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Hosoya M, Kurihara S, Koyama H, Komune N. Recent advances in Otology: Current landscape and future direction. Auris Nasus Larynx 2024; 51:605-616. [PMID: 38552424 DOI: 10.1016/j.anl.2024.02.009] [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: 08/22/2023] [Revised: 11/24/2023] [Accepted: 02/21/2024] [Indexed: 05/12/2024]
Abstract
Hearing is an essential sensation, and its deterioration leads to a significant decrease in the quality of life. Thus, great efforts have been made by otologists to preserve and recover hearing. Our knowledge regarding the field of otology has progressed with advances in technology, and otologists have sought to develop novel approaches in the field of otologic surgery to achieve higher hearing recovery or preservation rates. This requires knowledge regarding the anatomy of the temporal bone and the physiology of hearing. Basic research in the field of otology has progressed with advances in molecular biology and genetics. This review summarizes the current views and recent advances in the field of otology and otologic surgery, especially from the viewpoint of young Japanese clinician-scientists, and presents the perspectives and future directions for several topics in the field of otology. This review will aid next-generation researchers in understanding the recent advances and future challenges in the field of otology.
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Affiliation(s)
- Makoto Hosoya
- Department of Otolaryngology, Head and Neck Surgery, Keio University School of Medicine, Shinanomachi 35, Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Sho Kurihara
- Department of Otorhinolaryngology, The Jikei University School of Medicine, 3-25-8 Nishishimbashi Minato-ku, Tokyo, 105-8471, Japan
| | - Hajime Koyama
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8654, Japan
| | - Noritaka Komune
- Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, 3-1-1Maidashi Higashi-ku, Fukuoka 812-8582, Japan
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2
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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] [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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3
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Goodrich EJ, Deans MR. Emx2 lineage tracing reveals antecedent patterns of planar polarity in the mouse inner ear. Development 2024; 151:dev202425. [PMID: 38804528 DOI: 10.1242/dev.202425] [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] [Accepted: 04/18/2024] [Indexed: 05/01/2024]
Abstract
The planar polarized organization of hair cells in the vestibular maculae is unique because these sensory organs contain two groups of cells with oppositely oriented stereociliary bundles that meet at a line of polarity reversal (LPR). EMX2 is a transcription factor expressed by one hair cell group that reverses the orientation of their bundles, thereby forming the LPR. We generated Emx2-CreERt2 transgenic mice for genetic lineage tracing and demonstrate Emx2 expression before hair cell specification when the nascent utricle and saccule constitute a continuous prosensory domain. Precursors labeled by Emx2-CreERt2 at this stage give rise to hair cells located along one side of the LPR in the mature utricle or saccule, indicating that this boundary is first established in the prosensory domain. Consistent with this, Emx2-CreERt2 lineage tracing in Dreher mutants, where the utricle and saccule fail to segregate, labels a continuous field of cells along one side of a fused utriculo-saccular-cochlear organ. These observations reveal that LPR positioning is pre-determined in the developing prosensory domain, and that EMX2 expression defines lineages of hair cells with oppositely oriented stereociliary bundles.
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Affiliation(s)
- Ellison J Goodrich
- Department of Neurobiology, Spencer Fox Eccles School of Medicine at the University of Utah, Salt Lake City, UT 84112, USA
| | - Michael R Deans
- Department of Neurobiology, Spencer Fox Eccles School of Medicine at the University of Utah, Salt Lake City, UT 84112, USA
- Department of Otolaryngology - Head and Neck Surgery, Spencer Fox Eccles School of Medicine at the University of Utah, Salt Lake City, UT 84132, USA
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4
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Kacker S, Parsad V, Singh N, Hordiichuk D, Alvarez S, Gohar M, Kacker A, Rai SK. Planar Cell Polarity Signaling: Coordinated Crosstalk for Cell Orientation. J Dev Biol 2024; 12:12. [PMID: 38804432 PMCID: PMC11130840 DOI: 10.3390/jdb12020012] [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: 01/28/2024] [Revised: 04/08/2024] [Accepted: 04/13/2024] [Indexed: 05/29/2024] Open
Abstract
The planar cell polarity (PCP) system is essential for positioning cells in 3D networks to establish the proper morphogenesis, structure, and function of organs during embryonic development. The PCP system uses inter- and intracellular feedback interactions between components of the core PCP, characterized by coordinated planar polarization and asymmetric distribution of cell populations inside the cells. PCP signaling connects the anterior-posterior to left-right embryonic plane polarity through the polarization of cilia in the Kupffer's vesicle/node in vertebrates. Experimental investigations on various genetic ablation-based models demonstrated the functions of PCP in planar polarization and associated genetic disorders. This review paper aims to provide a comprehensive overview of PCP signaling history, core components of the PCP signaling pathway, molecular mechanisms underlying PCP signaling, interactions with other signaling pathways, and the role of PCP in organ and embryonic development. Moreover, we will delve into the negative feedback regulation of PCP to maintain polarity, human genetic disorders associated with PCP defects, as well as challenges associated with PCP.
