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Ten A, Kumeiko V, Farniev V, Gao H, Shevtsov M. Tumor Microenvironment Modulation by Cancer-Derived Extracellular Vesicles. Cells 2024; 13:682. [PMID: 38667297 PMCID: PMC11049026 DOI: 10.3390/cells13080682] [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: 02/11/2024] [Revised: 04/06/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
The tumor microenvironment (TME) plays an important role in the process of tumorigenesis, regulating the growth, metabolism, proliferation, and invasion of cancer cells, as well as contributing to tumor resistance to the conventional chemoradiotherapies. Several types of cells with relatively stable phenotypes have been identified within the TME, including cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), neutrophils, and natural killer (NK) cells, which have been shown to modulate cancer cell proliferation, metastasis, and interaction with the immune system, thus promoting tumor heterogeneity. Growing evidence suggests that tumor-cell-derived extracellular vesicles (EVs), via the transfer of various molecules (e.g., RNA, proteins, peptides, and lipids), play a pivotal role in the transformation of normal cells in the TME into their tumor-associated protumorigenic counterparts. This review article focuses on the functions of EVs in the modulation of the TME with a view to how exosomes contribute to the transformation of normal cells, as well as their importance for cancer diagnosis and therapy.
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Affiliation(s)
- Artem Ten
- School of Medicine and Life Sciences, Far Eastern Federal University, 690922 Vladivostok, Russia; (A.T.); (V.K.); (V.F.)
| | - Vadim Kumeiko
- School of Medicine and Life Sciences, Far Eastern Federal University, 690922 Vladivostok, Russia; (A.T.); (V.K.); (V.F.)
| | - Vladislav Farniev
- School of Medicine and Life Sciences, Far Eastern Federal University, 690922 Vladivostok, Russia; (A.T.); (V.K.); (V.F.)
| | - Huile Gao
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610064, China;
| | - Maxim Shevtsov
- School of Medicine and Life Sciences, Far Eastern Federal University, 690922 Vladivostok, Russia; (A.T.); (V.K.); (V.F.)
- Laboratory of Biomedical Nanotechnologies, Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Ave., 4, 194064 St. Petersburg, Russia
- Personalized Medicine Centre, Almazov National Medical Research Centre, Akkuratova Str., 2, 197341 St. Petersburg, Russia
- Department of Radiation Oncology, Technishe Universität München (TUM), Klinikum Rechts der Isar, Ismaninger Str., 22, 81675 Munich, Germany
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2
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Balendran V, Skidmore JM, Ritter KE, Gao J, Cimerman J, Beyer LA, Hurd EA, Raphael Y, Martin DM. Chromatin remodeler CHD7 is critical for cochlear morphogenesis and neurosensory patterning. Dev Biol 2021; 477:11-21. [PMID: 34004180 DOI: 10.1016/j.ydbio.2021.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 04/12/2021] [Accepted: 05/10/2021] [Indexed: 11/18/2022]
Abstract
Epigenetic regulation of gene transcription by chromatin remodeling proteins has recently emerged as an important contributing factor in inner ear development. Pathogenic variants in CHD7, the gene encoding Chromodomain Helicase DNA binding protein 7, cause CHARGE syndrome, which presents with malformations in the developing ear. Chd7 is broadly expressed in the developing mouse otocyst and mature auditory epithelium, yet the pathogenic effects of Chd7 loss in the cochlea are not well understood. Here we characterized cochlear epithelial phenotypes in mice with deletion of Chd7 throughout the otocyst (using Foxg1Cre/+ and Pax2Cre), in the otic mesenchyme (using TCre), in hair cells (using Atoh1Cre), in developing neuroblasts (using NgnCre), or in spiral ganglion neurons (using ShhCre/+). Pan-otic deletion of Chd7 resulted in shortened cochleae with aberrant projections and axonal looping, disorganized, supernumerary hair cells at the apical turn and a narrowed epithelium with missing hair cells in the middle region. Deletion of Chd7 in the otic mesenchyme had no effect on overall cochlear morphology. Loss of Chd7 in hair cells did not disrupt their formation or organization of the auditory epithelium. Similarly, absence of Chd7 in spiral ganglion neurons had no effect on axonal projections. In contrast, deletion of Chd7 in developing neuroblasts led to smaller spiral ganglia and disorganized cochlear neurites. Together, these observations reveal dosage-, tissue-, and time-sensitive cell autonomous roles for Chd7 in cochlear elongation and cochlear neuron organization, with minimal functions for Chd7 in hair cells. These studies provide novel information about roles for Chd7 in development of auditory neurons.
