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Pyott SJ, Pavlinkova G, Yamoah EN, Fritzsch B. Harmony in the Molecular Orchestra of Hearing: Developmental Mechanisms from the Ear to the Brain. Annu Rev Neurosci 2024; 47:1-20. [PMID: 38360566 DOI: 10.1146/annurev-neuro-081423-093942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Auditory processing in mammals begins in the peripheral inner ear and extends to the auditory cortex. Sound is transduced from mechanical stimuli into electrochemical signals of hair cells, which relay auditory information via the primary auditory neurons to cochlear nuclei. Information is subsequently processed in the superior olivary complex, lateral lemniscus, and inferior colliculus and projects to the auditory cortex via the medial geniculate body in the thalamus. Recent advances have provided valuable insights into the development and functioning of auditory structures, complementing our understanding of the physiological mechanisms underlying auditory processing. This comprehensive review explores the genetic mechanisms required for auditory system development from the peripheral cochlea to the auditory cortex. We highlight transcription factors and other genes with key recurring and interacting roles in guiding auditory system development and organization. Understanding these gene regulatory networks holds promise for developing novel therapeutic strategies for hearing disorders, benefiting millions globally.
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Affiliation(s)
- Sonja J Pyott
- Department of Otorhinolaryngology and Head and Neck Surgery, University Medical Center Groningen, Graduate School of Medical Sciences, and Research School of Behavioral and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology, Czech Academy of Sciences, Vestec, Czechia
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, Nevada, USA
| | - Bernd Fritzsch
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, Nebraska, USA;
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2
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Tu S, Zuo J. Systematic single cell RNA sequencing analysis reveals unique transcriptional regulatory networks of Atoh1-mediated hair cell conversion in adult mouse cochleae. PLoS One 2023; 18:e0284685. [PMID: 38079436 PMCID: PMC10712870 DOI: 10.1371/journal.pone.0284685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 04/05/2023] [Indexed: 12/18/2023] Open
Abstract
Regeneration of mammalian cochlear hair cells (HCs) by modulating molecular pathways or transcription factors is a promising approach to hearing restoration; however, immaturity of the regenerated HCs in vivo remains a major challenge. Here, we analyzed a single cell RNA sequencing (scRNA-seq) dataset during Atoh1-induced supporting cell (SC) to hair cell (HC) conversion in adult mouse cochleae (Yamashita et al. (2018)) using multiple high-throughput sequencing analytical tools (WGCNA, SCENIC, ARACNE, and VIPER). Instead of focusing on differentially expressed genes, we established independent expression modules and confirmed the existence of multiple conversion stages. Gene regulatory network (GRN) analysis uncovered previously unidentified key regulators, including Nhlh1, Lhx3, Barhl1 and Nfia, that guide converted HC differentiation. Comparison of the late-stage converted HCs with the scRNA-seq data from neonatal mouse cochleae (Kolla et al. (2020)) revealed that they closely resemble postnatal day 1 wild-type OHCs, in contrast to other developmental stages. Using ARACNE and VIPER, we discovered multiple key regulators likely to promote conversion to a more mature OHC-like state, including Zbtb20, Nfia, Zmiz1, Gm14418, Bhlhe40, Six2, Fosb and Klf9. Our findings provide insights into the regulation of HC regeneration in adult mammalian cochleae in vivo and demonstrate an approach for analyzing GRNs in large scRNA-seq datasets.
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Affiliation(s)
- Shu Tu
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States of America
| | - Jian Zuo
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE, United States of America
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3
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Lue PY, Oliver MH, Neeff M, Thorne PR, Suzuki-Kerr H. Sheep as a large animal model for hearing research: comparison to common laboratory animals and humans. Lab Anim Res 2023; 39:31. [PMID: 38012676 PMCID: PMC10680324 DOI: 10.1186/s42826-023-00182-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 11/10/2023] [Accepted: 11/15/2023] [Indexed: 11/29/2023] Open
Abstract
Sensorineural hearing loss (SNHL), caused by pathology in the cochlea, is the most common type of hearing loss in humans. It is generally irreversible with very few effective pharmacological treatments available to prevent the degenerative changes or minimise the impact. Part of this has been attributed to difficulty of translating "proof-of-concept" for novel treatments established in small animal models to human therapies. There is an increasing interest in the use of sheep as a large animal model. In this article, we review the small and large animal models used in pre-clinical hearing research such as mice, rats, chinchilla, guinea pig, rabbit, cat, monkey, dog, pig, and sheep to humans, and compare the physiology, inner ear anatomy, and some of their use as model systems for SNHL, including cochlear implantation surgeries. Sheep have similar cochlear anatomy, auditory threshold, neonatal auditory system development, adult and infant body size, and number of birth as humans. Based on these comparisons, we suggest that sheep are well-suited as a potential translational animal model that bridges the gap between rodent model research to the clinical use in humans. This is especially in areas looking at changes across the life-course or in specific areas of experimental investigation such as cochlear implantation and other surgical procedures, biomedical device development and age-related sensorineural hearing loss research. Combined use of small animals for research that require higher throughput and genetic modification and large animals for medical translation could greatly accelerate the overall translation of basic research in the field of auditory neuroscience from bench to clinic.
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Affiliation(s)
- Po-Yi Lue
- Department of Physiology, The University of Auckland, Auckland, New Zealand
- Eisdell Moore Centre, The University of Auckland, Auckland, New Zealand
| | - Mark H Oliver
- Liggins Institute, The University of Auckland, Auckland, New Zealand
- Ngapouri Research Farm Laboratory, University of Auckland, Waiotapu, New Zealand
| | - Michel Neeff
- Department of Physiology, The University of Auckland, Auckland, New Zealand
- Department of Surgery, Auckland District Health Board, Auckland, New Zealand
| | - Peter R Thorne
- Department of Physiology, The University of Auckland, Auckland, New Zealand
- Eisdell Moore Centre, The University of Auckland, Auckland, New Zealand
- Section of Audiology, The University of Auckland, Auckland, New Zealand
| | - Haruna Suzuki-Kerr
- Department of Physiology, The University of Auckland, Auckland, New Zealand.
- Eisdell Moore Centre, The University of Auckland, Auckland, New Zealand.
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4
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You D, Ni W, Huang Y, Zhou Q, Zhang Y, Jiang T, Chen Y, Li W. The proper timing of Atoh1 expression is pivotal for hair cell subtype differentiation and the establishment of inner ear function. Cell Mol Life Sci 2023; 80:349. [PMID: 37930405 PMCID: PMC10628023 DOI: 10.1007/s00018-023-04947-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/30/2023] [Accepted: 09/01/2023] [Indexed: 11/07/2023]
Abstract
Atoh1 overexpression is essential for hair cell (HC) regeneration in the sensory epithelium of mammalian auditory and vestibular organs. However, Atoh1 overexpression alone cannot induce fully mature and functional HCs in the mammalian inner ear. In the current study, we investigated the effect of Atoh1 constitutive overexpression in native HCs by manipulating Atoh1 expression at different developmental stages. We demonstrated that constitutive overexpression of Atoh1 in native vestibular HCs did not affect cell survival but did impair vestibular function by interfering with the subtype differentiation of HCs and hair bundle development. In contrast, Atoh1 overexpression in cochlear HCs impeded their maturation, eventually leading to gradual HC loss in the cochlea and hearing dysfunction. Our study suggests that time-restricted Atoh1 expression is essential for the differentiation and survival of HCs in the inner ear, and this is pivotal for both hearing and vestibular function re-establishment through Atoh1 overexpression-induced HC regeneration strategies.
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Affiliation(s)
- Dan You
- ENT Institute, Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200031, People's Republic of China
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, People's Republic of China
| | - Wenli Ni
- ENT Institute, Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200031, People's Republic of China
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, People's Republic of China
| | - Yikang Huang
- ENT Institute, Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200031, People's Republic of China
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, People's Republic of China
| | - Qin Zhou
- ENT Institute, Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200031, People's Republic of China
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, People's Republic of China
| | - Yanping Zhang
- ENT Institute, Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200031, People's Republic of China
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, People's Republic of China
| | - Tao Jiang
- ENT Institute, Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200031, People's Republic of China
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, People's Republic of China
| | - Yan Chen
- ENT Institute, Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200031, People's Republic of China.
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, People's Republic of China.
| | - Wenyan Li
- ENT Institute, Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200031, People's Republic of China.
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, People's Republic of China.
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5
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Nakamura T, Sakaguchi H, Mohri H, Ninoyu Y, Goto A, Yamaguchi T, Hishikawa Y, Matsuda M, Saito N, Ueyama T. Dispensable role of Rac1 and Rac3 after cochlear hair cell specification. J Mol Med (Berl) 2023; 101:843-854. [PMID: 37204479 PMCID: PMC10300165 DOI: 10.1007/s00109-023-02317-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 04/03/2023] [Accepted: 04/11/2023] [Indexed: 05/20/2023]
Abstract
Rac small GTPases play important roles during embryonic development of the inner ear; however, little is known regarding their function in cochlear hair cells (HCs) after specification. Here, we revealed the localization and activation of Racs in cochlear HCs using GFP-tagged Rac plasmids and transgenic mice expressing a Rac1-fluorescence resonance energy transfer (FRET) biosensor. Furthermore, we employed Rac1-knockout (Rac1-KO, Atoh1-Cre;Rac1flox/flox) and Rac1 and Rac3 double KO (Rac1/Rac3-DKO, Atoh1-Cre;Rac1flox/flox;Rac3-/-) mice, under the control of the Atoh1 promoter. However, both Rac1-KO and Rac1/Rac3-DKO mice exhibited normal cochlear HC morphology at 13 weeks of age and normal hearing function at 24 weeks of age. No hearing vulnerability was observed in young adult (6-week-old) Rac1/Rac3-DKO mice even after intense noise exposure. Consistent with prior reports, the results from Atoh1-Cre;tdTomato mice confirmed that the Atoh1 promoter became functional only after embryonic day 14 when the sensory HC precursors exit the cell cycle. Taken together, these findings indicate that although Rac1 and Rac3 contribute to the early development of sensory epithelia in cochleae, as previously shown, they are dispensable for the maturation of cochlear HCs in the postmitotic state or for hearing maintenance following HC maturation. KEY MESSAGES: Mice with Rac1 and Rac3 deletion were generated after HC specification. Knockout mice exhibit normal cochlear hair cell morphology and hearing. Racs are dispensable for hair cells in the postmitotic state after specification. Racs are dispensable for hearing maintenance after HC maturation.
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Affiliation(s)
- Takashi Nakamura
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Hirofumi Sakaguchi
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Hiroaki Mohri
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Yuzuru Ninoyu
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Akihiro Goto
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8315, Japan
| | - Taro Yamaguchi
- Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, 573-0101, Japan
| | - Yoshitaka Hishikawa
- Department of Anatomy, Histochemistry and Cell Biology, Faculty of Medicine, University of Miyazaki, Miyazaki, 889-1692, Japan
| | - Michiyuki Matsuda
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8315, Japan
| | - Naoaki Saito
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
| | - Takehiko Ueyama
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan.
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Reagor CC, Velez-Angel N, Hudspeth AJ. Depicting pseudotime-lagged causality across single-cell trajectories for accurate gene-regulatory inference. PNAS NEXUS 2023; 2:pgad113. [PMID: 37113980 PMCID: PMC10129065 DOI: 10.1093/pnasnexus/pgad113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 04/29/2023]
Abstract
Identifying the causal interactions in gene-regulatory networks requires an accurate understanding of the time-lagged relationships between transcription factors and their target genes. Here we describe DELAY (short for Depicting Lagged Causality), a convolutional neural network for the inference of gene-regulatory relationships across pseudotime-ordered single-cell trajectories. We show that combining supervised deep learning with joint probability matrices of pseudotime-lagged trajectories allows the network to overcome important limitations of ordinary Granger causality-based methods, for example, the inability to infer cyclic relationships such as feedback loops. Our network outperforms several common methods for inferring gene regulation and, when given partial ground-truth labels, predicts novel regulatory networks from single-cell RNA sequencing (scRNA-seq) and single-cell ATAC sequencing (scATAC-seq) data sets. To validate this approach, we used DELAY to identify important genes and modules in the regulatory network of auditory hair cells, as well as likely DNA-binding partners for two hair cell cofactors (Hist1h1c and Ccnd1) and a novel binding sequence for the hair cell-specific transcription factor Fiz1. We provide an easy-to-use implementation of DELAY under an open-source license at https://github.com/calebclayreagor/DELAY.
