in neonatal mouse utricle. Front Cell Neurosci 2015; 9:113. [PMID: 25883551 PMCID: PMC4381628 DOI: 10.3389/fncel.2015.00113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 03/12/2015] [Indexed: 01/08/2023] Open
Abstract
Damage-activated stem/progenitor cells play important roles in regenerating lost cells and in tissue repair. Previous studies reported that the mouse utricle has limited hair cell regeneration ability after hair cell ablation. However, the potential progenitor cell population regenerating new hair cells remains undiscovered. In this study, we first found that Lgr5, a Wnt target gene that is not usually expressed in the neonatal mouse utricle, can be activated by 24 h neomycin treatment in a sub-population of supporting cells in the striolar region of the neonatal mouse utricle. Lineage tracing demonstrated that these Lgr5-positive supporting cells could regenerate new hair cells in explant culture. We isolated the damage-activated Lgr5-positive cells with flow cytometry and found that these Lgr5-positive supporting cells could regenerate hair cells in vitro, and self-renew to form spheres, which maintained the capacity to differentiate into hair cells over seven generations of passages. Our results suggest that damage-activated Lgr5-positive supporting cells act as hair cell progenitors in the neonatal mouse utricle, which may help to uncover a potential route to regenerate hair cell in mammals.
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Affiliation(s)
- Jinchao Lin
- Department of Otolaryngology-Head and Neck Surgery, Quanzhou First Hospital Affiliated to Fujian Medical University Quanzhou, Fujian, China
| | - Xiaodong Zhang
- Department of Otolaryngology-Head and Neck Surgery, Quanzhou First Hospital Affiliated to Fujian Medical University Quanzhou, Fujian, China
| | - Fengfang Wu
- Department of Otolaryngology-Head and Neck Surgery, Quanzhou First Hospital Affiliated to Fujian Medical University Quanzhou, Fujian, China
| | - Weinian Lin
- Department of Otolaryngology-Head and Neck Surgery, Quanzhou First Hospital Affiliated to Fujian Medical University Quanzhou, Fujian, China
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pRb phosphorylation regulates the proliferation of supporting cells in gentamicin-damaged neonatal avian utricle. Neuroreport 2015; 25:1144-50. [PMID: 25100553 DOI: 10.1097/wnr.0000000000000241] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The ability of nonmammalian vertebrates to regenerate hair cells (HCs) after damage-induced HC loss has stimulated and inspired research in the field of HC regeneration. The protein pRb encoded by retinoblastoma gene Rb1 forces sensory progenitor cells to exit cell cycle and maintain differentiated HCs and supporting cells (SCs) in a quiescent state. pRb function is regulated by phosphorylation through the MEK/ERK or the pRb/Raf-1 signaling pathway. In our previous study, we have shown that pRb phosphorylation is crucial for progenitor cell proliferation and survival during the early embryonic stage of avian otocyst sensory epithelium development. However, in damaged avian utricle, the role of pRb in regulating the cell cycling of SCs or HCs regeneration still remains unclear. To further elucidate the function of pRb phosphorylation on SCs re-entering the cell cycle triggered by gentamycin-induced HCs damage, we isolated neonatal chicken utricles and treated them with the MEK inhibitor U0126 or the pRb/Raf-1 inhibitor RRD-251, respectively in vitro. We found that after gentamycin-induced HCs damage, pRb phosphorylation is important for the quiescent SCs re-entering the cell cycle in the neonatal chicken utricle. In addition, the proliferation of SCs decreased in a dose-dependent manner in response to both U0126 and RRD-251, which indicates that both the MEK/ERK and the pRb/Raf-1 signaling pathway play important roles in pRb phosphorylation in damaged neonatal chicken utricle. Together, these findings on the function of pRb in damaged neonatal chicken utricle improve our understanding of the regulation of the cell cycle of SCs after HCs loss and may shed light on the mammalian HC regeneration from SCs in damaged organs.
