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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: 1] [Impact Index Per Article: 1.0] [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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2
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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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3
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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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4
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Single-cell transcriptome analysis reveals three sequential phases of gene expression during zebrafish sensory hair cell regeneration. Dev Cell 2022; 57:799-819.e6. [PMID: 35316618 PMCID: PMC9188816 DOI: 10.1016/j.devcel.2022.03.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 11/19/2021] [Accepted: 02/28/2022] [Indexed: 12/20/2022]
Abstract
Loss of sensory hair cells (HCs) in the mammalian inner ear leads to permanent hearing and vestibular defects, whereas loss of HCs in zebrafish results in their regeneration. We used single-cell RNA sequencing (scRNA-seq) to characterize the transcriptional dynamics of HC regeneration in zebrafish at unprecedented spatiotemporal resolution. We uncovered three sequentially activated modules: first, an injury/inflammatory response and downregulation of progenitor cell maintenance genes within minutes after HC loss; second, the transient activation of regeneration-specific genes; and third, a robust re-activation of developmental gene programs, including HC specification, cell-cycle activation, ribosome biogenesis, and a metabolic switch to oxidative phosphorylation. The results are relevant not only for our understanding of HC regeneration and how we might be able to trigger it in mammals but also for regenerative processes in general. The data are searchable and publicly accessible via a web-based interface.
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Rai V, Tu S, Frank JR, Zuo J. Molecular Pathways Modulating Sensory Hair Cell Regeneration in Adult Mammalian Cochleae: Progress and Perspectives. Int J Mol Sci 2021; 23:ijms23010066. [PMID: 35008497 PMCID: PMC8745006 DOI: 10.3390/ijms23010066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 12/30/2022] Open
Abstract
Noise-induced, drug-related, and age-related disabling hearing loss is a major public health problem and affect approximately 466 million people worldwide. In non-mammalian vertebrates, the death of sensory hair cells (HCs) induces the proliferation and transdifferentiation of adjacent supporting cells into new HCs; however, this capacity is lost in juvenile and adult mammalian cochleae leading to permanent hearing loss. At present, cochlear implants and hearing devices are the only available treatments and can help patients to a certain extent; however, no biological approach or FDA-approved drug is effective to treat disabling hearing loss and restore hearing. Recently, regeneration of mammalian cochlear HCs by modulating molecular pathways or transcription factors has offered some promising results, although the immaturity of the regenerated HCs remains the biggest concern. Furthermore, most of the research done is in neonates and not in adults. This review focuses on critically summarizing the studies done in adult mammalian cochleae and discusses various strategies to elucidate novel transcription factors for better therapeutics.
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Affiliation(s)
| | | | | | - Jian Zuo
- Correspondence: ; Tel.: +1-(402)-280-2916
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6
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Martini A, Sorrentino F, Sorrentino U, Cassina M. Genetics & Epigenetics of Hereditary Deafness: An Historical Overview. Audiol Res 2021; 11:629-635. [PMID: 34842610 PMCID: PMC8628574 DOI: 10.3390/audiolres11040057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
Hearing loss (HL) is one of the most common sensory impairments worldwide and represents a critical medical and public health issue. Since the mid-1900s, great efforts have been aimed at understanding the etiology of both syndromic and non-syndromic HL and identifying correlations with specific audiological phenotypes. The extraordinary discoveries in the field of molecular genetics during the last three decades have contributed substantially to the current knowledge. Next-generation sequencing technologies have dramatically increased the diagnostic rate for genetic HL, enabling the detection of novel variants in known deafness-related genes and the discovery of new genes implicated in hearing disease. Overall, genetic factors account for at least 40% of the cases with HL, but a portion of affected patients still lack a definite molecular diagnosis. Important steps forward have been made, but many aspects still have to be clarified. In particular, the role of epigenetics in the development, function and pathology of hearing is a research field that still needs to be explored. This research is extremely challenging due to the time- and tissue-dependent variability of the epigenetic changes. Multisystem diseases are expected to be investigated at first: specific epi-signatures have been identified for several syndromic disorders and represent potential markers for molecular diagnostics.