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Affiliation(s)
| | - Nicolas Velez-Angel
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065, USA
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7
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Wang J, Zheng J, Wang H, He H, Li S, Zhang Y, Wang Y, Xu X, Wang S. Gene therapy: an emerging therapy for hair cells regeneration in the cochlea. Front Neurosci 2023; 17:1177791. [PMID: 37207182 PMCID: PMC10188948 DOI: 10.3389/fnins.2023.1177791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 04/12/2023] [Indexed: 05/21/2023] Open
Abstract
Sensorineural hearing loss is typically caused by damage to the cochlear hair cells (HCs) due to external stimuli or because of one's genetic factors and the inability to convert sound mechanical energy into nerve impulses. Adult mammalian cochlear HCs cannot regenerate spontaneously; therefore, this type of deafness is usually considered irreversible. Studies on the developmental mechanisms of HC differentiation have revealed that nonsensory cells in the cochlea acquire the ability to differentiate into HCs after the overexpression of specific genes, such as Atoh1, which makes HC regeneration possible. Gene therapy, through in vitro selection and editing of target genes, transforms exogenous gene fragments into target cells and alters the expression of genes in target cells to activate the corresponding differentiation developmental program in target cells. This review summarizes the genes that have been associated with the growth and development of cochlear HCs in recent years and provides an overview of gene therapy approaches in the field of HC regeneration. It concludes with a discussion of the limitations of the current therapeutic approaches to facilitate the early implementation of this therapy in a clinical setting.
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Affiliation(s)
- Jipeng Wang
- Department of Gastrointestinal Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jianwei Zheng
- Department of Biliary-Pancreatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Haiyan Wang
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Haoying He
- Department of Neurology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Shuang Li
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Ya Zhang
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - You Wang
- Department of Stomatology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
- *Correspondence: You Wang,
| | - Xiaoxiang Xu
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
- Xiaoxiang Xu,
| | - Shuyi Wang
- Department of Gastrointestinal Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
- Shuyi Wang,
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8
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Pouyo R, Chung K, Delacroix L, Malgrange B. The ubiquitin-proteasome system in normal hearing and deafness. Hear Res 2022; 426:108366. [PMID: 34645583 DOI: 10.1016/j.heares.2021.108366] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/03/2021] [Accepted: 09/23/2021] [Indexed: 12/16/2022]
Abstract
Post-translational modifications of proteins are essential for the proper development and function of many tissues and organs, including the inner ear. Ubiquitination is a highly selective post-translational modification that involves the covalent conjugation of ubiquitin to a substrate protein. The most common outcome of protein ubiquitination is degradation by the ubiquitin-proteasome system (UPS), preventing the accumulation of misfolded, damaged, and excess proteins. In addition to proteasomal degradation, ubiquitination regulates other cellular processes, such as transcription, translation, endocytosis, receptor activity, and subcellular localization. All of these processes are essential for cochlear development and maintenance, as several studies link impairment of UPS with altered cochlear development and hearing loss. In this review, we provide insight into the well-oiled machinery of UPS with a focus on its confirmed role in normal hearing and deafness and potential therapeutic strategies to prevent and treat UPS-associated hearing loss.
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Affiliation(s)
- Ronald Pouyo
- GIGA-Stem Cells, Developmental Neurobiology Unit, University of Liege, Avenue hippocrate 15, B36 1st Floor B, Liege 4000, Belgium
| | - Keshi Chung
- GIGA-Stem Cells, Developmental Neurobiology Unit, University of Liege, Avenue hippocrate 15, B36 1st Floor B, Liege 4000, Belgium
| | - Laurence Delacroix
- GIGA-Stem Cells, Developmental Neurobiology Unit, University of Liege, Avenue hippocrate 15, B36 1st Floor B, Liege 4000, Belgium
| | - Brigitte Malgrange
- GIGA-Stem Cells, Developmental Neurobiology Unit, University of Liege, Avenue hippocrate 15, B36 1st Floor B, Liege 4000, Belgium.
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9
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Iyer AA, Hosamani I, Nguyen JD, Cai T, Singh S, McGovern MM, Beyer L, Zhang H, Jen HI, Yousaf R, Birol O, Sun JJ, Ray RS, Raphael Y, Segil N, Groves AK. Cellular reprogramming with ATOH1, GFI1, and POU4F3 implicate epigenetic changes and cell-cell signaling as obstacles to hair cell regeneration in mature mammals. eLife 2022; 11:e79712. [PMID: 36445327 PMCID: PMC9708077 DOI: 10.7554/elife.79712] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 11/16/2022] [Indexed: 11/30/2022] Open
Abstract
Reprogramming of the cochlea with hair-cell-specific transcription factors such as ATOH1 has been proposed as a potential therapeutic strategy for hearing loss. ATOH1 expression in the developing cochlea can efficiently induce hair cell regeneration but the efficiency of hair cell reprogramming declines rapidly as the cochlea matures. We developed Cre-inducible mice to compare hair cell reprogramming with ATOH1 alone or in combination with two other hair cell transcription factors, GFI1 and POU4F3. In newborn mice, all transcription factor combinations tested produced large numbers of cells with the morphology of hair cells and rudimentary mechanotransduction properties. However, 1 week later, only a combination of ATOH1, GFI1 and POU4F3 could reprogram non-sensory cells of the cochlea to a hair cell fate, and these new cells were less mature than cells generated by reprogramming 1 week earlier. We used scRNA-seq and combined scRNA-seq and ATAC-seq to suggest at least two impediments to hair cell reprogramming in older animals. First, hair cell gene loci become less epigenetically accessible in non-sensory cells of the cochlea with increasing age. Second, signaling from hair cells to supporting cells, including Notch signaling, can prevent reprogramming of many supporting cells to hair cells, even with three hair cell transcription factors. Our results shed light on the molecular barriers that must be overcome to promote hair cell regeneration in the adult cochlea.
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Affiliation(s)
- Amrita A Iyer
- Department of Molecular & Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Ishwar Hosamani
- Department of Molecular & Human Genetics, Baylor College of MedicineHoustonUnited States
| | - John D Nguyen
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Biology at USCLos AngelesUnited States
| | - Tiantian Cai
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
| | - Sunita Singh
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Melissa M McGovern
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Lisa Beyer
- Department of Otolaryngology-Head and Neck Surgery, University of MichiganAnn ArborUnited States
| | - Hongyuan Zhang
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Hsin-I Jen
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Rizwan Yousaf
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Onur Birol
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
| | - Jenny J Sun
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Russell S Ray
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
| | - Yehoash Raphael
- Department of Otolaryngology-Head and Neck Surgery, University of MichiganAnn ArborUnited States
| | - Neil Segil
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Biology at USCLos AngelesUnited States
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern CaliforniaLos AngelesUnited States
| | - Andrew K Groves
- Department of Molecular & Human Genetics, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
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10
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Connolly K, Gonzalez-Cordero A. Modelling inner ear development and disease using pluripotent stem cells - a pathway to new therapeutic strategies. Dis Model Mech 2022; 15:dmm049593. [PMID: 36331565 PMCID: PMC10621662 DOI: 10.1242/dmm.049593] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023] Open
Abstract
The sensory epithelia of the mammalian inner ear enable sound and movement to be perceived. Damage to these epithelia can cause irreversible sensorineural hearing loss and vestibular dysfunction because they lack regenerative capacity. The human inner ear cannot be biopsied without causing permanent damage, significantly limiting the tissue samples available for research. Investigating disease pathology and therapeutic developments have therefore traditionally relied on animal models, which often cannot completely recapitulate the human otic systems. These challenges are now being partly addressed using induced pluripotent stem cell-derived cultures, which generate the sensory epithelial-like tissues of the inner ear. Here, we review how pluripotent stem cells have been used to produce two-dimensional and three-dimensional otic cultures, the strengths and limitations of these new approaches, and how they have been employed to investigate genetic and acquired forms of audiovestibular dysfunction. This Review provides an overview of the progress in pluripotent stem cell-derived otic cultures thus far, focusing on their applications in disease modelling and therapeutic trials. We survey their current limitations and future directions, highlighting their prospective utility for high-throughput drug screening and developing personalised medicine approaches.
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Affiliation(s)
- Keeva Connolly
- Stem Cell Medicine Group, Children's Medical Research Institute, Westmead, 2145 NSW, Australia
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Westmead, 2145 NSW, Australia
| | - Anai Gonzalez-Cordero
- Stem Cell Medicine Group, Children's Medical Research Institute, Westmead, 2145 NSW, Australia
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Westmead, 2145 NSW, Australia
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11
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Saeki T, Yoshimatsu S, Ishikawa M, Hon CC, Koya I, Shibata S, Hosoya M, Saegusa C, Ogawa K, Shin JW, Fujioka M, Okano H. Critical roles of FGF, RA, and WNT signalling in the development of the human otic placode and subsequent lineages in a dish. Regen Ther 2022; 20:165-186. [PMID: 35620640 PMCID: PMC9114627 DOI: 10.1016/j.reth.2022.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/19/2022] [Accepted: 04/26/2022] [Indexed: 11/30/2022] Open
Abstract
Introduction Efficient induction of the otic placode, the developmental origin of the inner ear from human pluripotent stem cells (hPSCs), provides a robust platform for otic development and sensorineural hearing loss modelling. Nevertheless, there remains a limited capacity of otic lineage specification from hPSCs by stepwise differentiation methods, since the critical factors for successful otic cell differentiation have not been thoroughly investigated. In this study, we developed a novel differentiation system involving the use of a three-dimensional (3D) floating culture with signalling factors for generating otic cell lineages via stepwise differentiation of hPSCs. Methods We differentiated hPSCs into preplacodal cells under a two-dimensional (2D) monolayer culture. Then, we transferred the induced preplacodal cells into a 3D floating culture under the control of the fibroblast growth factor (FGF), bone morphogenetic protein (BMP), retinoic acid (RA) and WNT signalling pathways. We evaluated the characteristics of the induced cells using immunocytochemistry, quantitative PCR (qPCR), population averaging, and single-cell RNA-seq (RNA-seq) analysis. We further investigated the methods for differentiating otic progenitors towards hair cells by overexpression of defined transcription factors. Results We demonstrated that hPSC-derived preplacodal cells acquired the potential to differentiate into posterior placodal cells in 3D floating culture with FGF2 and RA. Subsequent activation of WNT signalling induced otic placodal cell formation. By single-cell RNA-seq (scRNA-seq) analysis, we identified multiple clusters of otic placode- and otocyst marker-positive cells in the induced spheres. Moreover, the induced otic cells showed the potential to generate hair cell-like cells by overexpression of the transcription factors ATOH1, POU4F3 and GFI1. Conclusions We demonstrated the critical role of FGF2, RA and WNT signalling in a 3D environment for the in vitro differentiation of otic lineage cells from hPSCs. The induced otic cells had the capacity to differentiate into inner ear hair cells with stereociliary bundles and tip link-like structures. The protocol will be useful for in vitro disease modelling of sensorineural hearing loss and human inner ear development and thus contribute to drug screening and stem cell-based regenerative medicine. A 3D floating culture condition is critical for inducing otic placodal cells from hPSCs-derived preplacodal cells. Activation of FGF, RA, WNT signalling pathways is indispensable for differentiating otic lineage under the 3D condition. Overexpression of defined transcription factors facilitated the generation of hair cells from hPSCs-derived otic cells.
