1
|
Jurisch-Yaksi N, Wachten D, Gopalakrishnan J. The neuronal cilium - a highly diverse and dynamic organelle involved in sensory detection and neuromodulation. Trends Neurosci 2024; 47:383-394. [PMID: 38580512 DOI: 10.1016/j.tins.2024.03.004] [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: 03/04/2024] [Accepted: 03/14/2024] [Indexed: 04/07/2024]
Abstract
Cilia are fascinating organelles that act as cellular antennae, sensing the cellular environment. Cilia gained significant attention in the late 1990s after their dysfunction was linked to genetic diseases known as ciliopathies. Since then, several breakthrough discoveries have uncovered the mechanisms underlying cilia biogenesis and function. Like most cells in the animal kingdom, neurons also harbor cilia, which are enriched in neuromodulatory receptors. Yet, how neuronal cilia modulate neuronal physiology and animal behavior remains poorly understood. By comparing ciliary biology between the sensory and central nervous systems (CNS), we provide new perspectives on the functions of cilia in brain physiology.
Collapse
Affiliation(s)
- Nathalie Jurisch-Yaksi
- Department of Clinical and Molecular Medicine (IKOM), Faculty of Medicine and Health Science, Norwegian University of Science and Technology, Erling Skalgssons gate 1, 7491 Trondheim, Norway.
| | - Dagmar Wachten
- Department of Biophysical Imaging, Institute of Innate Immunity, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Jay Gopalakrishnan
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany; Institute for Human Genetics, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, 07740 Jena, Germany
| |
Collapse
|
2
|
Diana A, Ghilardi A, Del Giacco L. Differentiation and functioning of the lateral line organ in zebrafish require Smpx activity. Sci Rep 2024; 14:7862. [PMID: 38570547 PMCID: PMC10991396 DOI: 10.1038/s41598-024-58138-z] [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: 03/26/2024] [Indexed: 04/05/2024] Open
Abstract
The small muscle protein, X-linked (SMPX) gene encodes a cytoskeleton-associated protein, highly expressed in the inner ear hair cells (HCs), possibly regulating auditory function. In the last decade, several mutations in SMPX have been associated with X-chromosomal progressive non syndromic hearing loss in humans and, in line with this, Smpx-deficient animal models, namely zebrafish and mouse, showed significant impairment of inner ear HCs development, maintenance, and functioning. In this work, we uncovered smpx expression in the neuromast mechanosensory HCs of both Anterior and Posterior Lateral Line (ALL and PLL, respectively) of zebrafish larvae and focused our attention on the PLL. Smpx was subcellularly localized throughout the cytoplasm of the HCs, as well as in their primary cilium. Loss-of-function experiments, via both morpholino-mediated gene knockdown and CRISPR/Cas9 F0 gene knockout, revealed that the lack of Smpx led to fewer properly differentiated and functional neuromasts, as well as to a smaller PLL primordium (PLLp), the latter also Smpx-positive. In addition, the kinocilia of Smpx-deficient neuromast HCs appeared structurally and numerically altered. Such phenotypes were associated with a significant reduction in the mechanotransduction activity of the neuromast HCs, in line with their positivity for Smpx. In summary, this work highlights the importance of Smpx in lateral line development and, specifically, in proper HCs differentiation and/or maintenance, and in the mechanotransduction process carried out by the neuromast HCs. Because lateral line HCs are both functionally and structurally analogous to the cochlear HCs, the neuromasts might represent an invaluable-and easily accessible-tool to dissect the role of Smpx in HCs development/functioning and shed light on the underlying mechanisms involved in hearing loss.
Collapse
Affiliation(s)
- Alberto Diana
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milan, Italy
| | - Anna Ghilardi
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milan, Italy
| | - Luca Del Giacco
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milan, Italy.
| |
Collapse
|
3
|
Anselmi C, Fuller GK, Stolfi A, Groves AK, Manni L. Sensory cells in tunicates: insights into mechanoreceptor evolution. Front Cell Dev Biol 2024; 12:1359207. [PMID: 38550380 PMCID: PMC10973136 DOI: 10.3389/fcell.2024.1359207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Tunicates, the sister group of vertebrates, offer a unique perspective for evolutionary developmental studies (Evo-Devo) due to their simple anatomical organization. Moreover, the separation of tunicates from vertebrates predated the vertebrate-specific genome duplications. As adults, they include both sessile and pelagic species, with very limited mobility requirements related mainly to water filtration. In sessile species, larvae exhibit simple swimming behaviors that are required for the selection of a suitable substrate on which to metamorphose. Despite their apparent simplicity, tunicates display a variety of mechanoreceptor structures involving both primary and secondary sensory cells (i.e., coronal sensory cells). This review encapsulates two decades of research on tunicate mechanoreception focusing on the coronal organ's sensory cells as prime candidates for understanding the evolution of vertebrate hair cells of the inner ear and the lateral line organ. The review spans anatomical, cellular and molecular levels emphasizing both similarity and differences between tunicate and vertebrate mechanoreception strategies. The evolutionary significance of mechanoreception is discussed within the broader context of Evo-Devo studies, shedding light on the intricate pathways that have shaped the sensory system in chordates.
Collapse
Affiliation(s)
- Chiara Anselmi
- Hopkins Marine Station, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Pacific Grove, CA, United States
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, United States
| | - Gwynna K. Fuller
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Andrew K. Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Lucia Manni
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
| |
Collapse
|
4
|
Derrick CJ, Szenker-Ravi E, Santos-Ledo A, Alqahtani A, Yusof A, Eley L, Coleman AHL, Tohari S, Ng AYJ, Venkatesh B, Alharby E, Mansard L, Bonnet-Dupeyron MN, Roux AF, Vaché C, Roume J, Bouvagnet P, Almontashiri NAM, Henderson DJ, Reversade B, Chaudhry B. Functional analysis of germline VANGL2 variants using rescue assays of vangl2 knockout zebrafish. Hum Mol Genet 2024; 33:150-169. [PMID: 37815931 PMCID: PMC10772043 DOI: 10.1093/hmg/ddad171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/11/2023] [Accepted: 09/28/2023] [Indexed: 10/12/2023] Open
Abstract
Developmental studies have shown that the evolutionarily conserved Wnt Planar Cell Polarity (PCP) pathway is essential for the development of a diverse range of tissues and organs including the brain, spinal cord, heart and sensory organs, as well as establishment of the left-right body axis. Germline mutations in the highly conserved PCP gene VANGL2 in humans have only been associated with central nervous system malformations, and functional testing to understand variant impact has not been performed. Here we report three new families with missense variants in VANGL2 associated with heterotaxy and congenital heart disease p.(Arg169His), non-syndromic hearing loss p.(Glu465Ala) and congenital heart disease with brain defects p.(Arg135Trp). To test the in vivo impact of these and previously described variants, we have established clinically-relevant assays using mRNA rescue of the vangl2 mutant zebrafish. We show that all variants disrupt Vangl2 function, although to different extents and depending on the developmental process. We also begin to identify that different VANGL2 missense variants may be haploinsufficient and discuss evidence in support of pathogenicity. Together, this study demonstrates that zebrafish present a suitable pipeline to investigate variants of unknown significance and suggests new avenues for investigation of the different developmental contexts of VANGL2 function that are clinically meaningful.
Collapse
Affiliation(s)
- Christopher J Derrick
- Biosciences Institute, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | | | - Adrian Santos-Ledo
- Biosciences Institute, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | - Ahlam Alqahtani
- Biosciences Institute, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | - Amirah Yusof
- Genome Institute of Singapore (GIS), A*STAR, 60 Biopolis St, 138672, Singapore
| | - Lorraine Eley
- Biosciences Institute, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | - Alistair H L Coleman
- Biosciences Institute, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | - Sumanty Tohari
- Institute of Molecular and Cell Biology, A*STAR, 61 Biopolis Dr, Proteos, 138673, Singapore
| | - Alvin Yu-Jin Ng
- Institute of Molecular and Cell Biology, A*STAR, 61 Biopolis Dr, Proteos, 138673, Singapore
- MGI Tech Singapore Pte Ltd, 21 Biopolis Rd, 138567, Singapore
| | - Byrappa Venkatesh
- Institute of Molecular and Cell Biology, A*STAR, 61 Biopolis Dr, Proteos, 138673, Singapore
| | - Essa Alharby
- Center for Genetics and Inherited Diseases, Taibah University, 7534 Abdul Muhsin Ibn Abdul Aziz, Al Ihn, Al-Madinah al-Munawwarah 42318, Saudi Arabia
- Faculty of Applied Medical Sciences, Taibah University, Janadah Bin Umayyah Road, Tayba, Al-Madinah al-Munawwarah 42353, Saudi Arabia
| | - Luke Mansard
- Molecular Genetics Laboratory, University of Montpellier, CHU Montpellier, 163 Rue Auguste Broussonnet, 34090 Montpellier, France
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, Inserm, 80 Av. Augustin Fliche, 34000 Montpellier, France
| | | | - Anne-Francoise Roux
- Molecular Genetics Laboratory, University of Montpellier, CHU Montpellier, 163 Rue Auguste Broussonnet, 34090 Montpellier, France
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, Inserm, 80 Av. Augustin Fliche, 34000 Montpellier, France
| | - Christel Vaché
- Molecular Genetics Laboratory, University of Montpellier, CHU Montpellier, 163 Rue Auguste Broussonnet, 34090 Montpellier, France
- Institute for Neurosciences of Montpellier (INM), University of Montpellier, Inserm, 80 Av. Augustin Fliche, 34000 Montpellier, France
| | - Joëlle Roume
- Département de Génétique, CHI Poissy, St Germain-en-Laye, 10 Rue du Champ Gaillard, 78300 Poissy, France
| | - Patrice Bouvagnet
- CPDPN, Hôpital MFME, CHU de Martinique, Fort de France, Fort-de-France 97261, Martinique, France
| | - Naif A M Almontashiri
- Center for Genetics and Inherited Diseases, Taibah University, 7534 Abdul Muhsin Ibn Abdul Aziz, Al Ihn, Al-Madinah al-Munawwarah 42318, Saudi Arabia
- Faculty of Applied Medical Sciences, Taibah University, Janadah Bin Umayyah Road, Tayba, Al-Madinah al-Munawwarah 42353, Saudi Arabia
| | - Deborah J Henderson
- Biosciences Institute, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom
| | - Bruno Reversade
- Genome Institute of Singapore (GIS), A*STAR, 60 Biopolis St, 138672, Singapore
- Institute of Molecular and Cell Biology, A*STAR, 61 Biopolis Dr, Proteos, 138673, Singapore
- Smart-Health Initiative, BESE, KAUST, Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Medical Genetics Department, Koç Hospital Davutpaşa Caddesi 34010 Topkapı Istanbul, Istanbul, Turkey
| | - Bill Chaudhry
- Biosciences Institute, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom
| |
Collapse
|
5
|
Otsuka M, Sugita S, Shimizu D, Aoyama M, Matsuda M. Radial polarity in the first cranial neuromast of selected teleost fishes. J Morphol 2023; 284:e21654. [PMID: 37856275 DOI: 10.1002/jmor.21654] [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: 04/02/2023] [Revised: 10/02/2023] [Accepted: 10/08/2023] [Indexed: 10/21/2023]
Abstract
The neuromast is a sensory structure of the lateral line system in aquatic vertebrates, which consists of hair cells and supporting cells. Hair cells are mechanosensory cells, generally arranged with bidirectional polarity. Here, we describe a neuromast with hair cells arranged radially instead of bidirectionally in the first cranial neuromast of four teleost species: red seabream (Pagrus major), spotted halibut (Verasper variegatus), brown sole (Pseudopleuronectes herzensteini), and marbled sole (Pseudopleuronectes yokohamae). In these four species, this polarity was identified only in the first cranial neuromast, where it appeared at the rostral edge of the otic vesicle before hatching. We investigated the initial appearance and fate of this unique neuromast using scanning electron microscopy. We also assessed characteristics of radial neuromast pertaining to morphogenesis, development, and innervation using a vital fluorescent marker and immunohistochemistry in V. variegatus. The kinocilium initially appears at the center of each hair cell, then moves to its outer perimeter to form radial polarity by around 7 days postfertilization. However, hair cells arranged radially disappear about 15 days after hatching. This is followed by the appearance of bidirectionally arranged hair cells, indicating that polarity replacement from radial to bidirectional has occurred. In P. herzensteini, both afferent and efferent synapses between the nerve fibers and hair cells were observed by transmission electron microscopy, suggesting that radial neuromast is functional. Our discovery suggests that neuromasts with radial polarity could enable larval fish to assimilate multiaxial stimuli during this life stage, potentially assisting them in detecting small water vibrations or water pressure changes.
