1
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Lin Y, Zhang Q, Tong W, Wang Y, Wu L, Xiao H, Tang X, Dai M, Ye Z, Chai R, Zhang S. Conditional Overexpression of Net1 Enhances the Trans-Differentiation of Lgr5 + Progenitors into Hair Cells in the Neonatal Mouse Cochlea. Cell Prolif 2024:e13787. [PMID: 39675772 DOI: 10.1111/cpr.13787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Revised: 11/05/2024] [Accepted: 11/13/2024] [Indexed: 12/17/2024] Open
Abstract
Sensorineural hearing loss is mainly caused by damage to hair cells (HC), which cannot be regenerated spontaneously in adult mammals once damaged. Cochlear Lgr5+ progenitors are characterised by HC regeneration capacity in neonatal mice, and we previously screened several new genes that might induce HC regeneration from Lgr5+ progenitors. Net1, a guanine nucleotide exchange factor, is one of the screened new genes and is particularly active in cancer cells and is involved in cell proliferation and differentiation. Here, to explore in vivo roles of Net1 in HC regeneration, Net1loxp/loxp mice were constructed and crossed with Lgr5CreER/+ mice to conditionally overexpress (cOE) Net1 in cochlear Lgr5+ progenitors. We observed a large number of ectopic HCs in Lgr5CreER/+Net1loxp/loxp mouse cochlea, which showed a dose-dependent effect. Moreover, the EdU assay was unable to detect any EdU+/Sox2+ supporting cells, while lineage tracing showed significantly more regenerated tdTomato+ HCs in Lgr5CreER/+Net1loxp/loxptdTomato mice, which indicated that Net1 cOE enhanced HC regeneration by inducing the direct trans-differentiation of Lgr5+ progenitors rather than mitotic HC regeneration. Additionally, qPCR results showed that the transcription factors related to HC regeneration, including Atoh1, Gfi1 and Pou4f3, were significantly upregulated and are probably the mechanism behind the HC regeneration induced by Net1. In conclusion, our study provides new evidence for the role of Net1 in enhancing HC regeneration in the neonatal mouse cochlea.
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Affiliation(s)
- Yanqin Lin
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Qiuyue Zhang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Wei Tong
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Yintao Wang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Leilei Wu
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Hairong Xiao
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Xujun Tang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Mingchen Dai
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Zixuan Ye
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
| | - Renjie Chai
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, China
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Shasha Zhang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Southeast University Shenzhen Research Institute, Shenzhen, China
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2
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Karayay B, Olze H, Szczepek AJ. Mammalian Inner Ear-Resident Immune Cells-A Scoping Review. Cells 2024; 13:1528. [PMID: 39329712 PMCID: PMC11430779 DOI: 10.3390/cells13181528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2024] [Revised: 09/09/2024] [Accepted: 09/10/2024] [Indexed: 09/28/2024] Open
Abstract
BACKGROUND Several studies have demonstrated the presence of resident immune cells in the healthy inner ear. AIM This scoping review aimed to systematize this knowledge by collecting the data on resident immune cells in the inner ear of different species under steady-state conditions. METHODS The databases PubMed, MEDLINE (Ovid), CINAHL (EBSCO), and LIVIVO were used to identify articles. Systematic reviews, experimental studies, and clinical data in English and German were included without time limitations. RESULTS The search yielded 49 eligible articles published between 1979 and 2022. Resident immune cells, including macrophages, lymphocytes, leukocytes, and mast cells, have been observed in various mammalian inner ear structures under steady-state conditions. However, the physiological function of these cells in the healthy cochlea remains unclear, providing an opportunity for basic research in inner ear biology. CONCLUSIONS This review highlights the need for further investigation into the role of these cells, which is crucial for advancing the development of therapeutic methods for treating inner ear disorders, potentially transforming the field of otolaryngology and immunology.
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Affiliation(s)
- Betül Karayay
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany; (B.K.); (H.O.)
| | - Heidi Olze
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany; (B.K.); (H.O.)
| | - Agnieszka J. Szczepek
- Department of Otorhinolaryngology, Head and Neck Surgery, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117 Berlin, Germany; (B.K.); (H.O.)
- Faculty of Medicine and Health Sciences, University of Zielona Góra, 65-046 Zielona Góra, Poland
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3
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Mikulić P, Ogorevc M, Petričević M, Kaličanin D, Tafra R, Saraga-Babić M, Mardešić S. SOX2, JAGGED1, β-Catenin, and Vitamin D Receptor Expression Patterns during Early Development and Innervation of the Human Inner Ear. Int J Mol Sci 2024; 25:8719. [PMID: 39201406 PMCID: PMC11354891 DOI: 10.3390/ijms25168719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 08/02/2024] [Accepted: 08/08/2024] [Indexed: 09/02/2024] Open
Abstract
Sensorineural hearing loss can be caused by lesions to the inner ear during development. Understanding the events and signaling pathways that drive inner ear formation is crucial for determining the possible causes of congenital hearing loss. We have analyzed the innervation and expression of SOX2, JAGGED1, β-catenin (CTNNB1), and vitamin D receptor (VDR) in the inner ears of human conceptuses aged 5 to 10 weeks after fertilization (W) using immunohistochemistry. The prosensory domains of the human inner ear displayed SOX2 and JAGGED1 expression throughout the analyzed period, with SOX2 expression being more extensive in all the analyzed timepoints. Innervation of vestibular prosensory domains was present at 6 W and extensive at 10 W, while nerve fibers reached the base of the cochlear prosensory domain at 7-8 W. CTNNB1 and VDR expression was mostly membranous and present during all analyzed timepoints in the inner ear, being the strongest in the non-sensory epithelium. Their expression was stronger in the vestibular region compared to the cochlear duct. CTNNB1 and VDR expression displayed opposite expression trends during the analyzed period, but additional studies are needed to elucidate whether they interact during inner ear development.
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Affiliation(s)
- Petra Mikulić
- Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia; (P.M.); (R.T.)
| | - Marin Ogorevc
- Division of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (M.O.); (S.M.)
| | - Marin Petričević
- Institute of Emergency Medicine of Split-Dalmatia County, Spinčićeva 1, 21000 Split, Croatia;
| | - Dean Kaličanin
- Department of Medical Biology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia;
| | - Robert Tafra
- Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia; (P.M.); (R.T.)
| | - Mirna Saraga-Babić
- Division of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (M.O.); (S.M.)
| | - Snježana Mardešić
- Division of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (M.O.); (S.M.)
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4
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Beaulieu MO, Thomas ED, Raible DW. Transdifferentiation is temporally uncoupled from progenitor pool expansion during hair cell regeneration in the zebrafish inner ear. Development 2024; 151:dev202944. [PMID: 39045613 PMCID: PMC11361639 DOI: 10.1242/dev.202944] [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: 04/09/2024] [Accepted: 07/15/2024] [Indexed: 07/25/2024]
Abstract
Death of mechanosensory hair cells in the inner ear is a common cause of auditory and vestibular impairment in mammals, which have a limited ability to regrow these cells after damage. In contrast, non-mammalian vertebrates, including zebrafish, can robustly regenerate hair cells after severe organ damage. The zebrafish inner ear provides an understudied model system for understanding hair cell regeneration in organs that are highly conserved with their mammalian counterparts. Here, we quantitatively examine hair cell addition during growth and regeneration of the larval zebrafish inner ear. We used a genetically encoded ablation method to induce hair cell death and we observed gradual regeneration with correct spatial patterning over a 2-week period following ablation. Supporting cells, which surround and are a source of new hair cells, divide in response to hair cell ablation, expanding the possible progenitor pool. In parallel, nascent hair cells arise from direct transdifferentiation of progenitor pool cells temporally uncoupled from supporting cell division. These findings reveal a previously unrecognized mechanism of hair cell regeneration with implications for how hair cells may be encouraged to regenerate in the mammalian ear.
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Affiliation(s)
- Marielle O. Beaulieu
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology - Head and Neck Surgery, University of Washington, Seattle, WA 98195, USA
| | - Eric D. Thomas
- Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - David W. Raible
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology - Head and Neck Surgery, University of Washington, Seattle, WA 98195, USA
- Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
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5
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Beaulac HJ, Munnamalai V. Localization of cadherins in the postnatal cochlear epithelium and their relation to space formation. Dev Dyn 2024; 253:771-780. [PMID: 38264972 PMCID: PMC11266531 DOI: 10.1002/dvdy.692] [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: 10/23/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/25/2024] Open
Abstract
The sensory epithelium of the cochlea, the organ of Corti, has complex cytoarchitecture consisting of mechanosensory hair cells intercalated by epithelial support cells. The support cells provide important trophic and structural support to the hair cells. Thus, the support cells must be stiff yet compliant enough to withstand and modulate vibrations to the hair cells. Once the sensory cells are properly patterned, the support cells undergo significant remodeling from a simple epithelium into a structurally rigid epithelium with fluid-filled spaces in the murine cochlea. Cell adhesion molecules such as cadherins are necessary for sorting and connecting cells in an intact epithelium. To create the fluid-filled spaces, cell adhesion properties of adjoining cell membranes between cells must change to allow the formation of spaces within an epithelium. However, the dynamic localization of cadherins has not been properly analyzed as these spaces are formed. There are three cadherins that are reported to be expressed during the first postnatal week of development when the tunnel of Corti forms in the cochlea. In this study, we characterize the dynamic localization of cadherins that are associated with cytoskeletal remodeling at the contacting membranes of the inner and outer pillar cells flanking the tunnel of Corti.
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6
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Lipovsek M. Comparative biology of the amniote vestibular utricle. Hear Res 2024; 448:109035. [PMID: 38763033 DOI: 10.1016/j.heares.2024.109035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/21/2024]
Abstract
The sensory epithelia of the auditory and vestibular systems of vertebrates have shared developmental and evolutionary histories. However, while the auditory epithelia show great variation across vertebrates, the vestibular sensory epithelia appear seemingly more conserved. An exploration of the current knowledge of the comparative biology of the amniote utricle, a vestibular sensory epithelium that senses linear acceleration, shows interesting instances of variability between birds and mammals. The distribution of sensory hair cell types, the position of the line of hair bundle polarity reversal and the properties of supporting cells show marked differences, likely impacting vestibular function and hair cell regeneration potential.
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Affiliation(s)
- Marcela Lipovsek
- Ear Institute, Faculty of Brain Sciences, University College London, London, UK.
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7
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Kersbergen CJ, Bergles DE. Priming central sound processing circuits through induction of spontaneous activity in the cochlea before hearing onset. Trends Neurosci 2024; 47:522-537. [PMID: 38782701 PMCID: PMC11236524 DOI: 10.1016/j.tins.2024.04.007] [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: 12/22/2023] [Revised: 04/02/2024] [Accepted: 04/26/2024] [Indexed: 05/25/2024]
Abstract
Sensory systems experience a period of intrinsically generated neural activity before maturation is complete and sensory transduction occurs. Here we review evidence describing the mechanisms and functions of this 'spontaneous' activity in the auditory system. Both ex vivo and in vivo studies indicate that this correlated activity is initiated by non-sensory supporting cells within the developing cochlea, which induce depolarization and burst firing of groups of nearby hair cells in the sensory epithelium, activity that is conveyed to auditory neurons that will later process similar sound features. This stereotyped neural burst firing promotes cellular maturation, synaptic refinement, acoustic sensitivity, and establishment of sound-responsive domains in the brain. While sensitive to perturbation, the developing auditory system exhibits remarkable homeostatic mechanisms to preserve periodic burst firing in deaf mice. Preservation of this early spontaneous activity in the context of deafness may enhance the efficacy of later interventions to restore hearing.
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Affiliation(s)
- Calvin J Kersbergen
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - Dwight E Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD, USA.
