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Chen Z, Zhou W, Guo X, Ling S, Li W, Wang X, Yao J. Heat Stress Responsive Aux/IAA Protein, OsIAA29 Regulates Grain Filling Through OsARF17 Mediated Auxin Signaling Pathway. RICE (NEW YORK, N.Y.) 2024; 17:16. [PMID: 38374238 PMCID: PMC10876508 DOI: 10.1186/s12284-024-00694-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 02/13/2024] [Indexed: 02/21/2024]
Abstract
High temperature during grain filling considerably reduces yield and quality in rice, but its molecular mechanisms are not fully understood. We investigated the functions of a seed preferentially expressed Aux/IAA gene, OsIAA29, under high temperature-stress in grain filling using CRISPR/Cas9, RNAi, and overexpression. We observed that the osiaa29 had a higher percentage of shrunken and chalkiness seed, as well as lower 1000-grain weight than ZH11 under high temperature. Meanwhile, the expression of OsIAA29 was induced and the IAA content was remarkably reduced in the ZH11 seeds under high temperature. In addition, OsIAA29 may enhance the transcriptional activation activity of OsARF17 through competition with OsIAA21 binding to OsARF17. Finally, chromatin immunoprecipitation quantitative real-time PCR (ChIP-qPCR) results proved that OsARF17 regulated expression of several starch and protein synthesis related genes (like OsPDIL1-1, OsSS1, OsNAC20, OsSBE1, and OsC2H2). Therefore, OsIAA29 regulates seed development in high temperature through competition with OsIAA21 in the binding to OsARF17, mediating auxin signaling pathway in rice. This study provides a theoretical basis and gene resources for auxin signaling and effective molecular design breeding.
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Affiliation(s)
- Zhanghao Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wei Zhou
- College of Life Sciences, Xinyang Normal University, Xinyang, 464000, China
| | - Xianyu Guo
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sheng Ling
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wang Li
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xin Wang
- Key Laboratory of Molecular Biology and Genetic Engineering of Jiangxi Province, School of Life Sciences, Nanchang University, Nanchang, 330031, China.
| | - Jialing Yao
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
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2
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Nguyen JD, Llamas J, Shi T, Crump JG, Groves AK, Segil N. DNA methylation in the mouse cochlea promotes maturation of supporting cells and contributes to the failure of hair cell regeneration. Proc Natl Acad Sci U S A 2023; 120:e2300839120. [PMID: 37549271 PMCID: PMC10438394 DOI: 10.1073/pnas.2300839120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 07/11/2023] [Indexed: 08/09/2023] Open
Abstract
Mammalian hair cells do not functionally regenerate in adulthood but can regenerate at embryonic and neonatal stages in mice by direct transdifferentiation of neighboring supporting cells into new hair cells. Previous work showed loss of transdifferentiation potential of supporting cells is in part due to H3K4me1 enhancer decommissioning of the hair cell gene regulatory network during the first postnatal week. However, inhibiting this decommissioning only partially preserves transdifferentiation potential. Therefore, we explored other repressive epigenetic modifications that may be responsible for this loss of plasticity. We find supporting cells progressively accumulate DNA methylation at promoters of developmentally regulated hair cell genes. Specifically, DNA methylation overlaps with binding sites of Atoh1, a key transcription factor for hair cell fate. We further show that DNA hypermethylation replaces H3K27me3-mediated repression of hair cell genes in mature supporting cells, and is accompanied by progressive loss of chromatin accessibility, suggestive of facultative heterochromatin formation. Another subset of hair cell loci is hypermethylated in supporting cells, but not in hair cells. Ten-eleven translocation (TET) enzyme-mediated demethylation of these hypermethylated sites is necessary for neonatal supporting cells to transdifferentiate into hair cells. We also observe changes in chromatin accessibility of supporting cell subtypes at the single-cell level with increasing age: Gene programs promoting sensory epithelium development loses chromatin accessibility, in favor of gene programs that promote physiological maturation and function of the cochlea. We also find chromatin accessibility is partially recovered in a chronically deafened mouse model, which holds promise for future translational efforts in hearing restoration.
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Affiliation(s)
- 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 the University of Southern California, Los Angeles, CA90033
| | - Juan Llamas
- 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 the University of Southern California, Los Angeles, CA90033
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA90033
| | - Tuo Shi
- 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 the University of Southern California, Los Angeles, CA90033
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA90033
| | - J. Gage Crump
- 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 the University of Southern California, Los Angeles, CA90033
| | - Andrew K. Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Department of Neuroscience, Baylor College of Medicine, Houston, TX77030
| | - 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 the University of Southern California, Los Angeles, CA90033
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA90033
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3
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Xiao Y, Li D. The role of epigenetic modifications in sensory hair cell development, survival, and regulation. Front Cell Neurosci 2023; 17:1210279. [PMID: 37388412 PMCID: PMC10300351 DOI: 10.3389/fncel.2023.1210279] [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: 04/22/2023] [Accepted: 05/23/2023] [Indexed: 07/01/2023] Open
Abstract
The cochlea is the sensory organ in the periphery, and hair cells are its main sensory cells. The development and survival of hair cells are highly controlled processes. When cells face intracellular and environmental stimuli, epigenetic regulation controls the structure and function of the genome in response to different cell fates. During sensory hair cell development, different histone modifications can induce normal numbers of functional hair cells to generate. When individuals are exposed to environmental-related hair cell damage, epigenetic modification also plays a significant role in the regulation of hair cell fate. Since mammalian hair cells cannot regenerate, their loss can cause permanent sensorineural hearing loss. Many breakthroughs have been achieved in recent years in understanding the signaling pathways that determine hair cell regeneration, and it is fascinating to note that epigenetic regulation plays a significant role in hair cell regeneration. In this review, we discuss the role of epigenetics in inner ear cell development, survival and regeneration and the significant impact on hearing protection.
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4
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Zheng Z, Nan B, Liu C, Tang D, Li W, Zhao L, Nie G, He Y. Inhibition of histone methyltransferase PRMT5 attenuates cisplatin-induced hearing loss through the PI3K/Akt-mediated mitochondrial apoptotic pathway. J Pharm Anal 2023; 13:590-602. [PMID: 37440906 PMCID: PMC10334280 DOI: 10.1016/j.jpha.2023.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 07/15/2023] Open
Abstract
This study aimed to evaluate the therapeutic potential of inhibiting protein arginine methyltransferase 5 (PRMT5) in cisplatin-induced hearing loss. The effects of PRMT5 inhibition on cisplatin-induced auditory injury were determined using immunohistochemistry, apoptosis assays, and auditory brainstem response. The mechanism of PRMT5 inhibition on hair cell survival was assessed using RNA-seq and Cleavage Under Targets and Tagment-quantitative polymerase chain reaction (CUT&Tag-qPCR) analyses in the HEI-OC1 cell line. Pharmacological inhibition of PRMT5 significantly alleviated cisplatin-induced damage to hair cells and spiral ganglion neurons in the cochlea and decreased apoptosis by protecting mitochondrial function and preventing the accumulation of reactive oxygen species. CUT&Tag-qPCR analysis demonstrated that inhibition of PRMT5 in HEI-OC1 cells reduced the accumulation of H4R3me2s/H3R8me2s marks at the promoter region of the Pik3ca gene, thus activating the expression of Pik3ca. These findings suggest that PRMT5 inhibitors have strong potential as agents against cisplatin-induced ototoxicity and can lay the foundation for further research on treatment strategies of hearing loss.
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Affiliation(s)
- Zhiwei Zheng
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine (Fudan University), Fudan University, Shanghai, 200031, China
| | - Benyu Nan
- Department of Otorhinolaryngology-Head and Neck Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Chang Liu
- Department of Otolaryngology-Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China
| | - Dongmei Tang
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine (Fudan University), Fudan University, Shanghai, 200031, China
| | - Wen Li
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine (Fudan University), Fudan University, Shanghai, 200031, China
| | - Liping Zhao
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine (Fudan University), Fudan University, Shanghai, 200031, China
| | - Guohui Nie
- Department of Otolaryngology, Shenzhen Institute of Translational Medicine, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, 518035, Guangdong, China
| | - Yingzi He
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, NHC Key Laboratory of Hearing Medicine (Fudan University), Fudan University, Shanghai, 200031, China
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5
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Balendran V, Ritter KE, Martin DM. Epigenetic mechanisms of inner ear development. Hear Res 2022; 426:108440. [PMID: 35063312 PMCID: PMC9276839 DOI: 10.1016/j.heares.2022.108440] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/21/2021] [Accepted: 01/11/2022] [Indexed: 12/16/2022]
Abstract
Epigenetic factors are critically important for embryonic and postnatal development. Over the past decade, substantial technological advancements have occurred that now permit the study of epigenetic mechanisms that govern all aspects of inner ear development, from otocyst patterning to maturation and maintenance of hair cell stereocilia. In this review, we highlight how three major classes of epigenetic regulation (DNA methylation, histone modification, and chromatin remodeling) are essential for the development of the inner ear. We highlight open avenues for research and discuss how new tools enable the employment of epigenetic factors in regenerative and therapeutic approaches for hearing and balance disorders.
