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Bodenbender JP, Marino V, Philipp J, Tropitzsch A, Kernstock C, Stingl K, Kempf M, Haack TB, Zuleger T, Mazzola P, Kohl S, Weisschuh N, Dell'Orco D, Kühlewein L. Comprehensive analysis of two hotspot codons in the TUBB4B gene and associated phenotypes. Sci Rep 2024; 14:10551. [PMID: 38719929 PMCID: PMC11078972 DOI: 10.1038/s41598-024-61019-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 04/30/2024] [Indexed: 05/12/2024] Open
Abstract
Our purpose was to elucidate the genotype and ophthalmological and audiological phenotype in TUBB4B-associated inherited retinal dystrophy (IRD) and sensorineural hearing loss (SNHL), and to model the effects of all possible amino acid substitutions at the hotspot codons Arg390 and Arg391. Six patients from five families with heterozygous missense variants in TUBB4B were included in this observational study. Ophthalmological testing included best-corrected visual acuity, fundus examination, optical coherence tomography, fundus autofluorescence imaging, and full-field electroretinography (ERG). Audiological examination included pure-tone and speech audiometry in adult patients and auditory brainstem response testing in a child. Genetic testing was performed by disease gene panel analysis based on genome sequencing. The molecular consequences of the substitutions of residues 390 and 391 on TUBB4B and its interaction with α-tubulin were predicted in silico on its three-dimensional structure obtained by homology modelling. Two independent patients had amino acid exchanges at position 391 (p.(Arg391His) or p.(Arg391Cys)) of the TUBB4B protein. Both had a distinct IRD phenotype with peripheral round yellowish lesions with pigmented spots and mild or moderate SNHL, respectively. Yet the phenotype was milder with a sectorial pattern of bone spicules in one patient, likely due to a genetically confirmed mosaicism for p.(Arg391His). Three patients were heterozygous for an amino acid exchange at position 390 (p.(Arg390Gln) or p.(Arg390Trp)) and presented with another distinct retinal phenotype with well demarcated pericentral retinitis pigmentosa. All showed SNHL ranging from mild to severe. One additional patient showed a variant distinct from codon 390 or 391 (p.(Tyr310His)), and presented with congenital profound hearing loss and reduced responses in ERG. Variants at codon positions 390 and 391 were predicted to decrease the structural stability of TUBB4B and its complex with α-tubulin, as well as the complex affinity. In conclusion, the twofold larger reduction in heterodimer affinity exhibited by Arg391 substitutions suggested an association with the more severe retinal phenotype, compared to the substitution at Arg390.
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Affiliation(s)
- Jan-Philipp Bodenbender
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Valerio Marino
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| | - Julia Philipp
- Department of Otolaryngology-Head & Neck Surgery, Hearing Research Center, University of Tübingen Medical Center, Tübingen, Germany
| | - Anke Tropitzsch
- Department of Otolaryngology-Head & Neck Surgery, Hearing Research Center, University of Tübingen Medical Center, Tübingen, Germany
- Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Christoph Kernstock
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Melanie Kempf
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Tobias B Haack
- Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Theresia Zuleger
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Pascale Mazzola
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Nicole Weisschuh
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Daniele Dell'Orco
- Department of Neurosciences, Biomedicine and Movement Sciences, Section of Biological Chemistry, University of Verona, Verona, Italy
| | - Laura Kühlewein
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
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2
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Dodd DO, Mechaussier S, Yeyati PL, McPhie F, Anderson JR, Khoo CJ, Shoemark A, Gupta DK, Attard T, Zariwala MA, Legendre M, Bracht D, Wallmeier J, Gui M, Fassad MR, Parry DA, Tennant PA, Meynert A, Wheway G, Fares-Taie L, Black HA, Mitri-Frangieh R, Faucon C, Kaplan J, Patel M, McKie L, Megaw R, Gatsogiannis C, Mohamed MA, Aitken S, Gautier P, Reinholt FR, Hirst RA, O'Callaghan C, Heimdal K, Bottier M, Escudier E, Crowley S, Descartes M, Jabs EW, Kenia P, Amiel J, Bacci GM, Calogero C, Palazzo V, Tiberi L, Blümlein U, Rogers A, Wambach JA, Wegner DJ, Fulton AB, Kenna M, Rosenfeld M, Holm IA, Quigley A, Hall EA, Murphy LC, Cassidy DM, von Kriegsheim A, Papon JF, Pasquier L, Murris MS, Chalmers JD, Hogg C, Macleod KA, Urquhart DS, Unger S, Aitman TJ, Amselem S, Leigh MW, Knowles MR, Omran H, Mitchison HM, Brown A, Marsh JA, Welburn JPI, Ti SC, Horani A, Rozet JM, Perrault I, Mill P. Ciliopathy patient variants reveal organelle-specific functions for TUBB4B in axonemal microtubules. Science 2024; 384:eadf5489. [PMID: 38662826 DOI: 10.1126/science.adf5489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 03/20/2024] [Indexed: 05/03/2024]
Abstract
Tubulin, one of the most abundant cytoskeletal building blocks, has numerous isotypes in metazoans encoded by different conserved genes. Whether these distinct isotypes form cell type- and context-specific microtubule structures is poorly understood. Based on a cohort of 12 patients with primary ciliary dyskinesia as well as mouse mutants, we identified and characterized variants in the TUBB4B isotype that specifically perturbed centriole and cilium biogenesis. Distinct TUBB4B variants differentially affected microtubule dynamics and cilia formation in a dominant-negative manner. Structure-function studies revealed that different TUBB4B variants disrupted distinct tubulin interfaces, thereby enabling stratification of patients into three classes of ciliopathic diseases. These findings show that specific tubulin isotypes have distinct and nonredundant subcellular functions and establish a link between tubulinopathies and ciliopathies.