Collapse
Affiliation(s)
- Machiko Otsuka
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi, Japan
| | - Shoei Sugita
- Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Tochigi, Japan
| | | | - Masato Aoyama
- Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Tochigi, Japan
| | - Masaru Matsuda
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi, Japan
| |
Collapse
|
6
|
Yang S, Xie BL, Dong XP, Wang LX, Zhu GH, Wang T, Wu WJ, Lai RS, Tao R, Guan MX, Chen FY, Tan DH, Deng Z, Xie HP, Zeng Y, Xiao ZA, Xie DH. cdh23 affects congenital hearing loss through regulating purine metabolism. Front Mol Neurosci 2023; 16:1079529. [PMID: 37575969 PMCID: PMC10416109 DOI: 10.3389/fnmol.2023.1079529] [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: 10/25/2022] [Accepted: 02/13/2023] [Indexed: 08/15/2023] Open
Abstract
Introduction The pathogenic gene CDH23 plays a pivotal role in tip links, which is indispensable for mechanoelectrical transduction in the hair cells. However, the underlying molecular mechanism and signal regulatory networks that influence deafness is still largely unknown. Methods In this study, a congenital deafness family, whole exome sequencing revealed a new mutation in the pathogenic gene CDH23, subsequently; the mutation has been validated using Sanger sequencing method. Then CRISPR/Cas9 technology was employed to knockout zebrafish cdh23 gene. Startle response experiment was used to compare with wide-type, the response to sound stimulation between wide-type and cdh23-/-. To further illustrate the molecular mechanisms underlying congenital deafness, comparative transcriptomic profiling and multiple bioinformatics analyses were performed. Results The YO-PRO-1 assay result showed that in cdh23 deficient embryos, the YO-PRO-1 signal in inner ear and lateral line neuromast hair cells were completely lost. Startle response experiment showed that compared with wide-type, the response to sound stimulation decreased significantly in cdh23 mutant larvae. Comparative transcriptomic showed that the candidate genes such as atp1b2b and myof could affect hearing by regulating ATP production and purine metabolism in a synergetic way with cdh23. RT-qPCR results further confirmed the transcriptomics results. Further compensatory experiment showed that ATP treated cdh23-/- embryos can partially recover the mutant phenotype. Conclusion In conclusion, our study may shed light on deciphering the principal mechanism and provide a potential therapeutic method for congenital hearing loss under the condition of CDH23 mutation.
Collapse
Affiliation(s)
- Shu Yang
- Department of Otorhinolaryngology—Head & Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Bing-Lin Xie
- Laboratory of Animal Nutrition and Human Health, Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, College of Life Science, Hunan Normal University, Changsha, Hunan, China
| | - Xiao-ping Dong
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Science, Hunan Normal University, Changsha, Hunan, China
| | - Ling-xiang Wang
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Science, Hunan Normal University, Changsha, Hunan, China
| | - Gang-hua Zhu
- Department of Otorhinolaryngology—Head & Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Tian Wang
- Department of Otorhinolaryngology—Head & Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Wei-jing Wu
- Department of Otorhinolaryngology—Head & Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Ruo-sha Lai
- Department of Otorhinolaryngology—Head & Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Rong Tao
- Department of Otorhinolaryngology—Head & Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Min-xin Guan
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
- Department of Human Genetics, Zhejiang University School of Medicine, Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Fang-yi Chen
- Shenzhen Key Laboratory of Smart Healthcare Engineering, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Dong-hui Tan
- Department of Otolaryngology—Head and Neck Surgery, The Affiliated Hospital of Xiang Nan College, Chenzhou, China
| | - Zhong Deng
- Department of Otolaryngology—Head and Neck Surgery, The Affiliated Hospital of Xiang Nan College, Chenzhou, China
| | - Hua-ping Xie
- Laboratory of Animal Nutrition and Human Health, Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, College of Life Science, Hunan Normal University, Changsha, Hunan, China
| | - Yong Zeng
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Science, Hunan Normal University, Changsha, Hunan, China
| | - Zi-an Xiao
- Department of Otorhinolaryngology—Head & Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Ding-hua Xie
- Department of Otorhinolaryngology—Head & Neck Surgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| |
Collapse
|
7
|
Erickson T, Biggers WP, Williams K, Butland SE, Venuto A. Regionalized Protein Localization Domains in the Zebrafish Hair Cell Kinocilium. J Dev Biol 2023; 11:28. [PMID: 37367482 DOI: 10.3390/jdb11020028] [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: 01/29/2023] [Revised: 05/05/2023] [Accepted: 06/02/2023] [Indexed: 06/28/2023] Open
Abstract
Sensory hair cells are the receptors for auditory, vestibular, and lateral line sensory organs in vertebrates. These cells are distinguished by "hair"-like projections from their apical surface collectively known as the hair bundle. Along with the staircase arrangement of the actin-filled stereocilia, the hair bundle features a single, non-motile, true cilium called the kinocilium. The kinocilium plays an important role in bundle development and the mechanics of sensory detection. To understand more about kinocilial development and structure, we performed a transcriptomic analysis of zebrafish hair cells to identify cilia-associated genes that have yet to be characterized in hair cells. In this study, we focused on three such genes-ankef1a, odf3l2a, and saxo2-because human or mouse orthologs are either associated with sensorineural hearing loss or are located near uncharacterized deafness loci. We made transgenic fish that express fluorescently tagged versions of their proteins, demonstrating their localization to the kinocilia of zebrafish hair cells. Furthermore, we found that Ankef1a, Odf3l2a, and Saxo2 exhibit distinct localization patterns along the length of the kinocilium and within the cell body. Lastly, we have reported a novel overexpression phenotype of Saxo2. Overall, these results suggest that the hair cell kinocilium in zebrafish is regionalized along its proximal-distal axis and set the groundwork to understand more about the roles of these kinocilial proteins in hair cells.
Collapse
Affiliation(s)
- Timothy Erickson
- Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | | | - Kevin Williams
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Shyanne E Butland
- Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | - Alexandra Venuto
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| |
Collapse
|
8
|
Krey JF, Chatterjee P, Halford J, Cunningham CL, Perrin BJ, Barr-Gillespie PG. Control of stereocilia length during development of hair bundles. PLoS Biol 2023; 21:e3001964. [PMID: 37011103 PMCID: PMC10101650 DOI: 10.1371/journal.pbio.3001964] [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] [Revised: 04/13/2023] [Accepted: 03/14/2023] [Indexed: 04/05/2023] Open
Abstract
Assembly of the hair bundle, the sensory organelle of the inner ear, depends on differential growth of actin-based stereocilia. Separate rows of stereocilia, labeled 1 through 3 from tallest to shortest, lengthen or shorten during discrete time intervals during development. We used lattice structured illumination microscopy and surface rendering to measure dimensions of stereocilia from mouse apical inner hair cells during early postnatal development; these measurements revealed a sharp transition at postnatal day 8 between stage III (row 1 and 2 widening; row 2 shortening) and stage IV (final row 1 lengthening and widening). Tip proteins that determine row 1 lengthening did not accumulate simultaneously during stages III and IV; while the actin-bundling protein EPS8 peaked at the end of stage III, GNAI3 peaked several days later-in early stage IV-and GPSM2 peaked near the end of stage IV. To establish the contributions of key macromolecular assemblies to bundle structure, we examined mouse mutants that eliminated tip links (Cdh23v2J or Pcdh15av3J), transduction channels (TmieKO), or the row 1 tip complex (Myo15ash2). Cdh23v2J/v2J and Pcdh15av3J/av3J bundles had adjacent stereocilia in the same row that were not matched in length, revealing that a major role of these cadherins is to synchronize lengths of side-by-side stereocilia. Use of the tip-link mutants also allowed us to distinguish the role of transduction from effects of transduction proteins themselves. While levels of GNAI3 and GPSM2, which stimulate stereocilia elongation, were greatly attenuated at the tips of TmieKO/KO row 1 stereocilia, they accumulated normally in Cdh23v2J/v2J and Pcdh15av3J/av3J stereocilia. These results reinforced the suggestion that the transduction proteins themselves facilitate localization of proteins in the row 1 complex. By contrast, EPS8 concentrates at tips of all TmieKO/KO, Cdh23v2J/v2J, and Pcdh15av3J/av3J stereocilia, correlating with the less polarized distribution of stereocilia lengths in these bundles. These latter results indicated that in wild-type hair cells, the transduction complex prevents accumulation of EPS8 at the tips of shorter stereocilia, causing them to shrink (rows 2 and 3) or disappear (row 4 and microvilli). Reduced rhodamine-actin labeling at row 2 stereocilia tips of tip-link and transduction mutants suggests that transduction's role is to destabilize actin filaments there. These results suggest that regulation of stereocilia length occurs through EPS8 and that CDH23 and PCDH15 regulate stereocilia lengthening beyond their role in gating mechanotransduction channels.
Collapse
Affiliation(s)
- Jocelyn F. Krey
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Paroma Chatterjee
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Julia Halford
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Christopher L. Cunningham
- Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Benjamin J. Perrin
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States of America
| | - Peter G. Barr-Gillespie
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| |
Collapse
|
9
|
McQuate A, Knecht S, Raible DW. Activity regulates a cell type-specific mitochondrial phenotype in zebrafish lateral line hair cells. eLife 2023; 12:e80468. [PMID: 36912880 PMCID: PMC10129330 DOI: 10.7554/elife.80468] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 03/10/2023] [Indexed: 03/14/2023] Open
Abstract
Hair cells of the inner ear are particularly sensitive to changes in mitochondria, the subcellular organelles necessary for energy production in all eukaryotic cells. There are over 30 mitochondrial deafness genes, and mitochondria are implicated in hair cell death following noise exposure, aminoglycoside antibiotic exposure, as well as in age-related hearing loss. However, little is known about the basic aspects of hair cell mitochondrial biology. Using hair cells from the zebrafish lateral line as a model and serial block-face scanning electron microscopy, we have quantifiably characterized a unique hair cell mitochondrial phenotype that includes (1) a high mitochondrial volume and (2) specific mitochondrial architecture: multiple small mitochondria apically, and a reticular mitochondrial network basally. This phenotype develops gradually over the lifetime of the hair cell. Disrupting this mitochondrial phenotype with a mutation in opa1 impacts mitochondrial health and function. While hair cell activity is not required for the high mitochondrial volume, it shapes the mitochondrial architecture, with mechanotransduction necessary for all patterning, and synaptic transmission necessary for the development of mitochondrial networks. These results demonstrate the high degree to which hair cells regulate their mitochondria for optimal physiology and provide new insights into mitochondrial deafness.
Collapse
Affiliation(s)
- Andrea McQuate
- Department of Biological Structure, University of WashingtonSeattleUnited States
- Department of Otolaryngology-HNS, University of WashingtonSeattleUnited States
| | - Sharmon Knecht
- Department of Biological Structure, University of WashingtonSeattleUnited States
| | - David W Raible
- Department of Biological Structure, University of WashingtonSeattleUnited States
- Department of Otolaryngology-HNS, University of WashingtonSeattleUnited States
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Laureano AS, Flaherty K, Hinman AM, Jadali A, Nakamura T, Higashijima SI, Sabaawy HE, Kwan KY. shox2 is required for vestibular statoacoustic neuron development. Biol Open 2023; 11:286143. [PMID: 36594417 PMCID: PMC9838637 DOI: 10.1242/bio.059599] [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: 08/24/2022] [Accepted: 11/22/2022] [Indexed: 01/04/2023] Open
Abstract
Homeobox genes act at the top of genetic hierarchies to regulate cell specification and differentiation during embryonic development. We identified the short stature homeobox domain 2 (shox2) transcription factor that is required for vestibular neuron development. shox2 transcripts are initially localized to the otic placode of the developing inner ear where neurosensory progenitors reside. To study shox2 function, we generated CRISPR-mediated mutant shox2 fish. Mutant embryos display behaviors associated with vestibular deficits and showed reduced number of anterior statoacoustic ganglion neurons that innervate the utricle, the vestibular organ in zebrafish. Moreover, a shox2-reporter fish showed labeling of developing statoacoustic ganglion neurons in the anterior macula of the otic vesicle. Single cell RNA-sequencing of cells from the developing otic vesicle of shox2 mutants revealed altered otic progenitor profiles, while single molecule in situ assays showed deregulated levels of transcripts in developing neurons. This study implicates a role for shox2 in development of vestibular but not auditory statoacoustic ganglion neurons.