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Višnjar T, Maver A, Writzl K, Maloku O, Bergant G, Jaklič H, Neubauer D, Fogolari F, Pečarič Meglič N, Peterlin B. Biallelic ATOH1 Gene Variant in Siblings With Pontocerebellar Hypoplasia, Developmental Delay, and Hearing Loss. Neurol Genet 2022; 8:e677. [PMID: 35518571 PMCID: PMC9067583 DOI: 10.1212/nxg.0000000000000677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/04/2022] [Indexed: 11/15/2022]
Abstract
Background and Objectives To report on the novel association of biallelic variant in atonal basic helix-loop-helix transcription factor 1 (ATOH1) gene and pontocerebellar hypoplasia (PCH), severe global developmental delay, intellectual disability, and hearing loss in a family with 2 affected siblings. Methods A detailed clinical assessment and exome sequencing of peripheral blood sample were performed. Segregation analysis with Sanger sequencing and structural modeling of the variant was performed to support the pathogenicity of the variant. Results A homozygous missense variant (NM_005172.1:c.481C>G) in the ATOH1 gene was identified in the proband and his affected sister. The segregation analysis subsequently confirmed its segregation with an apparently recessive PCH in this family. ATOH1 encodes for the atonal basic helix-loop-helix (bHLH) transcription factor 1, a core transcription factor in the developing cerebellum, brainstem, and dorsal spinal cord, and in the ear. The identified variant results in the p.(Arg161Gly) amino acid substitution in the evolutionarily conserved DNA-binding bHLH domain of the ATOH1 protein. Biallelic missense variants in this domain were previously reported to result in disordered cerebellar development and hearing loss in animal models. In silico homology modeling revealed that p.Arg161Gly in ATOH1 protein probably disrupts a salt bridge with DNA backbone phosphate and increases the flexibility of the bHLH helix-both of which together affect the binding capability of the bHLH domain to the DNA. Discussion Based on the sequencing results and evidence from structural modeling of the identified variant, as well as with previous reports of ATOH1 gene disruption, we conclude that ATOH1 may represent a novel candidate gene associated with the phenotype of PCH, global developmental delay, and hearing loss in humans.
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Affiliation(s)
- Tanja Višnjar
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - Aleš Maver
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - Karin Writzl
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - Ornela Maloku
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - Gaber Bergant
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - Helena Jaklič
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - David Neubauer
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - Federico Fogolari
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - Nuška Pečarič Meglič
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
| | - Borut Peterlin
- Clinical Institute of Genomic Medicine (T.V., A.M., K.W., G.B., H.J., B.P.), University Medical Centre Ljubljana, Slovenia; Medical Faculty (K.W., D.N.), University of Ljubljana, Slovenia; Division of Paediatrics (D.N.), Department of Child, Adolescent & Developmental Neurology, University Medical Centre Ljubljana, Slovenia; Clinical Institute of Radiology (N.P.M.), University Medical Centre Ljubljana, Slovenia; and Department of Mathematics (O.M., F.F.), Informatics and Physics, University of Udine, Italy
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Rai V, Tu S, Frank JR, Zuo J. Molecular Pathways Modulating Sensory Hair Cell Regeneration in Adult Mammalian Cochleae: Progress and Perspectives. Int J Mol Sci 2021; 23:ijms23010066. [PMID: 35008497 PMCID: PMC8745006 DOI: 10.3390/ijms23010066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 12/30/2022] Open
Abstract
Noise-induced, drug-related, and age-related disabling hearing loss is a major public health problem and affect approximately 466 million people worldwide. In non-mammalian vertebrates, the death of sensory hair cells (HCs) induces the proliferation and transdifferentiation of adjacent supporting cells into new HCs; however, this capacity is lost in juvenile and adult mammalian cochleae leading to permanent hearing loss. At present, cochlear implants and hearing devices are the only available treatments and can help patients to a certain extent; however, no biological approach or FDA-approved drug is effective to treat disabling hearing loss and restore hearing. Recently, regeneration of mammalian cochlear HCs by modulating molecular pathways or transcription factors has offered some promising results, although the immaturity of the regenerated HCs remains the biggest concern. Furthermore, most of the research done is in neonates and not in adults. This review focuses on critically summarizing the studies done in adult mammalian cochleae and discusses various strategies to elucidate novel transcription factors for better therapeutics.
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Affiliation(s)
| | | | | | - Jian Zuo
- Correspondence: ; Tel.: +1-(402)-280-2916
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14
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He Z, Ding Y, Mu Y, Xu X, Kong W, Chai R, Chen X. Stem Cell-Based Therapies in Hearing Loss. Front Cell Dev Biol 2021; 9:730042. [PMID: 34746126 PMCID: PMC8567027 DOI: 10.3389/fcell.2021.730042] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 10/04/2021] [Indexed: 12/19/2022] Open
Abstract
In recent years, neural stem cell transplantation has received widespread attention as a new treatment method for supplementing specific cells damaged by disease, such as neurodegenerative diseases. A number of studies have proved that the transplantation of neural stem cells in multiple organs has an important therapeutic effect on activation and regeneration of cells, and restore damaged neurons. This article describes the methods for inducing the differentiation of endogenous and exogenous stem cells, the implantation operation and regulation of exogenous stem cells after implanted into the inner ear, and it elaborates the relevant signal pathways of stem cells in the inner ear, as well as the clinical application of various new materials. At present, stem cell therapy still has limitations, but the role of this technology in the treatment of hearing diseases has been widely recognized. With the development of related research, stem cell therapy will play a greater role in the treatment of diseases related to the inner ear.
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Affiliation(s)
- Zuhong He
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yanyan Ding
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yurong Mu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoxiang Xu
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Weijia Kong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Renjie Chai
- State Key Laboratory of Bioelectronics, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.,Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China.,Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, China
| | - Xiong Chen
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
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15
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Norrie disease protein is essential for cochlear hair cell maturation. Proc Natl Acad Sci U S A 2021; 118:2106369118. [PMID: 34544869 DOI: 10.1073/pnas.2106369118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2021] [Indexed: 11/18/2022] Open
Abstract
Mutations in the gene for Norrie disease protein (Ndp) cause syndromic deafness and blindness. We show here that cochlear function in an Ndp knockout mouse deteriorated with age: At P3-P4, hair cells (HCs) showed progressive loss of Pou4f3 and Gfi1, key transcription factors for HC maturation, and Myo7a, a specialized myosin required for normal function of HC stereocilia. Loss of expression of these genes correlated to increasing HC loss and profound hearing loss by 2 mo. We show that overexpression of the Ndp gene in neonatal supporting cells or, remarkably, up-regulation of canonical Wnt signaling in HCs rescued HCs and cochlear function. We conclude that Ndp secreted from supporting cells orchestrates a transcriptional network for the maintenance and survival of HCs and that increasing the level of β-catenin, the intracellular effector of Wnt signaling, is sufficient to replace the functional requirement for Ndp in the cochlea.
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Elliott KL, Pavlinkova G, Chizhikov VV, Yamoah EN, Fritzsch B. Neurog1, Neurod1, and Atoh1 are essential for spiral ganglia, cochlear nuclei, and cochlear hair cell development. Fac Rev 2021; 10:47. [PMID: 34131657 PMCID: PMC8170689 DOI: 10.12703/r/10-47] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
We review the molecular basis of three related basic helix–loop–helix (bHLH) genes (Neurog1, Neurod1, and Atoh1) and upstream regulators Eya1/Six1, Sox2, Pax2, Gata3, Fgfr2b, Foxg1, and Lmx1a/b during the development of spiral ganglia, cochlear nuclei, and cochlear hair cells. Neuronal development requires early expression of Neurog1, followed by its downstream target Neurod1, which downregulates Atoh1 expression. In contrast, hair cells and cochlear nuclei critically depend on Atoh1 and require Neurod1 and Neurog1 expression for various aspects of development. Several experiments show a partial uncoupling of Atoh1/Neurod1 (spiral ganglia and cochlea) and Atoh1/Neurog1/Neurod1 (cochlear nuclei). In this review, we integrate the cellular and molecular mechanisms that regulate the development of auditory system and provide novel insights into the restoration of hearing loss, beyond the limited generation of lost sensory neurons and hair cells.
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Affiliation(s)
- Karen L Elliott
- Department of Biology, University of Iowa, Iowa City, IA, USA
| | - Gabriela Pavlinkova
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czechia
| | - Victor V Chizhikov
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, University of Nevada, Reno, NV, USA
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA, USA
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17
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Elliott KL, Pavlínková G, Chizhikov VV, Yamoah EN, Fritzsch B. Development in the Mammalian Auditory System Depends on Transcription Factors. Int J Mol Sci 2021; 22:ijms22084189. [PMID: 33919542 PMCID: PMC8074135 DOI: 10.3390/ijms22084189] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/16/2022] Open
Abstract
We review the molecular basis of several transcription factors (Eya1, Sox2), including the three related genes coding basic helix–loop–helix (bHLH; see abbreviations) proteins (Neurog1, Neurod1, Atoh1) during the development of spiral ganglia, cochlear nuclei, and cochlear hair cells. Neuronal development requires Neurog1, followed by its downstream target Neurod1, to cross-regulate Atoh1 expression. In contrast, hair cells and cochlear nuclei critically depend on Atoh1 and require Neurod1 expression for interactions with Atoh1. Upregulation of Atoh1 following Neurod1 loss changes some vestibular neurons’ fate into “hair cells”, highlighting the significant interplay between the bHLH genes. Further work showed that replacing Atoh1 by Neurog1 rescues some hair cells from complete absence observed in Atoh1 null mutants, suggesting that bHLH genes can partially replace one another. The inhibition of Atoh1 by Neurod1 is essential for proper neuronal cell fate, and in the absence of Neurod1, Atoh1 is upregulated, resulting in the formation of “intraganglionic” HCs. Additional genes, such as Eya1/Six1, Sox2, Pax2, Gata3, Fgfr2b, Foxg1, and Lmx1a/b, play a role in the auditory system. Finally, both Lmx1a and Lmx1b genes are essential for the cochlear organ of Corti, spiral ganglion neuron, and cochlear nuclei formation. We integrate the mammalian auditory system development to provide comprehensive insights beyond the limited perception driven by singular investigations of cochlear neurons, cochlear hair cells, and cochlear nuclei. A detailed analysis of gene expression is needed to understand better how upstream regulators facilitate gene interactions and mammalian auditory system development.
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Affiliation(s)
- Karen L. Elliott
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA;
| | - Gabriela Pavlínková
- Institute of Biotechnology of the Czech Academy of Sciences, 25250 Vestec, Czechia;
| | - Victor V. Chizhikov
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA;
| | - Ebenezer N. Yamoah
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV 89557, USA;
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA;
- Correspondence:
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18
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Iyer AA, Groves AK. Transcription Factor Reprogramming in the Inner Ear: Turning on Cell Fate Switches to Regenerate Sensory Hair Cells. Front Cell Neurosci 2021; 15:660748. [PMID: 33854418 PMCID: PMC8039129 DOI: 10.3389/fncel.2021.660748] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/08/2021] [Indexed: 12/15/2022] Open
Abstract
Non-mammalian vertebrates can restore their auditory and vestibular hair cells naturally by triggering the regeneration of adjacent supporting cells. The transcription factor ATOH1 is a key regulator of hair cell development and regeneration in the inner ear. Following the death of hair cells, supporting cells upregulate ATOH1 and give rise to new hair cells. However, in the mature mammalian cochlea, such natural regeneration of hair cells is largely absent. Transcription factor reprogramming has been used in many tissues to convert one cell type into another, with the long-term hope of achieving tissue regeneration. Reprogramming transcription factors work by altering the transcriptomic and epigenetic landscapes in a target cell, resulting in a fate change to the desired cell type. Several studies have shown that ATOH1 is capable of reprogramming cochlear non-sensory tissue into cells resembling hair cells in young animals. However, the reprogramming ability of ATOH1 is lost with age, implying that the potency of individual hair cell-specific transcription factors may be reduced or lost over time by mechanisms that are still not clear. To circumvent this, combinations of key hair cell transcription factors have been used to promote hair cell regeneration in older animals. In this review, we summarize recent findings that have identified and studied these reprogramming factor combinations for hair cell regeneration. Finally, we discuss the important questions that emerge from these findings, particularly the feasibility of therapeutic strategies using reprogramming factors to restore human hearing in the future.