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Affiliation(s)
- Vinodh Balendran
- Departments of Pediatrics, The University of Michigan, Ann Arbor, MI, USA
| | | | - K Elaine Ritter
- Departments of Pediatrics, The University of Michigan, Ann Arbor, MI, USA
| | - Jingxia Gao
- Departments of Pediatrics, The University of Michigan, Ann Arbor, MI, USA
| | - Jelka Cimerman
- Departments of Pediatrics, The University of Michigan, Ann Arbor, MI, USA
| | - Lisa A Beyer
- Otolaryngology - Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | | | - Yehoash Raphael
- Otolaryngology - Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA
| | - Donna M Martin
- Departments of Pediatrics, The University of Michigan, Ann Arbor, MI, USA; Otolaryngology - Head and Neck Surgery, The University of Michigan, Ann Arbor, MI, USA; Human Genetics, The University of Michigan, Ann Arbor, MI, USA.
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3
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Méndez-Maldonado K, Vega-López GA, Aybar MJ, Velasco I. Neurogenesis From Neural Crest Cells: Molecular Mechanisms in the Formation of Cranial Nerves and Ganglia. Front Cell Dev Biol 2020; 8:635. [PMID: 32850790 PMCID: PMC7427511 DOI: 10.3389/fcell.2020.00635] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/24/2020] [Indexed: 12/15/2022] Open
Abstract
The neural crest (NC) is a transient multipotent cell population that originates in the dorsal neural tube. Cells of the NC are highly migratory, as they travel considerable distances through the body to reach their final sites. Derivatives of the NC are neurons and glia of the peripheral nervous system (PNS) and the enteric nervous system as well as non-neural cells. Different signaling pathways triggered by Bone Morphogenetic Proteins (BMPs), Fibroblast Growth Factors (FGFs), Wnt proteins, Notch ligands, retinoic acid (RA), and Receptor Tyrosine Kinases (RTKs) participate in the processes of induction, specification, cell migration and neural differentiation of the NC. A specific set of signaling pathways and transcription factors are initially expressed in the neural plate border and then in the NC cell precursors to the formation of cranial nerves. The molecular mechanisms of control during embryonic development have been gradually elucidated, pointing to an important role of transcriptional regulators when neural differentiation occurs. However, some of these proteins have an important participation in malformations of the cranial portion and their mutation results in aberrant neurogenesis. This review aims to give an overview of the role of cell signaling and of the function of transcription factors involved in the specification of ganglia precursors and neurogenesis to form the NC-derived cranial nerves during organogenesis.
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Affiliation(s)
- Karla Méndez-Maldonado
- Instituto de Fisiología Celular - Neurociencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.,Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Guillermo A Vega-López
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT), San Miguel de Tucumán, Argentina.,Instituto de Biología "Dr. Francisco D. Barbieri", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina
| | - Manuel J Aybar
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT), San Miguel de Tucumán, Argentina.,Instituto de Biología "Dr. Francisco D. Barbieri", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina
| | - Iván Velasco
- Instituto de Fisiología Celular - Neurociencias, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.,Laboratorio de Reprogramación Celular, Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", Ciudad de México, Mexico
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4
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Defourny J. Eph/ephrin signalling in the development and function of the mammalian cochlea. Dev Biol 2019; 449:35-40. [PMID: 30771305 DOI: 10.1016/j.ydbio.2019.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 02/10/2019] [Accepted: 02/11/2019] [Indexed: 12/12/2022]
Abstract
In mammals, the functional development of the cochlea requires the tight regulation of multiple molecules and signalling pathways including fibroblast growth factors, bone morphogenetic proteins, Wnt and Notch signalling pathways. Over the last decade, the Eph/ephrin system also emerged as a key player of the development and function of the mammalian cochlea. In this review, we discuss the recent advances on the role of Eph/ephrin signalling in patterning the cochlear sensory epithelium and the complex innervation of mechanosensory hair cells by spiral ganglion neurons. Finally, we address the issue of a syndromic form of hearing loss caused by a deficient member of the Eph/ephrin family.
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Affiliation(s)
- Jean Defourny
- GIGA-Neurosciences, Unit of Cell and Tissue Biology, University of Liège, C.H.U. B36, B-4000, Liège, Belgium.
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5
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Defourny J, Peuckert C, Kullander K, Malgrange B. EphA4-ADAM10 Interplay Patterns the Cochlear Sensory Epithelium through Local Disruption of Adherens Junctions. iScience 2018; 11:246-257. [PMID: 30639848 PMCID: PMC6327856 DOI: 10.1016/j.isci.2018.12.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 12/19/2018] [Accepted: 12/20/2018] [Indexed: 12/11/2022] Open
Abstract
The cochlear sensory epithelium contains a functionally important triangular fluid-filled space between adjacent pillar cells referred to as the tunnel of Corti. However, the molecular mechanisms leading to local cell-cell separation during development remain elusive. Here we show that EphA4 associates with ADAM10 to promote the destruction of E-cadherin-based adhesions between adjacent pillar cells. These cells fail to separate from each other, and E-cadherin abnormally persists at the pillar cell junction in EphA4 forward-signaling-deficient mice, as well as in the presence of ADAM10 inhibitor. Using immunolabeling and an in situ proximity ligation assay, we found that EphA4 forms a complex with E-cadherin and its sheddase ADAM10, which could be activated by ephrin-B2 across the pillar cell junction to trigger the cleavage of E-cadherin. Altogether, our findings provide a new molecular insight into the regulation of adherens junctions, which might be extended to a variety of physiological or pathological processes.
