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Foster T, Lim P, Jones M, Wagle SR, Kovacevic B, Ionescu CM, Wong EYM, Mooranian A, Al-Salami H. Polymer-Based Nanoparticles for Inner Ear Targeted Trans Differentiation Gene Therapy. ChemMedChem 2024; 19:e202400038. [PMID: 38818625 DOI: 10.1002/cmdc.202400038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 05/27/2024] [Accepted: 05/27/2024] [Indexed: 06/01/2024]
Abstract
Hearing loss is a significant disability that often goes under recognised, largely due to poor identification, prevention, and treatment. Steps are being made to amend these pitfalls in the investigation of hearing loss, however, the development of a cure to reverse advanced forms remains distant. This review details some current advances in the treatment of hearing loss, with a particular focus on genetic-based nanotechnology and how it may provide a useful avenue for further research. This review presents a broad background on the pathophysiology of hearing loss and some current interventions. We also highlight some potential genes that may be useful in the amelioration of hearing loss. Pathways of cellular differentiation from stem or supporting cell to functional hair cell are covered in detail, as this mechanism represents a key means of regenerating these cell types. Overall, we believe that polymer-based nanotechnology coupled with novel excipients represents a useful area of further research in the treatment of hearing loss, although further studies in this area are required.
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Affiliation(s)
- Thomas Foster
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Western Australia, Australia
- Department of Clinical Biochemistry, Pathwest Laboratory Medicine, Royal Perth Hospital, Perth, 6000, Western Australia, Australia
| | - Patrick Lim
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Western Australia, Australia
| | - Melissa Jones
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Western Australia, Australia
- Hearing Therapeutics Department, Ear Science Institute Australia, Queen Elizabeth II Medical Centre, Nedlands 6009, Perth, Western Australia, Australia
| | - Susbin Raj Wagle
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Western Australia, Australia
| | - Bozica Kovacevic
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Western Australia, Australia
| | - Corina Mihaela Ionescu
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Western Australia, Australia
| | - Elaine Y M Wong
- Hearing Therapeutics Department, Ear Science Institute Australia, Queen Elizabeth II Medical Centre, Nedlands 6009, Perth, Western Australia, Australia
| | - Armin Mooranian
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Western Australia, Australia
- School of Pharmacy, University of Otago, Dunedin 9016, Otago, New Zealand
| | - Hani Al-Salami
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley, 6102, Western Australia, Australia
- Medical School, The University of Western Australia, Crawley, 6009, Western Australia, Australia
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2
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Anselmi C, Fuller GK, Stolfi A, Groves AK, Manni L. Sensory cells in tunicates: insights into mechanoreceptor evolution. Front Cell Dev Biol 2024; 12:1359207. [PMID: 38550380 PMCID: PMC10973136 DOI: 10.3389/fcell.2024.1359207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Tunicates, the sister group of vertebrates, offer a unique perspective for evolutionary developmental studies (Evo-Devo) due to their simple anatomical organization. Moreover, the separation of tunicates from vertebrates predated the vertebrate-specific genome duplications. As adults, they include both sessile and pelagic species, with very limited mobility requirements related mainly to water filtration. In sessile species, larvae exhibit simple swimming behaviors that are required for the selection of a suitable substrate on which to metamorphose. Despite their apparent simplicity, tunicates display a variety of mechanoreceptor structures involving both primary and secondary sensory cells (i.e., coronal sensory cells). This review encapsulates two decades of research on tunicate mechanoreception focusing on the coronal organ's sensory cells as prime candidates for understanding the evolution of vertebrate hair cells of the inner ear and the lateral line organ. The review spans anatomical, cellular and molecular levels emphasizing both similarity and differences between tunicate and vertebrate mechanoreception strategies. The evolutionary significance of mechanoreception is discussed within the broader context of Evo-Devo studies, shedding light on the intricate pathways that have shaped the sensory system in chordates.
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Affiliation(s)
- Chiara Anselmi
- Hopkins Marine Station, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Pacific Grove, CA, United States
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, United States
| | - Gwynna K. Fuller
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Andrew K. Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Lucia Manni
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
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3
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Gao J, Skidmore JM, Cimerman J, Ritter KE, Qiu J, Wilson LMQ, Raphael Y, Kwan KY, Martin DM. CHD7 and SOX2 act in a common gene regulatory network during mammalian semicircular canal and cochlear development. Proc Natl Acad Sci U S A 2024; 121:e2311720121. [PMID: 38408234 PMCID: PMC10927591 DOI: 10.1073/pnas.2311720121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 01/19/2024] [Indexed: 02/28/2024] Open
Abstract
Inner ear morphogenesis requires tightly regulated epigenetic and transcriptional control of gene expression. CHD7, an ATP-dependent chromodomain helicase DNA-binding protein, and SOX2, an SRY-related HMG box pioneer transcription factor, are known to contribute to vestibular and auditory system development, but their genetic interactions in the ear have not been explored. Here, we analyzed inner ear development and the transcriptional regulatory landscapes in mice with variable dosages of Chd7 and/or Sox2. We show that combined haploinsufficiency for Chd7 and Sox2 results in reduced otic cell proliferation, severe malformations of semicircular canals, and shortened cochleae with ectopic hair cells. Examination of mice with conditional, inducible Chd7 loss by Sox2CreER reveals a critical period (~E9.5) of susceptibility in the inner ear to combined Chd7 and Sox2 loss. Data from genome-wide RNA-sequencing and CUT&Tag studies in the otocyst show that CHD7 regulates Sox2 expression and acts early in a gene regulatory network to control expression of key otic patterning genes, including Pax2 and Otx2. CHD7 and SOX2 directly bind independently and cooperatively at transcription start sites and enhancers to regulate otic progenitor cell gene expression. Together, our findings reveal essential roles for Chd7 and Sox2 in early inner ear development and may be applicable for syndromic and other forms of hearing or balance disorders.