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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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Du X, Li W, Gao X, West MB, Saltzman WM, Cheng CJ, Stewart C, Zheng J, Cheng W, Kopke RD. Regeneration of mammalian cochlear and vestibular hair cells through Hes1/Hes5 modulation with siRNA. Hear Res 2013; 304:91-110. [PMID: 23850665 DOI: 10.1016/j.heares.2013.06.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 05/16/2013] [Accepted: 06/27/2013] [Indexed: 12/31/2022]
Abstract
The Notch pathway is a cell signaling pathway determining initial specification and subsequent cell fate in the inner ear. Previous studies have suggested that new hair cells (HCs) can be regenerated in the inner ear by manipulating the Notch pathway. In the present study, delivery of siRNA to Hes1 and Hes5 using a transfection reagent or siRNA to Hes1 encapsulated within poly(lactide-co-glycolide acid) (PLGA) nanoparticles increased HC numbers in non-toxin treated organotypic cultures of cochleae and maculae of postnatal day 3 mouse pups. An increase in HCs was also observed in cultured cochleae and maculae of mouse pups pre-conditioned with a HC toxin (4-hydroxy-2-nonenal or neomycin) and then treated with the various siRNA formulations. Treating cochleae with siRNA to Hes1 associated with a transfection reagent or siRNA to Hes1 delivered by PLGA nanoparticles decreased Hes1 mRNA and up-regulated Atoh1 mRNA expression allowing supporting cells (SCs) to acquire a HC fate. Experiments using cochleae and maculae of p27(kip1)/-GFP transgenic mouse pups demonstrated that newly generated HCs trans-differentiated from SCs. Furthermore, PLGA nanoparticles are non-toxic to inner ear tissue, readily taken up by cells within the tissue of interest, and present a synthetic delivery system that is a safe alternative to viral vectors. These results indicate that when delivered using a suitable vehicle, Hes siRNAs are potential therapeutic molecules that may have the capacity to regenerate new HCs in the inner ear and possibly restore human hearing and balance function.
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Affiliation(s)
- Xiaoping Du
- Hough Ear Institute, P.O. Box 23206, Oklahoma City, OK 73112, USA
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Inner ear supporting cells: rethinking the silent majority. Semin Cell Dev Biol 2013; 24:448-59. [PMID: 23545368 DOI: 10.1016/j.semcdb.2013.03.009] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 03/21/2013] [Indexed: 11/21/2022]
Abstract
Sensory epithelia of the inner ear contain two major cell types: hair cells and supporting cells. It has been clear for a long time that hair cells play critical roles in mechanoreception and synaptic transmission. In contrast, until recently the more abundant supporting cells were viewed as serving primarily structural and homeostatic functions. In this review, we discuss the growing information about the roles that supporting cells play in the development, function and maintenance of the inner ear, their activities in pathological states, their potential for hair cell regeneration, and the mechanisms underlying these processes.
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Cell lineage analysis reveals three different progenitor pools for neurosensory elements in the otic vesicle. J Neurosci 2013; 32:16424-34. [PMID: 23152625 DOI: 10.1523/jneurosci.3686-12.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In the inner ear, sensory versus neuronal specification is achieved through few well-defined bHLH transcription factors. However, the molecular mechanisms regulating the generation of the appropriate cell type in the correct place and at the correct time are not completely understood yet. Various studies have shown that hair cell- and neuron-specifying genes partially overlap in the otic territory, suggesting that mutual interactions among these bHLH factors could direct the generation of the two cell types from a common neurosensory progenitor. Although there is little evidence for a clonal relationship between macular hair cells and sensory neurons, the existence of a single progenitor able to give both sensory and neuronal cell types remains an open question. Here, we identified a population of common neurosensory progenitors in the zebrafish inner ear and studied the proneural requirement for cell fate decision within this population. Expression analysis reveals that proneural genes for hair cells and neurons overlap within the posteromedial otic epithelium. Combined results from single-cell lineage and functional studies on neurog1 and neuroD1 further demonstrate the following: (1) in the anterior region of the ear, neuronal and sensory lineages have already segregated at the onset of proneural gene expression and are committed to a given fate very early; (2) in contrast, the posteromedial part of the ear harbors a population of common progenitors giving both neurons and hair cells until late stages; and finally (3) neuroD1 is required within this pool of bipotent progenitors to generate the hair cell fate.
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Rubel EW, Furrer SA, Stone JS. A brief history of hair cell regeneration research and speculations on the future. Hear Res 2013; 297:42-51. [PMID: 23321648 DOI: 10.1016/j.heares.2012.12.014] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 12/18/2012] [Accepted: 12/19/2012] [Indexed: 12/24/2022]
Abstract
Millions of people worldwide suffer from hearing and balance disorders caused by loss of the sensory hair cells that convert sound vibrations and head movements into electrical signals that are conveyed to the brain. In mammals, the great majority of hair cells are produced during embryogenesis. Hair cells that are lost after birth are virtually irreplaceable, leading to permanent disability. Other vertebrates, such as fish and amphibians, produce hair cells throughout life. However, hair cell replacement after damage to the mature inner ear was either not investigated or assumed to be impossible until studies in the late 1980s proved this to be false. Adult birds were shown to regenerate lost hair cells in the auditory sensory epithelium after noise- and ototoxic drug-induced damage. Since then, the field of hair cell regeneration has continued to investigate the capacity of the auditory and vestibular epithelia in vertebrates (fishes, birds, reptiles, and mammals) to regenerate hair cells and to recover function, the molecular mechanisms governing these regenerative capabilities, and the prospect of designing biologically-based treatments for hearing loss and balance disorders. Here, we review the major findings of the field during the past 25 years and speculate how future inner ear repair may one day be achieved.