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Affiliation(s)
- Jean Defourny
- GIGA-Neurosciences, Unit of Cell and Tissue Biology, University of Liège, C.H.U. B36, 4000 Liège, Belgium; GIGA-Neurosciences, Developmental Neurobiology Unit, University of Liège, C.H.U. B36, 4000 Liège, Belgium
| | - Christiane Peuckert
- Department of Neuroscience, Uppsala University, Box 593, Uppsala 75124, Sweden
| | - Klas Kullander
- Department of Neuroscience, Uppsala University, Box 593, Uppsala 75124, Sweden
| | - Brigitte Malgrange
- GIGA-Neurosciences, Developmental Neurobiology Unit, University of Liège, C.H.U. B36, 4000 Liège, Belgium.
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6
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Treffy RW, Collins D, Hoshino N, Ton S, Katsevman GA, Oleksiak M, Runge EM, Cho D, Russo M, Spec A, Gomulka J, Henkemeyer M, Rochlin MW. Ephrin-B/EphB Signaling Is Required for Normal Innervation of Lingual Gustatory Papillae. Dev Neurosci 2016; 38:124-38. [PMID: 27035151 PMCID: PMC4927353 DOI: 10.1159/000444748] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 02/17/2016] [Indexed: 02/02/2023] Open
Abstract
The innervation of taste buds is an excellent model system for studying the guidance of axons during targeting because of their discrete nature and the high fidelity of innervation. The pregustatory epithelium of fungiform papillae is known to secrete diffusible axon guidance cues such as BDNF and Sema3A that attract and repel, respectively, geniculate ganglion axons during targeting, but diffusible factors alone are unlikely to explain how taste axon terminals are restricted to their territories within the taste bud. Nondiffusible cell surface proteins such as Ephs and ephrins can act as receptors and/or ligands for one another and are known to control axon terminal positioning in several parts of the nervous system, but they have not been studied in the gustatory system. We report that ephrin-B2 linked β-galactosidase staining and immunostaining was present along the dorsal epithelium of the mouse tongue as early as embryonic day 15.5 (E15.5), but was not detected at E14.5, when axons first enter the epithelium. Ephrin-B1 immunolabeling was barely detected in the epithelium and found at a somewhat higher concentration in the mesenchyme subjacent to the epithelium. EphB1 and EphB2 were detected in lingual sensory afferents in vivo and geniculate neurites in vitro. Ephrin-B1 and ephrin-B2 were similarly effective in repelling or suppressing outgrowth by geniculate neurites in vitro. These in vitro effects were independent of the neurotrophin used to promote outgrowth, but were reduced by elevated levels of laminin. In vivo, mice null for EphB1 and EphB2 exhibited decreased gustatory innervation of fungiform papillae. These data provide evidence that ephrin-B forward signaling is necessary for normal gustatory innervation of the mammalian tongue.
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7
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Cochlear afferent innervation development. Hear Res 2015; 330:157-69. [DOI: 10.1016/j.heares.2015.07.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 06/02/2015] [Accepted: 07/21/2015] [Indexed: 01/11/2023]
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8
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Kim YJ, Ibrahim LA, Wang SZ, Yuan W, Evgrafov OV, Knowles JA, Wang K, Tao HW, Zhang LI. EphA7 regulates spiral ganglion innervation of cochlear hair cells. Dev Neurobiol 2015; 76:452-69. [PMID: 26178595 DOI: 10.1002/dneu.22326] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 06/10/2015] [Accepted: 07/14/2015] [Indexed: 01/11/2023]
Abstract
During the development of periphery auditory circuitry, spiral ganglion neurons (SGNs) form a spatially precise pattern of innervation of cochlear hair cells (HCs), which is an essential structural foundation for central auditory processing. However, molecular mechanisms underlying the developmental formation of this precise innervation pattern remain not well understood. Here, we specifically examined the involvement of Eph family members in cochlear development. By performing RNA-sequencing for different types of cochlear cell, in situ hybridization, and immunohistochemistry, we found that EphA7 was strongly expressed in a large subset of SGNs. In EphA7 deletion mice, there was a reduction in the number of inner radial bundles originating from SGNs and projecting to HCs as well as in the number of ribbon synapses on inner hair cells (IHCs), as compared with wild-type or heterozygous mutant mice, attributable to fewer type I afferent fibers. The overall activity of the auditory nerve in EphA7 deletion mice was also reduced, although there was no significant change in the hearing intensity threshold. In vitro analysis further suggested that the reduced innervation of HCs by SGNs could be attributed to a role of EphA7 in regulating outgrowth of SGN neurites as knocking down EphA7 in SGNs resulted in diminished SGN fibers. In addition, suppressing the activity of ERK1/2, a potential downstream target of EphA7 signaling, either with specific inhibitors in cultured explants or by knocking out Prkg1, also resulted in reduced SGN fibers. Together, our results suggest that EphA7 plays an important role in the developmental formation of cochlear innervation pattern through controlling SGN fiber ontogeny. Such regulation may contribute to the salience level of auditory signals presented to the central auditory system.