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Affiliation(s)
- Jingxia Gao
- Department of Pediatrics, The University of Michigan, Ann Arbor, MI48109
| | | | - Jelka Cimerman
- Department of Pediatrics, The University of Michigan, Ann Arbor, MI48109
| | - K. Elaine Ritter
- Department of Pediatrics, The University of Michigan, Ann Arbor, MI48109
| | - Jingyun Qiu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ08854
- Keck Center for Collaborative Neuroscience, Stem Cell Research Center, Rutgers University, Piscataway, NJ08854
| | - Lindsey M. Q. Wilson
- Medical Scientist Training Program, The University of Michigan, Ann Arbor, MI48109
| | - Yehoash Raphael
- Department of Otolaryngology-Head and Neck Surgery, The University of Michigan, Ann Arbor, MI48109
| | - Kelvin Y. Kwan
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ08854
- Keck Center for Collaborative Neuroscience, Stem Cell Research Center, Rutgers University, Piscataway, NJ08854
| | - Donna M. Martin
- Department of Pediatrics, The University of Michigan, Ann Arbor, MI48109
- Department of Human Genetics, The University of Michigan, Ann Arbor, MI48109
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4
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Mercurio S. SOX2-Sensing: Insights into the Role of SOX2 in the Generation of Sensory Cell Types in Vertebrates. Int J Mol Sci 2023; 24:ijms24087637. [PMID: 37108798 PMCID: PMC10141063 DOI: 10.3390/ijms24087637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/17/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
The SOX2 transcription factor is a key regulator of nervous system development, and its mutation in humans leads to a rare disease characterized by severe eye defects, cognitive defects, hearing defects, abnormalities of the CNS and motor control problems. SOX2 has an essential role in neural stem cell maintenance in specific regions of the brain, and it is one of the master genes required for the generation of induced pluripotent stem cells. Sox2 is expressed in sensory organs, and this review will illustrate how it regulates the differentiation of sensory cell types required for hearing, touching, tasting and smelling in vertebrates and, in particular, in mice.
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Affiliation(s)
- Sara Mercurio
- Department of Biotechnologies and Biosciences, University of Milan-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
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5
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Ciani Berlingeri AN, Pujol R, Cox BC, Stone JS. Sox2 is required in supporting cells for normal levels of vestibular hair cell regeneration in adult mice. Hear Res 2022; 426:108642. [PMID: 36334348 DOI: 10.1016/j.heares.2022.108642] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 09/16/2022] [Accepted: 10/19/2022] [Indexed: 11/04/2022]
Abstract
Sox2 is a transcription factor that is necessary in the mammalian inner ear for development of sensory hair cells and supporting cells. Sox2 is expressed in supporting cells of adult mammals, but its function in this context is poorly understood. Given its role in the developing inner ear, we hypothesized that Sox2 is required in vestibular supporting cells for regeneration of type II hair cells after damage. Using adult mice, we deleted Sox2 from Sox9-CreER-expressing supporting cells prior to diphtheria toxin-mediated hair cell destruction and used fate-mapping to assess regeneration. In utricles of control mice with normal Sox2 expression, supporting cells regenerated nearly 200 hair cells by 3 weeks post-damage, which doubled by 12 weeks. In contrast, mice with Sox2 deletion from supporting cells had approximately 20 fate-mapped hair cells at 3 weeks post-damage, and this number did not change significantly by 12 weeks, indicating regeneration was dramatically curtailed. We made similar observations for saccules and ampullae. We found no evidence that supporting cells lacking Sox2 had altered cellular density, morphology, or ultrastructure. However, some Sox2-negative supporting cell nuclei appeared to migrate apically but did not turn on hair cell markers, and type I hair cell survival was higher. Sox2 heterozygotes also had reduced regeneration in utricles, but more hair cells were replaced than mice with Sox2 deletion. Our study determined that Sox2 is required in supporting cells for normal levels of vestibular hair cell regeneration but found no other major requirements for Sox2 in adult supporting cells.
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Affiliation(s)
- Amanda N Ciani Berlingeri
- Department of Speech and Hearing Sciences, University of Washington, Seattle, Washington, United States; Department of Otolaryngology-Head and Neck Surgery and the Virginia Merrill Bloedel Research Center, University of Washington School of Medicine, Seattle, Washington, United States
| | - Rémy Pujol
- University of Montpellier, INM-INSERM Unit 1298, Montpellier, France
| | - Brandon C Cox
- Departments of Pharmacology and Otolaryngology, Southern Illinois University School of Medicine, Springfield, Illinois, United States
| | - Jennifer S Stone
- Department of Otolaryngology-Head and Neck Surgery and the Virginia Merrill Bloedel Research Center, University of Washington School of Medicine, Seattle, Washington, United States.
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6
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Riley BB. Comparative assessment of Fgf's diverse roles in inner ear development: A zebrafish perspective. Dev Dyn 2021; 250:1524-1551. [PMID: 33830554 DOI: 10.1002/dvdy.343] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/26/2021] [Accepted: 03/26/2021] [Indexed: 01/21/2023] Open
Abstract
Progress in understanding mechanisms of inner ear development has been remarkably rapid in recent years. The research community has benefited from the availability of several diverse model organisms, including zebrafish, chick, and mouse. The complexity of the inner ear has proven to be a challenge, and the complexity of the mammalian cochlea in particular has been the subject of intense scrutiny. Zebrafish lack a cochlea and exhibit a number of other differences from amniote species, hence they are sometimes seen as less relevant for inner ear studies. However, accumulating evidence shows that underlying cellular and molecular mechanisms are often highly conserved. As a case in point, consideration of the diverse functions of Fgf and its downstream effectors reveals many similarities between vertebrate species, allowing meaningful comparisons the can benefit the entire research community. In this review, I will discuss mechanisms by which Fgf controls key events in early otic development in zebrafish and provide direct comparisons with chick and mouse.
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Affiliation(s)
- Bruce B Riley
- Biology Department, Texas A&M University, College Station, Texas, USA
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7
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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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8
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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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9
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White PM. Perspectives on Human Hearing Loss, Cochlear Regeneration, and the Potential for Hearing Restoration Therapies. Brain Sci 2020; 10:E756. [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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10
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Holman HA, Wan Y, Rabbitt RD. Developmental GAD2 Expression Reveals Progenitor-like Cells with Calcium Waves in Mammalian Crista Ampullaris. iScience 2020; 23:101407. [PMID: 32771977 PMCID: PMC7415930 DOI: 10.1016/j.isci.2020.101407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/29/2020] [Accepted: 07/21/2020] [Indexed: 01/26/2023] Open
Abstract
Sense of motion, spatial orientation, and balance in vertebrates relies on sensory hair cells in the inner ear vestibular system. Vestibular supporting cells can regenerate hair cells that are lost from aging, ototoxicity, and trauma, although not all factors or specific cell types are known. Here we report a population of GAD2-positive cells in the mouse crista ampullaris and trace GAD2 progenitor-like cells that express pluripotent transcription factors SOX2, PROX1, and CTBP2. GAD2 progenitor-like cells organize into rosettes around a central branched structure in the eminentia cruciatum (EC) herein named the EC plexus. GCaMP5G calcium indicator shows spontaneous and acetylcholine-evoked whole-cell calcium waves in neonatal and adult mice. We present a hypothetical model that outlines the lineage and potential regenerative capacity of GAD2 cells in the mammalian vestibular neuroepithelium.