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8
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Heffer A, Lee C, Holt JC, Kiernan AE. Notch1 is required to maintain supporting cell identity and vestibular function during maturation of the mammalian balance organs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.21.600098. [PMID: 38948821 PMCID: PMC11212955 DOI: 10.1101/2024.06.21.600098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
The inner ear houses two sensory modalities: the hearing organ, located in the cochlea, and the balance organs, located throughout the vestibular regions of the ear. Both hearing and vestibular sensory regions are composed of similar cell types, including hair cells and associated supporting cells. Recently, we showed that Notch1 is required for maintaining supporting cell survival postnatally during cochlear maturation. However, it is not known whether Notch1 plays a similar role in the balance organs of the inner ear. To characterize the role of Notch during vestibular maturation, we conditionally deleted Notch1 from Sox2-expressing cells of the vestibular organs in the mouse at P0/P1. Histological analyses showed a dramatic loss of supporting cells accompanied by an increase in type II hair cells without cell death, indicating the supporting cells are converting to hair cells in the maturing vestibular regions. Analysis of 6-week old animals indicate that the converted hair cells survive, despite the reduction of supporting cells. Interestingly, measurements of vestibular sensory evoked potentials (VsEPs), known to be generated in the striolar regions of the vestibular afferents in the maculae, failed to show a response, indicating that NOTCH1 expression is critical for striolar function postnatally. Consistent with this, we find that the specialized type I hair cells in the striola fail to develop the complex calyces typical of these cells. These defects are likely due to the reduction in supporting cells, which have previously been shown to express factors critical for the striolar region. Similar to other mutants that lack proper striolar development, Notch1 mutants do not exhibit typical vestibular behaviors such as circling and head shaking, but do show difficulties in some vestibular tests, including the balance beam and forced swim test. These results indicate that, unlike the hearing organ in which the supporting cells undergo cell death, supporting cells in the balance regions retain the ability to convert to hair cells during maturation, which survive into adulthood despite the reduction in supporting cells.
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Affiliation(s)
- Alison Heffer
- Flaum Eye Institute, Department of Ophthalmology, University of Rochester Medical Center, Rochester, New York, 14642, USA
| | - Choongheon Lee
- Department of Otolaryngology, University of Rochester, Rochester, NY, 14642, USA
| | - Joseph C. Holt
- Department of Otolaryngology, University of Rochester, Rochester, NY, 14642, USA
- Dept. of Neuroscience, University of Rochester, Rochester, New York 14642, USA
| | - Amy E. Kiernan
- Flaum Eye Institute, Department of Ophthalmology, University of Rochester Medical Center, Rochester, New York, 14642, USA
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9
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Yu Y, Li Y, Wen C, Yang F, Chen X, Yi W, Deng L, Cheng X, Yu N, Huang L. High-frequency hearing vulnerability associated with the different supporting potential of Hensen's cells: SMART-Seq2 RNA sequencing. Biosci Trends 2024; 18:165-175. [PMID: 38583982 DOI: 10.5582/bst.2024.01044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Hearing loss is the third most prevalent physical condition affecting communication, well-being, and healthcare costs. Sensorineural hearing loss often occurs first in the high-frequency region (basal turn), then towards the low-frequency region (apical turn). However, the mechanism is still unclear. Supporting cells play a critical role in the maintenance of normal cochlear function. The function and supporting capacity of these cells may be different from different frequency regions. Hensen's cells are one of the unique supporting cell types characterized by lipid droplets (LDs) in the cytoplasm. Here, we investigated the morphological and gene expression differences of Hensen's cells along the cochlear axis. We observed a gradient change in the morphological characteristics of Hensen's cells along the cochlear tonotopic axis, with larger and more abundant LDs observed in apical Hensen's cells. Smart-seq2 RNA-seq revealed differentially expressed genes (DEGs) between apical and basal Hensen's cells that clustered in several pathways, including unsaturated fatty acid biosynthesis, cholesterol metabolism, and fatty acid catabolism, which are associated with different energy storage capacities and metabolic potential. These findings suggest potential differences in lipid metabolism and oxidative energy supply between apical and basal Hensen's cells, which is consistent with the morphological differences of Hensen's cells. We also found differential expression patterns of candidate genes associated with hereditary hearing loss (HHL), noise-induced hearing loss (NIHL), and age-related hearing loss (ARHL). These findings indicate functional heterogeneity of SCs along the cochlear axis, contribute to our understanding of cochlear physiology and provide molecular basis evidence for future studies of hearing loss.
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Affiliation(s)
- Yiding Yu
- Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing, China
- Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Yue Li
- Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing, China
- Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Cheng Wen
- Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing, China
- Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Fengbo Yang
- Otolaryngology Head and Neck Surgery, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Xuemin Chen
- College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Wenqi Yi
- College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Lin Deng
- Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing, China
- Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Xiaohua Cheng
- Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing, China
- Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Ning Yu
- College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Otolaryngologic Diseases, Beijing, China
| | - Lihui Huang
- Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Institute of Otolaryngology, Beijing, China
- Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
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10
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Heiman MG, Bülow HE. Dendrite morphogenesis in Caenorhabditis elegans. Genetics 2024; 227:iyae056. [PMID: 38785371 PMCID: PMC11151937 DOI: 10.1093/genetics/iyae056] [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: 12/18/2023] [Accepted: 04/02/2024] [Indexed: 05/25/2024] Open
Abstract
Since the days of Ramón y Cajal, the vast diversity of neuronal and particularly dendrite morphology has been used to catalog neurons into different classes. Dendrite morphology varies greatly and reflects the different functions performed by different types of neurons. Significant progress has been made in our understanding of how dendrites form and the molecular factors and forces that shape these often elaborately sculpted structures. Here, we review work in the nematode Caenorhabditis elegans that has shed light on the developmental mechanisms that mediate dendrite morphogenesis with a focus on studies investigating ciliated sensory neurons and the highly elaborated dendritic trees of somatosensory neurons. These studies, which combine time-lapse imaging, genetics, and biochemistry, reveal an intricate network of factors that function both intrinsically in dendrites and extrinsically from surrounding tissues. Therefore, dendrite morphogenesis is the result of multiple tissue interactions, which ultimately determine the shape of dendritic arbors.
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Affiliation(s)
- Maxwell G Heiman
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Hannes E Bülow
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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11
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Sabin KZ, Chen S, Hill EM, Weaver KJ, Yonke J, Kirkman M, Redwine WB, Klompen AML, Zhao X, Guo F, McKinney MC, Dewey JL, Gibson MC. Graded FGF activity patterns distinct cell types within the apical sensory organ of the sea anemone Nematostella vectensis. Dev Biol 2024; 510:50-65. [PMID: 38521499 DOI: 10.1016/j.ydbio.2024.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/26/2024] [Accepted: 02/28/2024] [Indexed: 03/25/2024]
Abstract
Bilaterian animals have evolved complex sensory organs comprised of distinct cell types that function coordinately to sense the environment. Each sensory unit has a defined architecture built from component cell types, including sensory cells, non-sensory support cells, and dedicated sensory neurons. Whether this characteristic cellular composition is present in the sensory organs of non-bilaterian animals is unknown. Here, we interrogate the cell type composition and gene regulatory networks controlling development of the larval apical sensory organ in the sea anemone Nematostella vectensis. Using single cell RNA sequencing and imaging approaches, we reveal two unique cell types in the Nematostella apical sensory organ, GABAergic sensory cells and a putative non-sensory support cell population. Further, we identify the paired-like (PRD) homeodomain gene prd146 as a specific sensory cell marker and show that Prd146+ sensory cells become post-mitotic after gastrulation. Genetic loss of function approaches show that Prd146 is essential for apical sensory organ development. Using a candidate gene knockdown approach, we place prd146 downstream of FGF signaling in the apical sensory organ gene regulatory network. Further, we demonstrate that an aboral FGF activity gradient coordinately regulates the specification of both sensory and support cells. Collectively, these experiments define the genetic basis for apical sensory organ development in a non-bilaterian animal and reveal an unanticipated degree of complexity in a prototypic sensory structure.
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Affiliation(s)
- Keith Z Sabin
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Shiyuan Chen
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Eric M Hill
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Kyle J Weaver
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Jacob Yonke
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | | | | | | | - Xia Zhao
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Fengli Guo
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | | | | | - Matthew C Gibson
- Stowers Institute for Medical Research, Kansas City, MO, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA.
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12
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Beaulieu MO, Thomas ED, Raible DW. Transdifferentiation is uncoupled from progenitor pool expansion during hair cell regeneration in the zebrafish inner ear. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.09.588777. [PMID: 38645220 PMCID: PMC11030336 DOI: 10.1101/2024.04.09.588777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Death of mechanosensory hair cells in the inner ear is a common cause of auditory and vestibular impairment in mammals, which have a limited ability to regrow these cells after damage. In contrast, non-mammalian vertebrates including zebrafish can robustly regenerate hair cells following severe organ damage. The zebrafish inner ear provides an understudied model system for understanding hair cell regeneration in organs that are highly conserved with their mammalian counterparts. Here we quantitatively examine hair cell addition during growth and regeneration of the larval zebrafish inner ear. We used a genetically encoded ablation method to induce hair cell death and observed gradual regeneration with correct spatial patterning over two weeks following ablation. Supporting cells, which surround and are a source of new hair cells, divide in response to hair cell ablation, expanding the possible progenitor pool. In parallel, nascent hair cells arise from direct transdifferentiation of progenitor pool cells uncoupled from progenitor division. These findings reveal a previously unrecognized mechanism of hair cell regeneration with implications for how hair cells may be encouraged to regenerate in the mammalian ear.
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Affiliation(s)
- Marielle O. Beaulieu
- Molecular and Cellular Biology Graduate Program, Seattle, WA
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology - Head and Neck Surgery, Seattle, WA
| | - Eric D. Thomas
- Neuroscience Graduate Program, Seattle, WA
- Department of Biological Structure University of Washington, Seattle, WA
| | - David W. Raible
- Molecular and Cellular Biology Graduate Program, Seattle, WA
- Virginia Merrill Bloedel Hearing Research Center, Department of Otolaryngology - Head and Neck Surgery, Seattle, WA
- Neuroscience Graduate Program, Seattle, WA
- Department of Biological Structure University of Washington, Seattle, WA
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13
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Una R, Glimm T. A Cellular Potts Model of the interplay of synchronization and aggregation. PeerJ 2024; 12:e16974. [PMID: 38435996 PMCID: PMC10909357 DOI: 10.7717/peerj.16974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/29/2024] [Indexed: 03/05/2024] Open
Abstract
We investigate the behavior of systems of cells with intracellular molecular oscillators ("clocks") where cell-cell adhesion is mediated by differences in clock phase between neighbors. This is motivated by phenomena in developmental biology and in aggregative multicellularity of unicellular organisms. In such systems, aggregation co-occurs with clock synchronization. To account for the effects of spatially extended cells, we use the Cellular Potts Model (CPM), a lattice agent-based model. We find four distinct possible phases: global synchronization, local synchronization, incoherence, and anti-synchronization (checkerboard patterns). We characterize these phases via order parameters. In the case of global synchrony, the speed of synchronization depends on the adhesive effects of the clocks. Synchronization happens fastest when cells in opposite phases adhere the strongest ("opposites attract"). When cells of the same clock phase adhere the strongest ("like attracts like"), synchronization is slower. Surprisingly, the slowest synchronization happens in the diffusive mixing case, where cell-cell adhesion is independent of clock phase. We briefly discuss potential applications of the model, such as pattern formation in the auditory sensory epithelium.
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Affiliation(s)
- Rose Una
- Department of Mathematics, Western Washington University, Bellingham, WA, United States of America
| | - Tilmann Glimm
- Department of Mathematics, Western Washington University, Bellingham, WA, United States of America
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14
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Strepay D, Olszewski RT, Nixon S, Korrapati S, Adadey S, Griffith AJ, Su Y, Liu J, Vishwasrao H, Gu S, Saunders T, Roux I, Hoa M. Transgenic Tg(Kcnj10-ZsGreen) fluorescent reporter mice allow visualization of intermediate cells in the stria vascularis. Sci Rep 2024; 14:3038. [PMID: 38321040 PMCID: PMC10847169 DOI: 10.1038/s41598-024-52663-7] [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: 09/27/2023] [Accepted: 01/22/2024] [Indexed: 02/08/2024] Open
Abstract
The stria vascularis (SV) is a stratified epithelium in the lateral wall of the mammalian cochlea, responsible for both endolymphatic ion homeostasis and generation of the endocochlear potential (EP) critical for normal hearing. The SV has three layers consisting predominantly of basal, intermediate, and marginal cells. Intermediate and marginal cells form an intricate interdigitated network of cell projections making discrimination of the cells challenging. To enable intermediate cell visualization, we engineered by BAC transgenesis, reporter mouse lines expressing ZsGreen fluorescent protein under the control of Kcnj10 promoter and regulatory sequences. Kcnj10 encodes KCNJ10 protein (also known as Kir4.1 or Kir1.2), an ATP-sensitive inwardly-rectifying potassium channel critical to EP generation, highly expressed in SV intermediate cells. In these transgenic mice, ZsGreen fluorescence mimics Kcnj10 endogenous expression in the cochlea and was detected in the intermediate cells of the SV, in the inner phalangeal cells, Hensen's, Deiters' and pillar cells, in a subset of spiral ganglion neurons, and in glial cells. We show that expression of the transgene in hemizygous mice does not alter auditory function, nor EP. These transgenic Tg(Kcnj10-ZsGreen) mice allow live and fixed tissue visualization of ZsGreen-expressing intermediate cells and will facilitate future studies of stria vascularis cell function.