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Affiliation(s)
- Young J Kim
- Zilkha Neurogenetic Institute, Keck School of Medicine, University Of Southern California, Los Angeles, California, 90033.,Neuroscience Graduate Program, University Of Southern California, Los Angeles, California
| | - Leena A Ibrahim
- Zilkha Neurogenetic Institute, Keck School of Medicine, University Of Southern California, Los Angeles, California, 90033.,Neuroscience Graduate Program, University Of Southern California, Los Angeles, California
| | - Sheng-Zhi Wang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University Of Southern California, Los Angeles, California, 90033
| | - Wei Yuan
- Department of Otolaryngology of Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Oleg V Evgrafov
- Zilkha Neurogenetic Institute, Keck School of Medicine, University Of Southern California, Los Angeles, California, 90033.,Department of Psychiatry, Keck School Of Medicine, University Of Southern California, Los Angeles, California
| | - James A Knowles
- Zilkha Neurogenetic Institute, Keck School of Medicine, University Of Southern California, Los Angeles, California, 90033.,Department of Psychiatry, Keck School Of Medicine, University Of Southern California, Los Angeles, California
| | - Kai Wang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University Of Southern California, Los Angeles, California, 90033.,Department of Psychiatry, Keck School Of Medicine, University Of Southern California, Los Angeles, California
| | - Huizhong W Tao
- Zilkha Neurogenetic Institute, Keck School of Medicine, University Of Southern California, Los Angeles, California, 90033.,Department of Cell And Neurobiology, Keck School Of Medicine, University Of Southern California, Los Angeles, California
| | - Li I Zhang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University Of Southern California, Los Angeles, California, 90033.,Department of Physiology and Biophysics, Keck School Of Medicine, University Of Southern California, Los Angeles, California
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9
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Lee KH, Warchol ME, Pawlowski KS, Shao D, Koulich E, Zhou CQ, Lee J, Henkemeyer MJ. Ephrins and Ephs in cochlear innervation and implications for advancing cochlear implant function. Laryngoscope 2014; 125:1189-97. [DOI: 10.1002/lary.25066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Kenneth H. Lee
- Department of Otolaryngology-Head & Neck Surgery; University of Texas Southwestern Medical Center; Dallas Texas
- Department of Developmental Biology; University of Texas Southwestern Medical Center; Dallas Texas
- Division of Pediatric Otolaryngology; Children's Medical Center; Dallas Texas
| | - Mark E. Warchol
- Department of Otolaryngology-Head & Neck Surgery; Washington University School of Medicine in St. Louis; St. Louis Missouri
| | - Karen S. Pawlowski
- Department of Otolaryngology-Head & Neck Surgery; University of Texas Southwestern Medical Center; Dallas Texas
| | - Dongmei Shao
- Department of Otolaryngology-Head & Neck Surgery; University of Texas Southwestern Medical Center; Dallas Texas
| | - Elena Koulich
- Department of Otolaryngology-Head & Neck Surgery; University of Texas Southwestern Medical Center; Dallas Texas
| | - Constance Q. Zhou
- Department of Otolaryngology-Head & Neck Surgery; University of Texas Southwestern Medical Center; Dallas Texas
| | - James Lee
- Department of Developmental Biology; University of Texas Southwestern Medical Center; Dallas Texas
- Department of Pathology; Harbor University of California Los Angeles Medical Medical Center; Los Angeles California U.S.A
| | - Mark J. Henkemeyer
- Department of Developmental Biology; University of Texas Southwestern Medical Center; Dallas Texas
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10
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Raft S, Coate TM, Kelley MW, Crenshaw EB, Wu DK. Pou3f4-mediated regulation of ephrin-b2 controls temporal bone development in the mouse. PLoS One 2014; 9:e109043. [PMID: 25299585 PMCID: PMC4192298 DOI: 10.1371/journal.pone.0109043] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 09/01/2014] [Indexed: 12/25/2022] Open
Abstract
The temporal bone encases conductive and sensorineural elements of the ear. Mutations of POU3F4 are associated with unique temporal bone abnormalities and X-linked mixed deafness (DFNX2/DFN3). However, the target genes and developmental processes controlled by POU3F4 transcription factor activity have remained largely uncharacterized. Ephrin-B2 (Efnb2) is a signaling molecule with well-documented effects on cell adhesion, proliferation, and migration. Our analyses of targeted mouse mutants revealed that Efnb2 loss-of-function phenocopies temporal bone abnormalities of Pou3f4 hemizygous null neonates: qualitatively identical malformations of the stapes, styloid process, internal auditory canal, and cochlear capsule were present in both mutants. Using failed/insufficient separation of the stapes and styloid process as a quantitative trait, we found that single gene Efnb2 loss-of-function and compound Pou3f4/Efnb2 loss-of-function caused a more severe phenotype than single gene Pou3f4 loss-of-function. Pou3f4 and Efnb2 gene expression domains overlapped at the site of impending stapes-styloid process separation and at subcapsular mesenchyme surrounding the cochlea; at both these sites, Efnb2 expression was attenuated in Pou3f4 hemizygous null mutants relative to control. Results of immunoprecipitation experiments using chromatin isolated from nascent middle ear mesenchyme supported the hypothesis of a physical association between Pou3f4 and specific non-coding sequence of Efnb2. We propose that Efnb2 is a target of Pou3f4 transcription factor activity and an effector of mesenchymal patterning during temporal bone development.