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Affiliation(s)
- Edwin W Rubel
- Virginia Merrill Bloedel Hearing Research Center and Department of Otolaryngology and Head & Neck Surgery, University of Washington, Seattle, WA 98195, USA.
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Lin Z, Perez P, Sun Z, Liu JJ, Shin JH, Hyrc KL, Samways D, Egan T, Holley MC, Bao J. Reprogramming of single-cell-derived mesenchymal stem cells into hair cell-like cells. Otol Neurotol 2012; 33:1648-55. [PMID: 23111404 PMCID: PMC3498597 DOI: 10.1097/mao.0b013e3182713680] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
HYPOTHESIS Adult mesenchymal stem cells (MSCs) can be converted into hair cell-like cells by transdetermination. BACKGROUND Given the fundamental role sensory hair cells play in sound detection and the irreversibility of their loss in mammals, much research has focused on developing methods to generate new hair cells as a means of treating permanent hearing loss. Although MSCs can differentiate into multiple cell lineages, no efficient means of reprogramming them into sensory hair cells exists. Earlier work has shown that the transcription factor Atoh1 is necessary for early development of hair cells, but it is not clear whether Atoh1 can be used to convert MSCs into hair cells. METHODS Clonal MSC cell lines were established and reprogrammed into hair cell-like cells by a combination of protein transfer, adenoviral based gene transfer, and co-culture with neurons. During transdetermination, inner ear molecular markers were analyzed using reverse transcriptase-polymerase chain reaction, and cell structures were examined using immunocytochemistry. RESULTS Atoh1 overexpression in MSCs failed to convert MSCs into hair cell-like cells, suggesting that the ability of Atoh1 to induce hair cell differentiation is context dependent. Because Atoh1 overexpression successfully transforms VOT-E36 cells into hair cell-like cells, we modified the cell context of MSCs by performing a total protein transfer from VOT-E36 cells before overexpressing Atoh1. The modified MSCs were transformed into hair cell-like cells and attracted contacts from spiral ganglion neurons in a co-culture model. CONCLUSION We established a new procedure, consisting of VOT-E36 protein transfer, Atoh1 overexpression, and co-culture with spiral ganglion neurons, which can transform MSCs into hair cell-like cells.
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Affiliation(s)
- Zhaoyu Lin
- Model Animal Research Center of Nanjing University, 12 Xue-Fu Road, Nanjing P.R. China, 210061
- Department of Otolaryngology, Washington University School of Medicine, 4566 Scott Avenue, St. Louis, MO 63110
| | - Philip Perez
- Department of Otolaryngology, Washington University School of Medicine, 4566 Scott Avenue, St. Louis, MO 63110
| | - Zhenyu Sun
- Department of Surgery, The Third Affiliated Hospital of Nantong University, 585 North Xingyuan Road, Wuxi, 214041 China
| | - Jan-Jan Liu
- Department of Otolaryngology, Washington University School of Medicine, 4566 Scott Avenue, St. Louis, MO 63110
| | - June Ho Shin
- Department of Otolaryngology, Washington University School of Medicine, 4566 Scott Avenue, St. Louis, MO 63110
| | - Krzysztof L. Hyrc
- Department of Neurology, Washington University School of Medicine, 4566 Scott Avenue, St. Louis, MO 63110
| | - Damien Samways
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 S. Grand Boulevard, St. Louis, MO, 63104
| | - Terry Egan
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 S. Grand Boulevard, St. Louis, MO, 63104
| | - Matthew C. Holley
- Department of Biomedical Science, Addison Building, Western Bank, Sheffield, S10 2TN, UK
| | - Jianxin Bao
- Department of Otolaryngology, Washington University School of Medicine, 4566 Scott Avenue, St. Louis, MO 63110
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Mackenzie SM, Raible DW. Proliferative regeneration of zebrafish lateral line hair cells after different ototoxic insults. PLoS One 2012; 7:e47257. [PMID: 23094043 PMCID: PMC3475690 DOI: 10.1371/journal.pone.0047257] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 09/11/2012] [Indexed: 11/25/2022] Open
Abstract
Sensory hair cells in the zebrafish lateral line regenerate rapidly and completely after damage. Previous studies have used a variety of ototoxins to kill lateral line hair cells to study different phenomena including mechanisms of hair cell death and regeneration. We sought to directly compare these ototoxins to determine if they differentially affected the rate and amount of hair cell replacement. In addition, previous studies have found evidence of proliferative hair cell regeneration in zebrafish, but both proliferation and non-mitotic direct transdifferentiation have been observed during hair cell regeneration in the sensory epithelia of birds and amphibians. We sought to test whether a similar combination of regenerative mechanisms exist in the fish. We analyzed the time course of regeneration after treatment with different ototoxic compounds and also labeled dividing hair cell progenitors. Certain treatments, including cisplatin and higher concentrations of dissolved copper, significantly delayed regeneration by one or more days. However, cisplatin did not block all regeneration as observed previously in the chick basilar papilla. The particular ototoxin did not appear to affect the mechanism of regeneration, as we observed evidence of recent proliferation in the majority of new hair cells in all cases. Inhibiting proliferation with flubendazole blocked the production of new hair cells and prevented the accumulation of additional precursors, indicating that proliferation has a dominant role during regeneration of lateral line hair cells.