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Affiliation(s)
- Holly A Holman
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA.
| | - Yong Wan
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Richard D Rabbitt
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA; Graduate Program in Neuroscience, University of Utah, Salt Lake City, UT 84112, USA; Department of Otolaryngology-Head & Neck Surgery, University of Utah, Salt Lake City, UT 84112, USA
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11
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Brown R, Groves AK. Hear, Hear for Notch: Control of Cell Fates in the Inner Ear by Notch Signaling. Biomolecules 2020; 10:biom10030370. [PMID: 32121147 PMCID: PMC7175228 DOI: 10.3390/biom10030370] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 02/08/2023] Open
Abstract
The vertebrate inner ear is responsible for detecting sound, gravity, and head motion. These mechanical forces are detected by mechanosensitive hair cells, arranged in a series of sensory patches in the vestibular and cochlear regions of the ear. Hair cells form synapses with neurons of the VIIIth cranial ganglion, which convey sound and balance information to the brain. They are surrounded by supporting cells, which nourish and protect the hair cells, and which can serve as a source of stem cells to regenerate hair cells after damage in non-mammalian vertebrates. The Notch signaling pathway plays many roles in the development of the inner ear, from the earliest formation of future inner ear ectoderm on the side of the embryonic head, to regulating the production of supporting cells, hair cells, and the neurons that innervate them. Notch signaling is re-deployed in non-mammalian vertebrates during hair cell regeneration, and attempts have been made to manipulate the Notch pathway to promote hair cell regeneration in mammals. In this review, we summarize the different modes of Notch signaling in inner ear development and regeneration, and describe how they interact with other signaling pathways to orchestrate the fine-grained cellular patterns of the ear.
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Affiliation(s)
- Rogers Brown
- Program in Developmental Biology; Baylor College of Medicine, Houston, TX 77030, USA;
| | - Andrew K. Groves
- Program in Developmental Biology; Baylor College of Medicine, Houston, TX 77030, USA;
- Department of Neuroscience; Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-713-798-8743
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12
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Munnamalai V, Fekete DM. The acquisition of positional information across the radial axis of the cochlea. Dev Dyn 2019; 249:281-297. [PMID: 31566832 DOI: 10.1002/dvdy.118] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Affiliation(s)
- Vidhya Munnamalai
- The Jackson Laboratory Bar Harbor Maine
- Graduate Program of Biomedical Sciences and EngineeringUniversity of Maine Orono Maine
- The Neuroscience ProgramSackler School of Biomedical Sciences, Tufts University Boston Massachusetts
| | - Donna M. Fekete
- Department of Biological SciencesPurdue University West Lafayette Indiana
- Purdue Institute for Integrative Neuroscience West Lafayette Indiana
- Purdue Center for Cancer Research West Lafayette Indiana
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13
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Steevens AR, Glatzer JC, Kellogg CC, Low WC, Santi PA, Kiernan AE. SOX2 is required for inner ear growth and cochlear nonsensory formation before sensory development. Development 2019; 146:dev.170522. [PMID: 31152002 DOI: 10.1242/dev.170522] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 05/13/2019] [Indexed: 12/16/2022]
Abstract
The transcription factor sex determining region Y-box 2 (SOX2) is required for the formation of hair cells and supporting cells in the inner ear and is a widely used sensory marker. Paradoxically, we demonstrate via fate mapping that, initially, SOX2 primarily marks nonsensory progenitors in the mouse cochlea, and is not specific to all sensory regions until late otic vesicle stages. SOX2 fate mapping reveals an apical-to-basal gradient of SOX2 expression in the sensory region of the cochlea, reflecting the pattern of cell cycle exit. To understand SOX2 function, we undertook a timed-deletion approach, revealing that early loss of SOX2 severely impaired morphological development of the ear, whereas later deletions resulted in sensory disruptions. During otocyst stages, SOX2 shifted dramatically from a lateral to medial domain over 24-48 h, reflecting the nonsensory-to-sensory switch observed by fate mapping. Early loss or gain of SOX2 function led to changes in otic epithelial volume and progenitor proliferation, impacting growth and morphological development of the ear. Our study demonstrates a novel role for SOX2 in early otic morphological development, and provides insights into the temporal and spatial patterns of sensory specification in the inner ear.
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Affiliation(s)
- Aleta R Steevens
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Jenna C Glatzer
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Courtney C Kellogg
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Walter C Low
- Department of Neurosurgery, University of Minnesota, Minneapolis, MN 55455, USA
| | - Peter A Santi
- Department of Otolaryngology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Amy E Kiernan
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA .,Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA
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14
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Zhang J, Wang Q, Abdul-Aziz D, Mattiacio J, Edge ASB, White PM. ERBB2 signaling drives supporting cell proliferation in vitro and apparent supernumerary hair cell formation in vivo in the neonatal mouse cochlea. Eur J Neurosci 2018; 48:3299-3316. [PMID: 30270571 DOI: 10.1111/ejn.14183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/07/2018] [Accepted: 09/03/2018] [Indexed: 12/29/2022]
Abstract
In mammals, cochlear hair cells are not regenerated once they are lost, leading to permanent hearing deficits. In other vertebrates, the adjacent supporting cells act as a stem cell compartment, in that they both proliferate and differentiate into de novo auditory hair cells. Although there is evidence that mammalian cochlear supporting cells can differentiate into new hair cells, the signals that regulate this process are poorly characterized. We hypothesize that signaling from the epidermal growth factor receptor (EGFR) family may play a role in cochlear regeneration. We focus on one such member, ERBB2, and report the effects of expressing a constitutively active ERBB2 receptor in neonatal mouse cochlear supporting cells, using viruses and transgenic expression. Lineage tracing with fluorescent reporter proteins was used to determine the relationships between cells with active ERBB2 signaling and cells that divided or differentiated into hair cells. In vitro, individual supporting cells harbouring a constitutively active ERBB2 receptor appeared to signal to their neighbouring supporting cells, inducing them to down-regulate a supporting cell marker and to proliferate. In vivo, we found supernumerary hair cell-like cells near supporting cells that expressed ERBB2 receptors. Both supporting cell proliferation and hair cell differentiation were largely reproduced in vitro using small molecules that we show also activate ERBB2. Our data suggest that signaling from the receptor tyrosine kinase ERBB2 can drive the activation of secondary signaling pathways to regulate regeneration, suggesting a new model where an interplay of cell signaling regulates regeneration by endogenous stem-like cells.
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Affiliation(s)
- Jingyuan Zhang
- Department of Biology, School of Arts and Sciences, University of Rochester, Rochester, New York
| | - Quan Wang
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
| | - Dunia Abdul-Aziz
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts
| | - Jonelle Mattiacio
- Department of Microbiology and Immunology, University of Rochester School of Medicine, Rochester, New York
| | - 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
| | - Patricia M White
- Department of Neuroscience, The Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine, Rochester, New York
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15
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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: 49] [Impact Index Per Article: 8.2] [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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16
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Abstract
The sensation of touch is mediated by mechanosensory neurons that are embedded in skin and relay signals from the periphery to the central nervous system. During embryogenesis, axons elongate from these neurons to make contact with the developing skin. Concurrently, the epithelium of skin transforms from a homogeneous tissue into a heterogeneous organ that is made up of distinct layers and microdomains. Throughout this process, each neuronal terminal must form connections with an appropriate skin region to serve its function. This Review presents current knowledge of the development of the sensory microdomains in mammalian skin and the mechanosensory neurons that innervate them.