Collapse
Affiliation(s)
- Alejandra S. Laureano
- Department of Cell Biology & Neuroscience, Rutgers University, Piscataway, NJ 08854, USA,Stem Cell Research Center and Keck Center for Collaborative Neuroscience, Rutgers University, NJ 08854, USA
| | - Kathleen Flaherty
- Department of Comparative Medicine Resources, Rutgers University, Piscataway, NJ 08854, USA
| | - Anna-Maria Hinman
- Department of Cell Biology & Neuroscience, Rutgers University, Piscataway, NJ 08854, USA,Stem Cell Research Center and Keck Center for Collaborative Neuroscience, Rutgers University, NJ 08854, USA
| | - Azadeh Jadali
- Department of Cell Biology & Neuroscience, Rutgers University, Piscataway, NJ 08854, USA,Stem Cell Research Center and Keck Center for Collaborative Neuroscience, Rutgers University, NJ 08854, USA
| | - Tetsuya Nakamura
- Department of Genetics, Rutgers University, Piscataway, NJ 08854, USA
| | - Shin-ichi Higashijima
- Institutes of Natural Sciences, Exploratory Research Center on Life and Living Systems, Okazaki, Aichi 444-8787, Japan
| | - Hatim E. Sabaawy
- Department of Medicine, Division of Medical Oncology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA,Department of Medicine RBHS-Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Kelvin Y. Kwan
- Department of Cell Biology & Neuroscience, Rutgers University, Piscataway, NJ 08854, USA,Stem Cell Research Center and Keck Center for Collaborative Neuroscience, Rutgers University, NJ 08854, USA,Author for correspondence ()
| |
Collapse
|
12
|
Shoenhard H, Jain RA, Granato M. The calcium-sensing receptor (CaSR) regulates zebrafish sensorimotor decision making via a genetically defined cluster of hindbrain neurons. Cell Rep 2022; 41:111790. [PMID: 36476852 PMCID: PMC9813870 DOI: 10.1016/j.celrep.2022.111790] [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: 05/04/2022] [Revised: 09/21/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
Decision making is a fundamental nervous system function that ranges widely in complexity and speed of execution. We previously established larval zebrafish as a model for sensorimotor decision making and identified the G-protein-coupled calcium-sensing receptor (CaSR) to be critical for this process. Here, we report that CaSR functions in neurons to dynamically regulate the bias between two behavioral outcomes: escapes and reorientations. By employing a computational guided transgenic strategy, we identify a genetically defined neuronal cluster in the hindbrain as a key candidate site for CaSR function. Finally, we demonstrate that transgenic CaSR expression targeting this cluster consisting of a few hundred neurons shifts behavioral bias in wild-type animals and restores decision making deficits in CaSR mutants. Combined, our data provide a rare example of a G-protein-coupled receptor that biases vertebrate sensorimotor decision making via a defined neuronal cluster.
Collapse
Affiliation(s)
- Hannah Shoenhard
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Roshan A. Jain
- Department of Biology, Haverford College, Haverford, PA 19041, USA
| | - Michael Granato
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA,Lead contact,Correspondence:
| |
Collapse
|
13
|
Kim SA, Kim L, Kim TH, An YJ. Assessing the size-dependent effects of microplastics on zebrafish larvae through fish lateral line system and gut damage. MARINE POLLUTION BULLETIN 2022; 185:114279. [PMID: 36330940 DOI: 10.1016/j.marpolbul.2022.114279] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
This study evaluated the size-dependent effects of high-density polyethylene (HDPE) fragments in zebrafish. Larvae were exposed to HDPE microplastic (MP) in three sizes, small (14.12 μm), medium (80.32 μm), and large (120.97 μm), at 20 mg/L. Size-dependent effects in terms of MP intake, subsequent gut damage, and behavioral changes were observed. The results showed that HDPE exposure did not affect the survivability of zebrafish larvae but caused two significant changes. First, exposure to large MPs caused the most serious damage to hair cells and mechanosensory receptors in the fish's lateral line system. Second, exposure to MPs < 100 μm resulted in their ingestion by larvae, thereby causing morphological changes in the gastrointestinal tract. All larvae exposed to MPs showed behavioral pattern changes associated with size differences. This study improves our understanding of the effects of MPs on aquatic organisms and highlights the need to implement efficient strategies for plastic waste management.
Collapse
Affiliation(s)
- Sang A Kim
- Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Lia Kim
- Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Tae Hee Kim
- Advanced Textile R&D Department, Korea Institute of Industrial Technology, Ansan 426-171, Republic of Korea
| | - Youn-Joo An
- Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
| |
Collapse
|
14
|
Gao G, Guo S, Zhang Q, Zhang H, Zhang C, Peng G. Kiaa1024L/Minar2 is essential for hearing by regulating cholesterol distribution in hair bundles. eLife 2022; 11:e80865. [PMID: 36317962 PMCID: PMC9714970 DOI: 10.7554/elife.80865] [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: 06/07/2022] [Accepted: 10/31/2022] [Indexed: 12/05/2022] Open
Abstract
Unbiased genetic screens implicated a number of uncharacterized genes in hearing loss, suggesting some biological processes required for auditory function remain unexplored. Loss of Kiaa1024L/Minar2, a previously understudied gene, caused deafness in mice, but how it functioned in the hearing was unclear. Here, we show that disruption of kiaa1024L/minar2 causes hearing loss in the zebrafish. Defects in mechanotransduction, longer and thinner hair bundles, and enlarged apical lysosomes in hair cells are observed in the kiaa1024L/minar2 mutant. In cultured cells, Kiaa1024L/Minar2 is mainly localized to lysosomes, and its overexpression recruits cholesterol and increases cholesterol labeling. Strikingly, cholesterol is highly enriched in the hair bundle membrane, and loss of kiaa1024L/minar2 reduces cholesterol localization to the hair bundles. Lowering cholesterol levels aggravates, while increasing cholesterol levels rescues the hair cell defects in the kiaa1024L/minar2 mutant. Therefore, cholesterol plays an essential role in hair bundles, and Kiaa1024L/Minar2 regulates cholesterol distribution and homeostasis to ensure normal hearing.
Collapse
Affiliation(s)
- Ge Gao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghaiChina
| | - Shuyu Guo
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghaiChina
| | - Quan Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghaiChina
| | - Hefei Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghaiChina
| | - Cuizhen Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghaiChina
| | - Gang Peng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghaiChina
| |
Collapse
|
15
|
Lukasz D, Beirl A, Kindt K. Chronic neurotransmission increases the susceptibility of lateral-line hair cells to ototoxic insults. eLife 2022; 11:77775. [PMID: 36047587 PMCID: PMC9473691 DOI: 10.7554/elife.77775] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 08/30/2022] [Indexed: 11/27/2022] Open
Abstract
Sensory hair cells receive near constant stimulation by omnipresent auditory and vestibular stimuli. To detect and encode these stimuli, hair cells require steady ATP production, which can be accompanied by a buildup of mitochondrial byproducts called reactive oxygen species (ROS). ROS buildup is thought to sensitize hair cells to ototoxic insults, including the antibiotic neomycin. Work in neurons has shown that neurotransmission is a major driver of ATP production and ROS buildup. Therefore, we tested whether neurotransmission is a significant contributor to ROS buildup in hair cells. Using genetics and pharmacology, we disrupted two key aspects of neurotransmission in zebrafish hair cells: presynaptic calcium influx and the fusion of synaptic vesicles. We find that chronic block of neurotransmission enhances hair-cell survival when challenged with the ototoxin neomycin. This reduction in ototoxin susceptibility is accompanied by reduced mitochondrial activity, likely due to a reduced ATP demand. In addition, we show that mitochondrial oxidation and ROS buildup are reduced when neurotransmission is blocked. Mechanistically, we find that it is the synaptic vesicle cycle rather than presynaptic- or mitochondrial-calcium influx that contributes most significantly to this metabolic stress. Our results comprehensively indicate that, over time, neurotransmission causes ROS buildup that increases the susceptibility of hair cells to ototoxins.
Collapse
Affiliation(s)
- Daria Lukasz
- Section on Sensory Cell Development and Function, National Institutes of Health, Bethesda, United States
| | - Alisha Beirl
- Section on Sensory Cell Development and Function, National Institutes of Health, Bethesda, United States
| | - Katie Kindt
- Section on Sensory Cell Development and Function, National Institutes of Health, Bethesda, United States
| |
Collapse
|
16
|
Ramkumar V, Sheth S, Dhukhwa A, Al Aameri R, Rybak L, Mukherjea D. Transient Receptor Potential Channels and Auditory Functions. Antioxid Redox Signal 2022; 36:1158-1170. [PMID: 34465184 PMCID: PMC9221156 DOI: 10.1089/ars.2021.0191] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Significance: Transient receptor potential (TRP) channels are cation-gated channels that serve as detectors of various sensory modalities, such as pain, heat, cold, and taste. These channels are expressed in the inner ear, suggesting that they could also contribute to the perception of sound. This review provides more details on the different types of TRP channels that have been identified in the cochlea to date, focusing on their cochlear distribution, regulation, and potential contributions to auditory functions. Recent Advances: To date, the effect of TRP channels on normal cochlear physiology in mammals is still unclear. These channels contribute, to a limited extent, to normal cochlear physiology such as the hair cell mechanoelectrical transduction channel and strial functions. More detailed information on a number of these channels in the cochlea awaits future studies. Several laboratories focusing on TRPV1 channels have shown that they are responsive to cochlear stressors, such as ototoxic drugs and noise, and regulate cytoprotective and/or cell death pathways. TRPV1 expression in the cochlea is under control of oxidative stress (produced primarily by NOX3 NADPH oxidase) as well as STAT1 and STAT3 transcription factors, which differentially modulate inflammatory and apoptotic signals in the cochlea. Inhibition of oxidative stress or inflammation reduces the expression of TRPV1 channels and protects against cochlear damage and hearing loss. Critical Issues: TRPV1 channels are activated by both capsaicin and cisplatin, which produce differential effects on the inner ear. How these differential actions are produced is yet to be determined. It is clear that TRPV1 is an essential component of cisplatin ototoxicity as knockdown of these channels protects against hearing loss. In contrast, activation of TRPV1 by capsaicin protected against subsequent hearing loss induced by cisplatin. The cellular targets that are influenced by these two drugs to account for their differential profiles need to be fully elucidated. Furthermore, the potential involvement of different TRP channels present in the cochlea in regulating cisplatin ototoxicity needs to be determined. Future Directions: TRPV1 has been shown to mediate the entry of aminoglycosides into the hair cells. Thus, novel otoprotective strategies could involve designing drugs to inhibit entry of aminoglycosides and possibly other ototoxins into cochlear hair cells. TRP channels, including TRPV1, are expressed on circulating and resident immune cells. These receptors modulate immune cell functions. However, whether they are activated by cochlear stressors to initiate cochlear inflammation and ototoxicity needs to be determined. A better understanding of the function and regulation of these TRP channels in the cochlea could enable development of novel treatments for treating hearing loss. Antioxid. Redox Signal. 36, 1158-1170.
Collapse
Affiliation(s)
- Vickram Ramkumar
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Sandeep Sheth
- Department of Pharmaceutical Sciences, Larkin University College of Pharmacy, Miami, Florida, USA
| | - Asmita Dhukhwa
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Raheem Al Aameri
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Leonard Rybak
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois, USA.,Department of Otolaryngology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| | - Debashree Mukherjea
- Department of Otolaryngology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
| |
Collapse
|
17
|
Zhang Q, Kindt KS. Using Light-Sheet Microscopy to Study Spontaneous Activity in the Developing Lateral-Line System. Front Cell Dev Biol 2022; 10:819612. [PMID: 35592245 PMCID: PMC9112283 DOI: 10.3389/fcell.2022.819612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
Hair cells are the sensory receptors in the auditory and vestibular systems of all vertebrates, and in the lateral-line system of aquatic vertebrates. The purpose of this work is to explore the zebrafish lateral-line system as a model to study and understand spontaneous activity in vivo. Our work applies genetically encoded calcium indicators along with light-sheet fluorescence microscopy to visualize spontaneous calcium activity in the developing lateral-line system. Consistent with our previous work, we show that spontaneous calcium activity is present in developing lateral-line hair cells. We now show that supporting cells that surround hair cells, and cholinergic efferent terminals that directly contact hair cells are also spontaneously active. Using two-color functional imaging we demonstrate that spontaneous activity in hair cells does not correlate with activity in either supporting cells or cholinergic terminals. We find that during lateral-line development, hair cells autonomously generate spontaneous events. Using localized calcium indicators, we show that within hair cells, spontaneous calcium activity occurs in two distinct domains—the mechanosensory bundle and the presynapse. Further, spontaneous activity in the mechanosensory bundle ultimately drives spontaneous calcium influx at the presynapse. Comprehensively, our results indicate that in developing lateral-line hair cells, autonomously generated spontaneous activity originates with spontaneous mechanosensory events.