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Affiliation(s)
- Scott M. Mackenzie
- Department of Biological Structure, University of Washington, Seattle, Washington, United States of America
- Graduate Program in Neurobiology and Behavior, University of Washington, Seattle, Washington, United States of America
| | - David W. Raible
- Department of Biological Structure, University of Washington, Seattle, Washington, United States of America
- Graduate Program in Neurobiology and Behavior, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Abstract
Auditory hair cells are surrounded on their basolateral aspects by supporting cells, and these two cell types together constitute the sensory epithelium of the organ of Corti, which is the hearing apparatus of the ear. We show here that Lgr5, a marker for adult stem cells, was expressed in a subset of supporting cells in the newborn and adult murine cochlea. Lgr5-expressing supporting cells, sorted by flow cytometry and cultured in a single-cell suspension, compared with unsorted cells, displayed an enhanced capacity for self-renewing neurosphere formation in response to Wnt and were converted to hair cells at a higher (>10-fold) rate. The greater differentiation of hair cells in the neurosphere assay showed that Lgr5-positive cells had the capacity to act as cochlear progenitor cells, and lineage tracing confirmed that Lgr5-expressing cells accounted for the cells that formed neurospheres and differentiated to hair cells. The responsiveness to Wnt of cells with a capacity for division and sensory cell formation suggests a potential route to new hair cell generation in the adult cochlea.
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Lewis RM, Hume CR, Stone JS. Atoh1 expression and function during auditory hair cell regeneration in post-hatch chickens. Hear Res 2012; 289:74-85. [PMID: 22543087 PMCID: PMC3371146 DOI: 10.1016/j.heares.2012.04.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 04/06/2012] [Accepted: 04/11/2012] [Indexed: 11/24/2022]
Abstract
Loss of hair cells in humans leads to irreversible hearing deficits, since auditory hair cells are not replaced. In contrast, hair cells are regenerated in the auditory epithelium of mature birds after damage by non-sensory supporting cells that transdifferentiate into hair cells by mitotic and/or non-mitotic mechanisms. Factors controlling these processes are poorly understood. The basic helix-loop-helix transcription factor ATOH1 is both necessary and sufficient for developmental hair cell differentiation, but it is unclear if it plays the same role in the mitotic and non-mitotic pathways in hair cell regeneration. We examined Atoh1 expression and function during hair cell regeneration in chickens. Atoh1 transcripts were increased in many supporting cells in the damaged auditory epithelium shortly after ototoxin administration and later became restricted to differentiating hair cells. Fate-mapping in vitro using an Atoh1 enhancer reporter demonstrated that only 56% of the supporting cells that spontaneously upregulate Atoh1 enhancer activity after damage acquired the hair cell fate. Inhibition of notch signaling using a gamma secretase antagonist stimulated an increase in Atoh1 reporter activity and induced a higher proportion of supporting cells with Atoh1 activity (73%) to differentiate as hair cells. Forced overexpression of Atoh1 in supporting cells triggered 66% of them to acquire the hair cell fate and nearly tripled their likelihood of cell cycle entry. These findings demonstrate that Atoh1 is broadly upregulated in supporting cells after damage, but a substantial proportion of supporting cells with Atoh1 activation fails to acquire hair cell features, in part due to gamma secretase-dependent activities.
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Affiliation(s)
- Rebecca M. Lewis
- Department of Speech and Hearing Sciences, University of Washington, Seattle, WA, USA
| | - Clifford R. Hume
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA, USA
- Department of Otolaryngology e Head and Neck Surgery, University of Washington, Seattle, WA, USA
| | - Jennifer S. Stone
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA, USA
- Department of Otolaryngology e Head and Neck Surgery, University of Washington, Seattle, WA, USA
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Feldman L, Sherman RA, Weissgarten J. N-acetylcysteine use for amelioration of aminoglycoside-induced ototoxicity in dialysis patients. Semin Dial 2012; 25:491-4. [PMID: 22708712 DOI: 10.1111/j.1525-139x.2012.01090.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Use of aminoglycoside antibiotics is associated with significant ototoxicity, especially on patients with decreased renal function. The risk of aminoglycoside ototoxicity may approach 60%. Oxidative stress has been suggested as a general mechanism of aminoglycoside ototoxicity and is prevalent in dialysis population. N-acetylcysteine (NAC) is an effective antioxidant and has been safely used in dialysis patients. New experimental and clinical data, explored in this review, provide a good case to recommend NAC administration to all dialysis patients, receiving aminoglycosides.