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Affiliation(s)
- Blair A Jenkins
- Department of Physiology & Cellular Biophysics and Department of Dermatology, Columbia University in the City of New York, New York, NY 10032, USA
| | - Ellen A Lumpkin
- Department of Physiology & Cellular Biophysics and Department of Dermatology, Columbia University in the City of New York, New York, NY 10032, USA
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17
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Rohacek AM, Bebee TW, Tilton RK, Radens CM, McDermott-Roe C, Peart N, Kaur M, Zaykaner M, Cieply B, Musunuru K, Barash Y, Germiller JA, Krantz ID, Carstens RP, Epstein DJ. ESRP1 Mutations Cause Hearing Loss due to Defects in Alternative Splicing that Disrupt Cochlear Development. Dev Cell 2017; 43:318-331.e5. [PMID: 29107558 PMCID: PMC5687886 DOI: 10.1016/j.devcel.2017.09.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 08/15/2017] [Accepted: 08/26/2017] [Indexed: 12/30/2022]
Abstract
Alternative splicing contributes to gene expression dynamics in many tissues, yet its role in auditory development remains unclear. We performed whole-exome sequencing in individuals with sensorineural hearing loss (SNHL) and identified pathogenic mutations in Epithelial Splicing-Regulatory Protein 1 (ESRP1). Patient-derived induced pluripotent stem cells showed alternative splicing defects that were restored upon repair of an ESRP1 mutant allele. To determine how ESRP1 mutations cause hearing loss, we evaluated Esrp1-/- mouse embryos and uncovered alterations in cochlear morphogenesis, auditory hair cell differentiation, and cell fate specification. Transcriptome analysis revealed impaired expression and splicing of genes with essential roles in cochlea development and auditory function. Aberrant splicing of Fgfr2 blocked stria vascularis formation due to erroneous ligand usage, which was corrected by reducing Fgf9 gene dosage. These findings implicate mutations in ESRP1 as a cause of SNHL and demonstrate the complex interplay between alternative splicing, inner ear development, and auditory function.
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Affiliation(s)
- Alex M Rohacek
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Clinical Research Building, Room 463, 415 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Thomas W Bebee
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Richard K Tilton
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Caleb M Radens
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Clinical Research Building, Room 463, 415 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Chris McDermott-Roe
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Natoya Peart
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Maninder Kaur
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Michael Zaykaner
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Benjamin Cieply
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kiran Musunuru
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yoseph Barash
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Clinical Research Building, Room 463, 415 Curie Boulevard, Philadelphia, PA 19104, USA
| | - John A Germiller
- Division of Pediatric Otolaryngology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ian D Krantz
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Clinical Research Building, Room 463, 415 Curie Boulevard, Philadelphia, PA 19104, USA; Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Russ P Carstens
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Douglas J Epstein
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Clinical Research Building, Room 463, 415 Curie Boulevard, Philadelphia, PA 19104, USA.
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18
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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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19
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Basch ML, Brown RM, Jen HI, Semerci F, Depreux F, Edlund RK, Zhang H, Norton CR, Gridley T, Cole SE, Doetzlhofer A, Maletic-Savatic M, Segil N, Groves AK. Fine-tuning of Notch signaling sets the boundary of the organ of Corti and establishes sensory cell fates. eLife 2016; 5:19921. [PMID: 27966429 PMCID: PMC5215100 DOI: 10.7554/elife.19921] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/12/2016] [Indexed: 01/08/2023] Open
Abstract
The signals that induce the organ of Corti and define its boundaries in the cochlea are poorly understood. We show that two Notch modifiers, Lfng and Mfng, are transiently expressed precisely at the neural boundary of the organ of Corti. Cre-Lox fate mapping shows this region gives rise to inner hair cells and their associated inner phalangeal cells. Mutation of Lfng and Mfng disrupts this boundary, producing unexpected duplications of inner hair cells and inner phalangeal cells. This phenotype is mimicked by other mouse mutants or pharmacological treatments that lower but not abolish Notch signaling. However, strong disruption of Notch signaling causes a very different result, generating many ectopic hair cells at the expense of inner phalangeal cells. Our results show that Notch signaling is finely calibrated in the cochlea to produce precisely tuned levels of signaling that first set the boundary of the organ of Corti and later regulate hair cell development. DOI:http://dx.doi.org/10.7554/eLife.19921.001
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Affiliation(s)
- Martin L Basch
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Rogers M Brown
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Hsin-I Jen
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Fatih Semerci
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Frederic Depreux
- Department of Cell Biology and Anatomy, Rosalind Franklin University of Medicine and Science, Chicago, United States
| | - Renée K Edlund
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Hongyuan Zhang
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | | | - Thomas Gridley
- Maine Medical Center Research Institute, Scarborough, United States
| | - Susan E Cole
- Department of Molecular Genetics, The Ohio State University, Columbus, United States
| | - Angelika Doetzlhofer
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, United States
| | - Mirjana Maletic-Savatic
- Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Program in Developmental Biology, Baylor College of Medicine, Houston, United States.,Department of Pediatrics, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, United States
| | - Neil Segil
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, United States
| | - Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Program in Developmental Biology, Baylor College of Medicine, Houston, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
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20
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Schäck L, Budde S, Lenarz T, Krettek C, Gross G, Windhagen H, Hoffmann A, Warnecke A. Induction of neuronal-like phenotype in human mesenchymal stem cells by overexpression of Neurogenin1 and treatment with neurotrophins. Tissue Cell 2016; 48:524-32. [PMID: 27423984 DOI: 10.1016/j.tice.2016.06.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 06/18/2016] [Accepted: 06/25/2016] [Indexed: 01/15/2023]
Abstract
AIM OF THE STUDY The induced expression of the transcription factors neurogenin1 (Neurog1) or neuronal differentiation 1 (NeuroD1) has previously been shown to initiate neuronal differentiation in embryonic stem cells (ESC). Human bone marrow-derived mesenchymal stem cells (hBMSCs) are ethically non-controversial stem cells. However, they are not pluripotent. In cochlear implantation, regeneration or replacement of lost spiral ganglion neurons may be a measure for the improvement of implant function. Thus, the aim of the study was to investigate whether the expression of Neurog1 or NeuroD1 is sufficient for induction of neuronal differentiation in hBMSCs. MATERIALS AND METHODS Human BMSCs were transduced with lentivirus expressing NeuroD1 or Neuorg1. Transduced cells were then treated with small molecules that enhanced neuronal differentiation. Markers of neuronal differentiation were evaluated. RESULTS Using quantitative reverse transcription PCR, the up-regulation of transcription factors expressed by developing primary auditory neurons, such as BRN3a (POU4F1) and GATA3, was quantified after induction of Neurog-1 expression. In addition, the expression of the receptor NTRK2 was induced by treatment with its specific ligand BDNF. The induction of expression of the vesicular glutamate transporter 1 was identified on gene and protein level. NeuroD1 seemed not sufficient to induce and maintain neuronal differentiation. CONCLUSIONS Induction of neuronal differentiation by overexpression of Neurog1 initiated important steps for the development of glutamatergic neurons such as the spiral ganglion neurons. However, it seems not sufficient to maintain the glutamatergic spiral ganglion neuron-like phenotype.