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Affiliation(s)
- Vinodh Balendran
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI, United States
| | - K Elaine Ritter
- Department of Pediatrics, Medical Center Drive, University of Michigan Medical School, 8220C MSRB III, 1150 W, Ann Arbor, MI 48109-5652, United States
| | - Donna M Martin
- Neuroscience Graduate Program, University of Michigan Medical School, Ann Arbor, MI, United States; Department of Pediatrics, Medical Center Drive, University of Michigan Medical School, 8220C MSRB III, 1150 W, Ann Arbor, MI 48109-5652, United States; Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, United States.
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6
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Cui C, Wang D, Huang B, Wang F, Chen Y, Lv J, Zhang L, Han L, Liu D, Chen ZY, Li GL, Li H, Shu Y. Precise detection of CRISPR-Cas9 editing in hair cells in the treatment of autosomal dominant hearing loss. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 29:400-412. [PMID: 36035752 PMCID: PMC9386031 DOI: 10.1016/j.omtn.2022.07.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/15/2022] [Indexed: 04/08/2023]
Abstract
Gene therapy would benefit from the effective editing of targeted cells with CRISPR-Cas9 tools. However, it is difficult to precisely assess the editing performance in vivo because the tissues contain many non-targeted cells, which is one of the major barriers to clinical translation. Here, in the Atoh1-GFP;Kcnq4 +/G229D mice, recapitulating a novel mutation we identified in a hereditary hearing loss pedigree, the high-efficiency editing of CRISPR-Cas9 in hair cells (34.10% on average) was precisely detected by sorting out labeled cells compared with only 1.45% efficiency in the whole cochlear tissue. After injection of the developed AAV_SaCas9-KKH_sgRNA agents, the Kcnq4 +/G229D mice showed significantly lower auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) thresholds, shorter ABR wave I latencies, higher ABR wave I amplitudes, increased number of surviving outer hair cells (OHCs), and more hyperpolarized resting membrane potentials of OHCs. These findings provide an innovative approach to accurately assess the underestimated editing efficiency of CRISPR-Cas9 in vivo and offer a promising strategy for the treatment of KCNQ4-related deafness.
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Affiliation(s)
- Chong Cui
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
| | - Daqi Wang
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
| | - Bowei Huang
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
| | - Fang Wang
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
| | - Yuxin Chen
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
| | - Jun Lv
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
| | - Luping Zhang
- Department of Otolaryngology-Head and Neck Surgery, Affiliated Hospital, Nantong University, Nantong 226006, China
| | - Lei Han
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
| | - Dong Liu
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226019, China
| | - Zheng-Yi Chen
- Department of Otolaryngology-Head and Neck Surgery, Graduate Program in Speech and Hearing Bioscience and Technology and Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles St., Boston, MA 02114, USA
| | - Geng-Lin Li
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai 200031, China
- NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai 200031, China
| | - Huawei Li
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
| | - Yilai Shu
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, 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
- Corresponding author Yilai Shu, ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai 200031, China.
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7
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Abstract
Cochlear hair cells (HCs) in the inner ear are responsible for sound detection. For HC fate specification, the master transcription factor Atoh1 is both necessary and sufficient. Atoh1 expression is dynamic and tightly regulated during development, but the cis-regulatory elements mediating this regulation remain unresolved. Unexpectedly, we found that deleting the only recognized Atoh1 enhancer, defined here as Eh1, failed to impair HC development. By using the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq), we discovered two additional Atoh1 enhancers: Eh2 and Eh3. Notably, Eh2 deletion was sufficient for impairing HC development, and concurrent deletion of Eh1 and Eh2 or all three enhancers resulted in nearly complete absence of HCs. Lastly, we showed that Atoh1 binds to all three enhancers, consistent with its autoregulatory function. Our findings reveal that the cooperative action of three distinct enhancers underpins effective Atoh1 regulation during HC development, indicating potential therapeutic approaches for HC regeneration.
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Ma X, Zhang S, Qin S, Guo J, Yuan J, Qiang R, Zhou S, Cao W, Yang J, Ma F, Chai R. Transcriptomic and epigenomic analyses explore the potential role of H3K4me3 in neomycin-induced cochlear Lgr5+ progenitor cell regeneration of hair cells. Hum Cell 2022; 35:1030-1044. [DOI: 10.1007/s13577-022-00727-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 05/17/2022] [Indexed: 12/14/2022]
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9
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Avraham KB, Khalaily L, Noy Y, Kamal L, Koffler-Brill T, Taiber S. The noncoding genome and hearing loss. Hum Genet 2022; 141:323-333. [PMID: 34491412 DOI: 10.1007/s00439-021-02359-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 08/29/2021] [Indexed: 12/16/2022]
Abstract
The age of sequencing has provided unprecedented insights into the human genome. The coding region of the genome comprises nearly 20,000 genes, of which approximately 4000 are associated with human disease. Beyond the protein-coding genome, which accounts for only 3% of the genome, lies a vast pool of regulatory elements in the form of promoters, enhancers, RNA species, and other intricate elements. These features undoubtably influence human health and disease, and as a result, a great deal of effort is currently being invested in deciphering their identity and mechanism. While a paucity of material has caused a lag in identifying these elements in the inner ear, the emergence of technologies for dealing with a minimal number of cells now has the field working overtime to catch up. Studies on microRNAs (miRNAs), long non-coding RNAs (lncRNAs), methylation, histone modifications, and more are ongoing. A number of microRNAs and other noncoding elements are known to be associated with hearing impairment and there is promise that regulatory elements will serve as future tools and targets of therapeutics and diagnostics. This review covers the current state of the field and considers future directions for the noncoding genome and implications for hearing loss.
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Affiliation(s)
- Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel.
| | - Lama Khalaily
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Yael Noy
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Lara Kamal
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Tal Koffler-Brill
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Shahar Taiber
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 6997801, Tel Aviv, Israel
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Zhang YL, Kang M, Wu JC, Xie MY, Xue RY, Tang Q, Yang H, Li LC. Small activating RNA activation of ATOH1 promotes regeneration of human inner ear hair cells. Bioengineered 2022; 13:6729-6739. [PMID: 35246011 PMCID: PMC8974106 DOI: 10.1080/21655979.2022.2045835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
The loss of inner ear hair cells leads to irreversible acoustic injury in mammals, and regeneration of inner ear hair cells to restore hearing loss is challenging. ATOH1 is a key gene in the development and regeneration of hair cells. Small activating RNAs (saRNAs) can target a gene to specifically upregulate its expression. This study aimed to explore whether small activating RNAs could induce the differentiation of human adipose-derived mesenchymal stem cells into hair cell-like cells with a combination of growth factors in vitro and thus provide a new strategy for hair cell regeneration and the treatment of sensorineural hearing loss. Fifteen small activating RNAs targeting the human ATOH1 gene were designed and screened in 293 T and human adipose-derived mesenchymal stem cells, and 3 of these candidates were found to be capable of effectively and stably activating ATOH1 gene expression. The selected small activating RNAs were then transfected into hair cell progenitor cells, and hair cell markers were examined 10 days after transfection. After transfection of the selected small activating RNAs, the expression of the characteristic markers of inner ear hair cells, POU class 4 homeobox 3 (POU4F3) and myosin VIIA (MYO7A), was detected. Human adipose-derived mesenchymal stem cells have the potential to differentiate into human hair cell progenitor cells. In vitro, small activating RNAs were able to induce the differentiation of hair cell progenitor cells into hair cell-like cells. Therefore, RNA activation technology has the potential to provide a new strategy for the regeneration of hair cells.
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Affiliation(s)
- Yong-Li Zhang
- Department of Otolaryngology, Peking Union Medical College and Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing, China
| | - Moorim Kang
- Ractigen Therapeutics, Nantong, Jiangsu, China
| | | | - Meng-Yao Xie
- Department of Otolaryngology, Peking Union Medical College and Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing, China
| | - Ruo-Yan Xue
- Department of Otolaryngology, Peking Union Medical College and Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing, China
| | - Qi Tang
- Department of Otolaryngology, Peking Union Medical College and Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing, China
| | - Hua Yang
- Department of Otolaryngology, Peking Union Medical College and Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing, China
| | - Long-Cheng Li
- Ractigen Therapeutics, Nantong, Jiangsu, China.,Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong, Jiangsu, China
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Kwan KY, White PM. Understanding the differentiation and epigenetics of cochlear sensory progenitors in pursuit of regeneration. Curr Opin Otolaryngol Head Neck Surg 2021; 29:366-372. [PMID: 34374667 PMCID: PMC8452321 DOI: 10.1097/moo.0000000000000741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE OF REVIEW Sensory hair cells (HCs) of the inner ear are responsible for our ability to hear and balance. Loss of these cells results in hearing loss. Stem cell replacement and in situ regeneration have the potential to replace lost HCs. Newly discovered contributions of transcription factor regulatory networks and epigenetic mechanisms in regulating HC differentiation and regeneration are placed into context of the literature. RECENT FINDINGS A wealth of new data has helped to define cochlear sensory progenitors in their developmental trajectories. This includes transcription factor networks, epigenetic manipulations, and cochlear HC subtype specification. SUMMARY Understanding how sensory progenitors differ and how HC subtypes arise will substantially inform efforts in hearing restoration.