Collapse
|
18
|
Evaluating the Death and Recovery of Lateral Line Hair Cells Following Repeated Neomycin Treatments. Life (Basel) 2021; 11:life11111180. [PMID: 34833056 PMCID: PMC8625531 DOI: 10.3390/life11111180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 10/30/2021] [Accepted: 11/01/2021] [Indexed: 11/16/2022] Open
Abstract
Acute chemical ablation of lateral line hair cells is an important tool to understand lateral line-mediated behaviors in free-swimming fish larvae and adults. However, lateral line-mediated behaviors have not been described in fish larvae prior to swim bladder inflation, possibly because single doses of ototoxin do not effectively silence lateral line function at early developmental stages. To determine whether ototoxins can disrupt lateral line hair cells during early development, we repeatedly exposed zebrafish larvae to the ototoxin neomycin during a 36 h period from 3 to 4 days post-fertilization (dpf). We use simultaneous transgenic and vital dye labeling of hair cells to compare 6-h and 12-h repeated treatment timelines and neomycin concentrations between 0 and 400 µM in terms of larval survival, hair cell death, regeneration, and functional recovery. Following exposure to neomycin, we find that the emergence of newly functional hair cells outpaces cellular regeneration, likely due to the maturation of ototoxin-resistant hair cells that survive treatment. Furthermore, hair cells of 4 dpf larvae exhibit faster recovery compared to 3 dpf larvae. Our data suggest that the rapid functional maturation of ototoxin-resistant hair cells limits the effectiveness of chemical-based methods to disrupt lateral line function. Furthermore, we show that repeated neomycin treatments can continually ablate functional lateral line hair cells between 3 and 4 dpf in larval zebrafish.
Collapse
|
19
|
Plazas PV, Elgoyhen AB. The Cholinergic Lateral Line Efferent Synapse: Structural, Functional and Molecular Similarities With Those of the Cochlea. Front Cell Neurosci 2021; 15:765083. [PMID: 34712122 PMCID: PMC8545859 DOI: 10.3389/fncel.2021.765083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 09/21/2021] [Indexed: 11/25/2022] Open
Abstract
Vertebrate hair cell (HC) systems are innervated by efferent fibers that modulate their response to external stimuli. In mammals, the best studied efferent-HC synapse, the cholinergic medial olivocochlear (MOC) efferent system, makes direct synaptic contacts with HCs. The net effect of MOC activity is to hyperpolarize HCs through the activation of α9α10 nicotinic cholinergic receptors (nAChRs) and the subsequent activation of Ca2+-dependent SK2 potassium channels. A serious obstacle in research on many mammalian sensory systems in their native context is that their constituent neurons are difficult to access even in newborn animals, hampering circuit observation, mapping, or controlled manipulation. By contrast, fishes and amphibians have a superficial and accessible mechanosensory system, the lateral line (LL), which circumvents many of these problems. LL responsiveness is modulated by efferent neurons which aid to distinguish between external and self-generated stimuli. One component of the LL efferent system is cholinergic and its activation inhibits LL afferent activity, similar to what has been described for MOC efferents. The zebrafish (Danio rerio) has emerged as a powerful model system for studying human hearing and balance disorders, since LL HC are structurally and functionally analogous to cochlear HCs, but are optically and pharmacologically accessible within an intact specimen. Complementing mammalian studies, zebrafish have been used to gain significant insights into many facets of HC biology, including mechanotransduction and synaptic physiology as well as mechanisms of both hereditary and acquired HC dysfunction. With the rise of the zebrafish LL as a model in which to study auditory system function and disease, there has been an increased interest in studying its efferent system and evaluate the similarity between mammalian and piscine efferent synapses. Advances derived from studies in zebrafish include understanding the effect of the LL efferent system on HC and afferent activity, and revealing that an α9-containing nAChR, functionally coupled to SK channels, operates at the LL efferent synapse. In this review, we discuss the tools and findings of these recent investigations into zebrafish efferent-HC synapse, their commonalities with the mammalian counterpart and discuss several emerging areas for future studies.
Collapse
Affiliation(s)
- Paola V Plazas
- Instituto de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ana Belén Elgoyhen
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| |
Collapse
|
20
|
Holmgren M, Ravicz ME, Hancock KE, Strelkova O, Kallogjeri D, Indzhykulian AA, Warchol ME, Sheets L. Mechanical overstimulation causes acute injury and synapse loss followed by fast recovery in lateral-line neuromasts of larval zebrafish. eLife 2021; 10:69264. [PMID: 34665127 PMCID: PMC8555980 DOI: 10.7554/elife.69264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 10/18/2021] [Indexed: 12/14/2022] Open
Abstract
Excess noise damages sensory hair cells, resulting in loss of synaptic connections with auditory nerves and, in some cases, hair-cell death. The cellular mechanisms underlying mechanically induced hair-cell damage and subsequent repair are not completely understood. Hair cells in neuromasts of larval zebrafish are structurally and functionally comparable to mammalian hair cells but undergo robust regeneration following ototoxic damage. We therefore developed a model for mechanically induced hair-cell damage in this highly tractable system. Free swimming larvae exposed to strong water wave stimulus for 2 hr displayed mechanical injury to neuromasts, including afferent neurite retraction, damaged hair bundles, and reduced mechanotransduction. Synapse loss was observed in apparently intact exposed neuromasts, and this loss was exacerbated by inhibiting glutamate uptake. Mechanical damage also elicited an inflammatory response and macrophage recruitment. Remarkably, neuromast hair-cell morphology and mechanotransduction recovered within hours following exposure, suggesting severely damaged neuromasts undergo repair. Our results indicate functional changes and synapse loss in mechanically damaged lateral-line neuromasts that share key features of damage observed in noise-exposed mammalian ear. Yet, unlike the mammalian ear, mechanical damage to neuromasts is rapidly reversible.
Collapse
Affiliation(s)
- Melanie Holmgren
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States
| | - Michael E Ravicz
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Kenneth E Hancock
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Olga Strelkova
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Dorina Kallogjeri
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States
| | - Artur A Indzhykulian
- Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, United States
| | - Mark E Warchol
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States.,Department of Neuroscience, Washington University School of Medicine, St Louis, United States
| | - Lavinia Sheets
- Department of Otolaryngology, Washington University School of Medicine, St Louis, United States.,Department of Developmental Biology, Washington University School of Medicine, St. Louis, United States
| |
Collapse
|
21
|
Jimenez E, Slevin CC, Colón-Cruz L, Burgess SM. Vestibular and Auditory Hair Cell Regeneration Following Targeted Ablation of Hair Cells With Diphtheria Toxin in Zebrafish. Front Cell Neurosci 2021; 15:721950. [PMID: 34489643 PMCID: PMC8416761 DOI: 10.3389/fncel.2021.721950] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/30/2021] [Indexed: 12/02/2022] Open
Abstract
Millions of Americans experience hearing or balance disorders due to loss of hair cells in the inner ear. The hair cells are mechanosensory receptors used in the auditory and vestibular organs of all vertebrates as well as the lateral line systems of aquatic vertebrates. In zebrafish and other non-mammalian vertebrates, hair cells turnover during homeostasis and regenerate completely after being destroyed or damaged by acoustic or chemical exposure. However, in mammals, destroying or damaging hair cells results in permanent impairments to hearing or balance. We sought an improved method for studying hair cell damage and regeneration in adult aquatic vertebrates by generating a transgenic zebrafish with the capacity for targeted and inducible hair cell ablation in vivo. This model expresses the human diphtheria toxin receptor (hDTR) gene under the control of the myo6b promoter, resulting in hDTR expressed only in hair cells. Cell ablation is achieved by an intraperitoneal injection of diphtheria toxin (DT) in adult zebrafish or DT dissolved in the water for larvae. In the lateral line of 5 days post fertilization (dpf) zebrafish, ablation of hair cells by DT treatment occurred within 2 days in a dose-dependent manner. Similarly, in adult utricles and saccules, a single intraperitoneal injection of 0.05 ng DT caused complete loss of hair cells in the utricle and saccule by 5 days post-injection. Full hair cell regeneration was observed for the lateral line and the inner ear tissues. This study introduces a new method for efficient conditional hair cell ablation in adult zebrafish inner ear sensory epithelia (utricles and saccules) and demonstrates that zebrafish hair cells will regenerate in vivo after this treatment.
Collapse
Affiliation(s)
| | | | | | - Shawn M. Burgess
- Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States
| |
Collapse
|
22
|
Hardy K, Amariutei AE, De Faveri F, Hendry A, Marcotti W, Ceriani F. Functional development and regeneration of hair cells in the zebrafish lateral line. J Physiol 2021; 599:3913-3936. [PMID: 34143497 PMCID: PMC7612129 DOI: 10.1113/jp281522] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 06/03/2021] [Indexed: 12/22/2022] Open
Abstract
Hair cells are mechanosensory receptors responsible for transducing auditory and vestibular information into electrical signals, which are then transmitted with remarkable precision to afferent neurons. Different from mammals, the hair cells of lower vertebrates, including those present in the neuromasts of the zebrafish lateral line, regenerate following environmental or chemical insults. Here we investigate the time-course of regeneration of hair cells in vivo using electrophysiology, 2-photon imaging and immunostaining applied to wild-type and genetically-encoded fluorescent indicator zebrafish lines. Functional hair cells drive spontaneous action potentials in the posterior lateral line afferent fibres, the frequency of which progressively increases over the first 10-days post-fertilization (dpf). Higher firing-rate fibres are only observed from ~6 dpf. Following copper treatment, newly formed hair cells become functional and are able to drive APs in the afferent fibres within 48 hours in both early-larval (≤8 dpf) and late-larval (12-17 dpf) zebrafish. However, the complete functional regeneration of the entire neuromast is delayed in late-larval compared to early-larval zebrafish. We propose that while individual regenerating hair cells can rapidly become active, the acquisition of fully functional neuromasts progresses faster at early-larval stages, a time when hair cells are still under development. At both ages, the afferent terminals in the regenerating neuromast appear to make initial contact with supporting cells. The ablation of the lateral line afferent neurons prevents the timely regeneration of supporting cells and hair cells. These findings indicate that the afferent system is likely to facilitate or promote the neuromast regeneration process.
Collapse
Affiliation(s)
- Katherine Hardy
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Ana E Amariutei
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | | | - Aenea Hendry
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Walter Marcotti
- Department of Biomedical Science, University of Sheffield, Sheffield, UK.,Sheffield Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Federico Ceriani
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| |
Collapse
|
23
|
De Faveri F, Marcotti W, Ceriani F. Sensory adaptation at ribbon synapses in the zebrafish lateral line. J Physiol 2021; 599:3677-3696. [PMID: 34047358 PMCID: PMC7612133 DOI: 10.1113/jp281646] [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: 03/15/2021] [Accepted: 05/20/2021] [Indexed: 11/22/2022] Open
Abstract
Adaptation is used by sensory systems to adjust continuously their sensitivity to match changes in environmental stimuli. In the auditory and vestibular systems, the release properties of glutamate-containing vesicles at the hair-cell ribbon synapses play a crucial role in sensory adaptation, thus shaping the neural response to sustained stimulation. How ribbon synapses regulate the release of glutamate and how they modulate afferent responses in vivo is still largely unknown. Here, we have used two-photon imaging and electrophysiology to investigate the synaptic transfer characteristics of the hair cells in the context of sensory adaptation in live zebrafish. Prolonged and repeated water-jet stimulation of the hair-cell stereociliary bundles caused adaptation of the action potential firing rate elicited in the afferent neurons. By monitoring glutamate at ribbon synapses using time-lapse imaging, we identified two kinetically distinct release components: a rapid response that was exhausted within 50-100 ms and a slower and sustained response lasting the entire stimulation. After repeated stimulations, the recovery of the fast component followed a biphasic time course. Depression of glutamate release was largely responsible for the rapid firing rate adaptation recorded in the afferent neurons. However, postsynaptic Ca2+ responses had a slower recovery time course than that of glutamate release, indicating that they are also likely to contribute to the afferent firing adaptation. Hair cells also exhibited a form of adaptation during inhibitory bundle stimulations. We conclude that hair cells have optimised their synaptic machinery to encode prolonged stimuli and to maintain their sensitivity to new incoming stimuli.