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Affiliation(s)
- Amrita A. Iyer
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Program in Genetics & Genomics, Houston, TX, United States
| | - Andrew K. Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Program in Genetics & Genomics, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
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Shibata SB, West MB, Du X, Iwasa Y, Raphael Y, Kopke RD. Gene therapy for hair cell regeneration: Review and new data. Hear Res 2020; 394:107981. [DOI: 10.1016/j.heares.2020.107981] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 04/19/2020] [Accepted: 04/22/2020] [Indexed: 02/06/2023]
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Fu Y, Yuan SS, Zhang LJ, Ji ZL, Quan XJ. Atonal bHLH transcription factor 1 is an important factor for maintaining the balance of cell proliferation and differentiation in tumorigenesis. Oncol Lett 2020; 20:2595-2605. [PMID: 32782577 PMCID: PMC7400680 DOI: 10.3892/ol.2020.11833] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 09/06/2019] [Indexed: 12/15/2022] Open
Abstract
Establishing the link between cellular processes and oncogenesis may aid the elucidation of targeted and effective therapies against tumor cell proliferation and metastasis. Previous studies have investigated the mechanisms involved in maintaining the balance between cell proliferation, differentiation and migration. There is increased interest in determining the conditions that allow cancer stem cells to differentiate as well as the identification of molecules that may serve as novel drug targets. Furthermore, the study of various genes, including transcription factors, which serve a crucial role in cellular processes, may present a promising direction for future therapy. The present review described the role of the transcription factor atonal bHLH transcription factor 1 (ATOH1) in signaling pathways in tumorigenesis, particularly in cerebellar tumor medulloblastoma and colorectal cancer, where ATOH1 serves as an oncogene or tumor suppressor, respectively. Additionally, the present review summarized the associated therapeutic interventions for these two types of tumors and discussed novel clinical targets and approaches.
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Affiliation(s)
- Ying Fu
- Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Lu He Hospital, Capital Medical University, Beijing 101149, P.R. China
| | - Sha-Sha Yuan
- Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Lu He Hospital, Capital Medical University, Beijing 101149, P.R. China
| | - Li-Jie Zhang
- Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Lu He Hospital, Capital Medical University, Beijing 101149, P.R. China
| | - Zhi-Li Ji
- Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Lu He Hospital, Capital Medical University, Beijing 101149, P.R. China
| | - Xiao-Jiang Quan
- Key Laboratory of Diabetes Prevention and Research, Endocrinology Center, Lu He Hospital, Capital Medical University, Beijing 101149, P.R. China.,Laboratory of Brain Development, Institut du Cerveau et de la Moelle Épinière, Hôpital Pitié-Salpêtrière, 75013 Paris, France
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Four Novel Variants in POU4F3 Cause Autosomal Dominant Nonsyndromic Hearing Loss. Neural Plast 2020; 2020:6137083. [PMID: 32684921 PMCID: PMC7349627 DOI: 10.1155/2020/6137083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/16/2020] [Accepted: 06/09/2020] [Indexed: 12/30/2022] Open
Abstract
Hereditary hearing loss is one of the most common sensory disabilities worldwide. Mutation of POU domain class 4 transcription factor 3 (POU4F3) is considered the pathogenic cause of autosomal dominant nonsyndromic hearing loss (ADNSHL), designated as autosomal dominant nonsyndromic deafness 15. In this study, four novel variants in POU4F3, c.696G>T (p.Glu232Asp), c.325C>T (p.His109Tyr), c.635T>C (p.Leu212Pro), and c.183delG (p.Ala62Argfs∗22), were identified in four different Chinese families with ADNSHL by targeted next-generation sequencing and Sanger sequencing. Based on the American College of Medical Genetics and Genomics guidelines, c.183delG (p.Ala62Argfs∗22) is classified as a pathogenic variant, c.696G>T (p.Glu232Asp) and c.635T>C (p.Leu212Pro) are classified as likely pathogenic variants, and c.325C>T (p.His109Tyr) is classified as a variant of uncertain significance. Based on previous reports and the results of this study, we speculated that POU4F3 pathogenic variants are significant contributors to ADNSHL in the East Asian population. Therefore, screening of POU4F3 should be a routine examination for the diagnosis of hereditary hearing loss.
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22
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Menendez L, Trecek T, Gopalakrishnan S, Tao L, Markowitz AL, Yu HV, Wang X, Llamas J, Huang C, Lee J, Kalluri R, Ichida J, Segil N. Generation of inner ear hair cells by direct lineage conversion of primary somatic cells. eLife 2020; 9:e55249. [PMID: 32602462 PMCID: PMC7326493 DOI: 10.7554/elife.55249] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/27/2020] [Indexed: 02/06/2023] Open
Abstract
The mechanoreceptive sensory hair cells in the inner ear are selectively vulnerable to numerous genetic and environmental insults. In mammals, hair cells lack regenerative capacity, and their death leads to permanent hearing loss and vestibular dysfunction. Their paucity and inaccessibility has limited the search for otoprotective and regenerative strategies. Growing hair cells in vitro would provide a route to overcome this experimental bottleneck. We report a combination of four transcription factors (Six1, Atoh1, Pou4f3, and Gfi1) that can convert mouse embryonic fibroblasts, adult tail-tip fibroblasts and postnatal supporting cells into induced hair cell-like cells (iHCs). iHCs exhibit hair cell-like morphology, transcriptomic and epigenetic profiles, electrophysiological properties, mechanosensory channel expression, and vulnerability to ototoxin in a high-content phenotypic screening system. Thus, direct reprogramming provides a platform to identify causes and treatments for hair cell loss, and may help identify future gene therapy approaches for restoring hearing.
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Affiliation(s)
- Louise Menendez
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
- Zilkha Neurogenetic Institute, University of Southern CaliforniaLos AngelesUnited States
| | - Talon Trecek
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
| | - Suhasni Gopalakrishnan
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
- Zilkha Neurogenetic Institute, University of Southern CaliforniaLos AngelesUnited States
| | - Litao Tao
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
| | - Alexander L Markowitz
- Zilkha Neurogenetic Institute, University of Southern CaliforniaLos AngelesUnited States
- USC Caruso Department of Otolaryngology – Head and Neck Surgery, University of Southern CaliforniaLos AngelesUnited States
| | - Haoze V Yu
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
| | - Xizi Wang
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
| | - Juan Llamas
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
| | | | - James Lee
- DRVision TechnologiesBellevueUnited States
| | - Radha Kalluri
- Zilkha Neurogenetic Institute, University of Southern CaliforniaLos AngelesUnited States
- USC Caruso Department of Otolaryngology – Head and Neck Surgery, University of Southern CaliforniaLos AngelesUnited States
| | - Justin Ichida
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
- Zilkha Neurogenetic Institute, University of Southern CaliforniaLos AngelesUnited States
| | - Neil Segil
- Department of Stem Cell and Regenerative Medicine, University of Southern CaliforniaLos AngelesUnited States
- Eli and Edythe Broad Center, University of Southern CaliforniaLos AngelesUnited States
- USC Caruso Department of Otolaryngology – Head and Neck Surgery, University of Southern CaliforniaLos AngelesUnited States
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23
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Zhang S, Qiang R, Dong Y, Zhang Y, Chen Y, Zhou H, Gao X, Chai R. Hair cell regeneration from inner ear progenitors in the mammalian cochlea. AMERICAN JOURNAL OF STEM CELLS 2020; 9:25-35. [PMID: 32699655 PMCID: PMC7364385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
Cochlear hair cells (HCs) are the mechanoreceptors of the auditory system, and because these cells cannot be spontaneously regenerated in adult mammals, hearing loss due to HC damage is permanent. However, cochleae of neonatal mice harbor some progenitor cells that retain limited ability to give rise to new HCs in vivo. Here we review the regulatory factors, signaling pathways, and epigenetic factors that have been reported to play roles in HC regeneration in the neonatal mammalian cochlea.
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Affiliation(s)
- Shasha Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing 210096, China
| | - Ruiying Qiang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing 210096, China
| | - Ying Dong
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing 210096, China
| | - Yuan Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing 210096, China
| | - Yin Chen
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory)Nanjing 210008, China
| | - Han Zhou
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory)Nanjing 210008, China
| | - Xia Gao
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory)Nanjing 210008, China
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing 210096, China
- Co-Innovation Center of Neuroregeneration, Nantong UniversityNantong 226001, China
- Institute for Stem Cell and Regeneration, Chinese Academy of ScienceBeijing, China
- Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast UniversityNanjing 211189, China
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory)Nanjing 210008, China
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24
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Yamoah EN, Li M, Shah A, Elliott KL, Cheah K, Xu PX, Phillips S, Young SM, Eberl DF, Fritzsch B. Using Sox2 to alleviate the hallmarks of age-related hearing loss. Ageing Res Rev 2020; 59:101042. [PMID: 32173536 PMCID: PMC7261488 DOI: 10.1016/j.arr.2020.101042] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 02/07/2023]
Abstract
Age-related hearing loss (ARHL) is the most prevalent sensory deficit. ARHL reduces the quality of life of the growing population, setting seniors up for the enhanced mental decline. The size of the needy population, the structural deficit, and a likely research strategy for effective treatment of chronic neurosensory hearing in the elderly are needed. Although there has been profound advancement in auditory regenerative research, there remain multiple challenges to restore hearing loss. Thus, additional investigations are required, using novel tools. We propose how the (1) flat epithelium, remaining after the organ of Corti has deteriorated, can be converted to the repaired-sensory epithelium, using Sox2. This will include (2) developing an artificial gene regulatory network transmitted by (3) large viral vectors to the flat epithelium to stimulate remnants of the organ of Corti to restore hair cells. We hope to unite with our proposal toward the common goal, eventually restoring a functional human hearing organ by transforming the flat epithelial cells left after the organ of Corti loss.
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Affiliation(s)
- Ebenezer N Yamoah
- Department of Physiology and Cell Biology, University of Nevada, Reno, USA
| | - Mark Li
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, USA
| | - Anit Shah
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, USA
| | - Karen L Elliott
- Department of Biology, CLAS, University of Iowa, Iowa City, USA
| | - Kathy Cheah
- Department of Biochemistry, Hong Kong University, Hong Kong, China
| | - Pin-Xian Xu
- Department of Biochemistry, Hong Kong University, Hong Kong, China
| | - Stacia Phillips
- Department of Biochemistry, Hong Kong University, Hong Kong, China
| | - Samuel M Young
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, USA; Department of Otolaryngology, Iowa Neuroscience Institute, University of Iowa, Iowa City, USA
| | - Daniel F Eberl
- Department of Biology, CLAS, University of Iowa, Iowa City, USA
| | - Bernd Fritzsch
- Department of Biology, CLAS, University of Iowa, Iowa City, USA.
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25
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Beach R, Abitbol JM, Allman BL, Esseltine JL, Shao Q, Laird DW. GJB2 Mutations Linked to Hearing Loss Exhibit Differential Trafficking and Functional Defects as Revealed in Cochlear-Relevant Cells. Front Cell Dev Biol 2020; 8:215. [PMID: 32300592 PMCID: PMC7142214 DOI: 10.3389/fcell.2020.00215] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/12/2020] [Indexed: 11/13/2022] Open
Abstract
GJB2 gene (that encodes Cx26) mutations are causal of hearing loss highlighting the importance of Cx26-based channel signaling amongst the supporting cells in the organ of Corti. While the majority of these GJB2 mutations are inherited in an autosomal recessive manner, others are inherited in an autosomal dominant manner and lead to syndromic hearing loss as well as skin diseases. To assess if common or divergent mechanisms are at the root of GJB2-linked hearing loss, we expressed several mutants in cochlear-relevant HEI-OC1 cells derived from the developing organ of Corti. Since supporting cells of the mature mammalian organ of Corti have negligible Cx43, but HEI-OC1 cells are rich in Cx43, we first used CRISPR-Cas9 to ablate endogenous Cx43, thus establishing a connexin-deficient platform for controlled reintroduction of hearing-relevant connexins and Cx26 mutants. We found three distinct outcomes and cellular phenotypes when hearing loss-linked Cx26 mutants were expressed in cochlear-relevant cells. The dominant syndromic Cx26 mutant N54K had trafficking defects and did not fully prevent wild-type Cx26 gap junction plaque formation but surprisingly formed gap junctions when co-expressed with Cx30. In contrast, the dominant syndromic S183F mutant formed gap junctions incapable of transferring dye and, as expected, co-localized in the same gap junctions as wild-type Cx26 and Cx30, but also gained the capacity to intermix with Cx43 within gap junctions. Both recessive non-syndromic Cx26 mutants (R32H and R184P) were retained in intracellular vesicles including early endosomes and did not co-localize with Cx30. As might be predicted, none of the Cx26 mutants prevented Cx43 gap junction plaque formation in Cx43-rich HEI-OC1 cells while Cx43-ablation had little effect on the expression of reference genes linked to auditory cell differentiation. We conclude from our studies in cochlear-relevant cells that the selected Cx26 mutants likely evoke hearing loss via three unique connexin defects that are independent of Cx43 status.