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Affiliation(s)
- Alessandro Martini
- Padova University Research Center “International Auditory Processing Project in Venice (I-APPROVE)”, “Santi Giovanni e Paolo” Hospital, 30122 Venice, Italy
| | - Flavia Sorrentino
- Otolaryngology Unit, Department of Neurosciences, University of Padova, 35128 Padova, Italy;
| | - Ugo Sorrentino
- Clinical Genetics Unit, Department of Women’s and Children’s Health, University of Padova, 35128 Padova, Italy;
| | - Matteo Cassina
- Clinical Genetics Unit, Department of Women’s and Children’s Health, University of Padova, 35128 Padova, Italy;
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7
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Lee S, Song JJ, Beyer LA, Swiderski DL, Prieskorn DM, Acar M, Jen HI, Groves AK, Raphael Y. Combinatorial Atoh1 and Gfi1 induction enhances hair cell regeneration in the adult cochlea. Sci Rep 2020; 10:21397. [PMID: 33293609 PMCID: PMC7722738 DOI: 10.1038/s41598-020-78167-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 11/19/2020] [Indexed: 12/17/2022] Open
Abstract
Mature mammalian cochlear hair cells (HCs) do not spontaneously regenerate once lost, leading to life-long hearing deficits. Attempts to induce HC regeneration in adult mammals have used over-expression of the HC-specific transcription factor Atoh1, but to date this approach has yielded low and variable efficiency of HC production. Gfi1 is a transcription factor important for HC development and survival. We evaluated the combinatorial effects of Atoh1 and Gfi1 over-expression on HC regeneration using gene transfer methods in neonatal cochlear explants, and in vivo in adult mice. Adenoviral over-expression of Atoh1 and Gfi1 in cultured neonatal cochlear explants resulted in numerous ectopic HC-like cells (HCLCs), with significantly more cells in Atoh1 + Gfi1 cultures than Atoh1 alone. In vitro, ectopic HCLCs emerged in regions medial to inner HCs as well as in the stria vascularis. In vivo experiments were performed in mature Pou4f3DTR mice in which HCs were completely and specifically ablated by administration of diphtheria toxin. Adenoviral expression of Atoh1 or Atoh1 + Gfi1 in cochlear supporting cells induced appearance of HCLCs, with Atoh1 + Gfi1 expression leading to 6.2-fold increase of new HCLCs after 4 weeks compared to Atoh1 alone. New HCLCs were detected throughout the cochlea, exhibited immature stereocilia and survived for at least 8 weeks. Combinatorial Atoh1 and Gfi1 induction is thus a promising strategy to promote HC regeneration in the mature mammalian cochlea.
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Affiliation(s)
- Sungsu Lee
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
- Department of Otolaryngology - Head and Neck Surgery, Chonnam National University Hospital, Gwangju, South Korea
| | - Jae-Jun Song
- Department of Otolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, South Korea
| | - Lisa A Beyer
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Donald L Swiderski
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Diane M Prieskorn
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Melih Acar
- Department of Medical Biology, School of Medicine, Bahcesehir University, Istanbul, Turkey
| | - Hsin-I Jen
- Department of Neuroscience, Baylor College of Medicine, Houston, USA
| | - Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine, Houston, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, USA
| | - Yehoash Raphael
- Kresge Hearing Research Institute, Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA.
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8
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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 PMCID: PMC8168289 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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9
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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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10
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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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11
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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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12
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Kempfle JS, Luu NNC, Petrillo M, Al-Asad R, Zhang A, Edge ASB. Lin28 reprograms inner ear glia to a neuronal fate. Stem Cells 2020; 38:890-903. [PMID: 32246510 PMCID: PMC10908373 DOI: 10.1002/stem.3181] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/05/2020] [Accepted: 02/08/2020] [Indexed: 12/16/2022]
Abstract
Sensorineural hearing loss is irreversible and can be caused by loss of auditory neurons. Regeneration of neural cells from endogenous cells may offer a future tool to restore the auditory circuit and to enhance the performance of implantable hearing devices. Neurons and glial cells in the peripheral nervous system are closely related and originate from a common progenitor. Prior work in our lab indicated that in the early postnatal mouse inner ear, proteolipid protein 1 (Plp1) expressing glial cells could act as progenitor cells for neurons in vitro. Here, we used a transgenic mouse model to transiently overexpress Lin28, a neural stem cell regulator, in Plp1-positive glial cells. Lin28 promoted proliferation and conversion of auditory glial cells into neurons in vitro. To study the effects of Lin28 on endogenous glial cells after loss of auditory neurons in vivo, we produced a model of auditory neuropathy by selectively damaging auditory neurons with ouabain. After neural damage was confirmed by the auditory brainstem response, we briefly upregulated the Lin28 in Plp1-expressing inner ear glial cells. One month later, we analyzed the cochlea for neural marker expression by quantitative RT-PCR and immunohistochemistry. We found that transient Lin28 overexpression in Plp1-expressing glial cells induced expression of neural stem cell markers and subsequent conversion into neurons. This suggests the potential for inner ear glia to be converted into neurons as a regeneration therapy for neural replacement in auditory neuropathy.