Collapse
Affiliation(s)
| | - Walter Marcotti
- Department of Biomedical Science, University of Sheffield, Sheffield, UK.,Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Federico Ceriani
- Department of Biomedical Science, University of Sheffield, Sheffield, UK
| |
Collapse
|
24
|
Santra P, Amack JD. Loss of vacuolar-type H+-ATPase induces caspase-independent necrosis-like death of hair cells in zebrafish neuromasts. Dis Model Mech 2021; 14:dmm048997. [PMID: 34296747 PMCID: PMC8319552 DOI: 10.1242/dmm.048997] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/15/2021] [Indexed: 01/24/2023] Open
Abstract
The vacuolar-type H+-ATPase (V-ATPase) is a multi-subunit proton pump that regulates cellular pH. V-ATPase activity modulates several cellular processes, but cell-type-specific functions remain poorly understood. Patients with mutations in specific V-ATPase subunits can develop sensorineural deafness, but the underlying mechanisms are unclear. Here, we show that V-ATPase mutations disrupt the formation of zebrafish neuromasts, which serve as a model to investigate hearing loss. V-ATPase mutant neuromasts are small and contain pyknotic nuclei that denote dying cells. Molecular markers and live imaging show that loss of V-ATPase induces mechanosensory hair cells in neuromasts, but not neighboring support cells, to undergo caspase-independent necrosis-like cell death. This is the first demonstration that loss of V-ATPase can lead to necrosis-like cell death in a specific cell type in vivo. Mechanistically, loss of V-ATPase reduces mitochondrial membrane potential in hair cells. Modulating the mitochondrial permeability transition pore, which regulates mitochondrial membrane potential, improves hair cell survival. These results have implications for understanding the causes of sensorineural deafness, and more broadly, reveal functions for V-ATPase in promoting survival of a specific cell type in vivo.
Collapse
Affiliation(s)
- Peu Santra
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
| | - Jeffrey D. Amack
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
- BioInspired Syracuse: Institute for Material and Living Systems, Syracuse, NY 13244, USA
| |
Collapse
|
25
|
Ghilardi A, Diana A, Bacchetta R, Santo N, Ascagni M, Prosperi L, Del Giacco L. Inner Ear and Muscle Developmental Defects in Smpx-Deficient Zebrafish Embryos. Int J Mol Sci 2021; 22:ijms22126497. [PMID: 34204426 PMCID: PMC8235540 DOI: 10.3390/ijms22126497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/09/2021] [Accepted: 06/12/2021] [Indexed: 12/20/2022] Open
Abstract
The last decade has witnessed the identification of several families affected by hereditary non-syndromic hearing loss (NSHL) caused by mutations in the SMPX gene and the loss of function has been suggested as the underlying mechanism. In the attempt to confirm this hypothesis we generated an Smpx-deficient zebrafish model, pointing out its crucial role in proper inner ear development. Indeed, a marked decrease in the number of kinocilia together with structural alterations of the stereocilia and the kinocilium itself in the hair cells of the inner ear were observed. We also report the impairment of the mechanotransduction by the hair cells, making SMPX a potential key player in the construction of the machinery necessary for sound detection. This wealth of evidence provides the first possible explanation for hearing loss in SMPX-mutated patients. Additionally, we observed a clear muscular phenotype consisting of the defective organization and functioning of muscle fibers, strongly suggesting a potential role for the protein in the development of muscle fibers. This piece of evidence highlights the need for more in-depth analyses in search for possible correlations between SMPX mutations and muscular disorders in humans, thus potentially turning this non-syndromic hearing loss-associated gene into the genetic cause of dysfunctions characterized by more than one symptom, making SMPX a novel syndromic gene.
Collapse
Affiliation(s)
- Anna Ghilardi
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy; (A.G.); (A.D.); (L.P.)
| | - Alberto Diana
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy; (A.G.); (A.D.); (L.P.)
| | - Renato Bacchetta
- Department of Environmental Science and Policy, Università degli Studi di Milano, 20133 Milan, Italy;
| | - Nadia Santo
- Unitech NOLIMITS, Università degli Studi di Milano, 20133 Milan, Italy; (N.S.); (M.A.)
| | - Miriam Ascagni
- Unitech NOLIMITS, Università degli Studi di Milano, 20133 Milan, Italy; (N.S.); (M.A.)
| | - Laura Prosperi
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy; (A.G.); (A.D.); (L.P.)
| | - Luca Del Giacco
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy; (A.G.); (A.D.); (L.P.)
- Correspondence:
| |
Collapse
|
26
|
Abstract
Congenital hearing loss is the most common birth defect, estimated to affect 2-3 in every 1000 births. Currently there is no cure for hearing loss. Treatment options are limited to hearing aids for mild and moderate cases, and cochlear implants for severe and profound hearing loss. Here we provide a literature overview of the environmental and genetic causes of congenital hearing loss, common animal models and methods used for hearing research, as well as recent advances towards developing therapies to treat congenital deafness. © 2021 The Authors.
Collapse
Affiliation(s)
- Justine M Renauld
- Department of Otolaryngology, Head & Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Martin L Basch
- Department of Otolaryngology, Head & Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, Ohio.,Department of Genetics and Genome Sciences, Case Western Reserve School of Medicine, Cleveland, Ohio.,Department of Biology, Case Western Reserve University, Cleveland, Ohio.,Department of Otolaryngology, Head & Neck Surgery, University Hospitals, Cleveland, Ohio
| |
Collapse
|
27
|
Sheets L, Holmgren M, Kindt KS. How Zebrafish Can Drive the Future of Genetic-based Hearing and Balance Research. J Assoc Res Otolaryngol 2021; 22:215-235. [PMID: 33909162 PMCID: PMC8110678 DOI: 10.1007/s10162-021-00798-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/23/2021] [Indexed: 02/06/2023] Open
Abstract
Over the last several decades, studies in humans and animal models have successfully identified numerous molecules required for hearing and balance. Many of these studies relied on unbiased forward genetic screens based on behavior or morphology to identify these molecules. Alongside forward genetic screens, reverse genetics has further driven the exploration of candidate molecules. This review provides an overview of the genetic studies that have established zebrafish as a genetic model for hearing and balance research. Further, we discuss how the unique advantages of zebrafish can be leveraged in future genetic studies. We explore strategies to design novel forward genetic screens based on morphological alterations using transgenic lines or behavioral changes following mechanical or acoustic damage. We also outline how recent advances in CRISPR-Cas9 can be applied to perform reverse genetic screens to validate large sequencing datasets. Overall, this review describes how future genetic studies in zebrafish can continue to advance our understanding of inherited and acquired hearing and balance disorders.
Collapse
Affiliation(s)
- Lavinia Sheets
- Department of Otolaryngology-Head & Neck Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - Melanie Holmgren
- Department of Otolaryngology-Head & Neck Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - Katie S Kindt
- Section On Sensory Cell Development and Function, National Institutes On Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, USA.
| |
Collapse
|
28
|
Ilami M, Bagheri H, Ahmed R, Skowronek EO, Marvi H. Materials, Actuators, and Sensors for Soft Bioinspired Robots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2003139. [PMID: 33346386 DOI: 10.1002/adma.202003139] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 08/15/2020] [Indexed: 05/23/2023]
Abstract
Biological systems can perform complex tasks with high compliance levels. This makes them a great source of inspiration for soft robotics. Indeed, the union of these fields has brought about bioinspired soft robotics, with hundreds of publications on novel research each year. This review aims to survey fundamental advances in bioinspired soft actuators and sensors with a focus on the progress between 2017 and 2020, providing a primer for the materials used in their design.
Collapse
Affiliation(s)
- Mahdi Ilami
- School for Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - Hosain Bagheri
- School for Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - Reza Ahmed
- School for Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - E Olga Skowronek
- School for Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - Hamid Marvi
- School for Engineering of Matter, Transport & Energy, Arizona State University, Tempe, AZ, 85287, USA
| |
Collapse
|
29
|
Parkinson L, Stawicki TM. alms1 mutant zebrafish do not show hair cell phenotypes seen in other cilia mutants. PLoS One 2021; 16:e0246844. [PMID: 33793549 PMCID: PMC8016283 DOI: 10.1371/journal.pone.0246844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/26/2021] [Indexed: 11/18/2022] Open
Abstract
Multiple cilia-associated genes have been shown to affect hair cells in zebrafish (Danio rerio), including the human deafness gene dcdc2, the radial spoke gene rsph9, and multiple intraflagellar transport (IFT) and transition zone genes. Recently a zebrafish alms1 mutant was generated. The ALMS1 gene is the gene mutated in the ciliopathy Alström Syndrome a disease that causes hearing loss among other symptoms. The hearing loss seen in Alström Syndrome may be due in part to hair cell defects as Alms1 mutant mice show stereocilia polarity defects and a loss of hair cells. Hair cell loss is also seen in postmortem analysis of Alström patients. The zebrafish alms1 mutant has metabolic defects similar to those seen in Alström syndrome and Alms1 mutant mice. We wished to investigate if it also had hair cell defects. We, however, failed to find any hair cell related phenotypes in alms1 mutant zebrafish. They had normal lateral line hair cell numbers as both larvae and adults and normal kinocilia formation. They also showed grossly normal swimming behavior, response to vibrational stimuli, and FM1-43 loading. Mutants also showed a normal degree of sensitivity to both short-term neomycin and long-term gentamicin treatment. These results indicate that cilia-associated genes differentially affect different hair cell types.
Collapse
Affiliation(s)
- Lauren Parkinson
- Neuroscience Program, Lafayette College, Easton, Pennsylvania, United States of America
| | - Tamara M. Stawicki
- Neuroscience Program, Lafayette College, Easton, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
30
|
Valera G, Markov DA, Bijari K, Randlett O, Asgharsharghi A, Baudoin JP, Ascoli GA, Portugues R, López-Schier H. A neuronal blueprint for directional mechanosensation in larval zebrafish. Curr Biol 2021; 31:1463-1475.e6. [PMID: 33545047 DOI: 10.1016/j.cub.2021.01.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/30/2020] [Accepted: 01/13/2021] [Indexed: 01/02/2023]
Abstract
Animals have a remarkable ability to use local cues to orient in space in the absence of a panoramic fixed reference frame. Here we use the mechanosensory lateral line in larval zebrafish to understand rheotaxis, an innate oriented swimming evoked by water currents. We generated a comprehensive light-microscopy cell-resolution projectome of lateralis afferent neurons (LANs) and used clustering techniques for morphological classification. We find surprising structural constancy among LANs. Laser-mediated microlesions indicate that precise topographic mapping of lateral-line receptors is not essential for rheotaxis. Recording neuronal-activity during controlled mechanical stimulation of neuromasts reveals unequal representation of water-flow direction in the hindbrain. We explored potential circuit architectures constrained by anatomical and functional data to suggest a parsimonious model under which the integration of lateralized signals transmitted by direction-selective LANs underlies the encoding of water-flow direction in the brain. These data provide a new framework to understand how animals use local mechanical cues to orient in space.
Collapse
Affiliation(s)
- Gema Valera
- Sensory Biology and Organogenesis, Helmholtz Zentrum Munich, Germany
| | | | - Kayvan Bijari
- Krasnow Institute for Advanced Study, George Mason University, VA, USA
| | - Owen Randlett
- Department of Molecular and Cellular Biology, Harvard University, MA, USA
| | | | | | - Giorgio A Ascoli
- Krasnow Institute for Advanced Study, George Mason University, VA, USA
| | | | - Hernán López-Schier
- Sensory Biology and Organogenesis, Helmholtz Zentrum Munich, Germany; Centre for Genomic Regulation, Barcelona, Spain.
| |
Collapse
|
31
|
Corkins ME, Krneta-Stankic V, Kloc M, Miller RK. Aquatic models of human ciliary diseases. Genesis 2021; 59:e23410. [PMID: 33496382 PMCID: PMC8593908 DOI: 10.1002/dvg.23410] [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: 11/09/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 11/06/2022]
Abstract
Cilia are microtubule-based structures that either transmit information into the cell or move fluid outside of the cell. There are many human diseases that arise from malfunctioning cilia. Although mammalian models provide vital insights into the underlying pathology of these diseases, aquatic organisms such as Xenopus and zebrafish provide valuable tools to help screen and dissect out the underlying causes of these diseases. In this review we focus on recent studies that identify or describe different types of human ciliopathies and outline how aquatic organisms have aided our understanding of these diseases.