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Affiliation(s)
- Dillon Strepay
- Auditory Development and Restoration Program, Neurotology Branch, National Institute On Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, 35 Convent Dr., Room 1F-226, Bethesda, MD, 20892-3745, USA
| | - Rafal T Olszewski
- Auditory Development and Restoration Program, Neurotology Branch, National Institute On Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, 35 Convent Dr., Room 1F-226, Bethesda, MD, 20892-3745, USA
| | - Sydney Nixon
- Auditory Development and Restoration Program, Neurotology Branch, National Institute On Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, 35 Convent Dr., Room 1F-226, Bethesda, MD, 20892-3745, USA
| | - Soumya Korrapati
- Auditory Development and Restoration Program, Neurotology Branch, National Institute On Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, 35 Convent Dr., Room 1F-226, Bethesda, MD, 20892-3745, USA
| | - Samuel Adadey
- Auditory Development and Restoration Program, Neurotology Branch, National Institute On Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, 35 Convent Dr., Room 1F-226, Bethesda, MD, 20892-3745, USA
| | - Andrew J Griffith
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Yijun Su
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Jiamin Liu
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Harshad Vishwasrao
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Shoujun Gu
- Auditory Development and Restoration Program, Neurotology Branch, National Institute On Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, 35 Convent Dr., Room 1F-226, Bethesda, MD, 20892-3745, USA
| | - Thomas Saunders
- Transgenic Animal Model Core, Biomedical Research Core Facility, University of Michigan, Ann Arbor, MI, USA
| | - Isabelle Roux
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, USA
| | - Michael Hoa
- Auditory Development and Restoration Program, Neurotology Branch, National Institute On Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, 35 Convent Dr., Room 1F-226, Bethesda, MD, 20892-3745, USA.
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15
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Pan X, Li Y, Huang P, Staecker H, He M. Extracellular vesicles for developing targeted hearing loss therapy. J Control Release 2024; 366:460-478. [PMID: 38182057 DOI: 10.1016/j.jconrel.2023.12.050] [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: 10/12/2023] [Revised: 12/19/2023] [Accepted: 12/28/2023] [Indexed: 01/07/2024]
Abstract
Substantial efforts have been made for local administration of small molecules or biologics in treating hearing loss diseases caused by either trauma, genetic mutations, or drug ototoxicity. Recently, extracellular vesicles (EVs) naturally secreted from cells have drawn increasing attention on attenuating hearing impairment from both preclinical studies and clinical studies. Highly emerging field utilizing diverse bioengineering technologies for developing EVs as the bioderived therapeutic materials, along with artificial intelligence (AI)-based targeting toolkits, shed the light on the unique properties of EVs specific to inner ear delivery. This review will illuminate such exciting research field from fundamentals of hearing protective functions of EVs to biotechnology advancement and potential clinical translation of functionalized EVs. Specifically, the advancements in assessing targeting ligands using AI algorithms are systematically discussed. The overall translational potential of EVs is reviewed in the context of auditory sensing system for developing next generation gene therapy.
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Affiliation(s)
- Xiaoshu Pan
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Yanjun Li
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, Florida 32610, United States
| | - Peixin Huang
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas 66160, United States
| | - Hinrich Staecker
- Department of Otolaryngology, Head and Neck Surgery, University of Kansas School of Medicine, Kansas City, Kansas 66160, United States.
| | - Mei He
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States.
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16
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Li L, Shen T, Liu S, Qi J, Zhao Y. Advancements and future prospects of adeno-associated virus-mediated gene therapy for sensorineural hearing loss. Front Neurosci 2024; 18:1272786. [PMID: 38327848 PMCID: PMC10847333 DOI: 10.3389/fnins.2024.1272786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 01/12/2024] [Indexed: 02/09/2024] Open
Abstract
Sensorineural hearing loss (SNHL), a highly prevalent sensory impairment, results from a multifaceted interaction of genetic and environmental factors. As we continually gain insights into the molecular basis of auditory development and the growing compendium of deafness genes identified, research on gene therapy for SNHL has significantly deepened. Adeno-associated virus (AAV), considered a relatively secure vector for gene therapy in clinical trials, can deliver various transgenes based on gene therapy strategies such as gene replacement, gene silencing, gene editing, or gene addition to alleviate diverse types of SNHL. This review delved into the preclinical advances in AAV-based gene therapy for SNHL, spanning hereditary and acquired types. Particular focus is placed on the dual-AAV construction method and its application, the vector delivery route of mouse inner ear models (local, systemic, fetal, and cerebrospinal fluid administration), and the significant considerations in transforming from AAV-based animal model inner ear gene therapy to clinical implementation.
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Affiliation(s)
- Linke Li
- Department of Otorhinolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Tian Shen
- Department of Otorhinolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Shixi Liu
- Department of Otorhinolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Jieyu Qi
- State Key Laboratory of Bioelectronics, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Yu Zhao
- Department of Otorhinolaryngology Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, China
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17
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Beaulac HJ, Munnamalai V. Localization of Cadherins in the postnatal cochlear epithelium and their relation to space formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.30.560287. [PMID: 37808730 PMCID: PMC10557783 DOI: 10.1101/2023.09.30.560287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The sensory epithelium of the cochlea, the organ of Corti, has complex cytoarchitecture consisting of mechanosensory hair cells intercalated by epithelial support cells. The support cells provide important trophic and structural support to the hair cells. Thus, the support cells must be stiff yet compliant enough to withstand and modulate vibrations to the hair cells. Once the sensory cells are properly patterned, the support cells undergo significant remodeling from a simple epithelium into a structurally rigid epithelium with fluid-filled spaces in the murine cochlea. Cell adhesion molecules such as cadherins are necessary for sorting and connecting cells in an intact epithelium. To create the fluid-filled spaces, cell adhesion properties of adjoining cell membranes between cells must change to allow the formation of spaces within an epithelium. However, the dynamic localization of cadherins has not been properly analyzed as these spaces are formed. There are three cadherins that are reported to be expressed during the first postnatal week of development when the tunnel of Corti forms in the cochlea. In this study, we characterize the dynamic localization of cadherins that are associated with cytoskeletal remodeling at the contacting membranes of the inner and outer pillar cells flanking the tunnel of Corti. Key findings F-actin remodeling occurs between E18.5 to P7 in the cochlear sensory epithelium.Transient changes of F-actin cytoskeleton drives epithelial morphogenesis.Fluid-filled spaces in epithelium is driven by changes in cell adhesion.
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18
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Strepay D, Olszewski RT, Nixon S, Korrapati S, Adadey S, Griffith AJ, Su Y, Liu J, Vishwasrao H, Gu S, Saunders T, Roux I, Hoa M. Transgenic Tg(Kcnj10-ZsGreen) Fluorescent Reporter Mice Allow Visualization of Intermediate Cells in the Stria Vascularis. RESEARCH SQUARE 2023:rs.3.rs-3393161. [PMID: 37886521 PMCID: PMC10602146 DOI: 10.21203/rs.3.rs-3393161/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The stria vascularis (SV) is a stratified epithelium in the lateral wall of the mammalian cochlea, responsible for both endolymphatic ion homeostasis and generation of the endocochlear potential (EP) critical for normal hearing. The SV has three layers consisting predominantly of basal, intermediate, and marginal cells. Intermediate and marginal cells form an intricate interdigitated network of cell projections making discrimination of the cells challenging. To enable intermediate cell visualization, we engineered by BAC transgenesis, reporter mouse lines expressing ZsGreen fluorescent protein under the control of Kcnj10 promoter and regulatory sequences. Kcnj10 encodes KCNJ10 protein (also known as Kir4.1 or Kir1.2), an ATP-sensitive inwardly-rectifying potassium channel critical to EP generation, highly expressed in SV intermediate cells. In these transgenic mice, ZsGreen fluorescence mimics Kcnj10 endogenous expression in the cochlea and was detected in the intermediate cells of the SV, in the inner phalangeal cells, Hensen's, Deiters' and pillar cells, in a subset of spiral ganglion neurons, and in glial cells. We show that expression of the transgene in hemizygous mice does not alter auditory function, nor EP These transgenic Tg(Kcnj10-ZsGreen) mice allow live and fixed tissue visualization of ZsGreen-expressing intermediate cells and will facilitate future studies of stria vascularis cell function.
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Affiliation(s)
- Dillon Strepay
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
| | - Rafal T Olszewski
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
| | - Sydney Nixon
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
| | - Soumya Korrapati
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
| | - Samuel Adadey
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
| | - Andrew J Griffith
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
| | - Yijun Su
- Advanced Imaging and Microscopy Resource, National Institutes of Health
| | - Jiamin Liu
- Advanced Imaging and Microscopy Resource, National Institutes of Health
| | | | - Shoujun Gu
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
| | - Thomas Saunders
- Transgenic Animal Model Core, Biomedical Research Core Facility, University of Michigan
| | - Isabelle Roux
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
| | - Michael Hoa
- Auditory Development and Restoration Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health
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19
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Hool SA, Jeng J, Jagger DJ, Marcotti W, Ceriani F. Age-related changes in P2Y receptor signalling in mouse cochlear supporting cells. J Physiol 2023; 601:4375-4395. [PMID: 37715703 PMCID: PMC10952729 DOI: 10.1113/jp284980] [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: 05/04/2023] [Accepted: 08/16/2023] [Indexed: 09/18/2023] Open
Abstract
Our sense of hearing depends on the function of a specialised class of sensory cells, the hair cells, which are found in the organ of Corti of the mammalian cochlea. The unique physiological environment in which these cells operate is maintained by a syncitium of non-sensory supporting cells, which are crucial for regulating cochlear physiology and metabolic homeostasis. Despite their importance for cochlear function, the role of these supporting cells in age-related hearing loss, the most common sensory deficit in the elderly, is poorly understood. Here, we investigated the age-related changes in the expression and function of metabotropic purinergic receptors (P2Y1 , P2Y2 and P2Y4 ) in the supporting cells of the cochlear apical coil. Purinergic signalling in supporting cells is crucial during the development of the organ of Corti and purinergic receptors are known to undergo changes in expression during ageing in several tissues. Immunolabelling and Ca2+ imaging experiments revealed a downregulation of P2Y receptor expression and a decrease of purinergic-mediated calcium responses after early postnatal stages in the supporting cells. An upregulation of P2Y receptor expression was observed in the aged cochlea when compared to 1 month-old adults. The aged mice also had significantly larger calcium responses and displayed calcium oscillations during prolonged agonist applications. We conclude that supporting cells in the aged cochlea upregulate P2Y2 and P2Y4 receptors and display purinergic-induced Ca2+ responses that mimic those observed during pre-hearing stages of development, possibly aimed at limiting or preventing further damage to the sensory epithelium. KEY POINTS: Age-related hearing loss is associated with lower hearing sensitivity and decreased ability to understand speech. We investigated age-related changes in the expression and function of metabotropic purinergic (P2Y) receptors in cochlear non-sensory supporting cells of mice displaying early-onset (C57BL/6N) and late-onset (C3H/HeJ) hearing loss. The expression of P2Y1 , P2Y2 and P2Y4 receptors in the supporting cells decreased during cochlear maturation, but that of P2Y2 and P2Y4 was upregulated in the aged cochlea. P2Y2 and P2Y4 receptors were primarily responsible for the ATP-induced Ca2+ responses in the supporting cells. The degree of purinergic expression upregulation in aged supporting cells mirrored hearing loss progression in the different mouse strains. We propose that the upregulation of purinergic-mediated signalling in the aged cochlea is subsequent to age-related changes in the hair cells and may act as a protective mechanism to limit or to avoid further damage to the sensory epithelium.