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Affiliation(s)
- Kelvin Y. Kwan
- Department of Cell Biology & Neuroscience, Rutgers University, Piscataway, New Jersey
| | - Patricia M. White
- Department of Neuroscience, Ernest J. Del Monte Institute of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
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12
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Hu Z, Singh A, Bojrab D, Sim N. Insights into the molecular mechanisms regulating mammalian hair cell regeneration. Curr Opin Otolaryngol Head Neck Surg 2021; 29:400-406. [PMID: 34374666 DOI: 10.1097/moo.0000000000000752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE OF REVIEW To give an overview of recent advances in mammalian auditory hair cell regeneration. RECENT FINDINGS Supporting cells act as progenitors to regenerate hair cells in the prehearing mammalian cochlea but not in the mature cochlea. To overcome this developmental obstacle, manipulation of multiple genes and intracellular pathways has been investigated, which has obtained promising data. This review focuses on recent advances in auditory hair cell regeneration, including synergic gene regulation associated with Atoh1 and Notch signaling, epigenetics, and functional recovery of regenerated hair cells. Co-manipulation of genes critical for hair cell development and cell cycle re-entry, including Atoh1, Isl1, Pou4f3, Gata3, Gfi1, P27kip1, RB, Myc, and Notch-signaling genes, has generated hair cell-like cells in the adult cochlea both in vitro and in vivo. The epigenetic mechanism has been studied in hair cell development and regeneration. Regeneration of hair cell function has a very limited progress, which lacks in-vitro and in-vivo electrophysiology data. SUMMARY Regeneration of adult auditory hair cells remains a major challenge. Manipulation of multiple genes and pathways together with epigenetic regulation might potentially regenerate functional hair cells in the adult mammalian cochlea.
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Affiliation(s)
- Zhengqing Hu
- John D. Dingell VA Medical Center
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit
| | - Aditi Singh
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit
| | - Dennis Bojrab
- Michigan Ear Institute, Farmington Hills, Michigan, USA
| | - Nathan Sim
- Department of Otolaryngology-Head and Neck Surgery, Wayne State University School of Medicine, Detroit
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13
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Beaulieu MO, Raible DW. Losing the license to regenerate hair cells. Dev Cell 2021; 56:2402-2404. [PMID: 34520763 DOI: 10.1016/j.devcel.2021.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Regenerative repair decreases in many organs as tissue matures. In this issue of Developmental Cell, Tao et al. (2021) identify epigenetic mechanisms that coincide with temporal loss of regenerative potential in the mammalian inner ear.
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Affiliation(s)
- Marielle O Beaulieu
- Molecular and Cellular Graduate Program, Departments of Otolaryngology-HNS and Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - David W Raible
- Molecular and Cellular Graduate Program, Departments of Otolaryngology-HNS and Biological Structure, University of Washington, Seattle, WA 98195, USA.
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14
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Enhancer decommissioning imposes an epigenetic barrier to sensory hair cell regeneration. Dev Cell 2021; 56:2471-2485.e5. [PMID: 34331868 DOI: 10.1016/j.devcel.2021.07.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/24/2021] [Accepted: 07/08/2021] [Indexed: 01/02/2023]
Abstract
Adult mammalian tissues such as heart, brain, retina, and the sensory structures of the inner ear do not effectively regenerate, although a latent capacity for regeneration exists at embryonic and perinatal times. We explored the epigenetic basis for this latent regenerative potential in the mouse inner ear and its rapid loss during maturation. In perinatal supporting cells, whose fate is maintained by Notch-mediated lateral inhibition, the hair cell enhancer network is epigenetically primed (H3K4me1) but silenced (active H3K27 de-acetylation and trimethylation). Blocking Notch signaling during the perinatal period of plasticity rapidly eliminates epigenetic silencing and allows supporting cells to transdifferentiate into hair cells. Importantly, H3K4me1 priming of the hair cell enhancers in supporting cells is removed during the first post-natal week, coinciding with the loss of transdifferentiation potential. We hypothesize that enhancer decommissioning during cochlear maturation contributes to the failure of hair cell regeneration in the mature organ of Corti.
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15
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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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16
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Mittal R, Bencie N, Liu G, Eshraghi N, Nisenbaum E, Blanton SH, Yan D, Mittal J, Dinh CT, Young JI, Gong F, Liu XZ. Recent advancements in understanding the role of epigenetics in the auditory system. Gene 2020; 761:144996. [PMID: 32738421 DOI: 10.1016/j.gene.2020.144996] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/21/2020] [Indexed: 11/19/2022]
Abstract
Sensorineural deafness in mammals is most commonly caused by damage to inner ear sensory epithelia, or hair cells, and can be attributed to genetic and environmental causes. After undergoing trauma, many non-mammalian organisms, including reptiles, birds, and zebrafish, are capable of regenerating damaged hair cells. Mammals, however, are not capable of regenerating damaged inner ear sensory epithelia, so that hair cell damage is permanent and can lead to hearing loss. The field of epigenetics, which is the study of various phenotypic changes caused by modification of genetic expression rather than alteration of DNA sequence, has seen numerous developments in uncovering biological mechanisms of gene expression and creating various medical treatments. However, there is a lack of information on the precise contribution of epigenetic modifications in the auditory system, specifically regarding their correlation with development of inner ear (cochlea) and consequent hearing impairment. Current studies have suggested that epigenetic modifications influence differentiation, development, and protection of auditory hair cells in cochlea, and can lead to hair cell degeneration. The objective of this article is to review the existing literature and discuss the advancements made in understanding epigenetic modifications of inner ear sensory epithelial cells. The analysis of the emerging epigenetic mechanisms related to inner ear sensory epithelial cells development, differentiation, protection, and regeneration will pave the way to develop novel therapeutic strategies for hearing loss.
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Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Nicole Bencie
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - George Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Nicolas Eshraghi
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Eric Nisenbaum
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Susan H Blanton
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jeenu Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Christine T Dinh
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Juan I Young
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Feng Gong
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genetics, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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17
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Recent advancements in understanding the role of epigenetics in the auditory system. Gene 2020. [DOI: 10.1016/j.gene.2020.144996
expr 848609818 + 898508594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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18
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White PM. Perspectives on Human Hearing Loss, Cochlear Regeneration, and the Potential for Hearing Restoration Therapies. Brain Sci 2020; 10:brainsci10100756. [PMID: 33092183 PMCID: PMC7589617 DOI: 10.3390/brainsci10100756] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/13/2020] [Accepted: 10/16/2020] [Indexed: 12/23/2022] Open
Abstract
Most adults who acquire hearing loss find it to be a disability that is poorly corrected by current prosthetics. This gap drives current research in cochlear mechanosensory hair cell regeneration and in hearing restoration. Birds and fish can spontaneously regenerate lost hair cells through a process that has become better defined in the last few years. Findings from these studies have informed new research on hair cell regeneration in the mammalian cochlea. Hair cell regeneration is one part of the greater problem of hearing restoration, as hearing loss can stem from a myriad of causes. This review discusses these issues and recent findings, and places them in the greater social context of need and community.
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Affiliation(s)
- Patricia M White
- Department of Neuroscience, Ernest J. Del Monte Institute for Neuroscience, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642, USA
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19
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Kannan-Sundhari A, Abad C, Maloof ME, Ayad NG, Young JI, Liu XZ, Walz K. Bromodomain Protein BRD4 Is Essential for Hair Cell Function and Survival. Front Cell Dev Biol 2020; 8:576654. [PMID: 33015071 PMCID: PMC7509448 DOI: 10.3389/fcell.2020.576654] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/18/2020] [Indexed: 12/13/2022] Open
Abstract
Hair cells (HCs) play crucial roles in perceiving sound, acceleration, and fluid motion. The tonotopic architecture of the sensory epithelium recognizes mechanical stimuli and convert them into electrical signals. The expression and regulation of the genes in the inner ear is very important to keep the sensory organ functional. Our study is the first to investigate the role of the epigenetic reader Brd4 in the mouse inner ear. We demonstrate that HC specific deletion of Brd4 in vivo in the mouse inner ear is sufficient to cause profound hearing loss (HL), degeneration of stereocilia, nerve fibers and HC loss postnatally in mouse; suggesting an important role in hearing function and maintenance.
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Affiliation(s)
- Abhiraami Kannan-Sundhari
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, FL, United States.,The Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, FL, United States
| | - Clemer Abad
- John P. Hussman Institute for Human Genomics, University of Miami, Miami, FL, United States
| | - Marie E Maloof
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Nagi G Ayad
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Juan I Young
- The Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, FL, United States.,John P. Hussman Institute for Human Genomics, University of Miami, Miami, FL, United States
| | - Xue Zhong Liu
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, FL, United States.,The Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, FL, United States.,John P. Hussman Institute for Human Genomics, University of Miami, Miami, FL, United States
| | - Katherina Walz
- The Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami, Miami, FL, United States.,John P. Hussman Institute for Human Genomics, University of Miami, Miami, FL, United States
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20
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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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21
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Hu CJ, Lu YC, Tsai YH, Cheng HY, Takeda H, Huang CY, Xiao R, Hsu CJ, Tsai JW, Vandenberghe LH, Wu CC, Cheng YF. Efficient in Utero Gene Transfer to the Mammalian Inner Ears by the Synthetic Adeno-Associated Viral Vector Anc80L65. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 18:493-500. [PMID: 32775487 PMCID: PMC7390729 DOI: 10.1016/j.omtm.2020.06.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/19/2020] [Indexed: 12/21/2022]
Abstract
Sensorineural hearing loss is one of the most common sensory disorders worldwide. Recent advances in vector design have paved the way for investigations into the use of adeno-associated vectors (AAVs) for hearing disorder gene therapy. Numerous AAV serotypes have been discovered to be applicable to inner ears, constituting a key advance for gene therapy for sensorineural hearing loss, where transduction efficiency of AAV in inner ear cells is critical for success. One such viral vector, AAV2/Anc80L65, has been shown to yield high expression in the inner ears of mice treated as neonates or adults. Here, to evaluate the feasibility of prenatal gene therapy for deafness, we assessed the transduction efficiency of AAV2/Anc80L65-eGFP (enhanced green fluorescent protein) after microinjection into otocysts in utero. This embryonic delivery method achieved high transduction efficiency in both inner and outer hair cells of the cochlea. Additionally, the transduction efficiency was high in the hair cells of the vestibules and semicircular canals and in spiral ganglion neurons. Our results support the potential of Anc80L65 as a gene therapy vehicle for prenatal inner ear disorders.