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Affiliation(s)
- Sandeep Kacker
- Department of Pharmacology, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis;
| | - Varuneshwar Parsad
- Department of Human Body Structure and Function, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis; (V.P.); (D.H.)
| | - Naveen Singh
- Department of Cerll and Molecular Biology, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis; (N.S.); (S.A.); (M.G.)
| | - Daria Hordiichuk
- Department of Human Body Structure and Function, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis; (V.P.); (D.H.)
| | - Stacy Alvarez
- Department of Cerll and Molecular Biology, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis; (N.S.); (S.A.); (M.G.)
| | - Mahnoor Gohar
- Department of Cerll and Molecular Biology, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis; (N.S.); (S.A.); (M.G.)
| | - Anshu Kacker
- Department of Histology and Human Physiology, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis;
| | - Sunil Kumar Rai
- Department of Cerll and Molecular Biology, Medical University of the Americas, Charlestown KN 1102, Saint Kitts and Nevis; (N.S.); (S.A.); (M.G.)
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5
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Piscitello-Gómez R, Gruber FS, Krishna A, Duclut C, Modes CD, Popović M, Jülicher F, Dye NA, Eaton S. Core PCP mutations affect short-time mechanical properties but not tissue morphogenesis in the Drosophila pupal wing. eLife 2023; 12:e85581. [PMID: 38117039 PMCID: PMC10843330 DOI: 10.7554/elife.85581] [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: 12/15/2022] [Accepted: 12/18/2023] [Indexed: 12/21/2023] Open
Abstract
How morphogenetic movements are robustly coordinated in space and time is a fundamental open question in biology. We study this question using the wing of Drosophila melanogaster, an epithelial tissue that undergoes large-scale tissue flows during pupal stages. Previously, we showed that pupal wing morphogenesis involves both cellular behaviors that allow relaxation of mechanical tissue stress, as well as cellular behaviors that appear to be actively patterned (Etournay et al., 2015). Here, we show that these active cellular behaviors are not guided by the core planar cell polarity (PCP) pathway, a conserved signaling system that guides tissue development in many other contexts. We find no significant phenotype on the cellular dynamics underlying pupal morphogenesis in mutants of core PCP. Furthermore, using laser ablation experiments, coupled with a rheological model to describe the dynamics of the response to laser ablation, we conclude that while core PCP mutations affect the fast timescale response to laser ablation they do not significantly affect overall tissue mechanics. In conclusion, our work shows that cellular dynamics and tissue shape changes during Drosophila pupal wing morphogenesis do not require core PCP as an orientational guiding cue.