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Affiliation(s)
- Sarah A. Hool
- School of BiosciencesUniversity of SheffieldSheffieldUK
| | - Jing‐Yi Jeng
- School of BiosciencesUniversity of SheffieldSheffieldUK
| | | | - Walter Marcotti
- School of BiosciencesUniversity of SheffieldSheffieldUK
- Neuroscience InstituteUniversity of SheffieldSheffieldUK
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20
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Nguyen JD, Llamas J, Shi T, Crump JG, Groves AK, Segil N. DNA methylation in the mouse cochlea promotes maturation of supporting cells and contributes to the failure of hair cell regeneration. Proc Natl Acad Sci U S A 2023; 120:e2300839120. [PMID: 37549271 PMCID: PMC10438394 DOI: 10.1073/pnas.2300839120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 07/11/2023] [Indexed: 08/09/2023] Open
Abstract
Mammalian hair cells do not functionally regenerate in adulthood but can regenerate at embryonic and neonatal stages in mice by direct transdifferentiation of neighboring supporting cells into new hair cells. Previous work showed loss of transdifferentiation potential of supporting cells is in part due to H3K4me1 enhancer decommissioning of the hair cell gene regulatory network during the first postnatal week. However, inhibiting this decommissioning only partially preserves transdifferentiation potential. Therefore, we explored other repressive epigenetic modifications that may be responsible for this loss of plasticity. We find supporting cells progressively accumulate DNA methylation at promoters of developmentally regulated hair cell genes. Specifically, DNA methylation overlaps with binding sites of Atoh1, a key transcription factor for hair cell fate. We further show that DNA hypermethylation replaces H3K27me3-mediated repression of hair cell genes in mature supporting cells, and is accompanied by progressive loss of chromatin accessibility, suggestive of facultative heterochromatin formation. Another subset of hair cell loci is hypermethylated in supporting cells, but not in hair cells. Ten-eleven translocation (TET) enzyme-mediated demethylation of these hypermethylated sites is necessary for neonatal supporting cells to transdifferentiate into hair cells. We also observe changes in chromatin accessibility of supporting cell subtypes at the single-cell level with increasing age: Gene programs promoting sensory epithelium development loses chromatin accessibility, in favor of gene programs that promote physiological maturation and function of the cochlea. We also find chromatin accessibility is partially recovered in a chronically deafened mouse model, which holds promise for future translational efforts in hearing restoration.
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Affiliation(s)
- John D. Nguyen
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Biology at the University of Southern California, Los Angeles, CA90033
| | - Juan Llamas
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Biology at the University of Southern California, Los Angeles, CA90033
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA90033
| | - Tuo Shi
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Biology at the University of Southern California, Los Angeles, CA90033
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA90033
| | - J. Gage Crump
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Biology at the University of Southern California, Los Angeles, CA90033
| | - Andrew K. Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX77030
- Department of Neuroscience, Baylor College of Medicine, Houston, TX77030
| | - Neil Segil
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of the University of Southern California, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Biology at the University of Southern California, Los Angeles, CA90033
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA90033
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21
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Ebeid M, Kishimoto I, Roy P, Zaidi MAA, Cheng AG, Huh SH. β-Catenin transcriptional activity is required for establishment of inner pillar cell identity during cochlear development. PLoS Genet 2023; 19:e1010925. [PMID: 37639482 PMCID: PMC10491406 DOI: 10.1371/journal.pgen.1010925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 09/08/2023] [Accepted: 08/16/2023] [Indexed: 08/31/2023] Open
Abstract
The mammalian cochlea is composed of sensory hair cells as well as multiple different types of non-sensory supporting cells. Pillar cells are one type of supporting cell that form the tunnel of Corti and include two morphologically and functionally distinct subtypes: inner pillar cells (IPCs) and outer pillar cells (OPCs). The processes of specification and differentiation of inner versus outer pillar cells are still unclear. Here, we show that β-Catenin is required for establishing IPC identity in the mammalian cochlea. To differentiate the transcriptional and adhesion roles of β-Catenin in establishing IPC identity, we examined two different models of β-Catenin deletion; one that deletes both transcriptional and structural functions and one which retains cell adhesion function but lacks transcriptional function. Here, we show that cochleae lacking β-Catenin transcriptional function lost IPCs and displayed extranumerary OPCs, indicating its requirement for establishing IPC identity. Overexpression of β-Catenin induced proliferation within IPCs but not ectopic IPCs. Single-cell transcriptomes of supporting cells lacking β-Catenin transcriptional function show a loss of the IPC and gain of OPC signatures. Finally, targeted deletion of β-Catenin in IPCs also led to the loss of IPC identity, indicating a cell autonomous role of β-Catenin in establishing IPC identity. As IPCs have the capacity to regenerate sensory hair cells in the postnatal cochlea, our results will aid in future IPC-based hair cell regeneration strategies.
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Affiliation(s)
- Michael Ebeid
- Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Ippei Kishimoto
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, United States of America
| | - Pooja Roy
- Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Mohd Ali Abbas Zaidi
- Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Alan G. Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, United States of America
| | - Sung-Ho Huh
- Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Otolaryngology-Head and Neck Surgery, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
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22
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Kersbergen CJ, Babola TA, Kanold PO, Bergles DE. Preservation of developmental spontaneous activity enables early auditory system maturation in deaf mice. PLoS Biol 2023; 21:e3002160. [PMID: 37368868 PMCID: PMC10298803 DOI: 10.1371/journal.pbio.3002160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 05/11/2023] [Indexed: 06/29/2023] Open
Abstract
Intrinsically generated neural activity propagates through the developing auditory system to promote maturation and refinement of sound processing circuits prior to hearing onset. This early patterned activity is induced by non-sensory supporting cells in the organ of Corti, which are highly interconnected through gap junctions containing connexin 26 (Gjb2). Although loss of function mutations in Gjb2 impair cochlear development and are the most common cause of congenital deafness, it is not known if these variants disrupt spontaneous activity and the developmental trajectory of sound processing circuits in the brain. Here, we show in a new mouse model of Gjb2-mediated congenital deafness that cochlear supporting cells adjacent to inner hair cells (IHCs) unexpectedly retain intercellular coupling and the capacity to generate spontaneous activity, exhibiting only modest deficits prior to hearing onset. Supporting cells lacking Gjb2 elicited coordinated activation of IHCs, leading to coincident bursts of activity in central auditory neurons that will later process similar frequencies of sound. Despite alterations in the structure of the sensory epithelium, hair cells within the cochlea of Gjb2-deficient mice were intact and central auditory neurons could be activated within appropriate tonotopic domains by loud sounds at hearing onset, indicating that early maturation and refinement of auditory circuits was preserved. Only after cessation of spontaneous activity following hearing onset did progressive hair cell degeneration and enhanced auditory neuron excitability manifest. This preservation of cochlear spontaneous neural activity in the absence of connexin 26 may increase the effectiveness of early therapeutic interventions to restore hearing.
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Affiliation(s)
- Calvin J. Kersbergen
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Travis A. Babola
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Patrick O. Kanold
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Dwight E. Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Otolaryngology Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland, United States of America
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, Maryland, United States of America
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23
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Jones M, Kovacevic B, Ionescu CM, Wagle SR, Quintas C, Wong EYM, Mikov M, Mooranian A, Al-Salami H. The applications of Targeted Delivery for Gene Therapies in Hearing Loss. J Drug Target 2023:1-22. [PMID: 37211674 DOI: 10.1080/1061186x.2023.2216900] [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: 10/16/2022] [Revised: 12/07/2022] [Accepted: 04/09/2023] [Indexed: 05/23/2023]
Abstract
Gene therapies are becoming more abundantly researched for use in a multitude of potential treatments, including for hearing loss. Hearing loss is a condition which impacts an increasing number of the population each year, with significant burdens associated. As such, this review will present the concept that delivering a gene effectively to the inner ear may assist in expanding novel treatment options and improving patient outcomes. Historically, several drawbacks have been associated with the use of gene therapies, some of which may be overcome via targeted delivery. Targeted delivery has the potential to alleviate off-target effects and permit a safer delivery profile. Viral vectors have often been described as a delivery method, however, there is an emerging depiction of the potential for nanotechnology to be used. Resulting nanoparticles may also be tuned to allow for targeted delivery. Therefore, this review will focus on hearing loss, gene delivery techniques and inner ear targets, including highlighting promising research. Targeted delivery is a key concept to permitting gene delivery in a safe effective manner, however, further research is required, both in the determination of genes to use in functional hearing recovery and formulating nanoparticles for targeted delivery.
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Affiliation(s)
- Melissa Jones
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley 6102, Perth, Western Australia, Australia
- Hearing Therapeutics Department, Ear Science Institute Australia, Queen Elizabeth II Medical Centre, Nedlands 6009, Perth, Western Australia, Australia
| | - Bozica Kovacevic
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley 6102, Perth, Western Australia, Australia
- Hearing Therapeutics Department, Ear Science Institute Australia, Queen Elizabeth II Medical Centre, Nedlands 6009, Perth, 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, Perth, 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, Perth, Western Australia, Australia
- Hearing Therapeutics Department, Ear Science Institute Australia, Queen Elizabeth II Medical Centre, Nedlands 6009, Perth, Western Australia, Australia
| | - Christina Quintas
- School of human sciences, University of Western Australia, Crawley 6009, Perth, 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
| | - Momir Mikov
- Department of Pharmacology, Toxicology and Clinical Pharmacology, Faculty of Medicine, University of Novi Sad, Hajduk Veljkova 3, 21101 Novi Sad, Serbia
| | - Armin Mooranian
- The Biotechnology and Drug Development Research Laboratory, Curtin Medical School & Curtin Health Innovation Research Institute, Curtin University, Bentley 6102, Perth, Western Australia, Australia
- Hearing Therapeutics Department, Ear Science Institute Australia, Queen Elizabeth II Medical Centre, Nedlands 6009, Perth, Western Australia, Australia
- School of Pharmacy, University of Otago, Dunedin, 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, Perth, Western Australia, Australia
- Hearing Therapeutics Department, Ear Science Institute Australia, Queen Elizabeth II Medical Centre, Nedlands 6009, Perth, Western Australia, Australia
- Medical School, University of Western Australia, Perth, Western Australia, Australia
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24
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Jiang L, Wang D, He Y, Shu Y. Advances in gene therapy hold promise for treating hereditary hearing loss. Mol Ther 2023; 31:934-950. [PMID: 36755494 PMCID: PMC10124073 DOI: 10.1016/j.ymthe.2023.02.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/30/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
Gene therapy focuses on genetic modification to produce therapeutic effects or treat diseases by repairing or reconstructing genetic material, thus being expected to be the most promising therapeutic strategy for genetic disorders. Due to the growing attention to hearing impairment, an increasing amount of research is attempting to utilize gene therapy for hereditary hearing loss (HHL), an important monogenic disease and the most common type of congenital deafness. Several gene therapy clinical trials for HHL have recently been approved, and, additionally, CRISPR-Cas tools have been attempted for HHL treatment. Therefore, in order to further advance the development of inner ear gene therapy and promote its broad application in other forms of genetic disease, it is imperative to review the progress of gene therapy for HHL. Herein, we address three main gene therapy strategies (gene replacement, gene suppression, and gene editing), summarizing the strategy that is most appropriate for particular monogenic diseases based on different pathogenic mechanisms, and then focusing on their successful applications for HHL in preclinical trials. Finally, we elaborate on the challenges and outlooks of gene therapy for HHL.
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Affiliation(s)
- Luoying Jiang
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai 200031, China; NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai 200031, China; Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Daqi Wang
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai 200031, China; NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai 200031, China; Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Yingzi He
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai 200031, China; NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai 200031, China.
| | - Yilai Shu
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai 200031, China; NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai 200031, China; Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China.
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25
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Deletion of Notch1 during Cochlear Maturation Leads to Rapid Supporting Cell Death and Profound Deafness. J Neurosci 2023; 43:199-210. [PMID: 36418183 PMCID: PMC9838715 DOI: 10.1523/jneurosci.1090-22.2022] [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: 06/03/2022] [Revised: 09/14/2022] [Accepted: 11/08/2022] [Indexed: 11/25/2022] Open
Abstract
The sensory region of the mammalian hearing organ contains two main cell types-hair cells and supporting cells. During development, Notch signaling plays an important role in whether a cell becomes either a hair cell or supporting cell by mediating lateral inhibition. However, once the cell fate decisions have been determined, little is understood about the role Notch plays in cochlear maturation. Here, we report that deletion of Notch1 from the early postnatal mouse cochlea in both male and female animals resulted in profound deafness at 6 weeks of age. Histologic analyses at 6 weeks revealed significant hair cell and supporting cell loss throughout the Notch1-deficient cochlea. Early analyses revealed a reduction in supporting cells in the outer hair cell region between postnatal day (P) 2 and P6, without a comparable increase in outer hair cell number, suggesting a mechanism other than lateral inhibition. Consistent with this, we found apoptotic cells in the outer supporting cell region of the cochlea at P1 and P2, indicating that Notch1 is required for outer supporting cell survival during early cochlear maturation. Interestingly, inner supporting cell types were not lost after Notch1 deletion. Surprisingly, we do not detect outer hair cell loss in Notch1 mutants until after the onset of hearing, around P14, suggesting that hair cell loss is caused by loss of the supporting cells. Together, these results demonstrate that Notch1 is required for supporting cell survival during early maturation and that loss of these cells causes later loss of the hair cells and cochlear dysfunction.SIGNIFICANCE STATEMENT During development, Notch signaling has been shown to be critical in regulating the cell fate choices between hair cells and supporting cells. However, little is known about how Notch functions after those cell fate choices are made. Here, we examine the role of Notch1 in the maturing cochlea. We demonstrate that deletion of Notch1 results in profound deafness by 6 weeks of age. Histologic analyses revealed rapid supporting cell death shortly after Notch1 deletion, followed by eventual loss of the hair cells. These results reveal an unexpected role for Notch in supporting cell survival during cochlear maturation.