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Affiliation(s)
- Judith S. Kempfle
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts
- University Department of Otolaryngology, Head and Neck Surgery, Tübingen, Germany
| | - Ngoc-Nhi C. Luu
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts
- University Department of Otolaryngology, Head and Neck Surgery, Zürich, Switzerland
| | - Marco Petrillo
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts
| | - Reef Al-Asad
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts
| | - Andrea Zhang
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts
| | - Albert S. B. Edge
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts
- Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, Massachusetts
- Harvard Stem Cell Institute, Cambridge, Massachusetts
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13
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Notch Signalling: The Multitask Manager of Inner Ear Development and Regeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1218:129-157. [DOI: 10.1007/978-3-030-34436-8_8] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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14
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Cousins RPC. Medicines discovery for auditory disorders: Challenges for industry. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3652. [PMID: 31795652 DOI: 10.1121/1.5132706] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Currently, no approved medicines are available for the prevention or treatment of hearing loss. Pharmaceutical industry productivity across all therapeutic indications has historically been disappointing, with a 90% chance of failure in delivering a marketed drug after entering clinical evaluation. To address these failings, initiatives have been applied in the three cornerstones of medicine discovery: target selection, clinical candidate selection, and clinical studies. These changes aimed to enable data-informed decisions on the translation of preclinical observations into a safe, clinically effective medicine by ensuring the best biological target is selected, the most appropriate chemical entity is advanced, and that the clinical studies enroll the correct patients. The specific underlying pathologies need to be known to allow appropriate patient selection, so improved diagnostics are required, as are methodologies for measuring in the inner ear target engagement, drug delivery and pharmacokinetics. The different therapeutic strategies of protecting hearing or preventing hearing loss versus restoring hearing are reviewed along with potential treatments for tinnitus. Examples of current investigational drugs are discussed to highlight key challenges in drug discovery and the learnings being applied to improve the probability of success of launching a marketed medicine.
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Affiliation(s)
- Rick P C Cousins
- University College London Ear Institute, University College London, London, WC1X 8EE, United Kingdom
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15
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Li A, You D, Li W, Cui Y, He Y, Li W, Chen Y, Feng X, Sun S, Chai R, Li H. Novel compounds protect auditory hair cells against gentamycin-induced apoptosis by maintaining the expression level of H3K4me2. Drug Deliv 2019; 25:1033-1043. [PMID: 30799660 PMCID: PMC6058728 DOI: 10.1080/10717544.2018.1461277] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Aminoglycoside-induced hair cell (HC) loss is a major cause of hearing impairment, and the effective prevention of HC loss remains an unmet medical need. Epigenetic mechanisms have been reported to be involved in protecting cochlear cells against ototoxic drug injury, and in this study we developed new bioactive compounds that have similar chemical structures as the epigenetics-related lysine-specific demethylase 1 (LSD1) inhibitors. LSD1 inhibitors have been reported to protect cochlear cells by preventing demethylation of dimethylated histone H3K4 (H3K4me2). To determine whether these new compounds exert similar protective effects on HCs, we treated mouse cochlear explant cultures with the new compounds together with gentamycin. There was a severe loss of HCs in the organ of Corti after gentamycin exposure, while co-treatment with the new compounds significantly protected against gentamycin-induced HC loss. H3K4me2 levels in the nuclei of HCs decreased after exposure to gentamycin, but H3K4me2 levels were maintained in the presence of the new compounds. Apoptosis is also involved in the injury process, and the new compounds protected the inner ear HCs against apoptosis by reducing caspase-3 activation. Together, our findings demonstrate that our new compounds prevent gentamycin-induced HC loss by preventing the demethylation of H3K4me2 and by inhibiting apoptosis, and these results might provide the theoretical basis for novel drug development for hearing protection.