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Affiliation(s)
- Luisa Schäck
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany; Department of Trauma Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany
| | - Stefan Budde
- Department of Orthopaedic Surgery, Hannover Medical School, Annastift, Anna von Borries-Str. 1-7, 30625 Hannover, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany; Cluster of Excellence "Hearing4all" of the German Research Foundation, Germany
| | - Christian Krettek
- Department of Trauma Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany
| | - Gerhard Gross
- Helmholtz Centre for Infection Research, Department of Gene Regulation and Differentiation, Inhoffenstr. 7, 38124 Braunschweig, Germany
| | - Henning Windhagen
- Department of Orthopaedic Surgery, Hannover Medical School, Annastift, Anna von Borries-Str. 1-7, 30625 Hannover, Germany
| | - Andrea Hoffmann
- Department of Trauma Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany; Department of Orthopaedic Surgery, Hannover Medical School, Annastift, Anna von Borries-Str. 1-7, 30625 Hannover, Germany
| | - Athanasia Warnecke
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Carl Neuberg-Str. 1, 30625 Hannover, Germany; Cluster of Excellence "Hearing4all" of the German Research Foundation, Germany.
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21
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Lineage tracing of Sox2-expressing progenitor cells in the mouse inner ear reveals a broad contribution to non-sensory tissues and insights into the origin of the organ of Corti. Dev Biol 2016; 414:72-84. [PMID: 27090805 DOI: 10.1016/j.ydbio.2016.03.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 03/09/2016] [Accepted: 03/26/2016] [Indexed: 11/22/2022]
Abstract
The transcription factor Sox2 is both necessary and sufficient for the generation of sensory regions of the inner ear. It regulates expression of the Notch ligand Jag1 in prosensory progenitors, which signal to neighboring cells to up-regulate Sox2 and sustain prosensory identity. However, the expression pattern of Sox2 in the early inner ear is very broad, suggesting that Sox2-expressing progenitors form a wide variety of cell types in addition to generating the sensory regions of the ear. We used Sox2-CreER mice to follow the fates of Sox2-expressing cells at different stages in ear development. We find that Sox2-expressing cells in the early otocyst give rise to large numbers of non-sensory structures throughout the inner ear, and that Sox2 only becomes a truly prosensory marker at embryonic day (E)11.5. Our fate map reveals the organ of Corti derives from a central domain on the medial side of the otocyst and shows that a significant amount of the organ of Corti derives from a Sox2-negative population in this region.
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22
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Zhou Y, Qing J, Dong Y, Nie J, Li J, Wang C, Liu Y, Peng T, Duan M, Liu X, Xie D. The role of transcription factors of neurosensory cells in non-syndromic sensorineural hearing loss with or without inner ear malformation. Acta Otolaryngol 2015; 136:277-82. [PMID: 26634621 DOI: 10.3109/00016489.2015.1109706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSIONS Previous studies have stated the roles and correlation of the four TFs (Sox2, Atoh1, Neurog1, and Neurod1) in the development of neurosensory cells. but whether they are inherited pathogenic factors to cause non-syndromic sensorineural hearing loss is unknown so far. This is the first time for screening the Sox2, Atoh1, Neurog1, and Neurod1 genes in children with NSHL. The c.133A > G in Neurod1 gene is a polymorphism, which is not associated with NSHL. Although these genes are the recognized TFs for modulating the development and transformation of NSCs, they may not be the inherited pathogenic factors to cause congenital severe or profound NSHL directly. OBJECTIVE To investigate the effect of the transcription factors (TFs) for the development of neurosensory cells (NSCs) and to explore the genetic etiology of congenital profound non-syndromic sensorineural hearing loss (NSHL). METHODS Children with NSHL, from multi-national and regional group, and control group were recruited to screen for the most common mutations for non-syndromic deafness among East Asian (mtDNA 12S rRNA: 1555A > G, 1494C > T; SLC26A4: IVS7-2 A > G, 2168 C > T). And mutational analysis of the coding regions in Sox2, Atoh1 and Neurog1, Neurod1 genes were performed. RESULTS Only the c.133A > G (p. Ala45Thr) in the Neurod1 gene was detected in this study. The allele frequencies of this variant were 88.00% and 84.88% in the inner ear malformation group and the normal inner ear group, respectively, while 90.85% of children in the control group carried c.133A > G. This variant existed in every group commonly and had no significant difference among them. No variant in the other two TFs was detected in this cohort.
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Affiliation(s)
- Yuan Zhou
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
| | - Jie Qing
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
| | - Yunpeng Dong
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
| | - Jin Nie
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
| | - Jingkun Li
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
| | - Chunmei Wang
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
| | - Yuyuan Liu
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
| | - Tao Peng
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
| | - Maoli Duan
- b Department of Clinical Science, Intervention and Technology, Department of Otolaryngology Head and Neck Surgery, Department of Neurotology and Audiology , Karolinska Institutet , Stockholm , Sweden
| | - Xuezhong Liu
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
- c Department of Otolaryngology, Miller School of Medicine , University of Miami , Miami , FL , USA
| | - Dinghua Xie
- a Department of Otolaryngology Head and Neck Surgery , Institute of Otology, the Second Xiangya Hospital, Central South University , Changsha , PR China
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23
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She ZY, Yang WX. SOX family transcription factors involved in diverse cellular events during development. Eur J Cell Biol 2015; 94:547-63. [PMID: 26340821 DOI: 10.1016/j.ejcb.2015.08.002] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 08/11/2015] [Accepted: 08/11/2015] [Indexed: 12/22/2022] Open
Abstract
In metazoa, SOX family transcription factors play many diverse roles. In vertebrate, they are well-known regulators of numerous developmental processes. Wide-ranging studies have demonstrated the co-expression of SOX proteins in various developing tissues and that they occur in an overlapping manner and show functional redundancy. In particular, studies focusing on the HMG box of SOX proteins have revealed that the HMG box regulates DNA-binding properties, and mediates both the nucleocytoplasmic shuttling of SOX proteins and their physical interactions with partner proteins. Posttranslational modifications are further implicated in the regulation of the transcriptional activities of SOX proteins. In this review, we discuss the underlying molecular mechanisms involved in the SOX-partner factor interactions and the functional modes of SOX-partner complexes during development. We particularly emphasize the representative roles of the SOX group proteins in major tissues during developmental and physiological processes.