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Affiliation(s)
- Chin-Ju Hu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Ying-Chang Lu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.,Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Hsiu Tsai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Haw-Yuan Cheng
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Hiroki Takeda
- Department of Otolaryngology-Head and Neck Surgery, Kumamoto University Graduate School of Medicine, Kumamoto City, Japan
| | - Chun-Ying Huang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ru Xiao
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye and Ear, Boston, MA, USA.,Ocular Genomics Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Chuan-Jen Hsu
- Department of Otolaryngology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan
| | - Jin-Wu Tsai
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Luk H Vandenberghe
- Grousbeck Gene Therapy Center, Schepens Eye Research Institute and Massachusetts Eye and Ear, Boston, MA, USA.,Ocular Genomics Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.,Harvard Stem Cell Institute, Cambridge, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Chen-Chi Wu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.,Department of Medical Research, National Taiwan University Hospital Biomedical Park Hospital, Hsinchu, Taiwan
| | - Yen-Fu Cheng
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan.,Department of Otolaryngology-Head and Neck Surgery, Taipei Veterans General Hospital, Taipei, Taiwan
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22
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Forge A, Jagger DJ, Gale JE. Restoring the balance: regeneration of hair cells in the vestibular system of the inner ear. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2019.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Gao Y, Yan Y, Tripathi S, Pentinmikko N, Amaral A, Päivinen P, Domènech-Moreno E, Andersson S, Wong IPL, Clevers H, Katajisto P, Mäkelä TP. LKB1 Represses ATOH1 via PDK4 and Energy Metabolism and Regulates Intestinal Stem Cell Fate. Gastroenterology 2020; 158:1389-1401.e10. [PMID: 31930988 DOI: 10.1053/j.gastro.2019.12.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 12/02/2019] [Accepted: 12/30/2019] [Indexed: 01/16/2023]
Abstract
BACKGROUND & AIMS In addition to the Notch and Wnt signaling pathways, energy metabolism also regulates intestinal stem cell (ISC) function. Tumor suppressor and kinase STK11 (also called LKB1) regulates stem cells and cell metabolism. We investigated whether loss of LKB1 alters ISC homeostasis in mice. METHODS We deleted LKB1 from ISCs in mice using Lgr5-regulated CRE-ERT2 (Lkb1Lgr5-KO mice) and the traced lineages by using a CRE-dependent TdTomato reporter. Intestinal tissues were collected and analyzed by immunohistochemical and immunofluorescence analyses. We purified ISCs and intestinal progenitors using flow cytometry and performed RNA-sequencing analysis. We measured organoid-forming capacity and ISC percentages using intestinal tissues from Lkb1Lgr5-KO mice. We analyzed human Ls174t cells with knockdown of LKB1 or other proteins by immunoblotting, real-time quantitative polymerase chain reaction, and the Seahorse live-cell metabolic assay. RESULTS Some intestinal crypts from Lkb1Lgr5-KO mice lost ISCs compared with crypts from control mice. However, most crypts from Lkb1Lgr5-KO mice contained functional ISCs that expressed increased levels of Atoh1 messenger RNA (mRNA), acquired a gene expression signature associated with secretory cells, and generated more cells in the secretory lineage compared with control mice. Knockdown of LKB1 in Ls174t cells induced expression of Atoh1 mRNA and a phenotype of increased mucin production; knockdown of ATOH1 prevented induction of this phenotype. The increased expression of Atoh1 mRNA after LKB1 loss from ISCs or Ls174t cells did not involve Notch or Wnt signaling. Knockdown of pyruvate dehydrogenase kinase 4 (PDK4) or inhibition with dichloroacetate reduced the up-regulation of Atoh1 mRNA after LKB1 knockdown in Ls174t cells. Cells with LKB1 knockdown had a reduced rate of oxygen consumption, which was partially restored by PDK4 inhibition with dichloroacetate. ISCs with knockout of LKB1 increased the expression of PDK4 and had an altered metabolic profile. CONCLUSIONS LKB1 represses transcription of ATOH1, via PDK4, in ISCs, restricting their differentiation into secretory lineages. These findings provide a connection between metabolism and the fate determination of ISCs.
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Affiliation(s)
- Yajing Gao
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland
| | - Yan Yan
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland.
| | - Sushil Tripathi
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland
| | - Nalle Pentinmikko
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland; Institute of Biotechnology, HiLIFE, University of Helsinki, Finland
| | - Ana Amaral
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Pekka Päivinen
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland
| | - Eva Domènech-Moreno
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland
| | - Simon Andersson
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland; Institute of Biotechnology, HiLIFE, University of Helsinki, Finland
| | - Iris P L Wong
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland
| | - Hans Clevers
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and Cancer Genomics Netherlands, University Medical Center Utrecht and Princess Máxima Centre, Utrecht, The Netherlands
| | - Pekka Katajisto
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland; Institute of Biotechnology, HiLIFE, University of Helsinki, Finland; Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Tomi P Mäkelä
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, Finland; HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland.
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24
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Liu LM, Zhao LP, Wu LJ, Guo L, Li WY, Chen Y. Characterization of the transcriptomes of Atoh1-induced hair cells in the mouse cochlea. AMERICAN JOURNAL OF STEM CELLS 2020; 9:1-15. [PMID: 32211215 PMCID: PMC7076321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 02/11/2020] [Indexed: 06/10/2023]
Abstract
Postnatal mammalian cochlear hair cells (HCs) can be regenerated by direct transdifferentiation or by mitotic regeneration from supporting cells through many pathways, including Atoh1, Wnt, Hedgehog and Notch signaling. However, most new HCs are immature HCs. In this study we used RNA-Seq analysis to compare the differences between the transcriptomes of Atoh1 overexpression-induced new HCs and the native HCs, and to define the factors that might help to promote the maturation of new HCs. As expected, we found Atoh1-induced new HCs had obvious HC characteristics as demonstrated by the expression of HC markers such as Pou4f3 and Myosin VIIA (Myo7a). However, Atoh1-induced new HCs had significantly lower expression of genes that are related to HC function such as Slc26a5 (Prestin), Slc17a8 and Otof. We found that genes related to HC cell differentiation and maturation (Kcnma1, Myo6, Myo7a, Grxcr1, Gfi1, Wnt5a, Fgfr1, Gfi1, Fgf8 etc.) had significantly lower expression levels in new HCs compared to native HCs. In conclusion, we found a set of genes that might regulate the differentiation and maturation of new HCs, and these genes might serve as potential new therapeutic targets for functional HC regeneration and hearing recovery.
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Affiliation(s)
- Li-Man Liu
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Fudan UniversityShanghai 200031, China
| | - Li-Ping Zhao
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Fudan UniversityShanghai 200031, China
- NHC Key Laboratory of Hearing Medicine (Fudan University)Shanghai 200031, China
| | - Ling-Jie Wu
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Fudan UniversityShanghai 200031, China
- NHC Key Laboratory of Hearing Medicine (Fudan University)Shanghai 200031, China
| | - Luo Guo
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Fudan UniversityShanghai 200031, China
- NHC Key Laboratory of Hearing Medicine (Fudan University)Shanghai 200031, China
| | - Wen-Yan Li
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Fudan UniversityShanghai 200031, China
- NHC Key Laboratory of Hearing Medicine (Fudan University)Shanghai 200031, China
| | - Yan Chen
- ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Fudan UniversityShanghai 200031, China
- NHC Key Laboratory of Hearing Medicine (Fudan University)Shanghai 200031, China
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25
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Hoa M, Olszewski R, Li X, Taukulis I, Gu S, DeTorres A, Lopez IA, Linthicum FH, Ishiyama A, Martin D, Morell RJ, Kelley MW. Characterizing Adult Cochlear Supporting Cell Transcriptional Diversity Using Single-Cell RNA-Seq: Validation in the Adult Mouse and Translational Implications for the Adult Human Cochlea. Front Mol Neurosci 2020; 13:13. [PMID: 32116546 PMCID: PMC7012811 DOI: 10.3389/fnmol.2020.00013] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 01/16/2020] [Indexed: 12/11/2022] Open
Abstract
Hearing loss is a problem that impacts a significant proportion of the adult population. Cochlear hair cell (HC) loss due to loud noise, chemotherapy and aging is the major underlying cause. A significant proportion of these individuals are dissatisfied with available treatment options which include hearing aids and cochlear implants. An alternative approach to restore hearing would be to regenerate HCs. Such therapy would require a recapitulation of the complex architecture of the organ of Corti, necessitating regeneration of both mature HCs and supporting cells (SCs). Transcriptional profiles of the mature cell types in the cochlea are necessary to can provide a metric for eventual regeneration therapies. To assist in this effort, we sought to provide the first single-cell characterization of the adult cochlear SC transcriptome. We performed single-cell RNA-Seq on FACS-purified adult cochlear SCs from the LfngEGFP adult mouse, in which SCs express GFP. We demonstrate that adult cochlear SCs are transcriptionally distinct from their perinatal counterparts. We establish cell-type-specific adult cochlear SC transcriptome profiles, and we validate these expression profiles through a combination of both fluorescent immunohistochemistry and in situ hybridization co-localization and quantitative polymerase chain reaction (qPCR) of adult cochlear SCs. Furthermore, we demonstrate the relevance of these profiles to the adult human cochlea through immunofluorescent human temporal bone histopathology. Finally, we demonstrate cell cycle regulator expression in adult SCs and perform pathway analyses to identify potential mechanisms for facilitating mitotic regeneration (cell proliferation, differentiation, and eventually regeneration) in the adult mammalian cochlea. Our findings demonstrate the importance of characterizing mature as opposed to perinatal SCs.