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Haugas M, Lilleväli K, Salminen M. Defects in sensory organ morphogenesis and generation of cochlear hair cells in Gata3-deficient mouse embryos. Hear Res 2011; 283:151-61. [PMID: 22094003 DOI: 10.1016/j.heares.2011.10.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 10/05/2011] [Accepted: 10/31/2011] [Indexed: 01/01/2023]
Abstract
The development of the inner ear sensory epithelia involves a complex network of transcription factors and signaling pathways and the whole process is not yet entirely understood. GATA3 is a DNA-binding factor that is necessary for otic morphogenesis and without GATA3 variable defects have been observed already at early stages in mouse embryos. In the less severe phenotypes, one small oval shaped vesicle is formed whereas in the more severe cases, the otic epithelium becomes disrupted and the endolymphatic domain becomes separated from the rest of the otic epithelium. Despite these defects, the early sensory fate specification occurs in Gata3-/- otic epithelium. However, due to the early lethality of Gata3-deficient embryos, the later morphogenesis and sensory development have remained unclear. To gain information of these later processes we produced drug-rescued Gata3-/- embryos that survived up to late gestation. In these older Gata3-/- embryos, a similar variability was observed as earlier. In the more severely affected ears, the development of the separate endolymphatic domain arrested completely whereas the remaining vesicle formed an empty cavity with variable forms, but without any distinguishable otic compartments or morphologically distinct sensory organs. However, the dorsal part of this vesicle was able to adopt a sensory fate and to produce some hair cells. In the less severe cases of Gata3-/- ears, distinct utricular, saccular and cochlear compartments were present and hair cells could be detected in the vestibular sensory epithelia. Although clear cristae and maculae formed, the morphology and size of these sensory areas were abnormal and they remained often un-separated. In contrast to the vestibule, the cochlear sensory compartment remained more immature and no hair or supporting cells could be detected. Our results suggest that GATA3 is critical for normal vestibular and cochlear morphogenesis and that it is especially important for cochlear sensory differentiation.
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Affiliation(s)
- Maarja Haugas
- Department of Veterinary Biosciences, University of Helsinki, Agnes Sjobergin katu 2, 00790 Helsinki, Finland.
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Bermingham-McDonogh O, Reh TA. Regulated reprogramming in the regeneration of sensory receptor cells. Neuron 2011; 71:389-405. [PMID: 21835338 DOI: 10.1016/j.neuron.2011.07.015] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2011] [Indexed: 12/15/2022]
Abstract
Vision, olfaction, hearing, and balance are mediated by receptors that reside in specialized sensory epithelial organs. Age-related degeneration of the photoreceptors in the retina and the hair cells in the cochlea, caused by macular degeneration and sensorineural hearing loss, respectively, affect a growing number of individuals. Although sensory receptor cells in the mammalian retina and inner ear show only limited or no regeneration, in many nonmammalian vertebrates, these sensory epithelia show remarkable regenerative potential. We summarize the current state of knowledge of regeneration in the specialized sense organs in both nonmammalian vertebrates and mammals and discuss possible areas where new advances in regenerative medicine might provide approaches to successfully stimulate sensory receptor cell regeneration. The field of regenerative medicine is still in its infancy, but new approaches using stem cells and reprogramming suggest ways in which the potential for regeneration may be restored in individuals suffering from sensory loss.
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Affiliation(s)
- Olivia Bermingham-McDonogh
- Department of Biological Structure, Institute for Stem Cells and Regenerative Medicine, University of Washington, Seattle, WA 98195, USA.
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Devarajan K, Staecker H, Detamore MS. A review of gene delivery and stem cell based therapies for regenerating inner ear hair cells. J Funct Biomater 2011; 2:249-70. [PMID: 24956306 PMCID: PMC4030941 DOI: 10.3390/jfb2030249] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 08/31/2011] [Accepted: 09/05/2011] [Indexed: 12/13/2022] Open
Abstract
Sensory neural hearing loss and vestibular dysfunction have become the most common forms of sensory defects, affecting millions of people worldwide. Developing effective therapies to restore hearing loss is challenging, owing to the limited regenerative capacity of the inner ear hair cells. With recent advances in understanding the developmental biology of mammalian and non-mammalian hair cells a variety of strategies have emerged to restore lost hair cells are being developed. Two predominant strategies have developed to restore hair cells: transfer of genes responsible for hair cell genesis and replacement of missing cells via transfer of stem cells. In this review article, we evaluate the use of several genes involved in hair cell regeneration, the advantages and disadvantages of the different viral vectors employed in inner ear gene delivery and the insights gained from the use of embryonic, adult and induced pluripotent stem cells in generating inner ear hair cells. Understanding the role of genes, vectors and stem cells in therapeutic strategies led us to explore potential solutions to overcome the limitations associated with their use in hair cell regeneration.