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26
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Abbott AC, García IE, Villanelo F, Flores-Muñoz C, Ceriani R, Maripillán J, Novoa-Molina J, Figueroa-Cares C, Pérez-Acle T, Sáez JC, Sánchez HA, Martínez AD. Expression of KID syndromic mutation Cx26S17F produces hyperactive hemichannels in supporting cells of the organ of Corti. Front Cell Dev Biol 2023; 10:1071202. [PMID: 36699003 PMCID: PMC9868548 DOI: 10.3389/fcell.2022.1071202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 12/15/2022] [Indexed: 01/11/2023] Open
Abstract
Some mutations in gap junction protein Connexin 26 (Cx26) lead to syndromic deafness, where hearing impairment is associated with skin disease, like in Keratitis Ichthyosis Deafness (KID) syndrome. This condition has been linked to hyperactivity of connexin hemichannels but this has never been demonstrated in cochlear tissue. Moreover, some KID mutants, like Cx26S17F, form hyperactive HCs only when co-expressed with other wild-type connexins. In this work, we evaluated the functional consequences of expressing a KID syndromic mutation, Cx26S17F, in the transgenic mouse cochlea and whether co-expression of Cx26S17F and Cx30 leads to the formation of hyperactive HCs. Indeed, we found that cochlear explants from a constitutive knock-in Cx26S17F mouse or conditional in vitro cochlear expression of Cx26S17F produces hyperactive HCs in supporting cells of the organ of Corti. These conditions also produce loss of hair cells stereocilia. In supporting cells, we found high co-localization between Cx26S17F and Cx30. The functional properties of HCs formed in cells co-expressing Cx26S17F and Cx30 were also studied in oocytes and HeLa cells. Under the recording conditions used in this study Cx26S17F did not form functional HCs and GJCs, but cells co-expressing Cx26S17F and Cx30 present hyperactive HCs insensitive to HCs blockers, Ca2+ and La3+, resulting in more Ca2+ influx and cellular damage. Molecular dynamic analysis of putative heteromeric HC formed by Cx26S17F and Cx30 presents alterations in extracellular Ca2+ binding sites. These results support that in KID syndrome, hyperactive HCs are formed by the interaction between Cx26S17F and Cx30 in supporting cells probably causing damage to hair cells associated to deafness.
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Affiliation(s)
- Ana C. Abbott
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile,Facultad de Medicina Veterinaria y Agronomía, Instituto de Ciencias Naturales, Universidad de las Américas, Viña del Mar, Chile
| | - Isaac E. García
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile,Laboratorio de Fisiología Molecular y Biofísica, Facultad de Odontología, Universidad de Valparaíso, Valparaíso, Chile,Centro de Investigaciones en Ciencias Odontológicas y Médicas, CICOM, Universidad de Valparaíso, Valparaíso, Chile
| | - Felipe Villanelo
- Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Santiago, Chile,Computational Biology Lab, Centro Basal Ciencia & Vida, Universidad San Sebastián, Santiago, Chile
| | - Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ricardo Ceriani
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile,Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso, Chile
| | - Jaime Maripillán
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Joel Novoa-Molina
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Cindel Figueroa-Cares
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Tomas Pérez-Acle
- Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Santiago, Chile,Computational Biology Lab, Centro Basal Ciencia & Vida, Universidad San Sebastián, Santiago, Chile
| | - Juan C. Sáez
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Helmuth A. Sánchez
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile,*Correspondence: Helmuth A. Sánchez, ; Agustín D. Martínez,
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencias de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile,*Correspondence: Helmuth A. Sánchez, ; Agustín D. Martínez,
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27
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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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28
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Moeinvaziri F, Zarkesh I, Pooyan P, Nunez DA, Baharvand H. Inner ear organoids: progress and outlook, with a focus on the vascularization. FEBS J 2022; 289:7368-7384. [PMID: 34331740 DOI: 10.1111/febs.16146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 06/11/2021] [Accepted: 07/30/2021] [Indexed: 01/13/2023]
Abstract
The inner ear is a complex organ that encodes sound, motion, and orientation in space. Given the complexity of the inner ear, it is not surprising that treatments are relatively limited despite the fact that, in 2015, hearing loss was the fourth leading cause of years lived with disability worldwide. Inner ear organoid models are a promising tool to advance the study of multiple aspects of the inner ear to aid the development of new treatments and validate drug-based therapies. The blood supply of the inner ear plays a pivotal role in growth, maturation, and survival of inner ear tissues and their physiological functions. This vasculature cannot be ignored in order to achieve a truly in vivo-like model that mimics the microenvironment and niches of organ development. However, this aspect of organoid development has remained largely absent in the generation of inner ear organoids. The current review focuses on three-dimensional inner ear organoid and how recent technical progress in generating in vitro vasculature can enhance the next generation of these models.
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Affiliation(s)
- Farideh Moeinvaziri
- Department of Developmental Biology, School of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, Tehran, Iran.,Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Ibrahim Zarkesh
- Department of Cell Engineering, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Paria Pooyan
- Department of Developmental Biology, School of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, Tehran, Iran
| | - Desmond A Nunez
- Division of Otolaryngology, Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Hossein Baharvand
- Department of Developmental Biology, School of Basic Sciences and Advanced Technologies in Biology, University of Science and Culture, Tehran, Iran.,Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
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29
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You D, Guo J, Zhang Y, Guo L, Lu X, Huang X, Sun S, Li H. The heterogeneity of mammalian utricular cells over the course of development. Clin Transl Med 2022; 12:e1052. [PMID: 36178017 PMCID: PMC9523683 DOI: 10.1002/ctm2.1052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 08/19/2022] [Accepted: 08/25/2022] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND The inner ear organ is a delicate tissue consisting of hair cells (HCs) and supporting cells (SCs).The mammalian inner ear HCs are terminally differentiated cells that cannot spontaneously regenerate in adults. Epithelial non-hair cells (ENHCs) in the utricle include HC progenitors and SCs, and the progenitors share similar characteristics with SCs in the neonatal inner ear. METHODS We applied single-cell sequencing to whole mouse utricles from the neonatal period to adulthood, including samples from postnatal day (P)2, P7 and P30 mice. Furthermore, using transgenic mice and immunostaining, we traced the source of new HC generation. RESULTS We identified several sensory epithelial cell clusters and further found that new HCs arose mainly through differentiation from Sox9+ progenitor cells and that only a few cells were produced by mitotic proliferation in both neonatal and adult mouse utricles. In addition, we identified the proliferative cells using the marker UbcH10 and demonstrated that in adulthood the mitotically generated HCs were primarily found in the extrastriola. Moreover, we observed that not only Type II, but also Type I HCs could be regenerated by either mitotic cell proliferation or progenitor cell differentiation. CONCLUSIONS Overall, our findings expand our understanding of ENHC cell fate and the characteristics of the vestibular organs in mammals over the course of development.
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Affiliation(s)
- Dan You
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina,Department of Otorhinolaryngology‐Head and Neck SurgeryZhongshan HospitalFudan UniversityShanghaiChina
| | - Jin Guo
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Yunzhong Zhang
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Luo Guo
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Xiaoling Lu
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Xinsheng Huang
- Department of Otorhinolaryngology‐Head and Neck SurgeryZhongshan HospitalFudan UniversityShanghaiChina
| | - Shan Sun
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Huawei Li
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina,Institutes of Biomedical SciencesFudan UniversityShanghaiChina,NHC Key Laboratory of Hearing Medicine, Fudan UniversityShanghaiChina,The Institutes of Brain Science and the Collaborative Innovation Center for Brain ScienceFudan UniversityShanghaiChina
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30
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Unbalanced bidirectional radial stiffness gradients within the organ of Corti promoted by TRIOBP. Proc Natl Acad Sci U S A 2022; 119:e2115190119. [PMID: 35737845 PMCID: PMC9245700 DOI: 10.1073/pnas.2115190119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Current understanding of cochlear mechanics assumes that stiffness of the cochlear partition varies only longitudinally along the cochlea. This work examines the stiffness of inner ear epithelium in individual cell types at the nanoscale level. We revealed unrecognized radial stiffness gradients of different magnitudes and opposite orientations within the epithelium. Remarkably, the observed bidirectional stiffness gradients are unbalanced between supporting and sensory cells. Deficiencies in deafness-associated Trio and F-actin binding protein (TRIOBP) caused diverse cytoskeletal ultrastructural remodeling in supporting and sensory cells and significantly diminishes the bidirectional radial stiffness gradients. These results demonstrate the complexity of the mechanical properties within the sensory epithelium and point to a hitherto unrecognized role of these gradients in sensitivity and frequency selectivity of hearing. Hearing depends on intricate morphologies and mechanical properties of diverse inner ear cell types. The individual contributions of various inner ear cell types into mechanical properties of the organ of Corti and the mechanisms of their integration are yet largely unknown. Using sub-100-nm spatial resolution atomic force microscopy (AFM), we mapped the Young’s modulus (stiffness) of the apical surface of the different cells of the freshly dissected P5–P6 cochlear epithelium from wild-type and mice lacking either Trio and F-actin binding protein (TRIOBP) isoforms 4 and 5 or isoform 5 only. Variants of TRIOBP are associated with deafness in human and in Triobp mutant mouse models. Remarkably, nanoscale AFM mapping revealed unrecognized bidirectional radial stiffness gradients of different magnitudes and opposite orientations between rows of wild-type supporting cells and sensory hair cells. Moreover, the observed bidirectional radial stiffness gradients are unbalanced, with sensory cells being stiffer overall compared to neighboring supporting cells. Deafness-associated TRIOBP deficiencies significantly disrupted the magnitude and orientation of these bidirectional radial stiffness gradients. In addition, serial sectioning with focused ion beam and backscatter scanning electron microscopy shows that a TRIOBP deficiency results in ultrastructural changes of supporting cell apical phalangeal microfilaments and bundled cortical F-actin of hair cell cuticular plates, correlating with messenger RNA and protein expression levels and AFM stiffness measurements that exposed a softening of the apical surface of the sensory epithelium in mutant mice. Altogether, this additional complexity in the mechanical properties of the sensory epithelium is hypothesized to be an essential contributor to frequency selectivity and sensitivity of mammalian hearing.
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31
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Jang MW, Lim J, Park MG, Lee JH, Lee CJ. Active role of glia-like supporting cells in the organ of Corti: Membrane proteins and their roles in hearing. Glia 2022; 70:1799-1825. [PMID: 35713516 DOI: 10.1002/glia.24229] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/23/2022] [Accepted: 05/30/2022] [Indexed: 12/13/2022]
Abstract
The organ of Corti, located in the cochlea in the inner ear, is one of the major sensory organs involved in hearing. The organ of Corti consists of hair cells, glia-like supporting cells, and the cochlear nerve, which work in harmony to receive sound from the outer ear and transmit auditory signals to the cochlear nucleus in the auditory ascending pathway. In this process, maintenance of the endocochlear potential, with a high potassium gradient and clearance of electrolytes and biochemicals in the inner ear, is critical for normal sound transduction. There is an emerging need for a thorough understanding of each cell type involved in this process to understand the sophisticated mechanisms of the organ of Corti. Hair cells have long been thought to be active, playing a primary role in the cochlea in actively detecting and transmitting signals. In contrast, supporting cells are thought to be silent and function to support hair cells. However, growing lines of evidence regarding the membrane proteins that mediate ionic movement in supporting cells have demonstrated that supporting cells are not silent, but actively play important roles in normal signal transduction. In this review, we summarize studies that characterize diverse membrane proteins according to the supporting cell subtypes involved in cochlear physiology and hearing. This review contributes to a better understanding of supporting cell functions and facilitates the development of potential therapeutic tools for hearing loss.