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Affiliation(s)
- Michael Hoa
- Auditory Restoration and Development Program, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Rafal Olszewski
- Auditory Restoration and Development Program, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Xiaoyi Li
- Auditory Restoration and Development Program, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Ian Taukulis
- Auditory Restoration and Development Program, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Shoujun Gu
- Auditory Restoration and Development Program, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Alvin DeTorres
- Auditory Restoration and Development Program, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Ivan A Lopez
- National Temporal Bone Laboratory at UCLA, UCLA School of Medicine, Los Angeles, CA, United States.,Cellular and Molecular Biology of the Inner Ear Laboratory, UCLA School of Medicine, Los Angeles, CA, United States
| | - Fred H Linthicum
- National Temporal Bone Laboratory at UCLA, UCLA School of Medicine, Los Angeles, CA, United States.,Cellular and Molecular Biology of the Inner Ear Laboratory, UCLA School of Medicine, Los Angeles, CA, United States
| | - Akira Ishiyama
- National Temporal Bone Laboratory at UCLA, UCLA School of Medicine, Los Angeles, CA, United States.,Cellular and Molecular Biology of the Inner Ear Laboratory, UCLA School of Medicine, Los Angeles, CA, United States
| | - Daniel Martin
- Biomedical Research Informatics Office, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD, United States
| | - Robert J Morell
- Genomics and Computational Biology Core, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
| | - Matthew W Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, NIH, Bethesda, MD, United States
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26
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He Y, Li W, Zheng Z, Zhao L, Li W, Wang Y, Li H. Inhibition of Protein arginine methyltransferase 6 reduces reactive oxygen species production and attenuates aminoglycoside- and cisplatin-induced hair cell death. Theranostics 2020; 10:133-150. [PMID: 31903111 PMCID: PMC6929624 DOI: 10.7150/thno.37362] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/12/2019] [Indexed: 02/06/2023] Open
Abstract
Hair cells in the inner ear have been shown to be susceptible to ototoxicity from some beneficial pharmaceutical drugs, such as aminoglycosides and cisplatin. Thus, there is great interest in discovering new targets or compounds that protect hair cells from these ototoxic drugs. Epigenetic regulation is closely related to inner ear development; however, little is known about epigenetic regulation in the process of ototoxic drugs-induced hearing loss. Methods: In this study, we investigated the role of protein arginine methyltransferase 6 (PRMT6) in aminoglycoside- and cisplatin-induced hair cell loss by using EPZ020411, a selective small molecule PRMT6 inhibitor, in vitro in neonatal mouse cochlear explants and in vivo in C57BL/6 mice. We also took advantage of the HEI-OC1 cell line to evaluate the anti-apoptosis effects of PRMT6 knockdown on cisplatin-induced ototoxicity. Apoptotic cells were identified using cleaved caspase-3 staining and TUNEL assay. The levels of reactive oxygen species (ROS) were evaluated by DCFH-DA and cellROX green staining. The mitochondrial membrane potential (ΔΨm) were determined by JC-1, TMRM, and rhodamine 123 staining. Results: We found that EPZ020411 significantly alleviated neomycin- and cisplatin-induced cell apoptosis and increased hair cell survival. Moreover, pretreatment with EPZ020411 could attenuate neomycin- and cisplatin-induced hearing loss in vivo. Mechanistic studies revealed that inhibition of PRMT6 could reverse the increased expression of caspase-3 and cytochrome c translocation, mitochondrial dysfunction, increased accumulation of ROS, and activation of cell apoptosis after cisplatin injury. Conclusions: Our findings suggested that PRMT6 might serve as a new therapeutic target to prevent hearing loss caused by aminoglycoside- and cisplatin-induced ototoxicity by preventing ROS formation and modulating the mitochondria-related damage and apoptosis.
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27
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Open chromatin dynamics in prosensory cells of the embryonic mouse cochlea. Sci Rep 2019; 9:9060. [PMID: 31227770 PMCID: PMC6588700 DOI: 10.1038/s41598-019-45515-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 06/10/2019] [Indexed: 12/13/2022] Open
Abstract
Hearing loss is often due to the absence or the degeneration of hair cells in the cochlea. Understanding the mechanisms regulating the generation of hair cells may therefore lead to better treatments for hearing disorders. To elucidate the transcriptional control mechanisms specifying the progenitor cells (i.e. prosensory cells) that generate the hair cells and support cells critical for hearing function, we compared chromatin accessibility using ATAC-seq in sorted prosensory cells (Sox2-EGFP+) and surrounding cells (Sox2-EGFP−) from E12, E14.5 and E16 cochlear ducts. In Sox2-EGFP+, we find greater accessibility in and near genes restricted in expression to the prosensory region of the cochlear duct including Sox2, Isl1, Eya1 and Pou4f3. Furthermore, we find significant enrichment for the consensus binding sites of Sox2, Six1 and Gata3—transcription factors required for prosensory development—in the open chromatin regions. Over 2,200 regions displayed differential accessibility with developmental time in Sox2-EGFP+ cells, with most changes in the E12-14.5 window. Open chromatin regions detected in Sox2-EGFP+ cells map to over 48,000 orthologous regions in the human genome that include regions in genes linked to deafness. Our results reveal a dynamic landscape of open chromatin in prosensory cells with potential implications for cochlear development and disease.
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28
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Epigenetics in neuronal regeneration. Semin Cell Dev Biol 2019; 97:63-73. [PMID: 30951894 DOI: 10.1016/j.semcdb.2019.04.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 03/22/2019] [Accepted: 04/01/2019] [Indexed: 12/20/2022]
Abstract
Damage to neuronal tissues in mammals leads to permanent loss of tissue function that can have major health consequences. While mammals have no inherent regenerative capacity to functionally repair neuronal tissue, other species such as amphibians and teleost fish readily replace damaged tissue. The exploration of development and native regeneration can thus inform the process of inducing regeneration in non-regenerative systems, which can be used to develop new therapeutics. Increasing evidence points to an epigenetic component in the regulation of the changes in cellular gene expression necessary for regeneration. In this review, we compare evidence of epigenetic roles in development and regeneration of neuronal tissue. We have focused on three key systems of important clinical significance: the neural retina, the inner ear, and the spinal cord in regenerative and non-regenerative species. While evidence for epigenetic regulation of regeneration is still limited, changes in DNA accessibility, histone acetylation and DNA methylation have all emerged as key elements in this process. To date, most studies have used broadly acting experimental manipulations to establish a role for epigenetics in regeneration, but the advent of more targeted approaches to modify the epigenome will be critical to dissecting the relative contributions of these regulatory factors in this process and the development of methods to stimulate the regeneration in those organisms like ourselves where only limited regeneration occurs in these neural systems.
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29
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Samarajeewa A, Jacques BE, Dabdoub A. Therapeutic Potential of Wnt and Notch Signaling and Epigenetic Regulation in Mammalian Sensory Hair Cell Regeneration. Mol Ther 2019; 27:904-911. [PMID: 30982678 PMCID: PMC6520458 DOI: 10.1016/j.ymthe.2019.03.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 03/25/2019] [Accepted: 03/26/2019] [Indexed: 02/07/2023] Open
Abstract
Hearing loss is one of the most prevalent sensory deficits worldwide and can result from the death of mechanosensory hair cells that transduce auditory signals in the cochlea. The mammalian cochlea lacks the capacity to regenerate these hair cells once damaged, and currently there are no biological therapies for hearing loss. Understanding the signaling pathways responsible for hair cell development can inform regenerative strategies and identify targets for treating hearing loss. The canonical Wnt and Notch pathways are critical for cochlear development; they converge on several key molecules, such as Atoh1, to regulate prosensory specification, proliferation, hair cell differentiation, and cellular organization. Much work has focused on Wnt and Notch modulation in the neonatal mouse cochlea, where they can promote hair cell regeneration. However, this regenerative response is limited in the adult cochlea and this might be attributed to age-dependent epigenetic modifications. Indeed, the epigenetic status at key gene loci undergoes dynamic changes during cochlear development, maturation, and aging. Therefore, strategies to improve regenerative success in the adult cochlea might require the modulation of Wnt, Notch, or other pathways, as well as targeted epigenetic modifications to alter the activity of key genes critical for supporting cell proliferation or transdifferentiation.