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Affiliation(s)
- Zhen-Yu She
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou 310058, China.
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24
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Whitfield TT. Development of the inner ear. Curr Opin Genet Dev 2015; 32:112-8. [DOI: 10.1016/j.gde.2015.02.006] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/11/2015] [Accepted: 02/13/2015] [Indexed: 02/04/2023]
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25
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Pinto-Teixeira F, Viader-Llargués O, Torres-Mejía E, Turan M, González-Gualda E, Pola-Morell L, López-Schier H. Inexhaustible hair-cell regeneration in young and aged zebrafish. Biol Open 2015; 4:903-9. [PMID: 26002931 PMCID: PMC4571094 DOI: 10.1242/bio.012112] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Animals have evolved two general strategies to counter injury and maintain physiological function. The most prevalent is protection by isolating vital organs into body cavities. However, protection is not optimal for sensory systems because their external components need to be exposed to the environment to fulfill their receptive function. Thus, a common strategy to maintain sensory abilities against persistent environmental insult involves repair and regeneration. However, whether age or frequent injuries affect the regenerative capacity of sensory organs remains unknown. We have found that neuromasts of the zebrafish lateral line regenerate mechanosensory hair cells after recurrent severe injuries and in adulthood. Moreover, neuromasts can reverse transient imbalances of Notch signaling that result in defective organ proportions during repair. Our results reveal inextinguishable hair-cell regeneration in the lateral line, and suggest that the neuromast epithelium is formed by plastic territories that are maintained by continuous intercellular communication.
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Affiliation(s)
- Filipe Pinto-Teixeira
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Oriol Viader-Llargués
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Elen Torres-Mejía
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Melissa Turan
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Estela González-Gualda
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Laura Pola-Morell
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Hernán López-Schier
- Laboratory of Sensory Cell Biology & Organogenesis, Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain
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26
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Sienknecht UJ. Current concepts of hair cell differentiation and planar cell polarity in inner ear sensory organs. Cell Tissue Res 2015; 361:25-32. [PMID: 25959294 DOI: 10.1007/s00441-015-2200-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 04/15/2015] [Indexed: 11/25/2022]
Abstract
Phylogenetically and ontogenetically, vertebrate development led to the generation of several inner ear sensory organs. During embryogenesis, cell fate specification determines whether each progenitor cell differentiates into a sensory hair cell or a supporting cell within the common sensory primordium. Finally, all sensory epithelia of the inner ear consist of a hair cell/supporting cell mosaic, albeit with anatomical differences depending on the sensory organ type. Hair cells develop a polarized bundle of stereovilli that is of functional importance for mechanotransduction. After initiating stereovillar development, hair cells align their bundles in a coordinated fashion, generating a characteristic hair cell orientation pattern, a process referred to as planar cell polarity (PCP). The pathway that controls PCP in the inner ear needs both to establish the development of a polarized morphology of the stereovillar bundle of the hair cell and to organize a systematic hair cell alignment. Because the hair cell orientation patterns of the various inner ear organs and vertebrate species differ fundamentally, it becomes apparent that in vertebrates, different aspects of PCP need to be independently controlled. In spite of important progress recently gained in the field of PCP research, we still need to identify the mechanisms (1) that initiate molecular asymmetries in cells, (2) that guide the transmission of polarity information from cell to cell, and (3) that consistently translate such polarity information into morphological asymmetries of hair cells.
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Affiliation(s)
- Ulrike J Sienknecht
- Department of Neuroscience, School of Medicine and Health Science, Research Center Neurosensory Science, Cluster of Excellence "Hearing4all", Carl von Ossietzky University Oldenburg, Carl von Ossietzky Strasse 9-11, 26129, Oldenburg, Germany,
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27
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Mellott AJ, Devarajan K, Shinogle HE, Moore DS, Talata Z, Laurence JS, Forrest ML, Noji S, Tanaka E, Staecker H, Detamore MS. Nonviral Reprogramming of Human Wharton's Jelly Cells Reveals Differences Between ATOH1 Homologues. Tissue Eng Part A 2015; 21:1795-809. [PMID: 25760435 DOI: 10.1089/ten.tea.2014.0340] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The transcription factor atonal homolog 1 (ATOH1) has multiple homologues that are functionally conserved across species and is responsible for the generation of sensory hair cells. To evaluate potential functional differences between homologues, human and mouse ATOH1 (HATH1 and MATH-1, respectively) were nonvirally delivered to human Wharton's jelly cells (hWJCs) for the first time. Delivery of HATH1 to hWJCs demonstrated superior expression of inner ear hair cell markers and characteristics than delivery of MATH-1. Inhibition of HES1 and HES5 signaling further increased the atonal effect. Transfection of hWJCs with HATH1 DNA, HES1 siRNA, and HES5 siRNA displayed positive identification of key hair cell and support cell markers found in the cochlea, as well as a variety of cell shapes, sizes, and features not native to hair cells, suggesting the need for further examination of other cell types induced by HATH1 expression. In the first side-by-side evaluation of HATH1 and MATH-1 in human cells, substantial differences were observed, suggesting that the two atonal homologues may not be interchangeable in human cells, and artificial expression of HATH1 in hWJCs requires further study. In the future, this line of research may lead to engineered systems that would allow for evaluation of drug ototoxicity or potentially even direct therapeutic use.