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Affiliation(s)
- Romina Piscitello-Gómez
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- DFG Excellence Cluster Physics of Life, Technische Universität DresdenDresdenGermany
| | - Franz S Gruber
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- National Phenotypic Screening Centre, University of DundeeDundeeUnited Kingdom
| | - Abhijeet Krishna
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- DFG Excellence Cluster Physics of Life, Technische Universität DresdenDresdenGermany
- Center for Systems Biology DresdenDresdenGermany
| | - Charlie Duclut
- Laboratoire Physico-Chimie Curie, CNRS UMR 168, Institut Curie, Université PSL, Sorbonne UniversitéParisFrance
- Max Planck Institute for Physics of Complex SystemsDresdenGermany
- Université Paris Cité, Laboratoire Matière et Systèmes ComplexesParisFrance
| | - Carl D Modes
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- DFG Excellence Cluster Physics of Life, Technische Universität DresdenDresdenGermany
- Center for Systems Biology DresdenDresdenGermany
| | - Marko Popović
- DFG Excellence Cluster Physics of Life, Technische Universität DresdenDresdenGermany
- Center for Systems Biology DresdenDresdenGermany
- Max Planck Institute for Physics of Complex SystemsDresdenGermany
| | - Frank Jülicher
- DFG Excellence Cluster Physics of Life, Technische Universität DresdenDresdenGermany
- Center for Systems Biology DresdenDresdenGermany
- Max Planck Institute for Physics of Complex SystemsDresdenGermany
| | - Natalie A Dye
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- DFG Excellence Cluster Physics of Life, Technische Universität DresdenDresdenGermany
- Mildred Scheel Nachwuchszentrum P2, Medical Faculty, Technische Universität DresdenDresdenGermany
| | - Suzanne Eaton
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- DFG Excellence Cluster Physics of Life, Technische Universität DresdenDresdenGermany
- Center for Systems Biology DresdenDresdenGermany
- Biotechnologisches Zentrum, Technische Universität DresdenDresdenGermany
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6
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Oyagi S, Nakamura R, Katsuno T, Sogami T, Kawai Y, Kishimoto Y, Omori K. Local coordination of epithelial planar polarity in the maintenance and regeneration of the adult rat airway. Cell Tissue Res 2023; 394:163-175. [PMID: 37460682 DOI: 10.1007/s00441-023-03809-y] [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: 03/20/2023] [Accepted: 07/05/2023] [Indexed: 10/07/2023]
Abstract
The maintenance of planar polarity in airway multiciliated cells (MCCs) has been poorly characterized. We recently reported that the direction of ciliary beating in a surgically inverted tracheal segment remained inverted beyond the time required for the turnover of cells, without adjustment to global distal-to-proximal polarity. We hypothesized that the local maintenance of tissue-level polarity occurs via locally reproduced cells. To provide further insight regarding this hypothetical property, we performed allotransplantation of an inverted tracheal segment between wild-type (donor) and tdTomato-expressing (host) rats, with and without scratching the mucosa of the transplants. The origin of cells in the transplants was assessed using tdTomato-specific immunostaining. Ciliary movement and structures were observed by high-speed video and electron microscopy to analyze MCC orientations. Variabilities in the orientations of closely and distantly located MCCs were analyzed to evaluate the local- and broad-scale coordination of polarity, respectively. The epithelium was maintained by donor-derived cells in the non-scratched inverted transplant over 6 months, beyond one cycle of turnover. The inverted orientation of MCCs was also maintained throughout the non-scratched transplant. MCCs regenerated in the scratched transplant were derived from the host and exhibited diverse orientations across the transplant. However, the orientations of adjacent regenerated MCCs were often coordinated, indicating that airway MCCs can locally coordinate their orientations. A steady-state airway may maintain MCC orientation by locally reproducing MCCs via the local coordination of polarity. This local coordination enables the formation and maintenance of tissue-level polarity in small regions after mucosal injury.
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Affiliation(s)
- Seiji Oyagi
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Min-iren Chuo Hospital, Kyoto, Japan
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Ryosuke Nakamura
- Department of Rehabilitation Medicine, New York University Grossman School of Medicine, New York, USA
| | - Tatsuya Katsuno
- Center of Anatomical, Pathological and Forensic Medical Researches, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Tohru Sogami
- Department of Otolaryngology-Head and Neck Surgery, SOSEIKAI hospital, Kyoto, Japan
| | - Yoshitaka Kawai
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Yo Kishimoto
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Koichi Omori
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan
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7
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Cetera M, Sharan R, Hayward-Lara G, Phillips B, Biswas A, Halley M, Beall E, vonHoldt B, Devenport D. Region-specific reversal of epidermal planar polarity in the rosette fancy mouse. Development 2023; 150:dev202078. [PMID: 37622728 PMCID: PMC10499026 DOI: 10.1242/dev.202078] [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: 06/13/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
The planar cell polarity (PCP) pathway collectively orients cells with respect to a body axis. Hair follicles of the murine epidermis provide a striking readout of PCP activity in their uniform alignment across the skin. Here, we characterize, from the molecular to tissue-scale, PCP establishment in the rosette fancy mouse, a natural variant with posterior-specific whorls in its fur, to understand how epidermal polarity is coordinated across the tissue. We find that rosette hair follicles emerge with reversed orientations specifically in the posterior region, creating a mirror image of epidermal polarity. The rosette trait is associated with a missense mutation in the core PCP gene Fzd6, which alters a consensus site for N-linked glycosylation, inhibiting its membrane localization. Unexpectedly, the Fzd6 trafficking defect does not block asymmetric localization of the other PCP proteins. Rather, the normally uniform axis of PCP asymmetry rotates where the PCP-directed cell movements that orient follicles are reversed, suggesting the PCP axis rotates 180°. Collectively, our multiscale analysis of epidermal polarity reveals PCP patterning can be regionally decoupled to produce posterior whorls in the rosette fancy mouse.