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Affiliation(s)
- Anshula Samarajeewa
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | | | - Alain Dabdoub
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON M4N 3M5, Canada; Department of Otolaryngology - Head & Neck Surgery, University of Toronto, Toronto, ON M5G 2C4, Canada.
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30
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Lenz DR, Gunewardene N, Abdul-Aziz DE, Wang Q, Gibson TM, Edge ASB. Applications of Lgr5-Positive Cochlear Progenitors (LCPs) to the Study of Hair Cell Differentiation. Front Cell Dev Biol 2019; 7:14. [PMID: 30873406 PMCID: PMC6401656 DOI: 10.3389/fcell.2019.00014] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 01/31/2019] [Indexed: 01/05/2023] Open
Abstract
The mouse cochlea contains approximately 15,000 hair cells. Its dimensions and location, and the small number of hair cells, make mechanistic, developmental and cellular replacement studies difficult. We recently published a protocol to expand and differentiate murine neonatal cochlear progenitor cells into 3D organoids that recapitulate developmental pathways and can generate large numbers of hair cells with intact stereociliary bundles, molecular markers of the native cells and mechanotransduction channel activity, as indicated by FM1-43 uptake. Here, we elaborate on the method and application of these Lgr5-positive cochlear progenitors, termed LCPs, to the study of inner ear development and differentiation. We demonstrate the use of these cells for testing several drug candidates, gene silencing and overexpression, as well as genomic modification using CRISPR/Cas9. We thus establish LCPs as a valuable in vitro tool for the analysis of progenitor cell manipulation and hair cell differentiation.
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Affiliation(s)
- Danielle R Lenz
- Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, United States
| | - Niliksha Gunewardene
- Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, United States
| | - Dunia E Abdul-Aziz
- Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, United States
| | - Quan Wang
- Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, United States
| | - Tyler M Gibson
- Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, United States
| | - Albert S B Edge
- Department of Otolaryngology, Harvard Medical School, Boston, MA, United States.,Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, MA, United States.,Harvard Stem Cell Institute, Cambridge, MA, United States
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31
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Walters BJ, Cox BC. Approaches for the study of epigenetic modifications in the inner ear and related tissues. Hear Res 2019; 376:69-85. [PMID: 30679030 DOI: 10.1016/j.heares.2019.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 12/12/2018] [Accepted: 01/11/2019] [Indexed: 12/12/2022]
Abstract
DNA methylation and histone modifications such as methylation, acetylation, and phosphorylation, are two types of epigenetic modifications that alter gene expression. These additions to DNA regulatory elements or to the tails of histones can be inherited or can also occur de novo. Since epigenetic modifications can have significant effects on various processes at both the cellular and organismal level, there has been a rapid increase in research on this topic throughout all fields of biology in recent years. However, epigenetic research is relativity new for the inner ear field, likely due to the limited number of cells present and their quiescent nature. Here, we provide an overview of methods used to detect DNA methylation and histone modifications with a focus on those that have been validated for use with limited cell numbers and a discussion of the strengths and limitations for each. We also provide examples for how these methods have been used to investigate the epigenetic landscape in the inner ear and related tissues.
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Affiliation(s)
- Bradley J Walters
- Departments of Neurobiology and Anatomical Sciences, and of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Brandon C Cox
- Departments of Pharmacology and Surgery, Division of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL 62711, USA.
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32
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Atkinson PJ, Kim GS, Cheng AG. Direct cellular reprogramming and inner ear regeneration. Expert Opin Biol Ther 2019; 19:129-139. [PMID: 30584811 DOI: 10.1080/14712598.2019.1564035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
INTRODUCTION Sound is integral to communication and connects us to the world through speech and music. Cochlear hair cells are essential for converting sounds into neural impulses. However, these cells are highly susceptible to damage from an array of factors, resulting in degeneration and ultimately irreversible hearing loss in humans. Since the discovery of hair cell regeneration in birds, there have been tremendous efforts to identify therapies that could promote hair cell regeneration in mammals. AREAS COVERED Here, we will review recent studies describing spontaneous hair cell regeneration and direct cellular reprograming as well as other factors that mediate mammalian hair cell regeneration. EXPERT OPINION Numerous combinatorial approaches have successfully reprogrammed non-sensory supporting cells to form hair cells, albeit with limited efficacy and maturation. Studies on epigenetic regulation and transcriptional network of hair cell progenitors may accelerate discovery of more promising reprogramming regimens.
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Affiliation(s)
- Patrick J Atkinson
- a Department of Otolaryngology-Head and Neck Surgery , Stanford University School of Medicine , Stanford , CA , USA
| | - Grace S Kim
- a Department of Otolaryngology-Head and Neck Surgery , Stanford University School of Medicine , Stanford , CA , USA
| | - Alan G Cheng
- a Department of Otolaryngology-Head and Neck Surgery , Stanford University School of Medicine , Stanford , CA , USA
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33
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Li C, Li Y, Zhou G, Gao Y, Ma S, Chen Y, Song J, Wang X. Whole-genome bisulfite sequencing of goat skins identifies signatures associated with hair cycling. BMC Genomics 2018; 19:638. [PMID: 30153818 PMCID: PMC6114738 DOI: 10.1186/s12864-018-5002-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/08/2018] [Indexed: 01/07/2023] Open
Abstract
Background Hair follicles (HFs), upon development, undergo repetitive cycles of growth (anagen), regression (catagen), and rest (telogen). The transition between the stages is determined by multiple molecular signals, including DNA methylation, which plays important roles in mammalian cellular identity and is essential for the development of HFs. Secondary hair follicles (SHFs) in cashmere goat exhibit classic cyclic hair development, and little has been done on a genome-wide scale to examine potentially methylated genes involved in the hair cyclic transition. Results Genome-wide DNA methylation profiles between skin tissues sampled during the anagen and telogen stages in cashmere goats were investigated using whole-genome bisulfite sequencing (WGBS). The methylation status was observed to be higher in the skin samples with HFs in the telogen than those in the anagen stage. A total of 1311 differentially methylated regions (DMRs) were identified between the two groups, which contained 493 fully annotated DMR-related genes (DMGs) (269 Hyper- DMGs and 224 Hypo-DMGs). Furthermore, a significant over-representation of the functional categories for DMGs related to immune response and intercellular crosstalk during hair cycling was observed. By integrating DNA methylation and mRNA expression data, we revealed that four genes (FMN1, PCOLCE, SPTLC3, and COL5A1) are crucial factors for elucidating epigenetic mechanisms contributing to the telogen-to-anagen transition. Conclusion Our study provided systematic methylome maps pertaining to the hair cycling stages (anagen vs telogen) at a single-base resolution, and revealed stage-specific methylation loci during cashmere growth or quiescence. Furthermore, we identified epigenetically regulated genes that are potentially involved in HF development and growth in cashmere goats, and likely in other mammal species. Electronic supplementary material The online version of this article (10.1186/s12864-018-5002-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chao Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Yan Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Guangxian Zhou
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Ye Gao
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Sen Ma
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Yulin Chen
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China
| | - Jiuzhou Song
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD, 20742, USA.
| | - Xiaolong Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China.
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34
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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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35
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High-resolution transcriptional dissection of in vivo Atoh1-mediated hair cell conversion in mature cochleae identifies Isl1 as a co-reprogramming factor. PLoS Genet 2018; 14:e1007552. [PMID: 30063705 PMCID: PMC6086484 DOI: 10.1371/journal.pgen.1007552] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 08/10/2018] [Accepted: 07/10/2018] [Indexed: 12/24/2022] Open
Abstract
In vivo direct conversion of differentiated cells holds promise for regenerative medicine; however, improving the conversion efficiency and producing functional target cells remain challenging. Ectopic Atoh1 expression in non-sensory supporting cells (SCs) in mouse cochleae induces their partial conversion to hair cells (HCs) at low efficiency. Here, we performed single-cell RNA sequencing of whole mouse sensory epithelia harvested at multiple time points after conditional overexpression of Atoh1. Pseudotemporal ordering revealed that converted HCs (cHCs) are present along a conversion continuum that correlates with both endogenous and exogenous Atoh1 expression. Bulk sequencing of isolated cell populations and single-cell qPCR confirmed 51 transcription factors, including Isl1, are differentially expressed among cHCs, SCs and HCs. In transgenic mice, co-overexpression of Atoh1 and Isl1 enhanced the HC conversion efficiency. Together, our study shows how high-resolution transcriptional profiling of direct cell conversion can identify co-reprogramming factors required for efficient conversion. The ongoing ATOH1 gene therapy clinical trial offers promise for hearing restoration in humans. However, in animal models, Atoh1-mediated sensory regeneration is inefficient and incomplete. Here we performed high-resolution gene expression profiling of single cochlear cells at multiple time points in a mouse model whereby we discovered a continuous regeneration process that leads to the formation of immature sensory cells. We identified 51 key reprogramming transcription factors that may increase the efficiency and completion of the regeneration process and confirmed that Isl1 in transgenic mice promotes Atoh1-mediated sensory regeneration as a co-reprogramming factor. Our studies identify molecular mechanisms and novel co-reprogramming factors for sensory restoration in humans with irreversible hearing loss.