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Affiliation(s)
| | - Hinrich Staecker
- Department of Otolaryngology Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, KS 66160, USA.
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Warchol ME. Sensory regeneration in the vertebrate inner ear: Differences at the levels of cells and species. Hear Res 2011; 273:72-9. [DOI: 10.1016/j.heares.2010.05.004] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 05/03/2010] [Accepted: 05/12/2010] [Indexed: 12/31/2022]
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Go W, Bessarab D, Korzh V. atp2b1a regulates Ca(2+) export during differentiation and regeneration of mechanosensory hair cells in zebrafish. Cell Calcium 2010; 48:302-13. [PMID: 21084119 DOI: 10.1016/j.ceca.2010.09.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Accepted: 09/30/2010] [Indexed: 12/16/2022]
Abstract
The molecular mechanisms of development of mechanosensory hair cells have been tackled successfully due to in vivo studies in the zebrafish lateral line. The enhancer trap (ET) transgenic line, SqET4 was instrumental in these studies even despite a lack of a link of its GFP expression pattern to a particular gene(s). We mapped the Tol2 transposon insertion of the SqET4 transgenics onto Chr. 4 next to a gene encoding Atp2b1a (Pmca1) - one of the four PMCAs acting to export Ca(2+) from a cell. atp2b1a expression recapitulates that of GFP during the development of mechanoreceptors of the inner ear and lateral line. atp2b1a expression correlates with the regeneration of these cells. Thus, SqET4 represents the Tg:atp2b1a-GFP line, which links Ca(2+) metabolism and the differentiation of mechanoreceptors. The morpholino-mediated knockdown of atp2b1a blocks Ca(2+) export and affects the division of hair cell progenitors, resulting in their accumulation. Under the control of a master gene of hair cells, Atoh1a, Atp2b1a functions during progenitor cell proliferation and hair cell differentiation. Given the similarity between the phenotypes of atp2b1a morphants and embryos treated with the pan-PMCA inhibitor 5(6)-carboxyeosin, Atp2b1a emerges as member of the Atp2b family responsible for Ca(2+) export during the development of hair cells.
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Affiliation(s)
- William Go
- Cancer and Developmental Cell Biology Division, Institute of Molecular and Cell Biology, Singapore
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Coffin AB, Ou H, Owens KN, Santos F, Simon JA, Rubel EW, Raible DW. Chemical screening for hair cell loss and protection in the zebrafish lateral line. Zebrafish 2010; 7:3-11. [PMID: 20192852 DOI: 10.1089/zeb.2009.0639] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In humans, most hearing loss results from death of hair cells, the mechanosensory receptors of the inner ear. Two goals of current hearing research are to protect hair cells from degeneration and to regenerate new hair cells, replacing those that are lost due to aging, disease, or environmental challenges. One limitation of research in the auditory field has been the relative inaccessibility of the mechanosensory systems in the inner ear. Zebrafish possess hair cells in both their inner ear and their lateral line system that are morphologically and functionally similar to human hair cells. The external location of the mechanosensory hair cells in the lateral line and the ease of in vivo labeling and imaging make the zebrafish lateral line a unique system for the study of hair cell toxicity, protection, and regeneration. This review focuses on the lateral line system as a model for understanding loss and protection of mechanosensory hair cells. We discuss chemical screens to identify compounds that induce hair cell loss and others that protect hair cells from known toxins and the potential application of these screens to human medicine.
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Affiliation(s)
- Allison B Coffin
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, Washington 98195-7923, USA.
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Abstract
Sensory hair cells of the inner ear are responsible for translating auditory or vestibular stimuli into electrical energy that can be perceived by the nervous system. Although hair cells are exquisitely mechanically sensitive, they can be easily damaged by excessive stimulation by ototoxic drugs and by the effects of aging. In mammals, auditory hair cells are never replaced, such that cumulative damage to the ear causes progressive and permanent deafness. In contrast, non-mammalian vertebrates are capable of replacing lost hair cells, which has led to efforts to understand the molecular and cellular basis of regenerative responses in different vertebrate species. In this review, we describe recent progress in understanding the limits to hair cell regeneration in mammals and discuss the obstacles that currently exist for therapeutic approaches to hair cell replacement.