Collapse
Affiliation(s)
- Mark E. Corkins
- Department of Pediatrics, Pediatric Research Center, UTHealth McGovern Medical School, Houston Texas 77030
| | - Vanja Krneta-Stankic
- Department of Pediatrics, Pediatric Research Center, UTHealth McGovern Medical School, Houston Texas 77030
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Program in Genes & Development, Houston Texas 77030
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Program in Genetics & Epigenetics, Houston, Texas 77030
| | - Malgorzata Kloc
- Houston Methodist, Research Institute, Houston Texas 77030
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston Texas 77030
| | - Rachel K. Miller
- Department of Pediatrics, Pediatric Research Center, UTHealth McGovern Medical School, Houston Texas 77030
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Program in Genetics & Epigenetics, Houston, Texas 77030
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston Texas 77030
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Program in Biochemistry & Cell Biology, Houston Texas 77030
| |
Collapse
|
32
|
Ohta S, Ji YR, Martin D, Wu DK. Emx2 regulates hair cell rearrangement but not positional identity within neuromasts. eLife 2020; 9:e60432. [PMID: 33377867 PMCID: PMC7806267 DOI: 10.7554/elife.60432] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 12/29/2020] [Indexed: 11/13/2022] Open
Abstract
Each hair cell (HC) precursor of zebrafish neuromasts divides to form two daughter HCs of opposite hair bundle orientations. Previously, we showed that transcription factor Emx2, expressed in only one of the daughter HCs, generates this bidirectional HC pattern (Jiang et al., 2017). Here, we asked whether Emx2 mediates this effect by changing location of hair bundle establishment or positions of HCs since daughter HCs are known to switch positions with each other. We showed this HC rearrangement, redefined as two processes named Rock and Roll, is required for positional acquisition of HCs. Apical protrusion formation of nascent HCs and planar polarity signaling are both important for the Rock and Roll. Emx2 facilitates Rock and Roll by delaying apical protrusion of its nascent HCs but it does not determine HCs' ultimate positions, indicating that Emx2 mediates bidirectional HC pattern by changing the location where hair bundle is established in HCs.
Collapse
Affiliation(s)
- Sho Ohta
- National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Young Rae Ji
- National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Daniel Martin
- Genomics and Computational Biology Core, National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Doris K Wu
- National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| |
Collapse
|
33
|
Retrograde Mitochondrial Transport Is Essential for Organelle Distribution and Health in Zebrafish Neurons. J Neurosci 2020; 41:1371-1392. [PMID: 33376159 PMCID: PMC7896009 DOI: 10.1523/jneurosci.1316-20.2020] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 11/25/2020] [Accepted: 12/01/2020] [Indexed: 12/12/2022] Open
Abstract
In neurons, mitochondria are transported by molecular motors throughout the cell to form and maintain functional neural connections. These organelles have many critical functions in neurons and are of high interest as their dysfunction is associated with disease. While the mechanics and impact of anterograde mitochondrial movement toward axon terminals are beginning to be understood, the frequency and function of retrograde (cell body directed) mitochondrial transport in neurons are still largely unexplored. While existing evidence indicates that some mitochondria are retrogradely transported for degradation in the cell body, the precise impact of disrupting retrograde transport on the organelles and the axon was unknown. Using long-term, in vivo imaging, we examined mitochondrial motility in zebrafish sensory and motor axons. We show that retrograde transport of mitochondria from axon terminals allows replacement of the axon terminal population within a day. By tracking these organelles, we show that not all mitochondria that leave the axon terminal are degraded; rather, they persist over several days. Disrupting retrograde mitochondrial flux in neurons leads to accumulation of aged organelles in axon terminals and loss of cell body mitochondria. Assays of neural circuit activity demonstrated that disrupting mitochondrial transport and function has no effect on sensory axon terminal activity but does negatively impact motor neuron axons. Taken together, our work supports a previously unappreciated role for retrograde mitochondrial transport in the maintenance of a homeostatic distribution of mitochondria in neurons and illustrates the downstream effects of disrupting this process on sensory and motor circuits. SIGNIFICANCE STATEMENT Disrupted mitochondrial transport has been linked to neurodegenerative disease. Retrograde transport of this organelle has been implicated in turnover of aged organelles through lysosomal degradation in the cell body. Consistent with this, we provide evidence that retrograde mitochondrial transport is important for removing aged organelles from axons; however, we show that these organelles are not solely degraded, rather they persist in neurons for days. Disrupting retrograde mitochondrial transport impacts the homeostatic distribution of mitochondria throughout the neuron and the function of motor, but not sensory, axon synapses. Together, our work shows the conserved reliance on retrograde mitochondrial transport for maintaining a healthy mitochondrial pool in neurons and illustrates the disparate effects of disrupting this process on sensory versus motor circuits.
Collapse
|
34
|
Jedrychowska J, Gasanov EV, Korzh V. Kcnb1 plays a role in development of the inner ear. Dev Biol 2020; 471:65-75. [PMID: 33316259 DOI: 10.1016/j.ydbio.2020.12.007] [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: 04/05/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
The function of the inner ear depends on the maintenance of high concentrations of K+ ions. The slow-inactivating delayed rectifier Kv2.1/KCNB1 channel works in the inner ear in mammals. The kcnb1 gene is expressed in the otic vesicle of developing zebrafish, suggesting its role in development of the inner ear. In the present study, we found that a Kcnb1 loss-of-function mutation affected development of the inner ear at multiple levels, including otic vesicle expansion, otolith formation, and the proliferation and differentiation of mechanosensory cells. This resulted in defects of kinocilia and stereocilia and abnormal function of the inner ear detected by behavioral assays. The quantitative transcriptional analysis of 75 genes demonstrated that the kcnb1 mutation affected the transcription of genes that are involved in K+ metabolism, cell proliferation, cilia development, and intracellular protein trafficking. These results demonstrate a role for Kv2.1/Kcnb1 channels in development of the inner ear in zebrafish.
Collapse
Affiliation(s)
- Justyna Jedrychowska
- International Institute of Molecular and Cell Biology in Warsaw, Poland; Postgraduate School of Molecular Medicine, Warsaw Medical University, Warsaw, Poland
| | - Eugene V Gasanov
- International Institute of Molecular and Cell Biology in Warsaw, Poland
| | - Vladimir Korzh
- International Institute of Molecular and Cell Biology in Warsaw, Poland.
| |
Collapse
|
35
|
Erzberger A, Jacobo A, Dasgupta A, Hudspeth AJ. Mechanochemical symmetry breaking during morphogenesis of lateral-line sensory organs. NATURE PHYSICS 2020; 16:949-957. [PMID: 33790985 PMCID: PMC8009062 DOI: 10.1038/s41567-020-0894-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Actively regulated symmetry breaking, which is ubiquitous in biological cells, underlies phenomena such as directed cellular movement and morphological polarization. Here we investigate how an organ-level polarity pattern emerges through symmetry breaking at the cellular level during the formation of a mechanosensory organ. Combining theory, genetic perturbations, and in vivo imaging, we study the development and regeneration of the fluid-motion sensors in the zebrafish's lateral line. We find that two interacting symmetry-breaking events - one mediated by biochemical signaling and the other by cellular mechanics - give rise to precise rotations of cell pairs, which produce a mirror-symmetric polarity pattern in the receptor organ.
Collapse
Affiliation(s)
- A. Erzberger
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
- These authors contributed equally
- ;
| | - A. Jacobo
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
- These authors contributed equally
| | - A. Dasgupta
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
| | - A. J. Hudspeth
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
- ;
| |
Collapse
|
36
|
Kröll-Hermi A, Ebstein F, Stoetzel C, Geoffroy V, Schaefer E, Scheidecker S, Bär S, Takamiya M, Kawakami K, Zieba BA, Studer F, Pelletier V, Eyermann C, Speeg-Schatz C, Laugel V, Lipsker D, Sandron F, McGinn S, Boland A, Deleuze JF, Kuhn L, Chicher J, Hammann P, Friant S, Etard C, Krüger E, Muller J, Strähle U, Dollfus H. Proteasome subunit PSMC3 variants cause neurosensory syndrome combining deafness and cataract due to proteotoxic stress. EMBO Mol Med 2020; 12:e11861. [PMID: 32500975 PMCID: PMC7338805 DOI: 10.15252/emmm.201911861] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 12/13/2022] Open
Abstract
The ubiquitin–proteasome system degrades ubiquitin‐modified proteins to maintain protein homeostasis and to control signalling. Whole‐genome sequencing of patients with severe deafness and early‐onset cataracts as part of a neurological, sensorial and cutaneous novel syndrome identified a unique deep intronic homozygous variant in the PSMC3 gene, encoding the proteasome ATPase subunit Rpt5, which lead to the transcription of a cryptic exon. The proteasome content and activity in patient's fibroblasts was however unaffected. Nevertheless, patient's cells exhibited impaired protein homeostasis characterized by accumulation of ubiquitinated proteins suggesting severe proteotoxic stress. Indeed, the TCF11/Nrf1 transcriptional pathway allowing proteasome recovery after proteasome inhibition is permanently activated in the patient's fibroblasts. Upon chemical proteasome inhibition, this pathway was however impaired in patient's cells, which were unable to compensate for proteotoxic stress although a higher proteasome content and activity. Zebrafish modelling for knockout in PSMC3 remarkably reproduced the human phenotype with inner ear development anomalies as well as cataracts, suggesting that Rpt5 plays a major role in inner ear, lens and central nervous system development.
Collapse
Affiliation(s)
- Ariane Kröll-Hermi
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France.,Karlsruhe Institute of Technology (KIT), Institut für Biologische und Chemische Systeme (IBCS, BIP), Eggenstein-Leopoldshafen, Germany
| | - Frédéric Ebstein
- Institut für Medizinische Biochemie und Molekularbiologie (IMBM), Universitätsmedizin Greifswald, Greifswald, Germany
| | - Corinne Stoetzel
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France
| | - Véronique Geoffroy
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France
| | - Elise Schaefer
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France.,Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Sophie Scheidecker
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France.,Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Séverine Bär
- Laboratoire de Génétique Moléculaire, Génomique, Microbiologie (GMGM), UMR7156, Centre National de Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, France
| | - Masanari Takamiya
- Karlsruhe Institute of Technology (KIT), Institut für Biologische und Chemische Systeme (IBCS, BIP), Eggenstein-Leopoldshafen, Germany
| | - Koichi Kawakami
- Laboratory of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan.,Department of Genetics, SOKENDAI (The Graduate University for Advanced Studies), Mishima, Japan
| | - Barbara A Zieba
- Institut für Medizinische Biochemie und Molekularbiologie (IMBM), Universitätsmedizin Greifswald, Greifswald, Germany
| | - Fouzia Studer
- Filière SENSGENE, Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Valerie Pelletier
- Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Filière SENSGENE, Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Carine Eyermann
- Service de chirurgie ORL, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Claude Speeg-Schatz
- Department of Ophthalmology, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Vincent Laugel
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France.,Service de Pédiatrie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Dan Lipsker
- Faculté de Médecine, Hôpitaux Universitaires, Université de Strasbourg et Clinique Dermatologique, Strasbourg, France
| | - Florian Sandron
- Centre National de Recherche en Génomique Humaine (CNRGH), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Steven McGinn
- Centre National de Recherche en Génomique Humaine (CNRGH), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Anne Boland
- Centre National de Recherche en Génomique Humaine (CNRGH), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France
| | - Jean-François Deleuze
- Centre National de Recherche en Génomique Humaine (CNRGH), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, Evry, France.,Centre d'études du polymorphisme humain-Fondation Jean Dausset, Paris, France
| | - Lauriane Kuhn
- CNRS FRC1589, Institut de Biologie Moléculaire et Cellulaire (IBMC), Plateforme Protéomique Strasbourg-Esplanade, Strasbourg, France
| | - Johana Chicher
- CNRS FRC1589, Institut de Biologie Moléculaire et Cellulaire (IBMC), Plateforme Protéomique Strasbourg-Esplanade, Strasbourg, France
| | - Philippe Hammann
- CNRS FRC1589, Institut de Biologie Moléculaire et Cellulaire (IBMC), Plateforme Protéomique Strasbourg-Esplanade, Strasbourg, France
| | - Sylvie Friant
- Laboratoire de Génétique Moléculaire, Génomique, Microbiologie (GMGM), UMR7156, Centre National de Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, France
| | - Christelle Etard
- Karlsruhe Institute of Technology (KIT), Institut für Biologische und Chemische Systeme (IBCS, BIP), Eggenstein-Leopoldshafen, Germany
| | - Elke Krüger
- Institut für Medizinische Biochemie und Molekularbiologie (IMBM), Universitätsmedizin Greifswald, Greifswald, Germany
| | - Jean Muller
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France.,Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Uwe Strähle
- Karlsruhe Institute of Technology (KIT), Institut für Biologische und Chemische Systeme (IBCS, BIP), Eggenstein-Leopoldshafen, Germany
| | - Hélène Dollfus
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France.,Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Filière SENSGENE, Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| |
Collapse
|
37
|
Disruption of tmc1/2a/2b Genes in Zebrafish Reveals Subunit Requirements in Subtypes of Inner Ear Hair Cells. J Neurosci 2020; 40:4457-4468. [PMID: 32371604 DOI: 10.1523/jneurosci.0163-20.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 01/11/2023] Open
Abstract
Detection of sound and head movement requires mechanoelectrical transduction (MET) channels at tips of hair-cell stereocilia. In vertebrates, the transmembrane channel-like (TMC) proteins TMC1 and TMC2 fulfill critical roles in MET, and substantial evidence implicates these TMCs as subunits of the MET channel. To identify developmental and functional roles of this Tmc subfamily in the zebrafish inner ear, we tested the effects of truncating mutations in tmc1, tmc2a, and tmc2b on in vivo mechanosensation at the onset of hearing and balance, before gender differentiation. We find that tmc1/2a/2b triple-mutant larvae cannot detect sound or orient with respect to gravity. They lack acoustic-evoked behavioral responses, vestibular-induced eye movements, and hair-cell activity as assessed with FM dye labeling and microphonic potentials. Despite complete loss of hair-cell function, tmc triple-mutant larvae retain normal gross morphology of hair bundles and proper trafficking of known MET components Protocadherin 15a (Pcdh15a), Lipoma HMGIC fusion partner-like 5 (Lhfpl5), and Transmembrane inner ear protein (Tmie). Transgenic, hair cell-specific expression of Tmc2b-mEGFP rescues the behavioral and physiological deficits in tmc triple mutants. Results from tmc single and double mutants evince a principle role for Tmc2a and Tmc2b in hearing and balance, respectively, whereas Tmc1 has lower overall impact. Our experiments reveal that, in developing cristae, hair cells stratify into an upper, Tmc2a-dependent layer of teardrop-shaped cells and a lower, Tmc1/2b-dependent tier of gourd-shaped cells. Collectively, our genetic evidence indicates that auditory/vestibular end organs and subsets of hair cells therein rely on distinct combinations of Tmc1/2a/2b.SIGNIFICANCE STATEMENT We assessed the effects of tmc1/2a/2b truncation mutations on mechanoelectrical transduction (MET) in the inner-ear hair cells of larval zebrafish. tmc triple mutants lacked behavioral responses to sound and head movements, while further assays demonstrated no observable mechanosensitivity in the tmc1/2a/2b triple mutant inner ear. Examination of tmc double mutants revealed major contributions from Tmc2a and Tmc2b to macular function; however, Tmc1 had less overall impact. FM labeling of lateral cristae in tmc double mutants revealed the presence of two distinct cell types, an upper layer of teardrop-shaped cells that rely on Tmc2a, and a lower layer of gourd-shaped cells that rely on Tmc1/2b.