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Affiliation(s)
- Adam J Mellott
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas
| | | | - Heather E Shinogle
- 3Microscopy and Analytical Imaging Lab, University of Kansas, Lawrence, Kansas
| | - David S Moore
- 3Microscopy and Analytical Imaging Lab, University of Kansas, Lawrence, Kansas
| | - Zsolt Talata
- 4Department of Mathematics, University of Kansas, Lawrence, Kansas
| | - Jennifer S Laurence
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas.,5Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas
| | - M Laird Forrest
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas.,5Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas
| | - Sumihare Noji
- 6Department of Life Systems, Institute of Technology and Science, The University of Tokushima, Minami-Jyosanjima-cho, Tokushima, Japan
| | - Eiji Tanaka
- 7Department of Orthodontics and Dentofacial Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho, Tokushima, Japan
| | - Hinrich Staecker
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas.,8Department of Otolaryngology, Head and Neck Surgery, University of Kansas Medical Center, Kansas City, Kansas
| | - Michael S Detamore
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas.,9Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, Kansas
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28
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Maass JC, Gu R, Basch ML, Waldhaus J, Lopez EM, Xia A, Oghalai JS, Heller S, Groves AK. Changes in the regulation of the Notch signaling pathway are temporally correlated with regenerative failure in the mouse cochlea. Front Cell Neurosci 2015; 9:110. [PMID: 25873862 PMCID: PMC4379755 DOI: 10.3389/fncel.2015.00110] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/10/2015] [Indexed: 12/20/2022] Open
Abstract
Sensorineural hearing loss is most commonly caused by the death of hair cells in the organ of Corti, and once lost, mammalian hair cells do not regenerate. In contrast, other vertebrates such as birds can regenerate hair cells by stimulating division and differentiation of neighboring supporting cells. We currently know little of the genetic networks which become active in supporting cells when hair cells die and that are activated in experimental models of hair cell regeneration. Several studies have shown that neonatal mammalian cochlear supporting cells are able to trans-differentiate into hair cells when cultured in conditions in which the Notch signaling pathway is blocked. We now show that the ability of cochlear supporting cells to trans-differentiate declines precipitously after birth, such that supporting cells from six-day-old mouse cochlea are entirely unresponsive to a blockade of the Notch pathway. We show that this trend is seen regardless of whether the Notch pathway is blocked with gamma secretase inhibitors, or by antibodies against the Notch1 receptor, suggesting that the action of gamma secretase inhibitors on neonatal supporting cells is likely to be by inhibiting Notch receptor cleavage. The loss of responsiveness to inhibition of the Notch pathway in the first postnatal week is due in part to a down-regulation of Notch receptors and ligands, and we show that this down-regulation persists in the adult animal, even under conditions of noise damage. Our data suggest that the Notch pathway is used to establish the repeating pattern of hair cells and supporting cells in the organ of Corti, but is not required to maintain this cellular mosaic once the production of hair cells and supporting cells is completed. Our results have implications for the proposed used of Notch pathway inhibitors in hearing restoration therapies.
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Affiliation(s)
- Juan C Maass
- Department of Neuroscience, Baylor College of Medicine Houston, TX, USA ; Department of Otolaryngology, Hospital Clínico Universidad de Chile Santiago, Chile ; Interdisciplinary Program of Physiology and Biophysics, ICBM Universidad de Chile Santiago, Chile ; Department of Otolaryngology, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana-Universidad del Desarrollo Santiago, Chile
| | - Rende Gu
- Department of Neuroscience, Baylor College of Medicine Houston, TX, USA
| | - Martin L Basch
- Department of Neuroscience, Baylor College of Medicine Houston, TX, USA
| | - Joerg Waldhaus
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine Palo Alto, CA, USA
| | | | - Anping Xia
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine Palo Alto, CA, USA
| | - John S Oghalai
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine Palo Alto, CA, USA
| | - Stefan Heller
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine Palo Alto, CA, USA
| | - Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine Houston, TX, USA ; Department of Molecular and Human Genetics, Baylor College of Medicine Houston, TX, USA ; Program in Developmental Biology, Baylor College of Medicine Houston, TX, USA
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29
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Mulvaney JF, Amemiya Y, Freeman SD, Ladher RK, Dabdoub A. Molecular cloning and functional characterisation of chicken Atonal homologue 1: a comparison with human Atoh1. Biol Cell 2015; 107:41-60. [PMID: 25412697 DOI: 10.1111/boc.201400078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 11/20/2014] [Indexed: 12/19/2022]
Abstract
BACKGROUND INFORMATION The vertebrate basic helix-loop-helix transcription factor Atoh1 is essential for maturation and survival of mechanosensory hair cells of the inner ear, neurogenesis, differentiation of the intestine, homeostasis of the colon and is implicated in cancer progression. Given that mutations in Atoh1 are detected in malignant tumours, study of functionally different Atoh1 alleles and homologues might yield useful avenues for investigation. The predicted sequence of chicken Atoh1 (cAtoh1) has large regions of dissimilarity to that of mammalian Atoh1 homologues. We hypothesise that cAtoh1 might have intrinsic functional differences to mammalian Atoh1. RESULTS In this study, we cloned and sequenced the full open reading frame of cAtoh1. In overexpression experiments, we show that this sequence is sufficient to generate a cAtoh1 protein capable of inducing hair cell markers when expressed in nonsensory regions of the developing inner ear, and that morpholino-mediated knock-down using a section of the sequence 5' to the start codon inhibits differentiation of hair cells in the chicken basilar papilla. Furthermore, we compare the behaviour of cAtoh1 and human Atoh1 (hAtoh1) in embryonic mouse cochlear explants, showing that cAtoh1 is a potent inducer of hair cell differentiation and that it can overcome Sox2-mediated repression of hair cell differentiation more effectively than hAtoh1. CONCLUSIONS cAtoh1 is both necessary and sufficient for avian mechanosensory hair cell differentiation. The non-conserved regions of the cAtoh1 coding region have functional consequences on its behaviour.
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Affiliation(s)
- Joanna F Mulvaney
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, M4N 3M5, Canada
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30
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Cai T, Groves AK. The Role of Atonal Factors in Mechanosensory Cell Specification and Function. Mol Neurobiol 2014; 52:1315-1329. [PMID: 25339580 DOI: 10.1007/s12035-014-8925-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 10/07/2014] [Indexed: 10/24/2022]
Abstract
Atonal genes are basic helix-loop-helix transcription factors that were first identified as regulating the formation of mechanoreceptors and photoreceptors in Drosophila. Isolation of vertebrate homologs of atonal genes has shown these transcription factors to play diverse roles in the development of neurons and their progenitors, gut epithelial cells, and mechanosensory cells in the inner ear and skin. In this article, we review the molecular function and regulation of atonal genes and their targets, with particular emphasis on the function of Atoh1 in the development, survival, and function of hair cells of the inner ear. We discuss cell-extrinsic signals that induce Atoh1 expression and the transcriptional networks that regulate its expression during development. Finally, we discuss recent work showing how identification of Atoh1 target genes in the cerebellum, spinal cord, and gut can be used to propose candidate Atoh1 targets in tissues such as the inner ear where cell numbers and biochemical material are limiting.
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Affiliation(s)
- Tiantian Cai
- Program in Developmental Biology, Baylor College of Medicine, Houston, USA
| | - Andrew K Groves
- Program in Developmental Biology, Baylor College of Medicine, Houston, USA. .,Department of Neuroscience, Baylor College of Medicine, Houston, USA. .,Department of Molecular and Human Genetics, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA.