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Affiliation(s)
- Ao Li
- a ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital , Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University , Shanghai , China.,b Department of Otorhinolaryngology Head and Neck Surgery , Affiliated Drum Tower Hospital of Nanjing University Medical School, Research Institution of Otorhinolaryngology, Jiangsu Provincial Key Medical Discipline (Laboratory) , Nanjing , China
| | - Dan You
- a ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital , Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University , Shanghai , China
| | - Wenyan Li
- a ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital , Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University , Shanghai , China
| | - Yingjie Cui
- c Knowshine (Shanghai) Pharmaceuticals Inc , Shanghai , China
| | - Yingzi He
- a ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital , Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University , Shanghai , China
| | - Wen Li
- a ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital , Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University , Shanghai , China
| | - Yan Chen
- a ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital , Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University , Shanghai , China
| | - Xiao Feng
- c Knowshine (Shanghai) Pharmaceuticals Inc , Shanghai , China
| | - Shan Sun
- a ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital , Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University , Shanghai , China
| | - Renjie Chai
- d Key Laboratory for Developmental Genes and Human Disease , Ministry of Education, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Institute of Life Sciences, Southeast University , Nanjing , China.,e Co-innovation Center of Neuroregeneration, Nantong University , Nantong , China
| | - Huawei Li
- a ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital , Key Laboratory of Hearing Medicine of NHFPC, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University , Shanghai , China.,f Institutes of Biomedical Sciences and The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University , Shanghai , China
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16
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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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17
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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 PMCID: PMC6456365 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] [MESH Headings] [Grants] [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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18
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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: 45] [Impact Index Per Article: 9.0] [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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19
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Ma JH, Kim HP, Shin JO. CTCF deficiency causes expansion of the sensory domain in the mouse cochlea. Biochem Biophys Res Commun 2019; 512:896-901. [PMID: 30929920 DOI: 10.1016/j.bbrc.2019.03.127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 01/08/2023]
Abstract
The cochlea in the mammalian inner ear is a sensitive and sharply organized sound-detecting structure. The proper specification of neurosensory-competent domain in the otic epithelium is required for the formation of mature neuronal and sensory domains. Genetic studies have provided many insights into inner ear development, but there have been few epigenetic studies of inner ear development. CTCF is an epigenetic factor that plays a pivotal role in the organization of global chromatin conformation. To determine the role of CTCF in the otic sensory formation, we made a conditional knockout of Ctcf in the developing otic epithelium by crossing Ctcffl/fl mice with Pax2-Cre mice. Ctcf deficiency resulted in extra rows of auditory hair cells in the shortened cochlea on mouse embryonic day 14.5 (E14.5) and E17.5. The massive and ectopic expression of sensory specifiers such as Jag1 and Sox2 indicated that the sensory domain was expanded in the Ctcf-deficient cochlea. Other regulators of the sensory domain such as Bmp4, Gata3, and Fgf10 were not affected. These results suggest that CTCF plays a role in the regulation of the sensory domain in mammalian cochlear development.
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Affiliation(s)
- Ji-Hyun Ma
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Hyoung-Pyo Kim
- Department of Environmental Medical Biology, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea; BK21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Jeong-Oh Shin
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea.
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20
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Hereditary hearing loss; about the known and the unknown. Hear Res 2019; 376:58-68. [PMID: 30665849 DOI: 10.1016/j.heares.2019.01.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/11/2018] [Accepted: 01/07/2019] [Indexed: 01/01/2023]
Abstract
Hereditary hearing loss is both clinically and genetically very heterogeneous. Despite the large number of genes that have been associated with the condition, many cases remain unexplained. Novel gene associations with hearing loss are to be expected but also are defects of regulatory regions of the genome which are currently not routinely addressed in molecular genetic testing and research. Inheritance patterns other than monogenic might be more common than assumed in isolated cases and diagnoses might have been missed because of misinterpretation of identified DNA variants. This review summarizes current insights in the genetics of hearing loss, the next steps that are being taken in research, and their challenges. Furthermore, genotype-phenotype correlations and modifying factors are discussed as these are instrumental in counselling hearing impaired individuals and/or their family members.