Collapse
|
38
|
Kozak EL, Palit S, Miranda-Rodríguez JR, Janjic A, Böttcher A, Lickert H, Enard W, Theis FJ, López-Schier H. Epithelial Planar Bipolarity Emerges from Notch-Mediated Asymmetric Inhibition of Emx2. Curr Biol 2020; 30:1142-1151.e6. [PMID: 32109392 DOI: 10.1016/j.cub.2020.01.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/28/2019] [Accepted: 01/08/2020] [Indexed: 12/24/2022]
Abstract
Most plane-polarized tissues are formed by identically oriented cells [1, 2]. A notable exception occurs in the vertebrate vestibular system and lateral-line neuromasts, where mechanosensory hair cells orient along a single axis but in opposite directions to generate bipolar epithelia [3-5]. In zebrafish neuromasts, pairs of hair cells arise from the division of a non-sensory progenitor [6, 7] and acquire opposing planar polarity via the asymmetric expression of the polarity-determinant transcription factor Emx2 [8-11]. Here, we reveal the initial symmetry-breaking step by decrypting the developmental trajectory of hair cells using single-cell RNA sequencing (scRNA-seq), diffusion pseudotime analysis, lineage tracing, and mutagenesis. We show that Emx2 is absent in non-sensory epithelial cells, begins expression in hair-cell progenitors, and is downregulated in one of the sibling hair cells via signaling through the Notch1a receptor. Analysis of Emx2-deficient specimens, in which every hair cell adopts an identical direction, indicates that Emx2 asymmetry does not result from auto-regulatory feedback. These data reveal a two-tiered mechanism by which the symmetric monodirectional ground state of the epithelium is inverted by deterministic initiation of Emx2 expression in hair-cell progenitors and a subsequent stochastic repression of Emx2 in one of the sibling hair cells breaks directional symmetry to establish planar bipolarity.
Collapse
Affiliation(s)
- Eva L Kozak
- Research Unit of Sensory Biology & Organogenesis, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Subarna Palit
- Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Jerónimo R Miranda-Rodríguez
- Research Unit of Sensory Biology & Organogenesis, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Aleksandar Janjic
- Department Biology II, Anthropology and Human Genomics, Ludwig Maximilians University of Munich, Großhaderner Straße 2, 82152 Martinsried, Germany
| | - Anika Böttcher
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany; German Center for Diabetes Research, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany; German Center for Diabetes Research, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany; School of Medicine, Technical University of Munich, Ismaninger Straße 22, 81675 Munich, Germany
| | - Wolfgang Enard
- Department Biology II, Anthropology and Human Genomics, Ludwig Maximilians University of Munich, Großhaderner Straße 2, 82152 Martinsried, Germany
| | - Fabian J Theis
- Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany; School of Life Sciences Weihenstephan, Technical University of Munich, Alte Akademie, 85354 Freising, Germany; Department of Mathematics, Technical University of Munich, Boltzmannstraße 3, 85748 Garching, Germany
| | - Hernán López-Schier
- Research Unit of Sensory Biology & Organogenesis, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
| |
Collapse
|
39
|
Schmid C, Alampi I, Briggs J, Tarcza K, Stawicki TM. Mechanotransduction Activity Facilitates Hair Cell Toxicity Caused by the Heavy Metal Cadmium. Front Cell Neurosci 2020; 14:37. [PMID: 32153368 PMCID: PMC7044240 DOI: 10.3389/fncel.2020.00037] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 02/05/2020] [Indexed: 11/13/2022] Open
Abstract
Hair cells are sensitive to many insults including environmental toxins such as heavy metals. We show here that cadmium can consistently kill hair cells of the zebrafish lateral line. Disrupting hair cell mechanotransduction genetically or pharmacologically significantly reduces the amount of hair cell death seen in response to cadmium, suggesting a role for mechanotransduction in this cell death process, possibly as a means for cadmium uptake into the cells. Likewise, when looking at multiple cilia-associated gene mutants that have previously been shown to be resistant to aminoglycoside-induced hair cell death, resistance to cadmium-induced hair cell death is only seen in those with mechanotransduction defects. In contrast to what was seen with mechanotransduction, significant protection was not consistently seen from other ions previously shown to compete for cadmium uptake into cells or tissue including zinc and copper. These results show that functional mechanotransduction activity is playing a significant role in cadmium-induced hair cell death.
Collapse
Affiliation(s)
- Caleigh Schmid
- Program in Neuroscience, Lafayette College, Easton, PA, United States
| | - Isabella Alampi
- Program in Neuroscience, Lafayette College, Easton, PA, United States
| | - Jay Briggs
- Department of Biological Structure, University of Washington, Seattle, WA, United States
| | - Kelly Tarcza
- Program in Neuroscience, Lafayette College, Easton, PA, United States
| | | |
Collapse
|
40
|
Abstract
The inner ear, which mediates the senses of hearing and balance, derives from a simple ectodermal vesicle in the vertebrate embryo. In the zebrafish, the otic placode and vesicle express a whole suite of genes required for ciliogenesis and ciliary motility. Every cell of the otic epithelium is ciliated at early stages; at least three different ciliary subtypes can be distinguished on the basis of length, motility, genetic requirements and function. In the early otic vesicle, most cilia are short and immotile. Long, immotile kinocilia on the first sensory hair cells tether the otoliths, biomineralized aggregates of calcium carbonate and protein. Small numbers of motile cilia at the poles of the otic vesicle contribute to the accuracy of otolith tethering, but neither the presence of cilia nor ciliary motility is absolutely required for this process. Instead, otolith tethering is dependent on the presence of hair cells and the function of the glycoprotein Otogelin. Otic cilia or ciliary proteins also mediate sensitivity to ototoxins and coordinate responses to extracellular signals. Other studies are beginning to unravel the role of ciliary proteins in cellular compartments other than the kinocilium, where they are important for the integrity and survival of the sensory hair cell. This article is part of the Theo Murphy meeting issue 'Unity and diversity of cilia in locomotion and transport'.
Collapse
Affiliation(s)
- Tanya T Whitfield
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK
| |
Collapse
|
41
|
Yao Q, Wang L, Mittal R, Yan D, Richmond MT, Denyer S, Requena T, Liu K, Varshney GK, Lu Z, Liu XZ. Transcriptomic Analyses of Inner Ear Sensory Epithelia in Zebrafish. Anat Rec (Hoboken) 2019; 303:527-543. [PMID: 31883312 DOI: 10.1002/ar.24331] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 08/01/2019] [Accepted: 11/18/2019] [Indexed: 12/25/2022]
Abstract
Analysis of gene expression has the potential to assist in the understanding of multiple cellular processes including proliferation, cell-fate specification, senesence, and activity in both healthy and disease states. Zebrafish model has been increasingly used to understand the process of hearing and the development of the vertebrate auditory system. Within the zebrafish inner ear, there are three otolith organs, each containing a sensory macula of hair cells. The saccular macula is primarily involved in hearing, the utricular macula is primarily involved in balance and the function of the lagenar macula is not completely understood. The goal of this study is to understand the transcriptional differences in the sensory macula associated with different otolith organs with the intention of understanding the genetic mechanisms responsible for the distinct role each organ plays in sensory perception. The sensory maculae of the saccule, utricle, and lagena were dissected out of adult Et(krt4:GFP)sqet4 zebrafish expressing green fluorescent protein in hair cells for transcriptional analysis. The total RNAs of the maculae were isolated and analyzed by RNA GeneChip microarray. Several of the differentially expressed genes are known to be involved in deafness, otolith development and balance. Gene expression among these otolith organs was very well conserved with less than 10% of genes showing differential expression. Data from this study will help to elucidate which genes are involved in hearing and balance. Furthermore, the findings of this study will assist in the development of the zebrafish model for human hearing and balance disorders. Anat Rec, 303:527-543, 2020. © 2019 American Association for Anatomy.
Collapse
Affiliation(s)
- Qi Yao
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida.,Department of Biology, University of Miami, Miami, Florida
| | - Lingyu Wang
- Department of Biology, University of Miami, Miami, Florida
| | - Rahul Mittal
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida
| | - Denise Yan
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida
| | | | - Steven Denyer
- Department of Biology, University of Miami, Miami, Florida
| | - Teresa Requena
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - Kaili Liu
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - Gaurav K Varshney
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma
| | - Zhongmin Lu
- Department of Biology, University of Miami, Miami, Florida
| | - Xue Zhong Liu
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, Florida.,Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| |
Collapse
|
42
|
Richardson GP, Petit C. Hair-Bundle Links: Genetics as the Gateway to Function. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a033142. [PMID: 30617060 DOI: 10.1101/cshperspect.a033142] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Up to five distinct cell-surface specializations interconnect the stereocilia and the kinocilium of the mature hair bundle in some species: kinocilial links, tip links, top connectors, shaft connectors, and ankle links. In developing hair bundles, transient lateral links are prominent. Mutations in genes encoding proteins associated with these links cause Usher deafness/blindness syndrome or nonsyndromic (isolated) forms of human hereditary deafness, and mice with constitutive or conditional alleles of these genes have provided considerable insight into the molecular composition and function of the different links. We describe the structure of these links and review evidence showing CDH23 and PCDH15 are components of the tip, kinocilial, and transient-lateral links, that stereocilin (STRC) and protein tyrosine phosphatase (PTPRQ) are associated with top and shaft connectors, respectively, and that USH2A and ADGRV1 are associated with the ankle links. Whereas tip links are required for mechanoelectrical transduction, all link proteins play key roles in the normal development and/or the maintenance of hair bundle structure and function. Recent crystallographic and single-particle analyses of PCDH15 and CDH23 provide insight as to how the structure of tip link may contribute to the elastic element predicted to lie in series with the hair cell's mechanoelectrical transducer channel.