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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, Bethesda, Maryland, United States of America
| | - Thomas M. Coate
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Matthew W. Kelley
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
| | - E. Bryan Crenshaw
- Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Doris K. Wu
- Section on Sensory Cell Regeneration and Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States of America
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11
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Cramer KS, Gabriele ML. Axon guidance in the auditory system: multiple functions of Eph receptors. Neuroscience 2014; 277:152-62. [PMID: 25010398 DOI: 10.1016/j.neuroscience.2014.06.068] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 06/05/2014] [Accepted: 06/28/2014] [Indexed: 11/29/2022]
Abstract
The neural pathways of the auditory system underlie our ability to detect sounds and to transform amplitude and frequency information into rich and meaningful perception. While it shares some organizational features with other sensory systems, the auditory system has some unique functions that impose special demands on precision in circuit assembly. In particular, the cochlear epithelium creates a frequency map rather than a space map, and specialized pathways extract information on interaural time and intensity differences to permit sound source localization. The assembly of auditory circuitry requires the coordinated function of multiple molecular cues. Eph receptors and their ephrin ligands constitute a large family of axon guidance molecules with developmentally regulated expression throughout the auditory system. Functional studies of Eph/ephrin signaling have revealed important roles at multiple levels of the auditory pathway, from the cochlea to the auditory cortex. These proteins provide graded cues used in establishing tonotopically ordered connections between auditory areas, as well as discrete cues that enable axons to form connections with appropriate postsynaptic partners within a target area. Throughout the auditory system, Eph proteins help to establish patterning in neural pathways during early development. This early targeting, which is further refined with neuronal activity, establishes the precision needed for auditory perception.
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Affiliation(s)
- K S Cramer
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, United States.
| | - M L Gabriele
- Department of Biology, James Madison University, Harrisonburg, VA 22807, United States
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12
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Liuzzo A, Gray L, Wallace M, Gabriele M. The effects of Eph-ephrin mutations on pre-pulse inhibition in mice. Physiol Behav 2014; 135:232-6. [PMID: 24949848 DOI: 10.1016/j.physbeh.2014.05.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 04/09/2014] [Accepted: 05/29/2014] [Indexed: 11/26/2022]
Abstract
Eph-ephrin signaling is known to be important in directing topographic projections in the afferent auditory pathway, including connections to various subdivisions of the inferior colliculus (IC). The acoustic startle-response (ASR) is a reliable reflexive behavioral response in mammals elicited by an unexpected intense acoustic startle-eliciting stimulus (ES). It is mediated by a sub-cortical pathway that includes the IC. The ASR amplitude can be measured with an accelerometer under the subject and can be decreased in amplitude by presenting a less intense, non-startling stimulus 5-300ms before the ES. This reflexive decrement in ASR is called pre-pulse inhibition (PPI) and indicates that the relatively soft pre-pulse was heard. PPI is a general trait among mammals. Mice have been used recently to study this response and to reveal how genetic mutations affect neural circuits and hence the ASR and PPI. In this experiment, we measured the effect of Eph-ephrin mutations using control mice (C57BL/6J), mice with compromised EphA4 signaling (EphA4(lacZ/+), EphA4(lacZ/lacZ)), and knockout ephrin-B3 mice (ephrin-B3 (+/-, -/-)). Control and EphA4(lacZ/+s)trains showed robust PPI (up to 75% decrement in ASR) to an offset of a 70dB SPL background noise at 50ms before the ES. Ephrin-B3 knockout mice and EphA4 homozygous mutants were only marginally significant in PPI (<25% decrement and <33% decrement, respectively) to the same conditions. This decrement in PPI highlights the importance of ephrin-B3 and EphA4 interactions in ordering auditory behavioral circuits. Thus, different mutations in certain members of the signaling family produce a full range of changes in PPI, from minimal to nearly maximal. This technique can be easily adapted to study other aspects of hearing in a wider range of mutations. Along with ongoing neuroanatomical studies, this allows careful quantification of how the auditory anatomical, physiological and now behavioral phenotype is affected by changes in Eph-ephrin expression and functionality.