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Affiliation(s)
- Minwoo Wendy Jang
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea.,Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, Republic of Korea
| | - Jiwoon Lim
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, Republic of Korea.,IBS School, University of Science and Technology (UST), Daejeon, Republic of Korea
| | - Mingu Gordon Park
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea.,Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, Republic of Korea
| | - Jae-Hun Lee
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, Republic of Korea
| | - C Justin Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea.,Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, Republic of Korea.,IBS School, University of Science and Technology (UST), Daejeon, Republic of Korea
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32
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Waissbluth S, Maass JC, Sanchez HA, Martínez AD. Supporting Cells and Their Potential Roles in Cisplatin-Induced Ototoxicity. Front Neurosci 2022; 16:867034. [PMID: 35573297 PMCID: PMC9104564 DOI: 10.3389/fnins.2022.867034] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
Cisplatin is a known ototoxic chemotherapy drug, causing irreversible hearing loss. Evidence has shown that cisplatin causes inner ear damage as a result of adduct formation, a proinflammatory environment and the generation of reactive oxygen species within the inner ear. The main cochlear targets for cisplatin are commonly known to be the outer hair cells, the stria vascularis and the spiral ganglion neurons. Further evidence has shown that certain transporters can mediate cisplatin influx into the inner ear cells including organic cation transporter 2 (OCT2) and the copper transporter Ctr1. However, the expression profiles for these transporters within inner ear cells are not consistent in the literature, and expression of OCT2 and Ctr1 has also been observed in supporting cells. Organ of Corti supporting cells are essential for hair cell activity and survival. Special interest has been devoted to gap junction expression by these cells as certain mutations have been linked to hearing loss. Interestingly, cisplatin appears to affect connexin expression in the inner ear. While investigations regarding cisplatin-induced hearing loss have been focused mainly on the known targets previously mentioned, the role of supporting cells for cisplatin-induced ototoxicity has been overlooked. In this mini review, we discuss the implications of supporting cells expressing OCT2 and Ctr1 as well as the potential role of gap junctions in cisplatin-induced cytotoxicity.
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Affiliation(s)
- Sofia Waissbluth
- Department of Otolaryngology, Pontificia Universidad Católica de Chile, Santiago, Chile
- *Correspondence: Sofia Waissbluth, ;
| | - Juan Cristóbal Maass
- Department of Otolaryngology, Hospital Clínico de la Universidad de Chile, Santiago, Chile
| | - Helmuth A. Sanchez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Instituto de Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
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Janesick AS, Scheibinger M, Benkafadar N, Kirti S, Heller S. Avian auditory hair cell regeneration is accompanied by JAK/STAT-dependent expression of immune-related genes in supporting cells. Development 2022; 149:dev200113. [PMID: 35420675 PMCID: PMC10656459 DOI: 10.1242/dev.200113] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 03/31/2022] [Indexed: 11/20/2023]
Abstract
The avian hearing organ is the basilar papilla that, in sharp contrast to the mammalian cochlea, can regenerate sensory hair cells and thereby recover from deafness within weeks. The mechanisms that trigger, sustain and terminate the regenerative response in vivo are largely unknown. Here, we profile the changes in gene expression in the chicken basilar papilla after aminoglycoside antibiotic-induced hair cell loss using RNA-sequencing. We identified changes in gene expression of a group of immune-related genes and confirmed with single-cell RNA-sequencing that these changes occur in supporting cells. In situ hybridization was used to further validate these findings. We determined that the JAK/STAT signaling pathway is essential for upregulation of the damage-response genes in supporting cells during the second day after induction of hair cell loss. Four days after ototoxic damage, we identified newly regenerated, nascent auditory hair cells that express genes linked to termination of the JAK/STAT signaling response. The robust, transient expression of immune-related genes in supporting cells suggests a potential functional involvement of JAK/STAT signaling in sensory hair cell regeneration.
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Affiliation(s)
- Amanda S. Janesick
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Mirko Scheibinger
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Nesrine Benkafadar
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Sakin Kirti
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Stefan Heller
- Department of Otolaryngology – Head & Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
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34
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Li XJ, Morgan C, Goff LA, Doetzlhofer A. Follistatin promotes LIN28B-mediated supporting cell reprogramming and hair cell regeneration in the murine cochlea. SCIENCE ADVANCES 2022; 8:eabj7651. [PMID: 35148175 PMCID: PMC8836811 DOI: 10.1126/sciadv.abj7651] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 12/18/2021] [Indexed: 05/27/2023]
Abstract
Hair cell (HC) loss within the inner ear cochlea is a leading cause for deafness in humans. Before the onset of hearing, immature supporting cells (SCs) in neonatal mice have some limited capacity for HC regeneration. Here, we show that in organoid culture, transient activation of the progenitor-specific RNA binding protein LIN28B and Activin antagonist follistatin (FST) enhances regenerative competence of maturing/mature cochlear SCs by reprogramming them into progenitor-like cells. Transcriptome profiling and mechanistic studies reveal that LIN28B drives SC reprogramming, while FST is required to counterbalance hyperactivation of transforming growth factor-β-type signaling by LIN28B. Last, we show that LIN28B and FST coactivation enhances spontaneous cochlear HC regeneration in neonatal mice and that LIN28B may be part of an endogenous repair mechanism that primes SCs for HC regeneration. These findings indicate that SC dedifferentiation is critical for HC regeneration and identify LIN28B and FST as main regulators.
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Affiliation(s)
- Xiao-Jun Li
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Charles Morgan
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Loyal A. Goff
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Angelika Doetzlhofer
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Otolaryngology and Center for Hearing and Balance, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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35
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Wang J, Serratrice N, Lee CJ, François F, Sweedler JV, Puel JL, Mothet JP, Ruel J. Physiopathological Relevance of D-Serine in the Mammalian Cochlea. Front Cell Neurosci 2022; 15:733004. [PMID: 34975405 PMCID: PMC8718999 DOI: 10.3389/fncel.2021.733004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/29/2021] [Indexed: 12/02/2022] Open
Abstract
NMDA receptors (NMDARs) populate the complex between inner hair cell (IHC) and spiral ganglion neurons (SGNs) in the developing and mature cochlea. However, in the mature cochlea, activation of NMDARs is thought to mainly occur under pathological conditions such as excitotoxicity. Ototoxic drugs such as aspirin enable cochlear arachidonic-acid-sensitive NMDAR responses, and induced chronic tinnitus was blocked by local application of NMDAR antagonists into the cochlear fluids. We largely ignore if other modulators are also engaged. In the brain, D-serine is the primary physiological co-agonist of synaptic NMDARs. Whether D-serine plays a role in the cochlea had remained unexplored. We now reveal the presence of D-serine and its metabolic enzymes prior to, and at hearing onset, in the sensory and non-neuronal cells of the cochlea of several vertebrate species. In vivo intracochlear perfusion of D-serine in guinea pigs reduces sound-evoked activity of auditory nerve fibers without affecting the receptor potentials, suggesting that D-serine acts specifically on the postsynaptic auditory neurons without altering the functional state of IHC or of the stria vascularis. Indeed, we demonstrate in vitro that agonist-induced activation of NMDARs produces robust calcium responses in rat SGN somata only in the presence of D-serine, but not of glycine. Surprisingly, genetic deletion in mice of serine racemase (SR), the enzyme that catalyzes D-serine, does not affect hearing function, but offers protection against noise-induced permanent hearing loss as measured 3 months after exposure. However, the mechanisms of activation of NMDA receptors in newborn rats may be different from those in adult guinea pigs. Taken together, these results demonstrate for the first time that the neuro-messenger D-serine has a pivotal role in the cochlea by promoting the activation of silent cochlear NMDAR in pathological situations. Thus, D-serine and its signaling pathway may represent a new druggable target for treating sensorineural hearing disorders (i.e., hearing loss, tinnitus).
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Affiliation(s)
- Jing Wang
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France.,ENT Department, Hospital and University of Montpellier, Montpellier, France
| | - Nicolas Serratrice
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Cindy J Lee
- Department of Chemistry, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Florence François
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Jonathan V Sweedler
- Department of Chemistry, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Jean-Luc Puel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France
| | - Jean-Pierre Mothet
- Laboratoire LuMin, Biophotonics and Synapse Physiopathology Team, Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), ENS Paris Saclay, Centrale Supélec, Gif-sur-Yvette, France
| | - Jérôme Ruel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, Institut National de la Santé et de la Recherche Médicale (INSERM), Montpellier, France.,Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), Laboratoire de Neurosciences Cognitives, Marseille, France
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36
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Wichmann C, Kuner T. Heterogeneity of glutamatergic synapses: cellular mechanisms and network consequences. Physiol Rev 2022; 102:269-318. [PMID: 34727002 DOI: 10.1152/physrev.00039.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Chemical synapses are commonly known as a structurally and functionally highly diverse class of cell-cell contacts specialized to mediate communication between neurons. They represent the smallest "computational" unit of the brain and are typically divided into excitatory and inhibitory as well as modulatory categories. These categories are subdivided into diverse types, each representing a different structure-function repertoire that in turn are thought to endow neuronal networks with distinct computational properties. The diversity of structure and function found among a given category of synapses is referred to as heterogeneity. The main building blocks for this heterogeneity are synaptic vesicles, the active zone, the synaptic cleft, the postsynaptic density, and glial processes associated with the synapse. Each of these five structural modules entails a distinct repertoire of functions, and their combination specifies the range of functional heterogeneity at mammalian excitatory synapses, which are the focus of this review. We describe synapse heterogeneity that is manifested on different levels of complexity ranging from the cellular morphology of the pre- and postsynaptic cells toward the expression of different protein isoforms at individual release sites. We attempt to define the range of structural building blocks that are used to vary the basic functional repertoire of excitatory synaptic contacts and discuss sources and general mechanisms of synapse heterogeneity. Finally, we explore the possible impact of synapse heterogeneity on neuronal network function.
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Affiliation(s)
- Carolin Wichmann
- Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience, InnerEarLab and Institute for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas Kuner
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Heidelberg, Germany
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37
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Tisi A, Rovers J, Vink HA, Ramekers D, Maccarone R, Versnel H. No Protective Effects of Hair Cells or Supporting Cells in Ototoxically Deafened Guinea Pigs upon Administration of BDNF. Brain Sci 2021; 12:2. [PMID: 35053747 PMCID: PMC8773526 DOI: 10.3390/brainsci12010002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 11/16/2022] Open
Abstract
We investigated whether treatment with brain-derived neurotrophic factor (BDNF), which is known to protect spiral ganglion cells (SGCs), could also protect hair cells (HCs) and supporting cells (SCs) in the organ of Corti of a guinea pig model of sensorineural hearing loss. Hearing loss was induced by administration of kanamycin/furosemide and two BDNF treatments were performed: (1) by gelatin sponge (BDNF-GS) with acute cochlear implantation (CI), and (2) through a mini-osmotic pump (BDNF-OP) with chronic CI. Outer HCs (OHCs), inner HCs (IHCs), Border, Phalangeal, Pillar, Deiters', and Hensen's cells were counted. The BDNF-GS cochleas had significantly fewer OHCs compared to the untreated ones, while the IHC and SC numbers did not differ between treated and untreated cochleas. The BDNF-OP group showed similar cell numbers to the untreated group. SGC packing density was not correlated with the total number of SCs for either BDNF group. Our data suggest that: (1) BDNF does not prevent cell death in the organ of Corti, and that the protection of SGCs could result from a direct targeting by BDNF; (2) BDNF might induce a different function/activity of the remaining cells in the organ of Corti (independently from cell number).
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Affiliation(s)
- Annamaria Tisi
- Department of Applied Clinical Sciences and Biotechnology, University of L′Aquila, 67100 L′Aquila, Italy; (A.T.); (R.M.)
| | - Jochebed Rovers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; (J.R.); (H.A.V.); (D.R.)
| | - Henk A. Vink
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; (J.R.); (H.A.V.); (D.R.)
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Dyan Ramekers
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; (J.R.); (H.A.V.); (D.R.)
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
| | - Rita Maccarone
- Department of Applied Clinical Sciences and Biotechnology, University of L′Aquila, 67100 L′Aquila, Italy; (A.T.); (R.M.)
| | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Room G.02.531, P.O. Box 85500, 3508 GA Utrecht, The Netherlands; (J.R.); (H.A.V.); (D.R.)