Collapse
Affiliation(s)
- Guy P Richardson
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, United Kingdom
| | - Christine Petit
- Institut Pasteur, 75724 Paris Cedex 15, France.,Collège de France, 75231 Paris Cedex 05, France
| |
Collapse
|
43
|
Jacobo A, Dasgupta A, Erzberger A, Siletti K, Hudspeth A. Notch-Mediated Determination of Hair-Bundle Polarity in Mechanosensory Hair Cells of the Zebrafish Lateral Line. Curr Biol 2019; 29:3579-3587.e7. [DOI: 10.1016/j.cub.2019.08.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 07/05/2019] [Accepted: 08/22/2019] [Indexed: 10/25/2022]
|
44
|
Wong HTC, Zhang Q, Beirl AJ, Petralia RS, Wang YX, Kindt K. Synaptic mitochondria regulate hair-cell synapse size and function. eLife 2019; 8:e48914. [PMID: 31609202 PMCID: PMC6879205 DOI: 10.7554/elife.48914] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 10/13/2019] [Indexed: 11/21/2022] Open
Abstract
Sensory hair cells in the ear utilize specialized ribbon synapses. These synapses are defined by electron-dense presynaptic structures called ribbons, composed primarily of the structural protein Ribeye. Previous work has shown that voltage-gated influx of Ca2+ through CaV1.3 channels is critical for hair-cell synapse function and can impede ribbon formation. We show that in mature zebrafish hair cells, evoked presynaptic-Ca2+ influx through CaV1.3 channels initiates mitochondrial-Ca2+ (mito-Ca2+) uptake adjacent to ribbons. Block of mito-Ca2+ uptake in mature cells depresses presynaptic-Ca2+ influx and impacts synapse integrity. In developing zebrafish hair cells, mito-Ca2+ uptake coincides with spontaneous rises in presynaptic-Ca2+ influx. Spontaneous mito-Ca2+ loading lowers cellular NAD+/NADH redox and downregulates ribbon size. Direct application of NAD+ or NADH increases or decreases ribbon size respectively, possibly acting through the NAD(H)-binding domain on Ribeye. Our results present a mechanism where presynaptic- and mito-Ca2+ couple to confer proper presynaptic function and formation.
Collapse
MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Animals, Genetically Modified
- Calcium/metabolism
- Calcium Channel Agonists/pharmacology
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Calcium Signaling
- Cell Size
- Embryo, Nonmammalian
- Evoked Potentials, Auditory/physiology
- Eye Proteins/chemistry
- Eye Proteins/genetics
- Eye Proteins/metabolism
- Gene Expression
- Hair Cells, Auditory/cytology
- Hair Cells, Auditory/drug effects
- Hair Cells, Auditory/metabolism
- Isradipine/pharmacology
- Mitochondria/drug effects
- Mitochondria/metabolism
- Mitochondria/ultrastructure
- NAD/metabolism
- Oxidation-Reduction
- Protein Binding
- Protein Interaction Domains and Motifs
- Ruthenium Compounds/pharmacology
- Synapses/drug effects
- Synapses/metabolism
- Synapses/ultrastructure
- Synaptic Transmission
- Zebrafish
- Zebrafish Proteins/agonists
- Zebrafish Proteins/antagonists & inhibitors
- Zebrafish Proteins/chemistry
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
Collapse
Affiliation(s)
- Hiu-tung C Wong
- Section on Sensory Cell Development and FunctionNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
- National Institutes of Health-Johns Hopkins University Graduate Partnership ProgramNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Qiuxiang Zhang
- Section on Sensory Cell Development and FunctionNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Alisha J Beirl
- Section on Sensory Cell Development and FunctionNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Ronald S Petralia
- Advanced Imaging CoreNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Ya-Xian Wang
- Advanced Imaging CoreNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Katie Kindt
- Section on Sensory Cell Development and FunctionNational Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| |
Collapse
|
45
|
Live Morphometric Classification of Sensory Neurons in Larval Zebrafish. Methods Mol Biol 2019. [PMID: 31552668 DOI: 10.1007/978-1-4939-9732-9_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Sensory systems convey environmental information to the brain. A comprehensive description of neuronal anatomy and connectivity is essential to understand how sensory information is acquired, transmitted, and processed. Here we describe a high-resolution live imaging technique to quantify the architecture of sensory neurons in larval zebrafish. This approach is ideal to assess neuronal-circuit plasticity and regeneration.
Collapse
|
46
|
PCP and Wnt pathway components act in parallel during zebrafish mechanosensory hair cell orientation. Nat Commun 2019; 10:3993. [PMID: 31488837 PMCID: PMC6728366 DOI: 10.1038/s41467-019-12005-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 08/05/2019] [Indexed: 12/03/2022] Open
Abstract
Planar cell polarity (PCP) plays crucial roles in developmental processes such as gastrulation, neural tube closure and hearing. Wnt pathway mutants are often classified as PCP mutants due to similarities between their phenotypes. Here, we show that in the zebrafish lateral line, disruptions of the PCP and Wnt pathways have differential effects on hair cell orientations. While mutations in the PCP genes vangl2 and scrib cause random orientations of hair cells, mutations in wnt11f1, gpc4 and fzd7a/b induce hair cells to adopt a concentric pattern. This concentric pattern is not caused by defects in PCP but is due to misaligned support cells. The molecular basis of the support cell defect is unknown but we demonstrate that the PCP and Wnt pathways work in parallel to establish proper hair cell orientation. Consequently, hair cell orientation defects are not solely explained by defects in PCP signaling, and some hair cell phenotypes warrant re-evaluation. Planar cell polarity (PCP) regulates hair cell orientation in the zebrafish lateral line. Here, the authors show that mutating Wnt pathway genes (wnt11f1, fzd7a/b, and gpc4) causes concentric hair cell patterns not regulated by PCP, thus showing PCP/Wnt pathway genes have different consequences on hair cell orientation.
Collapse
|
47
|
R Ferreira R, Fukui H, Chow R, Vilfan A, Vermot J. The cilium as a force sensor-myth versus reality. J Cell Sci 2019; 132:132/14/jcs213496. [PMID: 31363000 DOI: 10.1242/jcs.213496] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cells need to sense their mechanical environment during the growth of developing tissues and maintenance of adult tissues. The concept of force-sensing mechanisms that act through cell-cell and cell-matrix adhesions is now well established and accepted. Additionally, it is widely believed that force sensing can be mediated through cilia. Yet, this hypothesis is still debated. By using primary cilia sensing as a paradigm, we describe the physical requirements for cilium-mediated mechanical sensing and discuss the different hypotheses of how this could work. We review the different mechanosensitive channels within the cilium, their potential mode of action and their biological implications. In addition, we describe the biological contexts in which cilia are acting - in particular, the left-right organizer - and discuss the challenges to discriminate between cilium-mediated chemosensitivity and mechanosensitivity. Throughout, we provide perspectives on how quantitative analysis and physics-based arguments might help to better understand the biological mechanisms by which cells use cilia to probe their mechanical environment.
Collapse
Affiliation(s)
- Rita R Ferreira
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Hajime Fukui
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Renee Chow
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| | - Andrej Vilfan
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Department of Living Matter Physics, 37077 Göttingen, Germany .,J. Stefan Institute, 1000 Ljubljana, Slovenia
| | - Julien Vermot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France .,Centre National de la Recherche Scientifique, UMR7104, 67404 Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France.,Université de Strasbourg, 67404 Illkirch, France
| |
Collapse
|
48
|
Wissman JP, Sampath K, Freeman SE, Rohde CA. Capacitive Bio-Inspired Flow Sensing Cupula. SENSORS 2019; 19:s19112639. [PMID: 31212636 PMCID: PMC6603685 DOI: 10.3390/s19112639] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/05/2019] [Accepted: 06/08/2019] [Indexed: 11/16/2022]
Abstract
Submersible robotics have improved in efficiency and versatility by incorporating features found in aquatic life, ranging from thunniform kinematics to shark skin textures. To fully realize these benefits, sensor systems must be incorporated to aid in object detection and navigation through complex flows. Again, inspiration can be taken from biology, drawing on the lateral line sensor systems and neuromast structures found on fish. To maintain a truly soft-bodied robot, a man-made flow sensor must be developed that is entirely complaint, introducing no rigidity to the artificial “skin.” We present a capacitive cupula inspired by superficial neuromasts. Fabricated via lost wax methods and vacuum injection, our 5 mm tall device exhibits a sensitivity of 0.5 pF/mm (capacitance versus tip deflection) and consists of room temperature liquid metal plates embedded in a soft silicone body. In contrast to existing capacitive examples, our sensor incorporates the transducers into the cupula itself rather than at its base. We present a kinematic theory and energy-based approach to approximate capacitance versus flow, resulting in equations that are verified with a combination of experiments and COMSOL simulations.
Collapse
Affiliation(s)
- James P Wissman
- U.S. Naval Research Laboratory, Code 7165, Washington, DC 20375, USA.
| | - Kaushik Sampath
- U.S. Naval Research Laboratory, Code 7165, Washington, DC 20375, USA.
| | | | - Charles A Rohde
- U.S. Naval Research Laboratory, Code 7165, Washington, DC 20375, USA.
| |
Collapse
|
49
|
Regulation of the apical extension morphogenesis tunes the mechanosensory response of microvilliated neurons. PLoS Biol 2019; 17:e3000235. [PMID: 31002663 PMCID: PMC6493769 DOI: 10.1371/journal.pbio.3000235] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 05/01/2019] [Accepted: 04/03/2019] [Indexed: 12/25/2022] Open
Abstract
Multiple types of microvilliated sensory cells exhibit an apical extension thought to be instrumental in the detection of sensory cues. The investigation of the mechanisms underlying morphogenesis of sensory apparatus is critical to understand the biology of sensation. Most of what we currently know comes from the study of the hair bundle of the inner ear sensory cells, but morphogenesis and function of other sensory microvilliated apical extensions remain poorly understood. We focused on spinal sensory neurons that contact the cerebrospinal fluid (CSF) through the projection of a microvilliated apical process in the central canal, referred to as cerebrospinal fluid-contacting neurons (CSF-cNs). CSF-cNs respond to pH and osmolarity changes as well as mechanical stimuli associated with changes of flow and tail bending. In vivo time-lapse imaging in zebrafish embryos revealed that CSF-cNs are atypical neurons that do not lose their apical attachment and form a ring of actin at the apical junctional complexes (AJCs) that they retain during differentiation. We show that the actin-based protrusions constituting the microvilliated apical extension arise and elongate from this ring of actin, and we identify candidate molecular factors underlying every step of CSF-cN morphogenesis. We demonstrate that Crumbs 1 (Crb1), Myosin 3b (Myo3b), and Espin orchestrate the morphogenesis of CSF-cN apical extension. Using calcium imaging in crb1 and espin mutants, we further show that the size of the apical extension modulates the amplitude of CSF-cN sensory response to bending of the spinal cord. Based on our results, we propose that the apical actin ring could be a common site of initiation of actin-based protrusions in microvilliated sensory cells. Furthermore, our work provides a set of actors underlying actin-based protrusion elongation shared by different sensory cell types and highlights the critical role of the apical extension shape in sensory detection. A study of differentiating spinal sensory neurons in vivo uncovers critical factors required for the morphogenesis of sensory microvilli and reveals fine modulation of mechanosensory responses by microvillus length.
Collapse
|
50
|
Ó Maoiléidigh D, Ricci AJ. A Bundle of Mechanisms: Inner-Ear Hair-Cell Mechanotransduction. Trends Neurosci 2019; 42:221-236. [PMID: 30661717 PMCID: PMC6402798 DOI: 10.1016/j.tins.2018.12.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 10/27/2022]
Abstract
In the inner ear, the deflection of hair bundles, the sensory organelles of hair cells, activates mechanically-gated channels (MGCs). Hair bundles monitor orientation of the head, its angular and linear acceleration, and detect sound. Force applied to MGCs is shaped by intrinsic hair-bundle properties, by the mechanical load on the bundle, and by the filter imparted by the environment of the hair bundle. Channel gating and adaptation, the ability of the bundle to reset its operating point, contribute to hair-bundle mechanics. Recent data from mammalian hair cells challenge longstanding hypotheses regarding adaptation mechanisms and hair-bundle coherence. Variations between hair bundles from different organs in hair-bundle mechanics, mechanical load, channel gating, and adaptation may allow a hair bundle to selectively respond to specific sensory stimuli.
Collapse
Affiliation(s)
- Dáibhid Ó Maoiléidigh
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford CA 94305, USA
| | - Anthony J Ricci
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford CA 94305, USA.
| |
Collapse
|