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Affiliation(s)
- Andrea Liuzzo
- Dept. of Communication Sciences and Disorders, James Madison University, MSC 4304, 801 Carrier Dr., Harrisonburg, VA 22807, United States
| | - Lincoln Gray
- Dept. of Communication Sciences and Disorders, James Madison University, MSC 4304, 801 Carrier Dr., Harrisonburg, VA 22807, United States
| | - Matthew Wallace
- Dept. of Biology, James Madison University, MSC 7801, 951 Carrier Dr., Harrisonburg, VA 22807, United States
| | - Mark Gabriele
- Dept. of Biology, James Madison University, MSC 7801, 951 Carrier Dr., Harrisonburg, VA 22807, United States
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13
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Battisti AC, Fantetti KN, Moyers BA, Fekete DM. A subset of chicken statoacoustic ganglion neurites are repelled by Slit1 and Slit2. Hear Res 2014; 310:1-12. [PMID: 24456709 PMCID: PMC3979322 DOI: 10.1016/j.heares.2014.01.003] [Citation(s) in RCA: 10] [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: 03/11/2013] [Revised: 12/20/2013] [Accepted: 01/09/2014] [Indexed: 01/23/2023]
Abstract
Mechanosensory hair cells in the chicken inner ear are innervated by bipolar afferent neurons of the statoacoustic ganglion (SAG). During development, individual SAG neurons project their peripheral process to only one of eight distinct sensory organs. These neuronal subtypes may respond differently to guidance cues as they explore the periphery in search of their target. Previous gene expression data suggested that Slit repellants might channel SAG neurites into the sensory primordia, based on the presence of robo transcripts in the neurons and the confinement of slit transcripts to the flanks of the prosensory domains. This led to the prediction that excess Slit proteins would impede the outgrowth of SAG neurites. As predicted, axonal projections to the primordium of the anterior crista were reduced 2-3 days after electroporation of either slit1 or slit2 expression plasmids into the anterior pole of the otocyst on embryonic day 3 (E3). The posterior crista afferents, which normally grow through and adjacent to slit expression domains as they are navigating towards the posterior pole of the otocyst, did not show Slit responsiveness when similarly challenged by ectopic delivery of slit to their targets. The sensitivity to ectopic Slits shown by the anterior crista afferents was more the exception than the rule: responsiveness to Slits was not observed when the entire E4 SAG was challenged with Slits for 40 h in vitro. The corona of neurites emanating from SAG explants was unaffected by the presence of purified human Slit1 and Slit2 in the culture medium. Reduced axon outgrowth from E8 olfactory bulbs cultured under similar conditions for 24 h confirmed bioactivity of purified human Slits on chicken neurons. In summary, differential sensitivity to Slit repellents may influence the directional outgrowth of otic axons toward either the anterior or posterior otocyst.
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Affiliation(s)
- Andrea C Battisti
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, 915 W State St., West Lafayette, IN 47907-1392, USA.
| | - Kristen N Fantetti
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, 915 W State St., West Lafayette, IN 47907-1392, USA.
| | - Belle A Moyers
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, 915 W State St., West Lafayette, IN 47907-1392, USA.
| | - Donna M Fekete
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, 915 W State St., West Lafayette, IN 47907-1392, USA.