- UMC Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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38
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Milon B, Shulman ED, So KS, Cederroth CR, Lipford EL, Sperber M, Sellon JB, Sarlus H, Pregernig G, Shuster B, Song Y, Mitra S, Orvis J, Margulies Z, Ogawa Y, Shults C, Depireux DA, Palermo AT, Canlon B, Burns J, Elkon R, Hertzano R. A cell-type-specific atlas of the inner ear transcriptional response to acoustic trauma. Cell Rep 2021; 36:109758. [PMID: 34592158 PMCID: PMC8709734 DOI: 10.1016/j.celrep.2021.109758] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/29/2021] [Accepted: 09/03/2021] [Indexed: 01/26/2023] Open
Abstract
Noise-induced hearing loss (NIHL) results from a complex interplay of damage to the sensory cells of the inner ear, dysfunction of its lateral wall, axonal retraction of type 1C spiral ganglion neurons, and activation of the immune response. We use RiboTag and single-cell RNA sequencing to survey the cell-type-specific molecular landscape of the mouse inner ear before and after noise trauma. We identify induction of the transcription factors STAT3 and IRF7 and immune-related genes across all cell-types. Yet, cell-type-specific transcriptomic changes dominate the response. The ATF3/ATF4 stress-response pathway is robustly induced in the type 1A noise-resilient neurons, potassium transport genes are downregulated in the lateral wall, mRNA metabolism genes are downregulated in outer hair cells, and deafness-associated genes are downregulated in most cell types. This transcriptomic resource is available via the Gene Expression Analysis Resource (gEAR; https://umgear.org/NIHL) and provides a blueprint for the rational development of drugs to prevent and treat NIHL.
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Affiliation(s)
- Beatrice Milon
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Eldad D Shulman
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Kathy S So
- Decibel Therapeutics, Boston, MA 02215, USA
| | - Christopher R Cederroth
- Laboratory of Experimental Audiology, Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden; Hearing Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham NG7 2UH, UK
| | - Erika L Lipford
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Michal Sperber
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | | | - Heela Sarlus
- Laboratory of Experimental Audiology, Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden; Applied Immunology & Immunotherapy, Neuroimmunology Unit, Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska University Hospital, 171 77 Stockholm, Sweden
| | | | - Benjamin Shuster
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yang Song
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Sunayana Mitra
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Joshua Orvis
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Zachary Margulies
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yoko Ogawa
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Christopher Shults
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | | | - Barbara Canlon
- Laboratory of Experimental Audiology, Department of Physiology and Pharmacology, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Joe Burns
- Decibel Therapeutics, Boston, MA 02215, USA
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Ronna Hertzano
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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39
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Liu Q, Zhang L, Zhu MS, Wan G. High-throughput screening on cochlear organoids identifies VEGFR-MEK-TGFB1 signaling promoting hair cell reprogramming. Stem Cell Reports 2021; 16:2257-2273. [PMID: 34525385 PMCID: PMC8452601 DOI: 10.1016/j.stemcr.2021.08.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 01/06/2023] Open
Abstract
Hair cell degeneration is a major cause of sensorineural hearing loss. Hair cells in mammalian cochlea do not spontaneously regenerate, posing a great challenge for restoration of hearing. Here, we establish a robust, high-throughput cochlear organoid platform that facilitates 3D expansion of cochlear progenitor cells and differentiation of hair cells in a temporally regulated manner. High-throughput screening of the FDA-approved drug library identified regorafenib, a VEGFR inhibitor, as a potent small molecule for hair cell differentiation. Regorafenib also promotes reprogramming and maturation of hair cells in both normal and neomycin-damaged cochlear explants. Mechanistically, inhibition of VEGFR suppresses TGFB1 expression via the MEK pathway and TGFB1 downregulation directly mediates the effect of regorafenib on hair cell reprogramming. Our study not only demonstrates the power of a cochlear organoid platform in high-throughput analyses of hair cell physiology but also highlights VEGFR-MEK-TGFB1 signaling crosstalk as a potential target for hair cell regeneration and hearing restoration. Cochlear organoids can be derived from both LGR5+ and LGR5– supporting cells HTS using cochlear organoids identifies regorafenib for hair cell differentiation Regorafenib promotes hair cell reprogramming and maturation in cochlear explants Regorafenib acts via a NOTCH-independent and VEGFR-MEK-TGFB1-dependent mechanism
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Affiliation(s)
- Qing Liu
- MOE Key Laboratory of Model Animal for Disease Study, Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical School, Nanjing University, Nanjing 210032, China
| | - Linqing Zhang
- MOE Key Laboratory of Model Animal for Disease Study, Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical School, Nanjing University, Nanjing 210032, China
| | - Min-Sheng Zhu
- MOE Key Laboratory of Model Animal for Disease Study, Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical School, Nanjing University, Nanjing 210032, China
| | - Guoqiang Wan
- MOE Key Laboratory of Model Animal for Disease Study, Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical School, Nanjing University, Nanjing 210032, China; Research Institute of Otolaryngology, No. 321 Zhongshan Road, 210008 Nanjing, China; Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing 210032, China; Institute for Brain Sciences, Nanjing University, Nanjing 210032, China.
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40
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Tasdemir-Yilmaz OE, Druckenbrod NR, Olukoya OO, Dong W, Yung AR, Bastille I, Pazyra-Murphy MF, Sitko AA, Hale EB, Vigneau S, Gimelbrant AA, Kharchenko PV, Goodrich LV, Segal RA. Diversity of developing peripheral glia revealed by single-cell RNA sequencing. Dev Cell 2021; 56:2516-2535.e8. [PMID: 34469751 DOI: 10.1016/j.devcel.2021.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/31/2021] [Accepted: 08/06/2021] [Indexed: 12/22/2022]
Abstract
The peripheral nervous system responds to a wide variety of sensory stimuli, a process that requires great neuronal diversity. These diverse neurons are closely associated with glial cells originating from the neural crest. However, the molecular nature and diversity among peripheral glia are not understood. Here, we used single-cell RNA sequencing to profile developing and mature glia from somatosensory dorsal root ganglia and auditory spiral ganglia. We found that glial precursors (GPs) in these two systems differ in their transcriptional profiles. Despite their unique features, somatosensory and auditory GPs undergo convergent differentiation to generate molecularly uniform myelinating and non-myelinating Schwann cells. By contrast, somatosensory and auditory satellite glial cells retain system-specific features. Lastly, we identified a glial signature gene set, providing new insights into commonalities among glia across the nervous system. This survey of gene expression in peripheral glia constitutes a resource for understanding functions of glia across different sensory modalities.
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Affiliation(s)
- Ozge E Tasdemir-Yilmaz
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Noah R Druckenbrod
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Weixiu Dong
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA
| | - Andrea R Yung
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Isle Bastille
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Maria F Pazyra-Murphy
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Austen A Sitko
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Evan B Hale
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Sébastien Vigneau
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | | | - Peter V Kharchenko
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA
| | - Lisa V Goodrich
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Rosalind A Segal
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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41
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Ray S, Singhvi A. Charging Up the Periphery: Glial Ionic Regulation in Sensory Perception. Front Cell Dev Biol 2021; 9:687732. [PMID: 34458255 PMCID: PMC8385785 DOI: 10.3389/fcell.2021.687732] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/30/2021] [Indexed: 12/25/2022] Open
Abstract
The peripheral nervous system (PNS) receives diverse sensory stimuli from the environment and transmits this information to the central nervous system (CNS) for subsequent processing. Thus, proper functions of cells in peripheral sense organs are a critical gate-keeper to generating appropriate animal sensory behaviors, and indeed their dysfunction tracks sensory deficits, sensorineural disorders, and aging. Like the CNS, the PNS comprises two major cell types, neurons (or sensory cells) and glia (or glia-like supporting neuroepithelial cells). One classic function of PNS glia is to modulate the ionic concentration around associated sensory cells. Here, we review current knowledge of how non-myelinating support cell glia of the PNS regulate the ionic milieu around sensory cell endings across species and systems. Molecular studies reviewed here suggest that, rather than being a passive homeostatic response, glial ionic regulation may in fact actively modulate sensory perception, implying that PNS glia may be active contributors to sensorineural information processing. This is reminiscent of emerging studies suggesting analogous roles for CNS glia in modulating neural circuit processing. We therefore suggest that deeper molecular mechanistic investigations into critical PNS glial functions like ionic regulation are essential to comprehensively understand sensorineural health, disease, and aging.
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Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States.,Department of Biological Structure, School of Medicine, University of Washington, Seattle, WA, United States
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42
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Huang TW, Iyer AA, Manalo JM, Woo J, Bosquez Huerta NA, McGovern MM, Schrewe H, Pereira FA, Groves AK, Ohlemiller KK, Deneen B. Glial-Specific Deletion of Med12 Results in Rapid Hearing Loss via Degradation of the Stria Vascularis. J Neurosci 2021; 41:7171-7181. [PMID: 34253626 PMCID: PMC8387121 DOI: 10.1523/jneurosci.0070-21.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 06/11/2021] [Accepted: 07/05/2021] [Indexed: 11/21/2022] Open
Abstract
Mediator protein complex subunit 12 (Med12) is a core component of the basal transcriptional apparatus and plays a critical role in the development of many tissues. Mutations in Med12 are associated with X-linked intellectual disability syndromes and hearing loss; however, its role in nervous system function remains undefined. Here, we show that temporal conditional deletion of Med12 in astrocytes in the adult CNS results in region-specific alterations in astrocyte morphology. Surprisingly, behavioral studies revealed rapid hearing loss after adult deletion of Med12 that was confirmed by a complete abrogation of auditory brainstem responses. Cellular analysis of the cochlea revealed degeneration of the stria vascularis, in conjunction with disorganization of basal cells adjacent to the spiral ligament and downregulation of key cell adhesion proteins. Physiologic analysis revealed early changes in endocochlear potential, consistent with strial-specific defects. Together, our studies reveal that Med12 regulates auditory function in the adult by preserving the structural integrity of the stria vascularis.SIGNIFICANCE STATEMENT Mutations in Mediator protein complex subunit 12 (Med12) are associated with X-linked intellectual disability syndromes and hearing loss. Using temporal-conditional genetic approaches in CNS glia, we found that loss of Med12 results in severe hearing loss in adult animals through rapid degeneration of the stria vascularis. Our study describes the first animal model that recapitulates hearing loss identified in Med12-related disorders and provides a new system in which to examine the underlying cellular and molecular mechanisms of Med12 function in the adult nervous system.
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Affiliation(s)
- Teng-Wei Huang
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030
| | - Amrita A Iyer
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Program in Genetics & Genomics, Baylor College of Medicine, Houston, Texas 77030
| | - Jeanne M Manalo
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, Houston, Texas 77030
| | - Junsung Woo
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030
| | - Navish A Bosquez Huerta
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030
| | - Melissa M McGovern
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Heinrich Schrewe
- Department of Developmental Genetics, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Fredrick A Pereira
- Huffington Center on Aging, Baylor College of Medicine, Houston, Texas 77030
- Department of Otolaryngology, Baylor College of Medicine, Houston, Texas 77030
| | - Andrew K Groves
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030
- Program in Genetics & Genomics, Baylor College of Medicine, Houston, Texas 77030
| | - Kevin K Ohlemiller
- Department of Otolaryngolgy, Central Institute for the Deaf, Fay and Carl Simons Center for Biology of Hearing and Deafness, Washington University in St. Louis, St. Louis, Missouri 63110
| | - Benjamin Deneen
- Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas 77030
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43
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Moulden J, Sung CYW, Brizic I, Jonjic S, Britt W. Murine Models of Central Nervous System Disease following Congenital Human Cytomegalovirus Infections. Pathogens 2021; 10:1062. [PMID: 34451526 PMCID: PMC8400215 DOI: 10.3390/pathogens10081062] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 11/17/2022] Open
Abstract
Human cytomegalovirus infection of the developing fetus is a leading cause of neurodevelopmental disorders in infants and children, leading to long-term neurological sequela in a significant number of infected children. Current understanding of the neuropathogenesis of this intrauterine infection is limited because of the complexity of this infection, which includes maternal immunological responses that are overlaid on virus replication in the CNS during neurodevelopment. Furthermore, available data from human cases are observational, and tissues from autopsy studies have been derived from only the most severe infections. Animal models of this human infection are also limited by the strict species specificity of cytomegaloviruses. However, informative models including non-human primates and small animal models have been developed. These include several different murine models of congenital HCMV infection for the study of CMV neuropathogenesis. Although individual murine models do not completely recapitulate all aspects of the human infection, each model has provided significant information that has extended current understanding of the neuropathogenesis of this human infection. This review will compare and contrast different murine models in the context of available information from human studies of CNS disease following congenital HCMV infections.