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Affiliation(s)
- Maureen Cetera
- Department of Genetics, Cell Biology and Development, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Rishabh Sharan
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | | | - Brooke Phillips
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Abhishek Biswas
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
- Research Computing, Office of Information Technology, Princeton University, Princeton, NJ 08540, USA
| | - Madalene Halley
- Department of Genetics, Cell Biology and Development, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Evalyn Beall
- Department of Genetics, Cell Biology and Development, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Bridgett vonHoldt
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08540, USA
| | - Danelle Devenport
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
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8
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Jia S, Ratzan EM, Goodrich EJ, Abrar R, Heiland L, Tarchini B, Deans MR. The dark kinase STK32A regulates hair cell planar polarity opposite of EMX2 in the developing mouse inner ear. eLife 2023; 12:e84910. [PMID: 37144879 PMCID: PMC10202454 DOI: 10.7554/elife.84910] [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: 11/14/2022] [Accepted: 05/03/2023] [Indexed: 05/06/2023] Open
Abstract
The vestibular maculae of the inner ear contain sensory receptor hair cells that detect linear acceleration and contribute to equilibrioception to coordinate posture and ambulatory movements. These hair cells are divided between two groups, separated by a line of polarity reversal (LPR), with oppositely oriented planar-polarized stereociliary bundles that detect motion in opposite directions. The transcription factor EMX2 is known to establish this planar polarized organization in mouse by regulating the distribution of the transmembrane receptor GPR156 at hair cell boundaries in one group of cells. However, the genes regulated by EMX2 in this context were previously not known. Using mouse as a model, we have identified the serine threonine kinase STK32A as a downstream effector negatively regulated by EMX2. Stk32a is expressed in hair cells on one side of the LPR in a pattern complementary to Emx2 expression in hair cells on the opposite side. Stk32a is necessary to align the intrinsic polarity of the bundle with the core planar cell polarity (PCP) proteins in EMX2-negative regions, and is sufficient to reorient bundles when ectopically expressed in neighboring EMX2-positive regions. We demonstrate that STK32A reinforces LPR formation by regulating the apical localization of GPR156. These observations support a model in which bundle orientation is determined through separate mechanisms in hair cells on opposite sides of the maculae, with EMX2-mediated repression of Stk32a determining the final position of the LPR.
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Affiliation(s)
- Shihai Jia
- Department of Neurobiology, Spencer Fox Eccles School of Medicine at the University of UtahSalt Lake CityUnited States
| | - Evan M Ratzan
- Interdepartmental Program in Neuroscience, Spencer Fox Eccles School of Medicine at the University of UtahSalt Lake CityUnited States
- Departments of Otolaryngology and Neurology, Boston Children’s Hospital and Harvard Medical SchoolBostonUnited States
| | - Ellison J Goodrich
- Department of Neurobiology, Spencer Fox Eccles School of Medicine at the University of UtahSalt Lake CityUnited States
| | - Raisa Abrar
- Department of Neurobiology, Spencer Fox Eccles School of Medicine at the University of UtahSalt Lake CityUnited States
| | - Luke Heiland
- Department of Otolaryngology, Spencer Fox Eccles School of Medicine at the University of UtahSalt Lake CityUnited States
| | - Basile Tarchini
- The Jackson LaboratoryBar HarborUnited States
- Tufts University School of MedicineBostonUnited States
| | - Michael R Deans
- Department of Neurobiology, Spencer Fox Eccles School of Medicine at the University of UtahSalt Lake CityUnited States
- Department of Otolaryngology, Spencer Fox Eccles School of Medicine at the University of UtahSalt Lake CityUnited States
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9
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Sharkova M, Chow E, Erickson T, Hocking JC. The morphological and functional diversity of apical microvilli. J Anat 2023; 242:327-353. [PMID: 36281951 PMCID: PMC9919547 DOI: 10.1111/joa.13781] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/03/2022] [Accepted: 10/05/2022] [Indexed: 11/30/2022] Open
Abstract
Sensory neurons use specialized apical processes to perceive external stimuli and monitor internal body conditions. The apical apparatus can include cilia, microvilli, or both, and is adapted for the functions of the particular cell type. Photoreceptors detect light through a large, modified cilium (outer segment), that is supported by a surrounding ring of microvilli-like calyceal processes (CPs). Although first reported 150 years ago, CPs remain poorly understood. As a basis for future study, we therefore conducted a review of existing literature about sensory cell microvilli, which can act either as the primary sensory detector or as support for a cilia-based detector. While all microvilli are finger-like cellular protrusions with an actin core, the processes vary across cell types in size, number, arrangement, dynamics, and function. We summarize the current state of knowledge about CPs and the characteristics of the microvilli found on inner ear hair cells (stereocilia) and cerebral spinal fluid-contacting neurons, with comparisons to the brush border of the intestinal and renal epithelia. The structure, stability, and dynamics of the actin core are regulated by a complement of actin-binding proteins, which includes both common components and unique features when compared across cell types. Further, microvilli are often supported by lateral links, a glycocalyx, and a defined extracellular matrix, each adapted to the function and environment of the cell. Our comparison of microvillar features will inform further research into how CPs support photoreceptor function, and also provide a general basis for investigations into the structure and functions of apical microvilli found on sensory neurons.