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Affiliation(s)
- Rianne Beach
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Julia M. Abitbol
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Brian L. Allman
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Jessica L. Esseltine
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Qing Shao
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Dale W. Laird
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
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26
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Zhang S, Zhang Y, Dong Y, Guo L, Zhang Z, Shao B, Qi J, Zhou H, Zhu W, Yan X, Hong G, Zhang L, Zhang X, Tang M, Zhao C, Gao X, Chai R. Knockdown of Foxg1 in supporting cells increases the trans-differentiation of supporting cells into hair cells in the neonatal mouse cochlea. Cell Mol Life Sci 2020; 77:1401-1419. [PMID: 31485717 PMCID: PMC7113235 DOI: 10.1007/s00018-019-03291-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 08/08/2019] [Accepted: 08/28/2019] [Indexed: 12/17/2022]
Abstract
Foxg1 is one of the forkhead box genes that are involved in morphogenesis, cell fate determination, and proliferation, and Foxg1 was previously reported to be required for morphogenesis of the mammalian inner ear. However, Foxg1 knock-out mice die at birth, and thus the role of Foxg1 in regulating hair cell (HC) regeneration after birth remains unclear. Here we used Sox2CreER/+ Foxg1loxp/loxp mice and Lgr5-EGFPCreER/+ Foxg1loxp/loxp mice to conditionally knock down Foxg1 specifically in Sox2+ SCs and Lgr5+ progenitors, respectively, in neonatal mice. We found that Foxg1 conditional knockdown (cKD) in Sox2+ SCs and Lgr5+ progenitors at postnatal day (P)1 both led to large numbers of extra HCs, especially extra inner HCs (IHCs) at P7, and these extra IHCs with normal hair bundles and synapses could survive at least to P30. The EdU assay failed to detect any EdU+ SCs, while the SC number was significantly decreased in Foxg1 cKD mice, and lineage tracing data showed that much more tdTomato+ HCs originated from Sox2+ SCs in Foxg1 cKD mice compared to the control mice. Moreover, the sphere-forming assay showed that Foxg1 cKD in Lgr5+ progenitors did not significantly change their sphere-forming ability. All these results suggest that Foxg1 cKD promotes HC regeneration and leads to large numbers of extra HCs probably by inducing direct trans-differentiation of SCs and progenitors to HCs. Real-time qPCR showed that cell cycle and Notch signaling pathways were significantly down-regulated in Foxg1 cKD mice cochlear SCs. Together, this study provides new evidence for the role of Foxg1 in regulating HC regeneration from SCs and progenitors in the neonatal mouse cochlea.
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Affiliation(s)
- Shasha Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Yuan Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Ying Dong
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Lingna Guo
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Zhong Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Buwei Shao
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Jieyu Qi
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Han Zhou
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Weijie Zhu
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Xiaoqian Yan
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Guodong Hong
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Liyan Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Xiaoli Zhang
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Mingliang Tang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Chunjie Zhao
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, 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, Nanjing, 210008, China
| | - Renjie Chai
- 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.
- Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, China.
- Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 211189, China.
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, China.
- Key Laboratory of Hearing Medicine of NHFPC, ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China.
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27
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Zheng Y, Luo W, Ma R, Cong N, Ren D, Chi F, Yang J. The Atoh1 expression levels are correlated with the arrangement, ciliary morphology, and electrophysiological characteristics of ectopic hair cell-like cells. Neurosci Lett 2020; 720:134758. [PMID: 31945449 DOI: 10.1016/j.neulet.2020.134758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/15/2019] [Accepted: 01/13/2020] [Indexed: 10/25/2022]
Abstract
Previous reports have suggested that the level and duration of Atoh1 expression are correlated with the survival, arrangement and stereociliary bundle-related morphology of hair cells during development, but whether Atoh1 expression levels are correlated with the arrangement, bundle formation and electrophysiological characteristics of newly formed hair cells is unknown. To address this question, cultured cochlear explants obtained from neonatal rats were treated with different titers of a human adenovirus serotype 5 (Ad5) vector encoding Atoh1 and/or EGFP (EGFP-Atoh1+/-). The results showed that higher EGFP-Atoh1 concentrations led to higher initial Atoh1 mRNA expression levels and induced greater numbers of ectopic hair cell-like cells (EHCLCs) in the lesser epithelial ridge (LER). Furthermore, gradual increases in the number of EHCLCs were associated with the progressive conversion of the LER region similarly to that of hair cells during development. Some of the cilia on EHCLCs with higher Atoh1 expression were regularly arranged in a manner similar to that of normal hair bundles. As demonstrated through patch clamp recordings, high Atoh1 expression was associated with significantly decreased proportions of cells with Ih currents, significantly reduced proportions of transient potassium channel currents, and potassium channel currents with a greatly increased mean amplitude, which indicated that EHCLCs with high Atoh1 expression were more mature than those with low Atoh1 expression. Overall, the evidence suggests that the Atoh1 expression levels affect not only the arrangement and ciliary morphology of hair cells but also the electrophysiological characteristics of Atoh1-induced EHCLCs, and these findings provide important guidance for future therapies aimed at treating deafness.
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Affiliation(s)
- Yu Zheng
- Department of Otology and Skull Base Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai 200031, China; Shanghai Clinical Medical Center of Hearing Medicine, Shanghai 200031, China; Key Laboratory of Hearing Medicine of National Health Commission of the People's Republic of China, Shanghai 20031, China; Research Institute of Otolaryngology, Fudan University, Shanghai 200031, China
| | - Wenwei Luo
- Department of Otology and Skull Base Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai 200031, China; Shanghai Clinical Medical Center of Hearing Medicine, Shanghai 200031, China; Key Laboratory of Hearing Medicine of National Health Commission of the People's Republic of China, Shanghai 20031, China; Research Institute of Otolaryngology, Fudan University, Shanghai 200031, China
| | - Rui Ma
- Key Laboratory of Hearing Medicine of National Health Commission of the People's Republic of China, Shanghai 20031, China; Research Institute of Otolaryngology, Fudan University, Shanghai 200031, China
| | - Ning Cong
- Key Laboratory of Hearing Medicine of National Health Commission of the People's Republic of China, Shanghai 20031, China; Research Institute of Otolaryngology, Fudan University, Shanghai 200031, China
| | - Dongdong Ren
- Department of Otology and Skull Base Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai 200031, China; Shanghai Clinical Medical Center of Hearing Medicine, Shanghai 200031, China; Key Laboratory of Hearing Medicine of National Health Commission of the People's Republic of China, Shanghai 20031, China; Research Institute of Otolaryngology, Fudan University, Shanghai 200031, China.
| | - Fanglu Chi
- Department of Otology and Skull Base Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai 200031, China; Shanghai Clinical Medical Center of Hearing Medicine, Shanghai 200031, China; Key Laboratory of Hearing Medicine of National Health Commission of the People's Republic of China, Shanghai 20031, China; Research Institute of Otolaryngology, Fudan University, Shanghai 200031, China.
| | - Juanmei Yang
- Department of Otology and Skull Base Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai 200031, China; Shanghai Clinical Medical Center of Hearing Medicine, Shanghai 200031, China; Key Laboratory of Hearing Medicine of National Health Commission of the People's Republic of China, Shanghai 20031, China; Research Institute of Otolaryngology, Fudan University, Shanghai 200031, China.
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28
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Atoh1 is required in supporting cells for regeneration of vestibular hair cells in adult mice. Hear Res 2019; 385:107838. [PMID: 31751832 DOI: 10.1016/j.heares.2019.107838] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 10/17/2019] [Accepted: 11/01/2019] [Indexed: 11/20/2022]
Abstract
In amniotes, head movements are encoded by two types of vestibular hair cells (type I and type II) with unique morphology, physiology, and innervation. After hair cell destruction in mature rodents, supporting cells regenerate some type II hair cells, but no type I hair cells are replaced. The transcription factor Atoh1 is required for hair cell development, and Atoh1 is upregulated in supporting cells, the hair cell progenitors, in mature chickens and mice following hair cell damage. We investigated whether Atoh1 is required for type II hair cell regeneration in adult mice after genetic ablation of hair cells. First, we used a knock-in Atoh1 reporter to demonstrate that supporting cells in the utricle, a vestibular organ that detects linear acceleration of the head, upregulate Atoh1 expression by 7 days after hair cell destruction was initiated. Next, we labeled supporting cells prior to damage and fate-mapped them over time to test whether conditional deletion of Atoh1 from supporting cells prevented them from converting into hair cells after damage. In mice with normal Atoh1 expression, fate-mapped supporting cells in the adult utricle gave rise to hundreds of type II hair cells after hair cell destruction, but they did not form new type I hair cells. By contrast, mice with Atoh1 deletion prior to hair cell damage had only 10-20 fate-mapped type II hair cells per utricle at 3 weeks post-damage, and numbers did not change at 12 weeks after hair cell destruction. Supporting cells had normal cell shape and nuclear density up to 12 weeks after Atoh1 deletion. Similar observations were made in two other vestibular organs, the saccule and the lateral ampulla. Our findings demonstrate that Atoh1 is necessary in adult mouse supporting cells for regeneration of type II vestibular hair cells and that deletion of Atoh1 from supporting cells prior to damage does not appear to induce supporting cells to die or to proliferate.
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29
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Xia M, Ma J, Sun S, Li W, Li H. The biological strategies for hearing re-establishment based on the stem/progenitor cells. Neurosci Lett 2019; 711:134406. [PMID: 31377244 DOI: 10.1016/j.neulet.2019.134406] [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: 05/13/2019] [Revised: 07/18/2019] [Accepted: 07/27/2019] [Indexed: 01/04/2023]
Abstract
The cochlea is the essential organ for hearing and includes both auditory sensory hair cells and spiral ganglion neurons. The discovery of inner ear stem cell brings hope to the regeneration of hair cell and spiral ganglion neuron as well as the followed hearing re-establishment. Thus the investigation on characteristics of inner ear stem/progenitor cells and related regulating clue is important to make such regeneration a reality. In addition, attempts have also been made to transplant exogenous stem cells into the inner ear to restore hearing function. In this review, we describe recent advances in the characterization of mammalian inner ear progenitor/stem cells and the mechanisms of regulating their proliferation and differentiation, and summarize studies that have used exogenous stem cells to repair damaged hair cells and neurons in the inner ear.
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Affiliation(s)
- Mingyu Xia
- ENT Institute and Otorhinolaryngology Department of the Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
| | - Jiaoyao Ma
- ENT Institute and Otorhinolaryngology Department of the Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
| | - Shan Sun
- ENT Institute and Otorhinolaryngology Department of the Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
| | - Wenyan Li
- ENT Institute and Otorhinolaryngology Department of the Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China.
| | - Huawei Li
- ENT Institute and Otorhinolaryngology Department of the Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China; Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China; NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200031, China; Shanghai Engineering Research Centre of Cochlear Implant, Shanghai, 200031, China; The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China.