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Affiliation(s)
- Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine, BCM 295, 1 Baylor Plaza, Houston, TX 77030, USA.
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Shang J, Cafaro J, Nehmer R, Stone J. Supporting cell division is not required for regeneration of auditory hair cells after ototoxic injury in vitro. J Assoc Res Otolaryngol 2010; 11:203-22. [PMID: 20165896 DOI: 10.1007/s10162-009-0206-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 12/22/2009] [Indexed: 01/16/2023] Open
Abstract
In chickens, nonsensory supporting cells divide and regenerate auditory hair cells after injury. Anatomical evidence suggests that supporting cells can also transdifferentiate into hair cells without dividing. In this study, we characterized an organ culture model to study auditory hair cell regeneration, and we used these cultures to test if direct transdifferentiation alone can lead to significant hair cell regeneration. Control cultures (organs from posthatch chickens maintained without streptomycin) showed complete hair cell loss in the proximal (high-frequency) region by 5 days. In contrast, a 2-day treatment with streptomycin induced loss of hair cells from all regions by 3 days. Hair cell regeneration proceeded in culture, with the time course of supporting cell division and hair cell differentiation generally resembling in vivo patterns. The degree of supporting cell division depended upon the presence of streptomycin, the epithelial region, the type of culture media, and serum concentration. On average, 87% of the regenerated hair cells lacked the cell division marker BrdU despite its continuous presence, suggesting that most hair cells were regenerated via direct transdifferentiation. Addition of the DNA polymerase inhibitor aphidicolin to culture media prevented supporting cell division, but numerous hair cells were regenerated nonetheless. These hair cells showed signs of functional maturation, including stereociliary bundles and rapid uptake of FM1-43. These observations demonstrate that direct transdifferentiation is a significant mechanism of hair cell regeneration in the chicken auditory after streptomycin damage in vitro.
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Affiliation(s)
- Jialin Shang
- Department of Otolaryngology/Head and Neck Surgery, The Virginia Merrill Bloedel Hearing Research Center, University of Washington School of Medicine, Seattle, WA 98195-7923, USA
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Bodson M, Breuskin I, Lefebvre P, Malgrange B. Hair cell progenitors: identification and regulatory genes. Acta Otolaryngol 2010. [DOI: 10.3109/00016480903121057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
Humans and other mammals are highly susceptible to permanent hearing and balance deficits due to an inability to regenerate sensory hair cells lost to inner ear trauma. In contrast, nonmammalian vertebrates, such as birds, robustly regenerate replacement hair cells and restore hearing and balance functions to near-normal levels. There is considerable interest in understanding the cellular mechanisms responsible for this difference in regenerative capacity. Here we report on involvement of the TGFbeta superfamily type II activin receptors, Acvr2a and Acvr2b, in regulating proliferation in mature avian auditory sensory epithelium. Cultured, posthatch avian auditory sensory epithelium treated with Acvr2a and Acvr2b inhibitors shows decreased proliferation of support cells, the cell type that gives rise to new hair cells. Conversely, addition of activin A, an Acvr2a/b ligand, potentiates support cell proliferation. Neither treatment (inhibitor or ligand) affected hair cell survival, suggesting a specific effect of Acvr2a/b signaling on support cell mitogenicity. Using immunocytochemistry, Acvr2a, Acvr2b, and downstream Smad effector proteins were differentially localized in avian and mammalian auditory sensory epithelia. Collectively, these data suggest that signaling through Acvr2a/b promotes support cell proliferation in mature avian auditory sensory epithelium and that this signaling pathway may be incomplete, or actively blocked, in the adult mammalian ear.
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Bell TJ, Oberholtzer JC. cAMP-induced auditory supporting cell proliferation is mediated by ERK MAPK signaling pathway. J Assoc Res Otolaryngol 2010; 11:173-85. [PMID: 20107853 DOI: 10.1007/s10162-009-0205-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 12/16/2009] [Indexed: 11/28/2022] Open
Abstract
Sensorineural hearing deficiencies result from the loss of auditory hair cells. This hearing loss is permanent in humans and mammals because hair cells are not spontaneously replaced. In other animals such as birds, this is not the case. Damage to the avian cochlea evokes proliferation of supporting cells and the generation of functionally competent replacement hair cells. Signal transduction pathways are clinically useful as potential therapeutic targets, so there is significant interest in identifying the key signal transduction pathways that regulate the formation of replacement hair cells. In a previous study from our lab, we showed that forskolin (FSK) treatment induces auditory supporting cell proliferation and formation of replacement hair cells in the absence of sound or aminoglycoside treatment. Here, we show that FSK-induced supporting cell proliferation is mediated by cell-specific accumulation of cyclic adenosine monophosphate (cAMP) in avian supporting cells and the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) pathway. By a combination of immunostaining and pharmacological analyses, we show that FSK treatment increases cAMP levels in avian auditory supporting cells and that several ERK MAP inhibitors effectively block FSK-induced supporting cell proliferation. Next, we demonstrate by Western blotting and immunostaining analyses the expression of several ERK MAPK signaling molecules in the avian auditory epithelium and the cell-specific expression of B-Raf in avian auditory supporting cells. Collectively, these data suggest that FSK-induced supporting cell proliferation in the avian auditory epithelium is mediated by increases of cAMP levels in supporting cells and the cell-specific expression of the ERK MAPK family member B-Raf in supporting cells.