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Raft S, Andrade LR, Shao D, Akiyama H, Henkemeyer M, Wu DK. Ephrin-B2 governs morphogenesis of endolymphatic sac and duct epithelia in the mouse inner ear. Dev Biol 2014; 390:51-67. [PMID: 24583262 DOI: 10.1016/j.ydbio.2014.02.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 02/19/2014] [Indexed: 02/03/2023]
Abstract
Control over ionic composition and volume of the inner ear luminal fluid endolymph is essential for normal hearing and balance. Mice deficient in either the EphB2 receptor tyrosine kinase or the cognate transmembrane ligand ephrin-B2 (Efnb2) exhibit background strain-specific vestibular-behavioral dysfunction and signs of abnormal endolymph homeostasis. Using various loss-of-function mouse models, we found that Efnb2 is required for growth and morphogenesis of the embryonic endolymphatic epithelium, a precursor of the endolymphatic sac (ES) and duct (ED), which mediate endolymph homeostasis. Conditional inactivation of Efnb2 in early-stage embryonic ear tissues disrupted cell proliferation, cell survival, and epithelial folding at the origin of the endolymphatic epithelium. This correlated with apparent absence of an ED, mis-localization of ES ion transport cells relative to inner ear sensory organs, dysplasia of the endolymph fluid space, and abnormally formed otoconia (extracellular calcite-protein composites) at later stages of embryonic development. A comparison of Efnb2 and Notch signaling-deficient mutant phenotypes indicated that these two signaling systems have distinct and non-overlapping roles in ES/ED development. Homozygous deletion of the Efnb2 C-terminus caused abnormalities similar to those found in the conditional Efnb2 null homozygote. Analyses of fetal Efnb2 C-terminus deletion heterozygotes found mis-localized ES ion transport cells only in the genetic background exhibiting vestibular dysfunction. We propose that developmental dysplasias described here are a gene dose-sensitive cause of the vestibular dysfunction observed in EphB-Efnb2 signaling-deficient mice.
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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, Bethesda, MD 20892, USA.
| | - Leonardo R Andrade
- Laboratory of Biomineralization, Institute of Biomedical Sciences, CCS, Universidade Federal do Rio de Janeiro, RJ 21941-902, Brazil
| | - Dongmei Shao
- Department of Otolaryngology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Haruhiko Akiyama
- Department of Orthopedics, Gifu University, Gifu City 501-1194, Japan
| | - Mark Henkemeyer
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Doris K Wu
- Section on Sensory Cell Regeneration and Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA.
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15
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Lee KH, Lee J, Shao D, Dravis C, Henkemeyer M. Asymmetry in semicircular canal diameters may account for circling behavior in EphB-deficient mice. Laryngoscope 2013; 124:E278-82. [PMID: 24353053 DOI: 10.1002/lary.24506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 11/09/2022]
Abstract
OBJECTIVES/HYPOTHESIS Determine if differences in right and left semicircular size account for phenotypic behavior, indicating vestibulopathy in EphB deficient mice. STUDY DESIGN The diameters of the superior semicircular canals (SCC) were measured. The differences in the right and left superior SCC diameters were analyzed in homozygous EphB2 and EphB3 double knockout mice known to have head bobbing and circling behavior. Results were compared to similar analysis in wild type controls that displayed no signs of vestibulopathy. METHODS Axial frozen sections through the superior (SCC) were analyzed by light microscopy; and the diameters of the left and right canals were measured in μm for both EphB2 and EphB3 double knockout mice, as well as in wild type control mice. The differences in diameter between the left and right superior SCC was determined for each animal. RESULTS Overall, the EphB2 and EphB3 double knockout mice had smaller superior SCC diameters compared to wild type (109.0±21.4 μm vs. 185.0±5.2 μm (P<0.0001). The mean difference in left and right diameter of the superior SCC of EphB2/EphB3 double knockout mice was 29.0±8.7 μm; in wild-type controls this difference was 6.0±5.1 μm (P=0.002). In addition, the direction of circling appeared to be independent of the laterality of the smaller (or larger) superior SCC. CONCLUSION Mice deficient in EphB2/EphB3 signaling have smaller superior SCC and asymmetry in lumen sizes between the left and right sides. The laterality of the larger versus smaller is not correlated with the direction of circling behavior. LEVEL OF EVIDENCE N/A.
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Affiliation(s)
- Kenneth H Lee
- Department of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A
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16
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Allen-Sharpley MR, Tjia M, Cramer KS. Differential roles for EphA and EphB signaling in segregation and patterning of central vestibulocochlear nerve projections. PLoS One 2013; 8:e78658. [PMID: 24130906 PMCID: PMC3795076 DOI: 10.1371/journal.pone.0078658] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 09/13/2013] [Indexed: 11/18/2022] Open
Abstract
Auditory and vestibular afferents enter the brainstem through the VIIIth cranial nerve and find targets in distinct brain regions. We previously reported that the axon guidance molecules EphA4 and EphB2 have largely complementary expression patterns in the developing avian VIIIth nerve. Here, we tested whether inhibition of Eph signaling alters central targeting of VIIIth nerve axons. We first identified the central compartments through which auditory and vestibular axons travel. We then manipulated Eph-ephrin signaling using pharmacological inhibition of Eph receptors and in ovo electroporation to misexpress EphA4 and EphB2. Anterograde labeling of auditory afferents showed that inhibition of Eph signaling did not misroute axons to non-auditory target regions. Similarly, we did not find vestibular axons within auditory projection regions. However, we found that pharmacologic inhibition of Eph receptors reduced the volume of the vestibular projection compartment. Inhibition of EphB signaling alone did not affect auditory or vestibular central projection volumes, but it significantly increased the area of the auditory sensory epithelium. Misexpression of EphA4 and EphB2 in VIIIth nerve axons resulted in a significant shift of dorsoventral spacing between the axon tracts, suggesting a cell-autonomous role for the partitioning of projection areas along this axis. Cochlear ganglion volumes did not differ among treatment groups, indicating the changes seen were not due to a gain or loss of cochlear ganglion cells. These results suggest that Eph-ephrin signaling does not specify auditory versus vestibular targets but rather contributes to formation of boundaries for patterning of inner ear projections in the hindbrain.