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31
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Hu Z, Wang J. Histone deacetylase inhibitor induces the expression of select epithelial genes in mouse utricle sensory epithelia-derived progenitor cells. Cell Reprogram 2014; 16:266-75. [PMID: 24945595 DOI: 10.1089/cell.2013.0086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mouse utricle sensory epithelial cell-derived progenitor cells (MUCs), which have hair cell progenitor and mesenchymal features via epithelial-to-mesenchymal transition (EMT) as previously described, provide a potential approach for hair cell regeneration via cell transplantation. In this study, we treated MUCs with trichostatin A (TSA) to determine whether histone deacetylase inhibitor is able to stimulate the expression of epithelial genes in MUCs, an essential step for guiding mesenchymal-like MUCs to become sensory epithelial cells. After 72 h of TSA treatment, MUCs acquired epithelial-like features, which were indicated by increased expression of epithelial markers such as Cdh1, Krt18, and Dsp. Additionally, TSA decreased the expression of mesenchymal markers, including Zeb1, Zeb2, Snai1, and Snai2, and prosensory genes Lfng, Six1, and Dlx5. Moreover, the expression of the hair cell genes Atoh1 and Myo6 was increased in TSA-treated MUCs. We also observed significantly decreased expression of Hdac2 and Hdac3 in TSA-treated MUCs. However, no remarkable change was detected in protein expression using immunofluorescence, indicating that TSA-induced HDAC inhibition may contribute to the initial stage of the mesenchymal-to-epithelial phenotypic change. In the future, more work is needed to induce hair cell regeneration using inner ear tissue-derived progenitors to achieve an entire mesenchymal-to-epithelial transition.
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Affiliation(s)
- Zhengqing Hu
- Department of Otolaryngology-HNS, Wayne State University School of Medicine , Detroit, MI, 48201
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32
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Raft S, Groves AK. Segregating neural and mechanosensory fates in the developing ear: patterning, signaling, and transcriptional control. Cell Tissue Res 2014; 359:315-32. [PMID: 24902666 DOI: 10.1007/s00441-014-1917-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 05/08/2014] [Indexed: 12/21/2022]
Abstract
The vertebrate inner ear is composed of multiple sensory receptor epithelia, each of which is specialized for detection of sound, gravity, or angular acceleration. Each receptor epithelium contains mechanosensitive hair cells, which are connected to the brainstem by bipolar sensory neurons. Hair cells and their associated neurons are derived from the embryonic rudiment of the inner ear epithelium, but the precise spatial and temporal patterns of their generation, as well as the signals that coordinate these events, have only recently begun to be understood. Gene expression, lineage tracing, and mutant analyses suggest that both neurons and hair cells are generated from a common domain of neural and sensory competence in the embryonic inner ear rudiment. Members of the Shh, Wnt, and FGF families, together with retinoic acid signals, regulate transcription factor genes within the inner ear rudiment to establish the axial identity of the ear and regionalize neurogenic activity. Close-range signaling, such as that of the Notch pathway, specifies the fate of sensory regions and individual cell types. We also describe positive and negative interactions between basic helix-loop-helix and SoxB family transcription factors that specify either neuronal or sensory fates in a context-dependent manner. Finally, we review recent work on inner ear development in zebrafish, which demonstrates that the relative timing of neurogenesis and sensory epithelial formation is not phylogenetically constrained.
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Affiliation(s)
- Steven Raft
- Section on Sensory Cell Regeneration and Development, National Institute on Deafness and Other Communication Disorders National Institutes of Health, 35 Convent Drive, Bethesda, MD, 20892, USA,
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In vivo generation of immature inner hair cells in neonatal mouse cochleae by ectopic Atoh1 expression. PLoS One 2014; 9:e89377. [PMID: 24586731 PMCID: PMC3930725 DOI: 10.1371/journal.pone.0089377] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 01/18/2014] [Indexed: 01/14/2023] Open
Abstract
Regeneration of auditory hair cells (HCs) is a promising approach to restore hearing. Recent studies have demonstrated that induced pluripotent stem cells/embryonic stem cells or supporting cells (SCs) adjacent to HCs can be converted to adopt the HC fate. However, little is known about whether new HCs are characteristic of outer or inner HCs. Here, we showed in vivo conversion of 2 subtypes of SCs, inner border cells (IBs) and inner phalangeal cells (IPhs), to the inner HC (IHC) fate. This was achieved by ectopically activating Atoh1, a transcription factor necessary for HC fate, in IBs/IPhs at birth. Atoh1+ IBs/IPhs first turned on Pou4f3, another HC transcription factor, before expressing 8 HC markers. The conversion rate gradually increased from ∼2.4% at 1 week of age to ∼17.8% in adult. Interestingly, new HCs exhibited IHC characteristics such as straight line–shaped stereociliary bundles, expression of Fgf8 and otoferlin, and presence of larger outward currents than those of outer HCs. However, new HCs lacked the terminal differentiation IHC marker vGlut3, exhibited reduced density of presynaptic Cbtp2 puncta that had little postsynaptic GluR2 specialization, and displayed immature IHC outward currents. Our results demonstrate that the conversion rate of IBs/IPhs in vivo by Atoh1 ectopic expression into the IHC fate was higher and faster and the conversion was more complete than that of the 2 other SC subtypes underneath the outer HCs; however, these new IHCs are arrested before terminal differentiation. Thus, IBs/IPhs are good candidates to regenerate IHCs in vivo.
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34
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Locher H, Frijns JHM, van Iperen L, de Groot JCMJ, Huisman MA, Chuva de Sousa Lopes SM. Neurosensory development and cell fate determination in the human cochlea. Neural Dev 2013; 8:20. [PMID: 24131517 PMCID: PMC3854452 DOI: 10.1186/1749-8104-8-20] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 09/20/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hearing depends on correct functioning of the cochlear hair cells, and their innervation by spiral ganglion neurons. Most of the insight into the embryological and molecular development of this sensory system has been derived from animal studies. In contrast, little is known about the molecular expression patterns and dynamics of signaling molecules during normal fetal development of the human cochlea. In this study, we investigated the onset of hair cell differentiation and innervation in the human fetal cochlea at various stages of development. RESULTS At 10 weeks of gestation, we observed a prosensory domain expressing SOX2 and SOX9/SOX10 within the cochlear duct epithelium. In this domain, hair cell differentiation was consistently present from 12 weeks, coinciding with downregulation of SOX9/SOX10, to be followed several weeks later by downregulation of SOX2. Outgrowing neurites from spiral ganglion neurons were found penetrating into the cochlear duct epithelium prior to hair cell differentiation, and directly targeted the hair cells as they developed. Ubiquitous Peripherin expression by spiral ganglion neurons gradually diminished and became restricted to the type II spiral ganglion neurons by 18 weeks. At 20 weeks, when the onset of human hearing is thought to take place, the expression profiles in hair cells and spiral ganglion neurons matched the expression patterns of the adult mammalian cochleae. CONCLUSIONS Our study provides new insights into the fetal development of the human cochlea, contributing to our understanding of deafness and to the development of new therapeutic strategies to restore hearing.
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Affiliation(s)
| | | | | | | | | | - Susana M Chuva de Sousa Lopes
- Department of Anatomy and Embryology, Leiden University Medical Center, T-01-032, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
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