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Affiliation(s)
- Jerome Moulden
- Department of Microbiology, UAB School of Medicine, Birmingham, Al 35294, USA;
| | - Cathy Yea Won Sung
- Laboratory of Hearing Biology and Therapeutics, NIDCD, NIH, Bethesda, MD 20892, USA;
| | - Ilija Brizic
- Center for Proteomics and Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (I.B.); (S.J.)
| | - Stipan Jonjic
- Center for Proteomics and Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (I.B.); (S.J.)
| | - William Britt
- Department of Microbiology, UAB School of Medicine, Birmingham, Al 35294, USA;
- Department of Pediatrics and Neurobiology, UAB School of Medicine, Birmingham, Al 35294, USA
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44
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Jan TA, Eltawil Y, Ling AH, Chen L, Ellwanger DC, Heller S, Cheng AG. Spatiotemporal dynamics of inner ear sensory and non-sensory cells revealed by single-cell transcriptomics. Cell Rep 2021; 36:109358. [PMID: 34260939 PMCID: PMC8378666 DOI: 10.1016/j.celrep.2021.109358] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 12/25/2020] [Accepted: 06/17/2021] [Indexed: 11/28/2022] Open
Abstract
The utricle is a vestibular sensory organ that requires mechanosensitive hair cells to detect linear acceleration. In neonatal mice, new hair cells are derived from non-sensory supporting cells, yet cell type diversity and mechanisms of cell addition remain poorly characterized. Here, we perform computational analyses on single-cell transcriptomes to categorize cell types and resolve 14 individual sensory and non-sensory subtypes. Along the periphery of the sensory epithelium, we uncover distinct groups of transitional epithelial cells, marked by Islr, Cnmd, and Enpep expression. By reconstructing de novo trajectories and gene dynamics, we show that as the utricle expands, Islr+ transitional epithelial cells exhibit a dynamic and proliferative phase to generate new supporting cells, followed by coordinated differentiation into hair cells. Taken together, our study reveals a sequential and coordinated process by which non-sensory epithelial cells contribute to growth of the postnatal mouse sensory epithelium. The postnatal mouse utricle expands by more than 35% and doubles its number of hair cells during the first 8 days. Using single-cell transcriptomics, Jan et al. show that the surrounding transitional epithelial cells proliferate and contribute to the expansion of the sensory epithelium through a stepwise differentiation mechanism.
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Affiliation(s)
- Taha A Jan
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA; Department of Otolaryngology-Head and Neck Surgery, University of California San Francisco, San Francisco, CA 94115, USA
| | - Yasmin Eltawil
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Angela H Ling
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA; Department of Otolaryngology-Head and Neck Surgery, University of California San Francisco, San Francisco, CA 94115, USA
| | - Leon Chen
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Daniel C Ellwanger
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA; Genome Analysis Unit, Amgen Research, Amgen Inc., South San Francisco, CA 94080, USA
| | - Stefan Heller
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA.
| | - Alan G Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Palo Alto, CA 94305, USA.
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45
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Kohrman D, Borges BC, Cassinotti L, Ji L, Corfas G. Axon-glia interactions in the ascending auditory system. Dev Neurobiol 2021; 81:546-567. [PMID: 33561889 PMCID: PMC9004231 DOI: 10.1002/dneu.22813] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/25/2020] [Accepted: 02/05/2021] [Indexed: 11/09/2022]
Abstract
The auditory system detects and encodes sound information with high precision to provide a high-fidelity representation of the environment and communication. In mammals, detection occurs in the peripheral sensory organ (the cochlea) containing specialized mechanosensory cells (hair cells) that initiate the conversion of sound-generated vibrations into action potentials in the auditory nerve. Neural activity in the auditory nerve encodes information regarding the intensity and frequency of sound stimuli, which is transmitted to the auditory cortex through the ascending neural pathways. Glial cells are critical for precise control of neural conduction and synaptic transmission throughout the pathway, allowing for the precise detection of the timing, frequency, and intensity of sound signals, including the sub-millisecond temporal fidelity is necessary for tasks such as sound localization, and in humans, for processing complex sounds including speech and music. In this review, we focus on glia and glia-like cells that interact with hair cells and neurons in the ascending auditory pathway and contribute to the development, maintenance, and modulation of neural circuits and transmission in the auditory system. We also discuss the molecular mechanisms of these interactions, their impact on hearing and on auditory dysfunction associated with pathologies of each cell type.
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Affiliation(s)
- David Kohrman
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Beatriz C. Borges
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Luis Cassinotti
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Lingchao Ji
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Gabriel Corfas
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
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46
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A nonsense TMEM43 variant leads to disruption of connexin-linked function and autosomal dominant auditory neuropathy spectrum disorder. Proc Natl Acad Sci U S A 2021; 118:2019681118. [PMID: 34050020 PMCID: PMC8179140 DOI: 10.1073/pnas.2019681118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Genes that are primarily expressed in cochlear glia-like supporting cells (GLSs) have not been clearly associated with progressive deafness. Herein, we present a deafness locus mapped to chromosome 3p25.1 and an auditory neuropathy spectrum disorder (ANSD) gene, TMEM43, mainly expressed in GLSs. We identify p.(Arg372Ter) of TMEM43 by linkage analysis and exome sequencing in two large Asian families segregating ANSD, which is characterized by inability to discriminate speech despite preserved sensitivity to sound. The knock-in mouse with the p.(Arg372Ter) variant recapitulates a progressive hearing loss with histological abnormalities in GLSs. Mechanistically, TMEM43 interacts with the Connexin26 and Connexin30 gap junction channels, disrupting the passive conductance current in GLSs in a dominant-negative fashion when the p.(Arg372Ter) variant is introduced. Based on these mechanistic insights, cochlear implant was performed on three subjects, and speech discrimination was successfully restored. Our study highlights a pathological role of cochlear GLSs by identifying a deafness gene and its causal relationship with ANSD.
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47
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Nicolson T. Navigating Hereditary Hearing Loss: Pathology of the Inner Ear. Front Cell Neurosci 2021; 15:660812. [PMID: 34093131 PMCID: PMC8172992 DOI: 10.3389/fncel.2021.660812] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/26/2021] [Indexed: 11/13/2022] Open
Abstract
Inherited forms of deafness account for a sizable portion of hearing loss among children and adult populations. Many patients with sensorineural deficits have pathological manifestations in the peripheral auditory system, the inner ear. Within the hearing organ, the cochlea, most of the genetic forms of hearing loss involve defects in sensory detection and to some extent, signaling to the brain via the auditory cranial nerve. This review focuses on peripheral forms of hereditary hearing loss and how these impairments can be studied in diverse animal models or patient-derived cells with the ultimate goal of using the knowledge gained to understand the underlying biology and treat hearing loss.
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Affiliation(s)
- Teresa Nicolson
- Department of Otolaryngology, Stanford University, Stanford, CA, United States
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48
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Iyer AA, Groves AK. Transcription Factor Reprogramming in the Inner Ear: Turning on Cell Fate Switches to Regenerate Sensory Hair Cells. Front Cell Neurosci 2021; 15:660748. [PMID: 33854418 PMCID: PMC8039129 DOI: 10.3389/fncel.2021.660748] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/08/2021] [Indexed: 12/15/2022] Open
Abstract
Non-mammalian vertebrates can restore their auditory and vestibular hair cells naturally by triggering the regeneration of adjacent supporting cells. The transcription factor ATOH1 is a key regulator of hair cell development and regeneration in the inner ear. Following the death of hair cells, supporting cells upregulate ATOH1 and give rise to new hair cells. However, in the mature mammalian cochlea, such natural regeneration of hair cells is largely absent. Transcription factor reprogramming has been used in many tissues to convert one cell type into another, with the long-term hope of achieving tissue regeneration. Reprogramming transcription factors work by altering the transcriptomic and epigenetic landscapes in a target cell, resulting in a fate change to the desired cell type. Several studies have shown that ATOH1 is capable of reprogramming cochlear non-sensory tissue into cells resembling hair cells in young animals. However, the reprogramming ability of ATOH1 is lost with age, implying that the potency of individual hair cell-specific transcription factors may be reduced or lost over time by mechanisms that are still not clear. To circumvent this, combinations of key hair cell transcription factors have been used to promote hair cell regeneration in older animals. In this review, we summarize recent findings that have identified and studied these reprogramming factor combinations for hair cell regeneration. Finally, we discuss the important questions that emerge from these findings, particularly the feasibility of therapeutic strategies using reprogramming factors to restore human hearing in the future.
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Affiliation(s)
- Amrita A. Iyer
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Program in Genetics & Genomics, Houston, TX, United States
| | - Andrew K. Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Program in Genetics & Genomics, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
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49
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Stojkovic M, Han D, Jeong M, Stojkovic P, Stankovic KM. Human induced pluripotent stem cells and CRISPR/Cas-mediated targeted genome editing: Platforms to tackle sensorineural hearing loss. STEM CELLS (DAYTON, OHIO) 2021; 39:673-696. [PMID: 33586253 DOI: 10.1002/stem.3353] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/13/2020] [Indexed: 11/09/2022]
Abstract
Hearing loss (HL) is a major global health problem of pandemic proportions. The most common type of HL is sensorineural hearing loss (SNHL) which typically occurs when cells within the inner ear are damaged. Human induced pluripotent stem cells (hiPSCs) can be generated from any individual including those who suffer from different types of HL. The development of new differentiation protocols to obtain cells of the inner ear including hair cells (HCs) and spiral ganglion neurons (SGNs) promises to expedite cell-based therapy and screening of potential pharmacologic and genetic therapies using human models. Considering age-related, acoustic, ototoxic, and genetic insults which are the most frequent causes of irreversible damage of HCs and SGNs, new methods of genome editing (GE), especially the CRISPR/Cas9 technology, could bring additional opportunities to understand the pathogenesis of human SNHL and identify novel therapies. However, important challenges associated with both hiPSCs and GE need to be overcome before scientific discoveries are correctly translated to effective and patient-safe applications. The purpose of the present review is (a) to summarize the findings from published reports utilizing hiPSCs for studies of SNHL, hence complementing recent reviews focused on animal studies, and (b) to outline promising future directions for deciphering SNHL using disruptive molecular and genomic technologies.
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Affiliation(s)
- Miodrag Stojkovic
- Eaton Peabody Laboratories, Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Dongjun Han
- Eaton Peabody Laboratories, Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Minjin Jeong
- Eaton Peabody Laboratories, Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Petra Stojkovic
- Eaton Peabody Laboratories, Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Konstantina M Stankovic
- Eaton Peabody Laboratories, Department of Otolaryngology Head and Neck Surgery, Massachusetts Eye and Ear, Boston, Massachusetts, USA.,Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA.,Program in Speech and Hearing Bioscience and Technology, Harvard University, Cambridge, Massachusetts, USA.,Harvard Program in Therapeutic Science, Harvard Medical School, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
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50
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Raiders S, Han T, Scott-Hewitt N, Kucenas S, Lew D, Logan MA, Singhvi A. Engulfed by Glia: Glial Pruning in Development, Function, and Injury across Species. J Neurosci 2021; 41:823-833. [PMID: 33468571 PMCID: PMC7880271 DOI: 10.1523/jneurosci.1660-20.2020] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/20/2020] [Accepted: 10/26/2020] [Indexed: 02/07/2023] Open
Abstract
Phagocytic activity of glial cells is essential for proper nervous system sculpting, maintenance of circuitry, and long-term brain health. Glial engulfment of apoptotic cells and superfluous connections ensures that neuronal connections are appropriately refined, while clearance of damaged projections and neurotoxic proteins in the mature brain protects against inflammatory insults. Comparative work across species and cell types in recent years highlights the striking conservation of pathways that govern glial engulfment. Many signaling cascades used during developmental pruning are re-employed in the mature brain to "fine tune" synaptic architecture and even clear neuronal debris following traumatic events. Moreover, the neuron-glia signaling events required to trigger and perform phagocytic responses are impressively conserved between invertebrates and vertebrates. This review offers a compare-and-contrast portrayal of recent findings that underscore the value of investigating glial engulfment mechanisms in a wide range of species and contexts.
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Affiliation(s)
- Stephan Raiders
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington 98195
| | - Taeho Han
- UCSF Weill Institute for Neurosciences, University of California San Francisco, San Francisco, California 94158
| | - Nicole Scott-Hewitt
- F.M. Kirby Center for Neurobiology, Boston Children's Hospital, Boston, Massachusetts 02115
- Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Deborah Lew
- Department of Biological Sciences, Fordham University, Bronx, New York 10458
| | - Mary A Logan
- Jungers Center, Department of Neurology, Oregon Health and Science University, Portland, Oregon 97239
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington 98195
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