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Affiliation(s)
- Michelle R. Allen-Sharpley
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, California, United States of America
| | - Michelle Tjia
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, California, United States of America
| | - Karina S. Cramer
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, California, United States of America
- * E-mail:
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Allen-Sharpley MR, Cramer KS. Coordinated Eph-ephrin signaling guides migration and axon targeting in the avian auditory system. Neural Dev 2012; 7:29. [PMID: 22908944 PMCID: PMC3515360 DOI: 10.1186/1749-8104-7-29] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 07/26/2012] [Indexed: 12/21/2022] Open
Abstract
Background In the avian sound localization circuit, nucleus magnocellularis (NM) projects bilaterally to nucleus laminaris (NL), with ipsilateral and contralateral NM axon branches directed to dorsal and ventral NL dendrites, respectively. We previously showed that the Eph receptor EphB2 is expressed in NL neuropil and NM axons during development. Here we tested whether EphB2 contributes to NM-NL circuit formation. Results We found that misexpression of EphB2 in embryonic NM precursors significantly increased the number of axon targeting errors from NM to contralateral NL in a cell-autonomous manner when forward signaling was impaired. We also tested the effects of inhibiting forward signaling of different Eph receptor subclasses by injecting soluble unclustered Fc-fusion proteins at stages when NM axons are approaching their NL target. Again we found an increase in axon targeting errors compared to controls when forward signaling was impaired, an effect that was significantly increased when both Eph receptor subclasses were inhibited together. In addition to axon targeting errors, we also observed morphological abnormalities of the auditory nuclei when EphB2 forward signaling was increased by E2 transfection, and when Eph-ephrin forward signaling was inhibited by E6-E8 injection of Eph receptor fusion proteins. Conclusions These data suggest that EphB signaling has distinct functions in axon guidance and morphogenesis. The results provide evidence that multiple Eph receptors work synergistically in the formation of precise auditory circuitry.
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Affiliation(s)
- Michelle R Allen-Sharpley
- Department of Neurobiology and Behavior, University of California Irvine, Irvine, CA 92697-4550, USA
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Coate TM, Raft S, Zhao X, Ryan AK, Crenshaw EB, Kelley MW. Otic mesenchyme cells regulate spiral ganglion axon fasciculation through a Pou3f4/EphA4 signaling pathway. Neuron 2012; 73:49-63. [PMID: 22243746 DOI: 10.1016/j.neuron.2011.10.029] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2011] [Indexed: 10/14/2022]
Abstract
Peripheral axons from auditory spiral ganglion neurons (SGNs) form an elaborate series of radially and spirally oriented projections that interpret complex aspects of the auditory environment. However, the developmental processes that shape these axon tracts are largely unknown. Radial bundles are comprised of dense SGN fascicles that project through otic mesenchyme to form synapses within the cochlea. Here, we show that radial bundle fasciculation and synapse formation are disrupted when Pou3f4 (DFNX2) is deleted from otic mesenchyme. Further, we demonstrate that Pou3f4 binds to and directly regulates expression of Epha4, Epha4⁻/⁻ mice present similar SGN defects, and exogenous EphA4 promotes SGN fasciculation in the absence of Pou3f4. Finally, Efnb2 deletion in SGNs leads to similar fasciculation defects, suggesting that ephrin-B2/EphA4 interactions are critical during this process. These results indicate a model whereby Pou3f4 in the otic mesenchyme establishes an Eph/ephrin-mediated fasciculation signal that promotes inner radial bundle formation.
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Affiliation(s)
- Thomas M Coate
- Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA.
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Defourny J, Lallemend F, Malgrange B. Structure and development of cochlear afferent innervation in mammals. Am J Physiol Cell Physiol 2011; 301:C750-61. [PMID: 21753183 DOI: 10.1152/ajpcell.00516.2010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In mammals, sensorineural deafness results from damage to the auditory receptors of the inner ear, the nerve pathways to the brain or the cortical area that receives sound information. In this review, we first focused on the cellular and molecular events taking part to spiral ganglion axon growth, extension to the organ of Corti, and refinement. In the second half, we considered the functional maturation of synaptic contacts between sensory hair cells and their afferent projections. A better understanding of all these processes could open insights into novel therapeutic strategies aimed to re-establish primary connections from sound transducers to the ascending auditory nerve pathways.
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