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30
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Michalski N, Petit C. Genes Involved in the Development and Physiology of Both the Peripheral and Central Auditory Systems. Annu Rev Neurosci 2019; 42:67-86. [DOI: 10.1146/annurev-neuro-070918-050428] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The genetic approach, based on the study of inherited forms of deafness, has proven to be particularly effective for deciphering the molecular mechanisms underlying the development of the peripheral auditory system, the cochlea and its afferent auditory neurons, and how this system extracts the physical parameters of sound. Although this genetic dissection has provided little information about the central auditory system, scattered data suggest that some genes may have a critical role in both the peripheral and central auditory systems. Here, we review the genes controlling the development and function of the peripheral and central auditory systems, focusing on those with demonstrated intrinsic roles in both systems and highlighting the current underappreciation of these genes. Their encoded products are diverse, from transcription factors to ion channels, as are their roles in the central auditory system, mostly evaluated in brainstem nuclei. We examine the ontogenetic and evolutionary mechanisms that may underlie their expression at different sites.
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Affiliation(s)
- Nicolas Michalski
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75015 Paris, France;,
- Institut National de la Santé et de la Recherche Médicale, UMRS 1120, 75015 Paris, France
- Sorbonne Universités, 75005 Paris, France
| | - Christine Petit
- Unité de Génétique et Physiologie de l'Audition, Institut Pasteur, 75015 Paris, France;,
- Institut National de la Santé et de la Recherche Médicale, UMRS 1120, 75015 Paris, France
- Sorbonne Universités, 75005 Paris, France
- Syndrome de Usher et Autres Atteintes Rétino-Cochléaires, Institut de la Vision, 75012 Paris, France
- Collège de France, 75005 Paris, France
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Hou K, Jiang H, Karim MR, Zhong C, Xu Z, Liu L, Guan M, Shao J, Huang X. A Critical E-box in Barhl1 3' Enhancer Is Essential for Auditory Hair Cell Differentiation. Cells 2019; 8:cells8050458. [PMID: 31096644 PMCID: PMC6562609 DOI: 10.3390/cells8050458] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 02/05/2023] Open
Abstract
Barhl1, a mouse homologous gene of Drosophila BarH class homeobox genes, is highly expressed within the inner ear and crucial for the long-term maintenance of auditory hair cells that mediate hearing and balance, yet little is known about the molecular events underlying Barhl1 regulation and function in hair cells. In this study, through data mining and in vitro report assay, we firstly identified Barhl1 as a direct target gene of Atoh1 and one E-box (E3) in Barhl1 3’ enhancer is crucial for Atoh1-mediated Barhl1 activation. Then we generated a mouse embryonic stem cell (mESC) line carrying disruptions on this E3 site E-box (CAGCTG) using CRISPR/Cas9 technology and this E3 mutated mESC line is further subjected to an efficient stepwise hair cell differentiation strategy in vitro. Disruptions on this E3 site caused dramatic loss of Barhl1 expression and significantly reduced the number of induced hair cell-like cells, while no affections on the differentiation toward early primitive ectoderm-like cells and otic progenitors. Finally, through RNA-seq profiling and gene ontology (GO) enrichment analysis, we found that this E3 box was indispensable for Barhl1 expression to maintain hair cell development and normal functions. We also compared the transcriptional profiles of induced cells from CDS mutated and E3 mutated mESCs, respectively, and got very consistent results except the Barhl1 transcript itself. These observations indicated that Atoh1-mediated Barhl1 expression could have important roles during auditory hair cell development. In brief, our findings delineate the detail molecular mechanism of Barhl1 expression regulation in auditory hair cell differentiation.
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Affiliation(s)
- Kun Hou
- Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Hui Jiang
- Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Md Rezaul Karim
- Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
- Department of Biotechnology and Genetic Engineering, Faculty of Biological Sciences, Islamic University, Kushtia 7003, Bangladesh.
| | - Chao Zhong
- Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Zhouwen Xu
- Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Lin Liu
- Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
| | - Minxin Guan
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China.
| | - Jianzhong Shao
- Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
- Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China.
| | - Xiao Huang
- Institute of Cell and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
- Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China.
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Zhong C, Fu Y, Pan W, Yu J, Wang J. Atoh1 and other related key regulators in the development of auditory sensory epithelium in the mammalian inner ear: function and interplay. Dev Biol 2019; 446:133-141. [DOI: 10.1016/j.ydbio.2018.12.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/30/2018] [Accepted: 12/30/2018] [Indexed: 01/08/2023]
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Zhang Y, Tang Q, Xue R, Gao J, Yang H, Gao Z, Lin G. Absence of Atoh1 induced partially different cell fates of cochlear and vestibular sensory epithelial cells in mice. Acta Otolaryngol 2018; 138:972-976. [PMID: 30686130 DOI: 10.1080/00016489.2018.1497855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Background: Atoh1, also named Math1, is essential for the development of inner ear hair cells. Many studies have confirmed that the absence of Atoh1 resulted in a total loss of inner ear hair cells, which indicates that Atoh1 plays very similar roles in the development of hair cells in the cochlea and vestibule. Objective: The aim of this study was to evaluate whether Atoh1 plays different roles in the cochlea and vestibule. MATERIAL AND METHODS We generated Atoh1-null mice by inbreeding Atoh1cre/+ heterozygous mice and compared with the epithelial cell status of the cochlea and vestibule. RESULTS We found that no inner ear hair cells were detected in Atoh1-null mice. However, a different cell status was found in the mutant cochlea and vestibule on the last embryonic day (E18.5). In the Atoh1-null cochlea, the epithelial cells that should develop into hair cells were totally absent, while in the Atoh1-null vestibule, most of the epithelial cells that should develop into hair cells still survived. CONCLUSIONS Our data indicate that Atoh1 may have similar but partially different functions in the development of hair cells in the cochlea and vestibule.
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Affiliation(s)
- Yongli Zhang
- Department of Otolaryngology, Peking Union Medical College Hospital, Beijing, China
| | - Qi Tang
- Department of Otolaryngology, Peking Union Medical College Hospital, Beijing, China
| | - Ruoyan Xue
- Department of Otolaryngology, Peking Union Medical College Hospital, Beijing, China
| | - Juanjuan Gao
- Department of Otolaryngology, Peking Union Medical College Hospital, Beijing, China
| | - Hua Yang
- Department of Otolaryngology, Peking Union Medical College Hospital, Beijing, China
| | - Zhiqiang Gao
- Department of Otolaryngology, Peking Union Medical College Hospital, Beijing, China
| | - Gan Lin
- Department of Ophthalmology, University of Rochester, Rochester, NY, USA
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Grifone R, Saquet A, Xu Z, Shi DL. Expression patterns of Rbm24 in lens, nasal epithelium, and inner ear during mouse embryonic development. Dev Dyn 2018; 247:1160-1169. [PMID: 30133047 DOI: 10.1002/dvdy.24666] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/13/2018] [Accepted: 08/17/2018] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND RNA-binding proteins plays critical roles in several post-transcriptional regulatory processes. The RNA-binding protein, Rbm24, has been shown to be involved in the development of the heart and skeletal muscles by regulating different post-transcriptional processes such as splicing and stabilization of specific target mRNAs. Here, by performing a detailed expression and localization analysis in mice embryos, we show that Rbm24 protein is not only expressed in heart and skeletal muscles as previously reported, but it is also strongly and specifically detected in specific regions of all the head sensory organs during mouse development. RESULTS Rbm24 expression is indeed found to be activated in the lens, in the sensory olfactory epithelium and in mechanosensory cells of the auditory and vestibular systems. Within these territories, Rbm24 is shown to be restricted to distinct subdomains, potentially regulating cell specificity and proliferation. Moreover, Rbm24 protein is found to be restricted to the cytoplasmic compartment in all these organs, thus providing clues to the posttranscriptional activity that it may exert in these cells. CONCLUSIONS Altogether, these results highlight that Rbm24 may potentially function as a novel key regulator for the development of the eye, nasal epithelium, and inner ear in vertebrates. Developmental Dynamics 247:1160-1169, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Raphaëlle Grifone
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR7622, IBPS-Developmental Biology Laboratory, Paris, France
| | - Audrey Saquet
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR7622, IBPS-Developmental Biology Laboratory, Paris, France
| | - Zhigang Xu
- School of Life Sciences, Shandong University, Jinan, China
| | - De-Li Shi
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR7622, IBPS-Developmental Biology Laboratory, Paris, France
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Wang L, Kempton JB, Brigande JV. Gene Therapy in Mouse Models of Deafness and Balance Dysfunction. Front Mol Neurosci 2018; 11:300. [PMID: 30210291 PMCID: PMC6123355 DOI: 10.3389/fnmol.2018.00300] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/06/2018] [Indexed: 12/16/2022] Open
Abstract
Therapeutic strategies to restore hearing and balance in mouse models of inner ear disease aim to rescue sensory function by gene replacement, augmentation, knock down or knock out. Modalities to achieve therapeutic effects have utilized virus-mediated transfer of wild type genes and small interfering ribonucleic acids; systemic and focal administration of antisense oligonucleotides (ASO) and designer small molecules; and lipid-mediated transfer of Cas 9 ribonucleoprotein (RNP) complexes. This work has established that gene or drug administration to the structurally and functionally immature, early neonatal mouse inner ear prior to hearing onset is a prerequisite for the most robust therapeutic responses. These observations may have significant implications for translating mouse inner ear gene therapies to patients. The human fetus hears by gestational week 19, suggesting that a corollary window of therapeutic efficacy closes early in the second trimester of pregnancy. We hypothesize that fetal therapeutics deployed prior to hearing onset may be the most effective approach to preemptively manage genetic mutations that cause deafness and vestibular dysfunction. We assert that gene therapy studies in higher vertebrate model systems with fetal hearing onset and a comparable acoustic range and sensitivity to that of humans are an essential step to safely and effectively translate murine gene therapies to the clinic.
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Affiliation(s)
- Lingyan Wang
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, Portland, OR, United States
| | - J Beth Kempton
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, Portland, OR, United States
| | - John V Brigande
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, Portland, OR, United States
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36
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Ma JH, Kim HP, Bok J, Shin JO. CTCF is required for maintenance of auditory hair cells and hearing function in the mouse cochlea. Biochem Biophys Res Commun 2018; 503:2646-2652. [PMID: 30107916 DOI: 10.1016/j.bbrc.2018.08.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 08/02/2018] [Indexed: 12/14/2022]
Abstract
Auditory hair cells play an essential role in hearing. These cells convert sound waves, mechanical stimuli, into electrical signals that are conveyed to the brain via spiral ganglion neurons. The hair cells are located in the organ of Corti within the cochlea. They assemble in a special arrangement with three rows of outer hair cells and one row of inner hair cells. The proper differentiation and preservation of auditory hair cells are essential for acquiring and maintaining hearing function, respectively. Many genetic regulatory mechanisms underlying hair-cell differentiation and maintenance have been elucidated to date. However, the role of epigenetic regulation in hair-cell differentiation and maintenance has not been definitively demonstrated. CTCF is an essential epigenetic component that plays a primary role in the organization of global chromatin architecture. To determine the role of CTCF in mammalian hair cells, we specifically deleted Ctcf in developing hair cells by crossing Ctcffl/fl mice with Gfi1Cre/+ mice. Gfi1Cre; Ctcffl/fl mice did not exhibit obvious developmental defects in hair cells until postnatal day 8. However, at 3 weeks, the Ctcf deficiency caused intermittent degeneration of the stereociliary bundles of outer hair cells, resulting in profound hearing impairment. At 5 weeks, most hair cells were degenerated in Gfi1Cre; Ctcffl/fl mice, and defects in other structures of the organ of Corti, such as the tunnel of Corti and Nuel's space, became apparent. These results suggest that CTCF plays an essential role in maintaining hair cells and hearing function in mammalian cochlea.