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Affiliation(s)
- Thomas J Bell
- Division of Neuropathology, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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Abstract
PURPOSE OF REVIEW In evaluating strategies to preserve or regenerate the cochlea, understanding the process of labyrinthine injury on a cellular and molecular level is crucial. Examination of inner ear injury reveals mechanism-specific types of damage, often at specific areas within the cochlea. Site-specific interventions can then be considered. RECENT FINDINGS The review will briefly summarize the historical perspective of advancements in hearing science through 2006. Areas of research covered include hair cell protection, hair cell regeneration, spiral ganglion cell regeneration, and stria vascularis metabolic regulation. SUMMARY The review will briefly summarize the early development of a few such site-specific interventions for inner ear functional rehabilitation, for work done prior to 2006. The outstanding reviews of cutting edge research from this year's and last year's Hearing Science section of Current Opinion in Otolaryngology - Head and Neck Surgery can then be understood and appreciated in a more informed manner.
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Hartman BH, Basak O, Nelson BR, Taylor V, Bermingham-McDonogh O, Reh TA. Hes5 expression in the postnatal and adult mouse inner ear and the drug-damaged cochlea. J Assoc Res Otolaryngol 2009; 10:321-40. [PMID: 19373512 PMCID: PMC2757554 DOI: 10.1007/s10162-009-0162-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 02/09/2009] [Indexed: 11/30/2022] Open
Abstract
The Notch signaling pathway is known to have multiple roles during development of the inner ear. Notch signaling activates transcription of Hes5, a homologue of Drosophila hairy and enhancer of split, which encodes a basic helix-loop-helix transcriptional repressor. Previous studies have shown that Hes5 is expressed in the cochlea during embryonic development, and loss of Hes5 leads to overproduction of auditory and vestibular hair cells. However, due to technical limitations and inconsistency between previous reports, the precise spatial and temporal pattern of Hes5 expression in the postnatal and adult inner ear has remained unclear. In this study, we use Hes5-GFP transgenic mice and in situ hybridization to report the expression pattern of Hes5 in the inner ear. We find that Hes5 is expressed in the developing auditory epithelium of the cochlea beginning at embryonic day 14.5 (E14.5), becomes restricted to a particular subset of cochlear supporting cells, is downregulated in the postnatal cochlea, and is not present in adults. In the vestibular system, we detect Hes5 in developing supporting cells as early as E12.5 and find that Hes5 expression is maintained in some adult vestibular supporting cells. In order to determine the effect of hair cell damage on Notch signaling in the cochlea, we damaged cochlear hair cells of adult Hes5-GFP mice in vivo using injection of kanamycin and furosemide. Although outer hair cells were killed in treated animals and supporting cells were still present after damage, supporting cells did not upregulate Hes5-GFP in the damaged cochlea. Therefore, absence of Notch-Hes5 signaling in the normal and damaged adult cochlea is correlated with lack of regeneration potential, while its presence in the neonatal cochlea and adult vestibular epithelia is associated with greater capacity for plasticity or regeneration in these tissues; which suggests that this pathway may be involved in regulating regenerative potential.
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Affiliation(s)
- Byron H. Hartman
- />Department of Biological Structure, University of Washington, Box 357420, Seattle, WA 98195 USA
| | - Onur Basak
- />Department of Molecular Embryology, Max-Planck Institute of Immunobiology, Stubeweg 51, 79108 Freiburg, Germany
| | - Branden R. Nelson
- />Department of Biological Structure, University of Washington, Box 357420, Seattle, WA 98195 USA
| | - Verdon Taylor
- />Department of Molecular Embryology, Max-Planck Institute of Immunobiology, Stubeweg 51, 79108 Freiburg, Germany
| | - Olivia Bermingham-McDonogh
- />Department of Biological Structure, University of Washington, Box 357420, Seattle, WA 98195 USA
- />Virginia Merrill Bloedel Hearing Research Center at the University of Washington, Seattle, WA 98195 USA
| | - Thomas A. Reh
- />Department of Biological Structure, University of Washington, Box 357420, Seattle, WA 98195 USA
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