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36
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Shin JO, Lee JJ, Kim M, Chung YW, Min H, Kim JY, Kim HP, Bok J. CTCF Regulates Otic Neurogenesis via Histone Modification in the Neurog1 Locus. Mol Cells 2018; 41:695-702. [PMID: 30008200 PMCID: PMC6078853 DOI: 10.14348/molcells.2018.0230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 06/04/2018] [Indexed: 11/27/2022] Open
Abstract
The inner ear is a complex sensory organ responsible for hearing and balance. Formation of the inner ear is dependent on tight regulation of spatial and temporal expression of genes that direct a series of developmental processes. Recently, epigenetic regulation has emerged as a crucial regulator of the development of various organs. However, what roles higher-order chromatin organization and its regulator molecules play in inner ear development are unclear. CCCTC-binding factor (CTCF) is a highly conserved 11-zinc finger protein that regulates the three-dimensional architecture of chromatin, and is involved in various gene regulation processes. To delineate the role of CTCF in inner ear development, the present study investigated inner ear-specific Ctcf knockout mouse embryos (Pax2-Cre; Ctcffl/fl ). The loss of Ctcf resulted in multiple defects of inner ear development and severely compromised otic neurogenesis, which was partly due to a loss of Neurog1 expression. Furthermore, reduced Neurog1 gene expression by CTCF knockdown was found to be associated with changes in histone modification at the gene's promoter, as well as its upstream enhancer. The results of the present study demonstrate that CTCF plays an essential role in otic neurogenesis by modulating histone modification in the Neurog1 locus.
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Affiliation(s)
- Jeong-Oh Shin
- Department of Anatomy, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Jong-Joo Lee
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul 03722,
Korea
- BK21 PLUS project for Medical Science, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Mikyoung Kim
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Youn Wook Chung
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Hyehyun Min
- Department of Anatomy, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Jae-Yoon Kim
- Department of Anatomy, Yonsei University College of Medicine, Seoul 03722,
Korea
- BK21 PLUS project for Medical Science, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Hyoung-Pyo Kim
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul 03722,
Korea
- BK21 PLUS project for Medical Science, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Jinwoong Bok
- Department of Anatomy, Yonsei University College of Medicine, Seoul 03722,
Korea
- BK21 PLUS project for Medical Science, Yonsei University College of Medicine, Seoul 03722,
Korea
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul 03722,
Korea
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37
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Gálvez H, Tena JJ, Giraldez F, Abelló G. The Repression of Atoh1 by Neurogenin1 during Inner Ear Development. Front Mol Neurosci 2017; 10:321. [PMID: 29104531 PMCID: PMC5655970 DOI: 10.3389/fnmol.2017.00321] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/21/2017] [Indexed: 01/01/2023] Open
Abstract
Atonal homolog 1 (Atoh1) and Neurogenin1 (Neurog1) are basic Helix-Loop-Helix (bHLH) transcription factors crucial for the generation of hair cells (HCs) and neurons in the inner ear. Both genes are induced early in development, but the expression of Atoh1 is counteracted by Neurog1. As a result, HC development is prevented during neurogenesis. This work aimed at understanding the molecular basis of this interaction. Atoh1 regulation depends on a 3'Atoh1-enhancer that is the site for Atoh1 autoregulation. Reporter assays on chick embryos and P19 cells show that Neurog1 hampers the autoactivation of Atoh1, the effect being cell autonomous and independent on Notch activity. Assay for Transposase-Accessible Chromatin with high throughput sequencing (ATAC-Seq) analysis shows that the region B of the 3'Atoh1-enhancer is accessible during development and sufficient for both activation and repression. Neurog1 requires the regions flanking the class A E-box to show its repressor effect, however, it does not require binding to DNA for Atoh1 repression. This depends on the dimerization domains Helix-1 and Helix-2 and the reduction of Atoh1 protein levels. The results point towards the acceleration of Atoh1 mRNA degradation as the potential mechanism for the reduction of Atoh1 levels. Such a mechanism dissociates the prevention of Atoh1 expression in neurosensory progenitors from the unfolding of the neurogenic program.
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Affiliation(s)
- Héctor Gálvez
- DCEXS, Universitat Pompeu Fabra (UPF) - Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
| | - Juan J Tena
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - Fernando Giraldez
- DCEXS, Universitat Pompeu Fabra (UPF) - Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
| | - Gina Abelló
- DCEXS, Universitat Pompeu Fabra (UPF) - Parc de Recerca Biomèdica de Barcelona (PRBB), Barcelona, Spain
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38
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Gálvez H, Abelló G, Giraldez F. Signaling and Transcription Factors during Inner Ear Development: The Generation of Hair Cells and Otic Neurons. Front Cell Dev Biol 2017; 5:21. [PMID: 28393066 PMCID: PMC5364141 DOI: 10.3389/fcell.2017.00021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 03/02/2017] [Indexed: 12/21/2022] Open
Abstract
Integration between cell signals and bHLH transcription factors plays a prominent role during the development of hair cells of the inner ear. Hair cells are the sensory receptors of the inner ear, responsible for the mechano-transduction of sound waves into electrical signals. They derive from multipotent progenitors that reside in the otic placode. Progenitor commitment is the result of cell signaling from the surrounding tissues that result in the restricted expression of SoxB1 transcription factors, Sox2 and Sox3. In turn, they induce the expression of Neurog1 and Atoh1, two bHLH factors that specify neuronal and hair cell fates, respectively. Neuronal and hair cell development, however, do not occur simultaneously. Hair cell development is prevented during neurogenesis and prosensory stages, resulting in the delay of hair cell development with respect to neuron production. Negative interactions between Neurog1 and Atoh1, and of Atoh1 with other bHLH factors driven by Notch signaling, like Hey1 and Hes5, account for this delay. In summary, the regulation of Atoh1 and hair cell development relies on interactions between cell signaling and bHLH transcription factors that dictate cell fate and timing decisions during development. Interestingly, these mechanisms operate as well during hair cell regeneration after damage and during stem cell directed differentiation, making developmental studies instrumental for improving therapies for hearing impairment.
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Affiliation(s)
- Héctor Gálvez
- Developmental Biology, CEXS, Parc de Recerca Biomèdica de Barcelona, Universitat Pompeu Fabra Barcelona, Spain
| | - Gina Abelló
- Developmental Biology, CEXS, Parc de Recerca Biomèdica de Barcelona, Universitat Pompeu Fabra Barcelona, Spain
| | - Fernando Giraldez
- Developmental Biology, CEXS, Parc de Recerca Biomèdica de Barcelona, Universitat Pompeu Fabra Barcelona, Spain
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39
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Laos M, Sulg M, Herranen A, Anttonen T, Pirvola U. Indispensable role of Mdm2/p53 interaction during the embryonic and postnatal inner ear development. Sci Rep 2017; 7:42216. [PMID: 28181574 PMCID: PMC5299844 DOI: 10.1038/srep42216] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 01/05/2017] [Indexed: 02/06/2023] Open
Abstract
p53 is a key component of a signaling network that protects cells against various stresses. As excess p53 is detrimental to cells, its levels are tightly controlled by several mechanisms. The E3 ubiquitin ligase Mdm2 is a major negative regulator of p53. The significance of balanced p53 levels in normal tissues, at different stages of lifetime, is poorly understood. We have studied in vivo how the disruption of Mdm2/p53 interaction affects the early-embryonic otic progenitor cells and their descendants, the auditory supporting cells and hair cells. We found that p53 accumulation, as a consequence of Mdm2 abrogation, is lethal to both proliferative progenitors and non-proliferating, differentiating cells. The sensitivity of postmitotic supporting cells to excess p53 decreases along maturation, suggesting that maturation-related mechanisms limit p53′s transcriptional activity towards pro-apoptotic factors. We have also investigated in vitro whether p53 restricts supporting cell’s regenerative capacity. Unlike in several other regenerative cellular models, p53 inactivation did not alter supporting cell’s proliferative quiescence nor transdifferentiation capacity. Altogether, the postmitotic status of developing hair cells and supporting cells does not confer protection against the detrimental effects of p53 upregulation. These findings might be linked to auditory disturbances observed in developmental syndromes with inappropriate p53 upregulation.