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Affiliation(s)
- Maria Sharkova
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Erica Chow
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Timothy Erickson
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Jennifer C Hocking
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Division of Anatomy, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
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10
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Lindner LA, Derstroff D, Oliver D, Reimann K. Distribution of ciliary adaptor proteins tubby and TULP3 in the organ of Corti. Front Neurosci 2023; 17:1162937. [PMID: 37144094 PMCID: PMC10151737 DOI: 10.3389/fnins.2023.1162937] [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: 02/10/2023] [Accepted: 03/28/2023] [Indexed: 05/06/2023] Open
Abstract
Tubby-like proteins are membrane-associated adaptors that mediate directional trafficking into primary cilia. In inner ear sensory epithelia, cilia-including the hair cell's kinocilium-play important roles as organizers of polarity, tissue architecture and cellular function. However, auditory dysfunction in tubby mutant mice was recently found to be related to a non-ciliary function of tubby, the organization of a protein complex in sensory hair bundles of auditory outer hair cells (OHCs). Targeting of signaling components into cilia in the cochlea might therefore rather rely on closely related tubby-like proteins (TULPs). In this study, we compared cellular and subcellular localization of tubby and TULP3 in the mouse inner ear sensory organs. Immunofluorescence microscopy confirmed the previously reported highly selective localization of tubby in the stereocilia tips of OHCs and revealed a previously unnoticed transient localization to kinocilia during early postnatal development. TULP3 was detected in the organ of Corti and vestibular sensory epithelium, where it displayed a complex spatiotemporal pattern. TULP3 localized to kinocilia of cochlear and vestibular hair cells in early postnatal development but disappeared subsequently before the onset of hearing. This pattern suggested a role in targeting ciliary components into kinocilia, possibly related to the developmental processes that shape the sensory epithelia. Concurrent with loss from kinocilia, pronounced TULP3 immunolabeling progressively appeared at microtubule bundles in non-sensory Pillar (PCs) and Deiters cells (DC). This subcellular localization may indicate a novel function of TULP proteins associated with the formation or regulation of microtubule-based cellular structures.
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Affiliation(s)
- Laura A. Lindner
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Marburg, Philipps-University Marburg, Marburg, Germany
| | - Dennis Derstroff
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Marburg, Philipps-University Marburg, Marburg, Germany
| | - Dominik Oliver
- Department of Neurophysiology, Institute of Physiology and Pathophysiology, Philipps-University Marburg, Marburg, Germany
| | - Katrin Reimann
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Marburg, Philipps-University Marburg, Marburg, Germany
- *Correspondence: Katrin Reimann,
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11
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Wang J, Zheng J, Wang H, He H, Li S, Zhang Y, Wang Y, Xu X, Wang S. Gene therapy: an emerging therapy for hair cells regeneration in the cochlea. Front Neurosci 2023; 17:1177791. [PMID: 37207182 PMCID: PMC10188948 DOI: 10.3389/fnins.2023.1177791] [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: 03/02/2023] [Accepted: 04/12/2023] [Indexed: 05/21/2023] Open
Abstract
Sensorineural hearing loss is typically caused by damage to the cochlear hair cells (HCs) due to external stimuli or because of one's genetic factors and the inability to convert sound mechanical energy into nerve impulses. Adult mammalian cochlear HCs cannot regenerate spontaneously; therefore, this type of deafness is usually considered irreversible. Studies on the developmental mechanisms of HC differentiation have revealed that nonsensory cells in the cochlea acquire the ability to differentiate into HCs after the overexpression of specific genes, such as Atoh1, which makes HC regeneration possible. Gene therapy, through in vitro selection and editing of target genes, transforms exogenous gene fragments into target cells and alters the expression of genes in target cells to activate the corresponding differentiation developmental program in target cells. This review summarizes the genes that have been associated with the growth and development of cochlear HCs in recent years and provides an overview of gene therapy approaches in the field of HC regeneration. It concludes with a discussion of the limitations of the current therapeutic approaches to facilitate the early implementation of this therapy in a clinical setting.