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Affiliation(s)
- Ji-Hyun Ma
- Department of Anatomy, Republic of Korea
| | - Hyoung-Pyo Kim
- Department of Environmental Medical Biology, Republic of Korea; BK21 PLUS Project for Medical Science, Republic of Korea
| | - Jinwoong Bok
- Department of Anatomy, Republic of Korea; BK21 PLUS Project for Medical Science, Republic of Korea; Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
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37
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Duran Alonso MB, Lopez Hernandez I, de la Fuente MA, Garcia-Sancho J, Giraldez F, Schimmang T. Transcription factor induced conversion of human fibroblasts towards the hair cell lineage. PLoS One 2018; 13:e0200210. [PMID: 29979748 PMCID: PMC6034836 DOI: 10.1371/journal.pone.0200210] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 06/21/2018] [Indexed: 12/25/2022] Open
Abstract
Hearing loss is the most common sensorineural disorder, affecting over 5% of the population worldwide. Its most frequent cause is the loss of hair cells (HCs), the mechanosensory receptors of the cochlea. HCs transduce incoming sounds into electrical signals that activate auditory neurons, which in turn send this information to the brain. Although some spontaneous HC regeneration has been observed in neonatal mammals, the very small pool of putative progenitor cells that have been identified in the adult mammalian cochlea is not able to replace the damaged HCs, making any hearing impairment permanent. To date, guided differentiation of human cells to HC-like cells has only been achieved using either embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs). However, use of such cell types suffers from a number of important disadvantages, such as the risk of tumourigenicity if transplanted into the host´s tissue. We have obtained cells expressing hair cell markers from cultures of human fibroblasts by overexpression of GFI1, Pou4f3 and ATOH1 (GPA), three genes that are known to play a critical role in the development of HCs. Immunocytochemical, qPCR and RNAseq analyses demonstrate the expression of genes typically expressed by HCs in the transdifferentiated cells. Our protocol represents a much faster approach than the methods applied to ESCs and iPSCs and validates the combination of GPA as a set of genes whose activation leads to the direct conversion of human somatic cells towards the hair cell lineage. Our observations are expected to contribute to the development of future therapies aimed at the regeneration of the auditory organ and the restoration of hearing.
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Affiliation(s)
- María Beatriz Duran Alonso
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, C/Sanz y Forés 3, Valladolid, Spain
| | - Iris Lopez Hernandez
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, C/Sanz y Forés 3, Valladolid, Spain
| | - Miguel Angel de la Fuente
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, C/Sanz y Forés 3, Valladolid, Spain
| | - Javier Garcia-Sancho
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, C/Sanz y Forés 3, Valladolid, Spain
| | - Fernando Giraldez
- CEXS, Universitat Pompeu Fabra, Parc de Recerca Biomédica de Barcelona, Barcelona, Spain
| | - Thomas Schimmang
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, C/Sanz y Forés 3, Valladolid, Spain
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38
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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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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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40
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Notch pathway signaling in the skin antagonizes Merkel cell development. Dev Biol 2018; 434:207-214. [DOI: 10.1016/j.ydbio.2017.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/08/2017] [Accepted: 12/09/2017] [Indexed: 01/16/2023]
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Zhang T, Xu J, Maire P, Xu PX. Six1 is essential for differentiation and patterning of the mammalian auditory sensory epithelium. PLoS Genet 2017; 13:e1006967. [PMID: 28892484 PMCID: PMC5593176 DOI: 10.1371/journal.pgen.1006967] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 08/08/2017] [Indexed: 11/19/2022] Open
Abstract
The organ of Corti in the cochlea is a two-cell layered epithelium: one cell layer of mechanosensory hair cells that align into one row of inner and three rows of outer hair cells interdigitated with one cell layer of underlying supporting cells along the entire length of the cochlear spiral. These two types of epithelial cells are derived from common precursors in the four- to five-cell layered primordium and acquire functionally important shapes during terminal differentiation through the thinning process and convergent extension. Here, we have examined the role of Six1 in the establishment of the auditory sensory epithelium. Our data show that prior to terminal differentiation of the precursor cells, deletion of Six1 leads to formation of only a few hair cells and defective patterning of the sensory epithelium. Previous studies have suggested that downregulation of Sox2 expression in differentiating hair cells must occur after Atoh1 mRNA activation in order to allow Atoh1 protein accumulation due to antagonistic effects between Atoh1 and Sox2. Our analysis indicates that downregulation of Sox2 in the differentiating hair cells depends on Six1 activity. Furthermore, we found that Six1 is required for the maintenance of Fgf8 expression and dynamic distribution of N-cadherin and E-cadherin in the organ of Corti during differentiation. Together, our analyses uncover essential roles of Six1 in hair cell differentiation and formation of the organ of Corti in the mammalian cochlea.
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Affiliation(s)
- Ting Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Jinshu Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Pascal Maire
- INSERM U1016, Institut Cochin, Paris, France; CNRS UMR 8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Pin-Xian Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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42
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Roy S, Yun D, Madahian B, Berry MW, Deng LY, Goldowitz D, Homayouni R. Navigating the Functional Landscape of Transcription Factors via Non-Negative Tensor Factorization Analysis of MEDLINE Abstracts. Front Bioeng Biotechnol 2017; 5:48. [PMID: 28894735 PMCID: PMC5581332 DOI: 10.3389/fbioe.2017.00048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/31/2017] [Indexed: 01/09/2023] Open
Abstract
In this study, we developed and evaluated a novel text-mining approach, using non-negative tensor factorization (NTF), to simultaneously extract and functionally annotate transcriptional modules consisting of sets of genes, transcription factors (TFs), and terms from MEDLINE abstracts. A sparse 3-mode term × gene × TF tensor was constructed that contained weighted frequencies of 106,895 terms in 26,781 abstracts shared among 7,695 genes and 994 TFs. The tensor was decomposed into sub-tensors using non-negative tensor factorization (NTF) across 16 different approximation ranks. Dominant entries of each of 2,861 sub-tensors were extracted to form term–gene–TF annotated transcriptional modules (ATMs). More than 94% of the ATMs were found to be enriched in at least one KEGG pathway or GO category, suggesting that the ATMs are functionally relevant. One advantage of this method is that it can discover potentially new gene–TF associations from the literature. Using a set of microarray and ChIP-Seq datasets as gold standard, we show that the precision of our method for predicting gene–TF associations is significantly higher than chance. In addition, we demonstrate that the terms in each ATM can be used to suggest new GO classifications to genes and TFs. Taken together, our results indicate that NTF is useful for simultaneous extraction and functional annotation of transcriptional regulatory networks from unstructured text, as well as for literature based discovery. A web tool called Transcriptional Regulatory Modules Extracted from Literature (TREMEL), available at http://binf1.memphis.edu/tremel, was built to enable browsing and searching of ATMs.
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Affiliation(s)
- Sujoy Roy
- Bioinformatics Program, University of Memphis, Memphis, TN, United States.,Center for Translational Informatics, University of Memphis, Memphis, TN, United States
| | - Daqing Yun
- Computer and Information Sciences Program, Harrisburg University of Science and Technology, Harrisburg, PA, United States
| | - Behrouz Madahian
- Department of Mathematical Sciences, University of Memphis, Memphis, TN, United States
| | - Michael W Berry
- Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, United States
| | - Lih-Yuan Deng
- Department of Mathematical Sciences, University of Memphis, Memphis, TN, United States
| | - Daniel Goldowitz
- Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Ramin Homayouni
- Bioinformatics Program, University of Memphis, Memphis, TN, United States.,Center for Translational Informatics, University of Memphis, Memphis, TN, United States.,Department of Biological Sciences, University of Memphis, Memphis, TN, United States
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An Atoh1-S193A Phospho-Mutant Allele Causes Hearing Deficits and Motor Impairment. J Neurosci 2017; 37:8583-8594. [PMID: 28729444 DOI: 10.1523/jneurosci.0295-17.2017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 06/20/2017] [Accepted: 06/29/2017] [Indexed: 12/21/2022] Open
Abstract
Atonal homolog 1 (Atoh1) is a basic helix-loop-helix (bHLH) transcription factor that is essential for the genesis, survival, and maturation of a variety of neuronal and non-neuronal cell populations, including those involved in proprioception, interoception, balance, respiration, and hearing. Such diverse functions require fine regulation at the transcriptional and protein levels. Here, we show that serine 193 (S193) is phosphorylated in Atoh1's bHLH domain in vivo Knock-in mice of both sexes bearing a GFP-tagged phospho-dead S193A allele on a null background (Atoh1S193A/lacZ) exhibit mild cerebellar foliation defects, motor impairments, partial pontine nucleus migration defects, cochlear hair cell degeneration, and profound hearing loss. We also found that Atoh1 heterozygous mice of both sexes (Atoh1lacZ/+) have adult-onset deafness. These data indicate that different cell types have different degrees of vulnerability to loss of Atoh1 function and that hypomorphic Atoh1 alleles should be considered in human hearing loss.SIGNIFICANCE STATEMENT The discovery that Atonal homolog 1 (Atoh1) governs the development of the sensory hair cells in the inner ear led to therapeutic efforts to restore these cells in cases of human deafness. Because prior studies of Atoh1-heterozygous mice did not examine or report on hearing loss in mature animals, it has not been clinical practice to sequence ATOH1 in people with deafness. Here, in seeking to understand how phosphorylation of Atoh1 modulates its effects in vivo, we discovered that inner ear hair cells are much more vulnerable to loss of Atoh1 function than other Atoh1-positive cell types and that heterozygous mice actually develop hearing loss late in life. This opens up the possibility that missense mutations in ATOH1 could increase human vulnerability to loss of hair cells because of aging or trauma.
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Costa A, Powell LM, Lowell S, Jarman AP. Atoh1 in sensory hair cell development: constraints and cofactors. Semin Cell Dev Biol 2017; 65:60-68. [DOI: 10.1016/j.semcdb.2016.10.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/26/2016] [Accepted: 10/13/2016] [Indexed: 11/28/2022]
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Cheng C, Guo L, Lu L, Xu X, Zhang S, Gao J, Waqas M, Zhu C, Chen Y, Zhang X, Xuan C, Gao X, Tang M, Chen F, Shi H, Li H, Chai R. Characterization of the Transcriptomes of Lgr5+ Hair Cell Progenitors and Lgr5- Supporting Cells in the Mouse Cochlea. Front Mol Neurosci 2017; 10:122. [PMID: 28491023 PMCID: PMC5405134 DOI: 10.3389/fnmol.2017.00122] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 04/11/2017] [Indexed: 12/27/2022] Open
Abstract
Cochlear supporting cells (SCs) have been shown to be a promising resource for hair cell (HC) regeneration in the neonatal mouse cochlea. Previous studies have reported that Lgr5+ SCs can regenerate HCs both in vitro and in vivo and thus are considered to be inner ear progenitor cells. Lgr5+ progenitors are able to regenerate more HCs than Lgr5- SCs, and it is important to understand the mechanism behind the proliferation and HC regeneration of these progenitors. Here, we isolated Lgr5+ progenitors and Lgr5- SCs from Lgr5-EGFP-CreERT2/Sox2-CreERT2/Rosa26-tdTomato mice via flow cytometry. As expected, we found that Lgr5+ progenitors had significantly higher proliferation and HC regeneration ability than Lgr5- SCs. Next, we performed RNA-Seq to determine the gene expression profiles of Lgr5+ progenitors and Lgr5- SCs. We analyzed the genes that were enriched and differentially expressed in Lgr5+ progenitors and Lgr5- SCs, and we found 8 cell cycle genes, 9 transcription factors, and 24 cell signaling pathway genes that were uniquely expressed in one population but not the other. Last, we made a protein–protein interaction network to further analyze the role of these differentially expressed genes. In conclusion, we present a set of genes that might regulate the proliferation and HC regeneration ability of Lgr5+ progenitors, and these might serve as potential new therapeutic targets for HC regeneration.