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Affiliation(s)
- M Laos
- Division of Physiology and Neuroscience, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
| | - M Sulg
- Division of Physiology and Neuroscience, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
| | - A Herranen
- Division of Physiology and Neuroscience, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
| | - T Anttonen
- Division of Physiology and Neuroscience, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
| | - U Pirvola
- Division of Physiology and Neuroscience, Department of Biosciences, University of Helsinki, 00014 Helsinki, Finland
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40
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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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41
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Kelley MW, Stone JS. Development and Regeneration of Sensory Hair Cells. AUDITORY DEVELOPMENT AND PLASTICITY 2017. [DOI: 10.1007/978-3-319-21530-3_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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42
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Zheng F, Zuo J. Cochlear hair cell regeneration after noise-induced hearing loss: Does regeneration follow development? Hear Res 2016; 349:182-196. [PMID: 28034617 DOI: 10.1016/j.heares.2016.12.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 11/22/2016] [Accepted: 12/20/2016] [Indexed: 12/14/2022]
Abstract
Noise-induced hearing loss (NIHL) affects a large number of military personnel and civilians. Regenerating inner-ear cochlear hair cells (HCs) is a promising strategy to restore hearing after NIHL. In this review, we first summarize recent transcriptome profile analysis of zebrafish lateral lines and chick utricles where spontaneous HC regeneration occurs after HC damage. We then discuss recent studies in other mammalian regenerative systems such as pancreas, heart and central nervous system. Both spontaneous and forced HC regeneration occurs in mammalian cochleae in vivo involving proliferation and direct lineage conversion. However, both processes are inefficient and incomplete, and decline with age. For direct lineage conversion in vivo in cochleae and in other systems, further improvement requires multiple factors, including transcription, epigenetic and trophic factors, with appropriate stoichiometry in appropriate architectural niche. Increasing evidence from other systems indicates that the molecular paths of direct lineage conversion may be different from those of normal developmental lineages. We therefore hypothesize that HC regeneration does not have to follow HC development and that epigenetic memory of supporting cells influences the HC regeneration, which may be a key to successful cochlear HC regeneration. Finally, we discuss recent efforts in viral gene therapy and drug discovery for HC regeneration. We hope that combination therapy targeting multiple factors and epigenetic signaling pathways will provide promising avenues for HC regeneration in humans with NIHL and other types of hearing loss.
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Affiliation(s)
- Fei Zheng
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, MS 322, Memphis, TN 38105, United States.
| | - Jian Zuo
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, MS 322, Memphis, TN 38105, United States.
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43
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Doetzlhofer A, Avraham KB. Insights into inner ear-specific gene regulation: Epigenetics and non-coding RNAs in inner ear development and regeneration. Semin Cell Dev Biol 2016; 65:69-79. [PMID: 27836639 DOI: 10.1016/j.semcdb.2016.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/14/2016] [Accepted: 11/03/2016] [Indexed: 12/12/2022]
Abstract
The vertebrate inner ear houses highly specialized sensory organs, tuned to detect and encode sound, head motion and gravity. Gene expression programs under the control of transcription factors orchestrate the formation and specialization of the non-sensory inner ear labyrinth and its sensory constituents. More recently, epigenetic factors and non-coding RNAs emerged as an additional layer of gene regulation, both in inner ear development and disease. In this review, we provide an overview on how epigenetic modifications and non-coding RNAs, in particular microRNAs (miRNAs), influence gene expression and summarize recent discoveries that highlight their critical role in the proper formation of the inner ear labyrinth and its sensory organs. Finally, we discuss recent insights into how epigenetic factors and miRNAs may facilitate, or in the case of mammals, restrict inner ear sensory hair cell regeneration.
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Affiliation(s)
- Angelika Doetzlhofer
- The Solomon H. Snyder Department of Neuroscience, the Center for Sensory Biology, the Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
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44
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Chen Y, Li W, Li W, Chai R, Li H. Spatiotemporal expression of Ezh2 in the developing mouse cochlear sensory epithelium. Front Med 2016; 10:330-5. [PMID: 27465826 DOI: 10.1007/s11684-016-0459-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 05/20/2016] [Indexed: 10/21/2022]
Abstract
The enhancer of zeste 2 polycomb repressive complex 2 subunit (Ezh2) is a histone-lysine Nmethyltransferase enzyme that participates in DNA methylation. Ezh2 has also been reported to play crucial roles in stem cell proliferation and differentiation. However, the detailed expression profile of Ezh2 during mouse cochlear development has not been investigated. Here, we examined the spatiotemporal expression of Ezh2 in the cochlea during embryonic and postnatal development. Ezh2 expression began to be observed in the whole otocyst nuclei at embryonic day 9.5 (E9.5). At E12.5, Ezh2 was expressed in the nuclei of the cochlear prosensory epithelium. At E13.5 and E15.5, Ezh2 was expressed from the apical to the basal turns in the nuclei of the differentiating cochlear epithelium. At postnatal day (P) 0 and 7, the Ezh2 expression was located in the nuclei of the cochlear epithelium in all three turns and could be clearly seen in outer and inner hair cells, supporting cells, the stria vascularis, and spiral ganglion cells. Ezh2 continued to be expressed in the cochlear epithelium of adult mice. Our results provide the basic Ezh2 expression pattern and might be useful for further investigating the detailed role of Ezh2 during cochlear development.
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Affiliation(s)
- Yan Chen
- Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China.,Central Laboratory, Affiliated Eye and ENT Hospital, Fudan University, Shanghai, 200031, China.,Key Laboratory of Hearing Medicine of the National Health and Family Planning Commission, Shanghai, 200031, China
| | - Wenyan Li
- Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China.,Key Laboratory of Hearing Medicine of the National Health and Family Planning Commission, Shanghai, 200031, China
| | - Wen Li
- Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China.,Central Laboratory, Affiliated Eye and ENT Hospital, Fudan University, Shanghai, 200031, China.,Key Laboratory of Hearing Medicine of the National Health and Family Planning Commission, Shanghai, 200031, China
| | - Renjie Chai
- MOE Key Laboratory of Developmental Genes and Human Disease, State Key Laboratory of Bioelectronics, Institute of Life Sciences, Southeast University, Nanjing, 210096, China. .,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
| | - Huawei Li
- Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China. .,Key Laboratory of Hearing Medicine of the National Health and Family Planning Commission, Shanghai, 200031, China. .,Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China.
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45
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Mateo Sánchez S, Freeman SD, Delacroix L, Malgrange B. The role of post-translational modifications in hearing and deafness. Cell Mol Life Sci 2016; 73:3521-33. [PMID: 27147466 PMCID: PMC11108544 DOI: 10.1007/s00018-016-2257-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 12/20/2022]
Abstract
Post-translational modifications (PTMs) are key molecular events that modify proteins after their synthesis and modulate their ultimate functional properties by affecting their stability, localisation, interaction potential or activity. These chemical changes expand the size of the proteome adding diversity to the molecular pathways governing the biological outcome of cells. PTMs are, thus, crucial in regulating a variety of cellular processes such as apoptosis, proliferation and differentiation and have been shown to be instrumental during embryonic development. In addition, alterations in protein PTMs have been implicated in the pathogenesis of many human diseases, including deafness. In this review, we summarize the recent progress made in understanding the roles of PTMs during cochlear development, with particular emphasis on the enzymes driving protein phosphorylation, acetylation, methylation, glycosylation, ubiquitination and SUMOylation. We also discuss how these enzymes may contribute to hearing impairment and deafness.
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Affiliation(s)
- Susana Mateo Sánchez
- Developmental Neurobiology Unit, GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), Avenue Hippocrate 15, Tour 4, 1er étage, Bât. B36, 4000, Liège, Belgium
| | - Stephen D Freeman
- Developmental Neurobiology Unit, GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), Avenue Hippocrate 15, Tour 4, 1er étage, Bât. B36, 4000, Liège, Belgium
| | - Laurence Delacroix
- Developmental Neurobiology Unit, GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), Avenue Hippocrate 15, Tour 4, 1er étage, Bât. B36, 4000, Liège, Belgium
| | - Brigitte Malgrange
- Developmental Neurobiology Unit, GIGA-Neurosciences, University of Liège, Quartier Hôpital (CHU), Avenue Hippocrate 15, Tour 4, 1er étage, Bât. B36, 4000, Liège, Belgium.
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46
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Puligilla C, Kelley MW. Dual role for Sox2 in specification of sensory competence and regulation of Atoh1 function. Dev Neurobiol 2016; 77:3-13. [PMID: 27203669 DOI: 10.1002/dneu.22401] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 11/08/2022]
Abstract
The formation of inner ear sensory epithelia is believed to occur in two steps, initial specification of sensory competent (prosensory) regions followed by determination of specific cell-types, such as hair cells (HCs) and supporting cells. However, studies in which the HC determination factor Atoh1 was ectopically expressed in nonprosensory regions indicated that expression of Atoh1 alone is sufficient to induce HC formation suggesting that prosensory formation may not be a prerequisite for HC development. To test this hypothesis, interactions between Sox2 and Atoh1, which are required for prosensory and HC formation respectively, were examined. Forced expression of Atoh1 in nonprosensory cells resulted in transient expression of Sox2 prior to HC formation, suggesting that expression of Sox2 is required for formation of ectopic HCs. Moreover, Atoh1 overexpression failed to induce HC formation in Sox2 mutants, confirming that Sox2 is required for prosensory competence. To determine whether expression of Sox2 alone is sufficient to induce prosensory identity, Sox2 was transiently activated in a manner that mimicked endogenous expression. Following transient Sox2 activation, nonprosensory cells developed as HCs, a result that was never observed in response to persistent expression of Sox2. These results, suggest a dual role for Sox2 in inner ear formation. Initially, Sox2 is required to specify prosensory competence, but subsequent down-regulation of Sox2 must occur to allow Atoh1 expression, most likely through a direct interaction with the Atoh1 promoter. These results implicate Sox2-mediated changes in prosensory cells as an essential step in their ability to develop as HCs. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 3-13, 2017.
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Affiliation(s)
- Chandrakala Puligilla
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina, 29425
| | - Matthew W Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, 20982
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