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21
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Liester MB, Sullivan EE. A review of epigenetics in human consciousness. COGENT PSYCHOLOGY 2019. [DOI: 10.1080/23311908.2019.1668222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Mitchell B. Liester
- Department of Psychiatry, University of Colorado School of Medicine, P.O. Box 302 153 N. Washington Street, Suite 103, Monument, CO 80132, USA
| | - Erin E. Sullivan
- Computer Science, University of Oklahoma, P.O. Box 302, Monument, CO 80132, USA
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22
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Tarchini B, Longo-Guess C, Tian C, Tadenev ALD, Devanney N, Johnson KR. A spontaneous mouse deletion in Mctp1 uncovers a long-range cis-regulatory region crucial for NR2F1 function during inner ear development. Dev Biol 2018; 443:153-164. [PMID: 30217595 PMCID: PMC6214362 DOI: 10.1016/j.ydbio.2018.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 09/10/2018] [Accepted: 09/11/2018] [Indexed: 12/12/2022]
Abstract
Hundreds of thousands of cis-regulatory DNA sequences are predicted in vertebrate genomes, but unlike genes themselves, few have been characterized at the functional level or even unambiguously paired with a target gene. Here we serendipitously identified and started investigating the first reported long-range regulatory region for the Nr2f1 (Coup-TFI) transcription factor gene. NR2F1 is temporally and spatially regulated during development and required for patterning and regionalization in the nervous system, including sensory hair cell organization in the auditory epithelium of the cochlea. Analyzing the deaf wanderer (dwnd) spontaneous mouse mutation, we traced back the cause of its associated circling behavior to a 53 kb deletion removing five exons and adjacent intronic regions of the poorly characterized Mctp1 gene. Interestingly, loss of Mctp1 function cannot account for the hearing loss, inner ear dysmorphology and sensory hair cell disorganization observed in dwnd mutants. Instead, we found that the Mctp1dwnd deletion affects the Nr2f1 gene located 1.4 Mb away, downregulating transcription and protein expression in the embryonic cochlea. Remarkably, the Mctp1dwnd allele failed to complement a targeted inactivation allele of Nr2f1, and transheterozygotes or Mctp1dwnd homozygotes exhibit the same morphological defects observed in inner ears of Nr2f1 mutants without sharing their early life lethality. Defects include improper separation of the utricle and saccule in the vestibule not described previously, which can explain the circling behavior that first brought the spontaneous mutation to attention. By contrast, mice homozygous for a targeted inactivation of Mctp1 have normal hearing and inner ear structures. We conclude that the 53 kb Mctp1dwnd deletion encompasses a long-range cis-regulatory region essential for proper Nr2f1 expression in the embryonic inner ear, providing a first opportunity to investigate Nr2f1 function in postnatal inner ears. This work adds to the short list of long-range regulatory regions characterized as essential to drive expression of key developmental control genes.
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Affiliation(s)
- Basile Tarchini
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; Department of Medicine, Tufts University, Boston 02111, MA, USA; Graduate School of Biomedical Science and Engineering (GSBSE), University of Maine, Orono 04469, ME, USA.
| | | | - Cong Tian
- The Jackson Laboratory, Bar Harbor, ME 04609, USA; Graduate School of Biomedical Science and Engineering (GSBSE), University of Maine, Orono 04469, ME, USA
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23
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Abstract
Drug delivery to the inner ear is an ideal method to treat a wide variety of otologic conditions. A broad range of potential applications is just beginning to be explored. New approaches combine principles of inner ear pharmacokinetics with emerging technologies of drug delivery including novel delivery systems, drug-device combinations, and new categories of drugs. Strategies include cell-specific targeting, manipulation of gene expression, local activation following systemic delivery, and use of stem cells, viral vectors, and gene editing systems. Translation of these therapies to the clinic remains challenging given the potential risks of intracochlear and intralabyrinthine trauma, our limited understanding of the etiologies of particular inner ear disorders, and paucity of accurate diagnostic tools at the cellular level. This review provides an overview of future methods, delivery systems, disease targets, and clinical considerations required for translation to clinical medicine.