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Affiliation(s)
- Cheng Cheng
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China.,Research Institute of OtolaryngologyNanjing, China.,Co-innovation Center of Neuroregeneration, Nantong UniversityNantong, China
| | - Luo Guo
- Department of Otorhinolaryngology, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan UniversityShanghai, China.,Key Laboratory of Hearing Medicine of National Health and Family Planning CommissionShanghai, China
| | - Ling Lu
- Department of Otolaryngology-Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical SchoolNanjing, China.,Department of Otolaryngology-Head and Neck Surgery, Drum Tower Clinical Medical College of Nanjing Medical UniversityNanjing, China
| | - Xiaochen Xu
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - ShaSha Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - Junyan Gao
- Health Management and Policy, College of Public Health, Saint Louis University, St. LouisMO, USA
| | - Muhammad Waqas
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China.,Department of Biotechnology, Federal Urdu University of Arts, Science and TechnologyGulshan-e-Iqbal, Pakistan
| | - Chengwen Zhu
- Department of Otolaryngology-Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical SchoolNanjing, China
| | - Yan Chen
- Department of Otorhinolaryngology, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan UniversityShanghai, China.,Key Laboratory of Hearing Medicine of National Health and Family Planning CommissionShanghai, China
| | - Xiaoli Zhang
- Department of Otolaryngology-Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical SchoolNanjing, China
| | - Chuanying Xuan
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - Xia Gao
- Department of Otolaryngology-Head and Neck Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical SchoolNanjing, China
| | - Mingliang Tang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and TechnologyShenzhen, China
| | - Haibo Shi
- Department of Otorhinolaryngology Head and Neck Surgery, The Sixth People's Hospital, Shanghai Jiao Tong UniversityShanghai, China
| | - Huawei Li
- Department of Otorhinolaryngology, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan UniversityShanghai, China.,Key Laboratory of Hearing Medicine of National Health and Family Planning CommissionShanghai, China.,Institutes of Biomedical Sciences, Fudan UniversityShanghai, China.,Shanghai Engineering Research Centre of Cochlear ImplantShanghai, China
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China.,Research Institute of OtolaryngologyNanjing, China.,Co-innovation Center of Neuroregeneration, Nantong UniversityNantong, China
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Lee S, Jeong HS, Cho HH. Atoh1 as a Coordinator of Sensory Hair Cell Development and Regeneration in the Cochlea. Chonnam Med J 2017; 53:37-46. [PMID: 28184337 PMCID: PMC5299128 DOI: 10.4068/cmj.2017.53.1.37] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/22/2016] [Accepted: 09/23/2016] [Indexed: 12/18/2022] Open
Abstract
Cochlear sensory hair cells (HCs) are crucial for hearing as mechanoreceptors of the auditory systems. Clarification of transcriptional regulation for the cochlear sensory HC development is crucial for the improvement of cell replacement therapies for hearing loss. Transcription factor Atoh1 is the key player during HC development and regeneration. In this review, we will focus on Atoh1 and its related signaling pathways (Notch, fibroblast growth factor, and Wnt/β-catenin signaling) involved in the development of cochlear sensory HCs. We will also discuss the potential applicability of these signals for the induction of HC regeneration.
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Affiliation(s)
- Sungsu Lee
- Department of Otolaryngology-Head and Neck Surgery, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Korea.; Research Institute of Medical Sciences, Chonnam National University, Gwangju, Korea
| | - Han-Seong Jeong
- Research Institute of Medical Sciences, Chonnam National University, Gwangju, Korea.; Department of Physiology, Chonnam National University Medical School, Gwangju, Korea
| | - Hyong-Ho Cho
- Department of Otolaryngology-Head and Neck Surgery, Chonnam National University Hospital, Chonnam National University Medical School, Gwangju, Korea.; Research Institute of Medical Sciences, Chonnam National University, Gwangju, Korea
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Franco B, Malgrange B. Concise Review: Regeneration in Mammalian Cochlea Hair Cells: Help from Supporting Cells Transdifferentiation. Stem Cells 2017; 35:551-556. [PMID: 28102558 DOI: 10.1002/stem.2554] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/16/2016] [Accepted: 11/27/2016] [Indexed: 12/28/2022]
Abstract
It is commonly assumed that mammalian cochlear cells do not regenerate. Therefore, if hair cells are lost following an injury, no recovery could occur. However, during the first postnatal week, mice harbor some progenitor cells that retain the ability to give rise to new hair cells. These progenitor cells are in fact supporting cells. Upon hair cells loss, those cells are able to generate new hair cells both by direct transdifferentiation or following cell cycle re-entry and differentiation. However, this property of supporting cells is progressively lost after birth. Here, we review the molecular mechanisms that are involved in mammalian hair cell development and regeneration. Manipulating pathways used during development constitute good candidates for inducing hair cell regeneration after injury. Despite these promising studies, there is still no evidence for a recovery following hair cells loss in adult mammals. Stem Cells 2017;35:551-556.
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Affiliation(s)
- Bénédicte Franco
- Developmental Neurobiology Unit - GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), B-4000, Liège, Belgium
| | - Brigitte Malgrange
- Developmental Neurobiology Unit - GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), B-4000, Liège, Belgium
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48
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Luo WW, Han Z, Ren DD, Wang XW, Chi FL, Yang JM. Notch pathway inhibitor DAPT enhances Atoh1 activity to generate new hair cells in situ in rat cochleae. Neural Regen Res 2017; 12:2092-2099. [PMID: 29323051 PMCID: PMC5784360 DOI: 10.4103/1673-5374.221169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Atoh1 overexpression in cochlear epithelium induces new hair cell formation. Use of adenovirus-mediated Atoh1 overexpression has mainly focused on the rat lesser epithelial ridge and induces ectopic hair cell regeneration. The sensory region of rat cochlea is difficult to transfect, thus new hair cells are rarely produced in situ in rat cochlear explants. After culturing rat cochleae in medium containing 10% fetal bovine serum, adenovirus successfully infected the sensory region as the width of the supporting cell area was significantly increased. Adenovirus encoding Atoh1 infected the sensory region and induced hair cell formation in situ. Combined application of the Notch inhibitor DAPT and Atoh1 increased the Atoh1 expression level and decreased hes1 and hes5 levels, further promoting hair cell generation. Our results demonstrate that DAPT enhances Atoh1 activity to promote hair cell regeneration in rat cochlear sensory epithelium in vitro.
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Affiliation(s)
- Wen-Wei Luo
- Department of Otolaryngology, Eye & ENT Hospital of Fudan University; Research Institute of Otolaryngology, Fudan University, Shanghai, China
| | - Zhao Han
- Department of Otolaryngology, Eye & ENT Hospital of Fudan University; Research Institute of Otolaryngology, Fudan University, Shanghai, China
| | - Dong-Dong Ren
- Department of Otolaryngology, Eye & ENT Hospital of Fudan University; Research Institute of Otolaryngology, Fudan University, Shanghai, China
| | - Xin-Wei Wang
- Department of Otolaryngology, Eye & ENT Hospital of Fudan University; Research Institute of Otolaryngology, Fudan University, Shanghai, China
| | - Fang-Lu Chi
- Department of Otolaryngology, Eye & ENT Hospital of Fudan University; Research Institute of Otolaryngology, Fudan University, Shanghai, China
| | - Juan-Mei Yang
- Department of Otolaryngology, Eye & ENT Hospital of Fudan University; Research Institute of Otolaryngology, Fudan University, Shanghai, China
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Barclay M, Constable R, James NR, Thorne PR, Montgomery JM. Reduced sensory stimulation alters the molecular make-up of glutamatergic hair cell synapses in the developing cochlea. Neuroscience 2016; 325:50-62. [PMID: 27012610 DOI: 10.1016/j.neuroscience.2016.03.043] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 02/26/2016] [Accepted: 03/16/2016] [Indexed: 12/20/2022]
Abstract
Neural activity during early development is known to alter innervation pathways in the central and peripheral nervous systems. We sought to examine how reduced sound-induced sensory activity in the cochlea affected the consolidation of glutamatergic synapses between inner hair cells (IHC) and the primary auditory neurons as these synapses play a primary role in transmitting sound information to the brain. A unilateral conductive hearing loss was induced prior to the onset of sound-mediated stimulation of the sensory hair cells, by rupturing the tympanic membrane and dislocating the auditory ossicles in the left ear of P11 mice. Auditory brainstem responses at P15 and P21 showed a 40-50-dB increase in thresholds for frequencies 8-32kHz in the dislocated ear relative to the control ear. Immunohistochemistry and confocal microscopy were subsequently used to examine the effect of this attenuation of sound stimulation on the expression of RIBEYE, which comprises the presynaptic ribbons, Shank-1, a postsynaptic scaffolding protein, and the GluA2/3 and 4 subunits of postsynaptic AMPA receptors. Our results show that dislocation did not alter the number of pre- or postsynaptic protein puncta. However, dislocation did increase the size of RIBEYE, GluA4, GluA2/3 and Shank-1 puncta, with postsynaptic changes preceding presynaptic changes. Our data suggest that a reduction in sound stimulation during auditory development induces plasticity in the molecular make-up of IHC glutamatergic synapses, but does not affect the number of these synapses. Up-regulation of synaptic proteins with sound attenuation may facilitate a compensatory increase in synaptic transmission due to the reduced sensory stimulation of the IHC.
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Affiliation(s)
- M Barclay
- Department of Physiology and Centre for Brain Research, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - R Constable
- Department of Physiology and Centre for Brain Research, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - N R James
- Department of Physiology and Centre for Brain Research, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - P R Thorne
- Department of Physiology and Centre for Brain Research, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Section of Audiology, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - J M Montgomery
- Department of Physiology and Centre for Brain Research, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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Ebbers L, Satheesh SV, Janz K, Rüttiger L, Blosa M, Hofmann F, Morawski M, Griesemer D, Knipper M, Friauf E, Nothwang HG. L-type Calcium Channel Cav1.2 Is Required for Maintenance of Auditory Brainstem Nuclei. J Biol Chem 2015; 290:23692-710. [PMID: 26242732 DOI: 10.1074/jbc.m115.672675] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Indexed: 12/13/2022] Open
Abstract
Cav1.2 and Cav1.3 are the major L-type voltage-gated Ca(2+) channels in the CNS. Yet, their individual in vivo functions are largely unknown. Both channel subunits are expressed in the auditory brainstem, where Cav1.3 is essential for proper maturation. Here, we investigated the role of Cav1.2 by targeted deletion in the mouse embryonic auditory brainstem. Similar to Cav1.3, loss of Cav1.2 resulted in a significant decrease in the volume and cell number of auditory nuclei. Contrary to the deletion of Cav1.3, the action potentials of lateral superior olive (LSO) neurons were narrower compared with controls, whereas the firing behavior and neurotransmission appeared unchanged. Furthermore, auditory brainstem responses were nearly normal in mice lacking Cav1.2. Perineuronal nets were also unaffected. The medial nucleus of the trapezoid body underwent a rapid cell loss between postnatal days P0 and P4, shortly after circuit formation. Phosphorylated cAMP response element-binding protein (CREB), nuclear NFATc4, and the expression levels of p75NTR, Fas, and FasL did not correlate with cell death. These data demonstrate for the first time that both Cav1.2 and Cav1.3 are necessary for neuronal survival but are differentially required for the biophysical properties of neurons. Thus, they perform common as well as distinct functions in the same tissue.
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Affiliation(s)
- Lena Ebbers
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Somisetty V Satheesh
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Katrin Janz
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Lukas Rüttiger
- the Department of Otolaryngology, Hearing Research Centre Tübingen (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede Aulhorn Strasse 5, 72076 Tübingen, Germany
| | - Maren Blosa
- the Paul Flechsig Institute of Brain Research, Faculty of Medicine, University Leipzig, Liebigstrasse 19, 04103 Leipzig, Germany
| | - Franz Hofmann
- the Institut für Pharmakologie und Toxikologie, Technische Universität, Biedersteiner Strasse 29, D-80802 München, and
| | - Markus Morawski
- the Paul Flechsig Institute of Brain Research, Faculty of Medicine, University Leipzig, Liebigstrasse 19, 04103 Leipzig, Germany
| | - Désirée Griesemer
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Marlies Knipper
- the Department of Otolaryngology, Hearing Research Centre Tübingen (THRC), Molecular Physiology of Hearing, University of Tübingen, Elfriede Aulhorn Strasse 5, 72076 Tübingen, Germany
| | - Eckhard Friauf
- the Animal Physiology Group, Department of Biology, University of Kaiserlautern, P. O. Box 3049, 67663 Kaiserslautern, Germany
| | - Hans Gerd Nothwang
- From the Neurogenetics Group, Center of Excellence Hearing4All, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany, the Research Center for Neurosensory Science, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
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