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Affiliation(s)
- Jipeng Wang
- Department of Gastrointestinal Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jianwei Zheng
- Department of Biliary-Pancreatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Haiyan Wang
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Haoying He
- Department of Neurology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Shuang Li
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Ya Zhang
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - You Wang
- Department of Stomatology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
- *Correspondence: You Wang,
| | - Xiaoxiang Xu
- Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
- Xiaoxiang Xu,
| | - Shuyi Wang
- Department of Gastrointestinal Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
- Shuyi Wang,
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Akturk A, Day M, Tarchini B. RGS12 polarizes the GPSM2-GNAI complex to organize and elongate stereocilia in sensory hair cells. SCIENCE ADVANCES 2022; 8:eabq2826. [PMID: 36260679 PMCID: PMC9581478 DOI: 10.1126/sciadv.abq2826] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/31/2022] [Indexed: 06/10/2023]
Abstract
Inhibitory G proteins (GNAI/Gαi) bind to the scaffold G protein signaling modulator 2 (GPSM2) to form a conserved polarity complex that regulates cytoskeleton organization. GPSM2 keeps GNAI in a guanosine diphosphate (GDP)-bound state, but how GPSM2-GNAI is generated or relates to heterotrimeric G protein signaling remains unclear. We find that RGS12, a GTPase-activating protein (GAP), is required to polarize GPSM2-GNAI at the hair cell apical membrane and to organize mechanosensory stereocilia in rows of graded heights. Accordingly, RGS12 and the guanine nucleotide exchange factor (GEF) DAPLE are asymmetrically co-enriched at the hair cell apical junction, and Rgs12 mouse mutants are deaf. GPSM2 and RGS12 share GoLoco motifs that stabilize GNAI(GDP), and GPSM2 outcompetes RGS12 to bind GNAI. Our results suggest that polarized GEF/GAP junctional activity might dissociate heterotrimeric G proteins, generating free GNAI(GDP) for GPSM2 at the adjacent apical membrane. GPSM2-GNAI(GDP), in turn, imparts asymmetry to the forming stereocilia to enable sensory function in hair cells.
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Affiliation(s)
- Anil Akturk
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Matthew Day
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Basile Tarchini
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
- School of Medicine, Tufts University, Boston, MA 02111, USA
- Graduate School of Biomedical Science and Engineering (GSBSE), University of Maine, Orono, ME 04469, USA
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Emerging Roles of RNA-Binding Proteins in Inner Ear Hair Cell Development and Regeneration. Int J Mol Sci 2022; 23:ijms232012393. [PMID: 36293251 PMCID: PMC9604452 DOI: 10.3390/ijms232012393] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/07/2022] [Accepted: 10/14/2022] [Indexed: 11/05/2022] Open
Abstract
RNA-binding proteins (RBPs) regulate gene expression at the post-transcriptional level. They play major roles in the tissue- and stage-specific expression of protein isoforms as well as in the maintenance of protein homeostasis. The inner ear is a bi-functional organ, with the cochlea and the vestibular system required for hearing and for maintaining balance, respectively. It is relatively well documented that transcription factors and signaling pathways are critically involved in the formation of inner ear structures and in the development of hair cells. Accumulating evidence highlights emerging functions of RBPs in the post-transcriptional regulation of inner ear development and hair cell function. Importantly, mutations of splicing factors of the RBP family and defective alternative splicing, which result in inappropriate expression of protein isoforms, lead to deafness in both animal models and humans. Because RBPs are critical regulators of cell proliferation and differentiation, they present the potential to promote hair cell regeneration following noise- or ototoxin-induced damage through mitotic and non-mitotic mechanisms. Therefore, deciphering RBP-regulated events during inner ear development and hair cell regeneration can help define therapeutic strategies for treatment of hearing loss. In this review, we outline our evolving understanding of the implications of RBPs in hair cell formation and hearing disease with the aim of promoting future research in this field.
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