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24
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Atkinson PJ, Dong Y, Gu S, Liu W, Najarro EH, Udagawa T, Cheng AG. Sox2 haploinsufficiency primes regeneration and Wnt responsiveness in the mouse cochlea. J Clin Invest 2018; 128:1641-1656. [PMID: 29553487 DOI: 10.1172/jci97248] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 02/01/2018] [Indexed: 12/31/2022] Open
Abstract
During development, Sox2 is indispensable for cell division and differentiation, yet its roles in regenerating tissues are less clear. Here, we used combinations of transgenic mouse models to reveal that Sox2 haploinsufficiency (Sox2haplo) increases rather than impairs cochlear regeneration in vivo. Sox2haplo cochleae had delayed terminal mitosis and ectopic sensory cells, yet normal auditory function. Sox2haplo amplified and expanded domains of damage-induced Atoh1+ transitional cell formation in neonatal cochlea. Wnt activation via β-catenin stabilization (β-cateninGOF) alone failed to induce proliferation or transitional cell formation. By contrast, β-cateninGOF caused proliferation when either Sox2haplo or damage was present, and transitional cell formation when both were present in neonatal, but not mature, cochlea. Mechanistically, Sox2haplo or damaged neonatal cochleae showed lower levels of Sox2 and Hes5, but not of Wnt target genes. Together, our study unveils an interplay between Sox2 and damage in directing tissue regeneration and Wnt responsiveness and thus provides a foundation for potential combinatorial therapies aimed at stimulating mammalian cochlear regeneration to reverse hearing loss in humans.
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Affiliation(s)
- Patrick J Atkinson
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Yaodong Dong
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA.,Department of Otology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Shuping Gu
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Wenwen Liu
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Elvis Huarcaya Najarro
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Tomokatsu Udagawa
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Alan G Cheng
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
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25
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Jimenez-Gonzalez A, García-Concejo A, León-Lobera F, Rodriguez RE. Morphine delays neural stem cells differentiation by facilitating Nestin overexpression. Biochim Biophys Acta Gen Subj 2017; 1862:474-484. [PMID: 29111275 DOI: 10.1016/j.bbagen.2017.10.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 09/30/2017] [Accepted: 10/26/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Morphine is used as an analgesic although it causes important secondary effects. These effects are triggered by several mechanisms leading to the dysregulation of gene expression. Here we aimed to study these alterations on neural stem cells (NSC) during CNS development. METHODS AB strain and tg nestin:GFP zebrafish embryos, zebrafish primary neuron culture and mouse embryonic stem cells were used to assess the effect of morphine by qPCR, time lapse microscopy and western blot. ChIP-qPCR and bisulfite conversion assay were performed to determine the changes exerted by morphine in a Nestin candidate enhancer. RESULTS Morphine increases GFP in nestin:GFP embryos and overexpresses the NSC marker Nestin. Morphine also exerts a hyperacetylation effect on H3K27 and decreases DNA methylation within a region located 18 Kb upstream nestin transcription starting site. Here, a binding site for the transcription factor complex Sox2/Oct4/Nanog was predicted. These factors are also upregulated by morphine. Besides, morphine increases the histone acetyl transferase p300. The inhibition of p300 activity decreases Nestin. CONCLUSIONS Morphine facilitates Nestin increase by several mechanisms which include hyperacetylation of H3K27, decreased DNA methylation and the overexpression of the transcription factors sox2, oct4 and nanog. It has also been demonstrated that nestin levels depend on p300 activity. The facilitated Nestin expression delays the normal differentiation of neural stem cells. GENERAL SIGNIFICANCE The present work provides novel evidence of the effects induced by morphine in the normal differentiation of NSCs, altering Nestin through changes on p300, H3K27ac, DNA methylation and Oct4, Sox2, and Nanog.
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Affiliation(s)
- Ada Jimenez-Gonzalez
- Institute of Neurosciences of Castilla y Leon (INCyL). University of Salamanca, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Salamanca, Spain
| | - Adrián García-Concejo
- Institute of Neurosciences of Castilla y Leon (INCyL). University of Salamanca, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Salamanca, Spain
| | - Fernando León-Lobera
- Institute of Neurosciences of Castilla y Leon (INCyL). University of Salamanca, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Salamanca, Spain
| | - Raquel E Rodriguez
- Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca, Spain; Institute of Neurosciences of Castilla y Leon (INCyL). University of Salamanca, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Salamanca, Spain.
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