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Affiliation(s)
- Daniel O Dodd
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Sabrina Mechaussier
- Laboratory of Genetics in Ophthalmology, INSERM UMR_1163, Institute of Genetic Diseases, Institut Imagine, Université de Paris, Paris 75015, France
| | - Patricia L Yeyati
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Fraser McPhie
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Jacob R Anderson
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Chen Jing Khoo
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Amelia Shoemark
- Respiratory Research Group, Molecular and Cellular Medicine, University of Dundee, Dundee DD1 9SY, UK
- Respiratory Paediatrics, Royal Brompton Hospital, London SW3 6NP, UK
| | - Deepesh K Gupta
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Thomas Attard
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Maimoona A Zariwala
- Department of Pathology and Laboratory Medicine, Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7248, USA
| | - Marie Legendre
- Molecular Genetics Laboratory, Sorbonne Université, Assistance Publique - Hôpitaux de Paris (AP-HP), Hôpital Armand Trousseau, Paris 75012, France
- Sorbonne Université, INSERM, Childhood Genetic Disorders, Paris 75012, France
| | - Diana Bracht
- Department of General Pediatrics, University Children's Hospital Münster, Münster 48149, Germany
| | - Julia Wallmeier
- Department of General Pediatrics, University Children's Hospital Münster, Münster 48149, Germany
| | - Miao Gui
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Mahmoud R Fassad
- Genetics and Genomic Medicine Department, UCL Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Human Genetics, Medical Research Institute, Alexandria University, Alexandria 21561, Egypt
| | - David A Parry
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Peter A Tennant
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Alison Meynert
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | - Lucas Fares-Taie
- Laboratory of Genetics in Ophthalmology, INSERM UMR_1163, Institute of Genetic Diseases, Institut Imagine, Université de Paris, Paris 75015, France
| | - Holly A Black
- Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- South East of Scotland Genetics Service, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Rana Mitri-Frangieh
- Department of Anatomy, Cytology and Pathology, Hôpital Intercommuncal de Créteil, Créteil 94000, France
- Biomechanics and Respiratory Apparatus, IMRB, U955 INSERM - Université Paris Est Créteil, CNRS ERL 7000, Créteil 94000, France
| | - Catherine Faucon
- Department of Anatomy, Cytology and Pathology, Hôpital Intercommuncal de Créteil, Créteil 94000, France
| | - Josseline Kaplan
- Laboratory of Genetics in Ophthalmology, INSERM UMR_1163, Institute of Genetic Diseases, Institut Imagine, Université de Paris, Paris 75015, France
| | - Mitali Patel
- Genetics and Genomic Medicine Department, UCL Institute of Child Health, University College London, London WC1N 1EH, UK
- MRC Prion Unit, Institute of Prion Diseases, University College London, London W1W 7FF, UK
| | - Lisa McKie
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Roly Megaw
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- Princess Alexandra Eye Pavilion, Edinburgh EH3 9HA, UK
| | - Christos Gatsogiannis
- Center for Soft Nanoscience and Institute of Medical Physics and Biophysics, Münster 48149, Germany
| | - Mai A Mohamed
- Genetics and Genomic Medicine Department, UCL Institute of Child Health, University College London, London WC1N 1EH, UK
- Biochemistry Division, Chemistry Department, Faculty of Science, Zagazig University, Ash Sharqiyah 44519, Egypt
| | - Stuart Aitken
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Philippe Gautier
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Finn R Reinholt
- Core Facility for Electron Microscopy, Department of Pathology, Oslo University Hospital-Rikshospitalet, Oslo 0372, Norway
| | - Robert A Hirst
- Centre for PCD Diagnosis and Research, Department of Respiratory Sciences, University of Leicester, Leicester LE1 9HN, UK
| | - Chris O'Callaghan
- Centre for PCD Diagnosis and Research, Department of Respiratory Sciences, University of Leicester, Leicester LE1 9HN, UK
| | - Ketil Heimdal
- Department of Medical Genetics, Oslo University Hospital, Oslo 0407, Norway
| | - Mathieu Bottier
- Respiratory Research Group, Molecular and Cellular Medicine, University of Dundee, Dundee DD1 9SY, UK
| | - Estelle Escudier
- Sorbonne Université, INSERM, Childhood Genetic Disorders, Paris 75012, France
- Department of Anatomy, Cytology and Pathology, Hôpital Intercommuncal de Créteil, Créteil 94000, France
| | - Suzanne Crowley
- Paediatric Department of Allergy and Lung Diseases, Oslo University Hospital, Oslo 0407, Norway
| | - Maria Descartes
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0024, USA
| | - Ethylin W Jabs
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York 10029-6504, New York, USA
- Department of Clinical Genomics, Mayo Clinic, Rochester, NY 55905, USA
| | - Priti Kenia
- Department of Paediatric Respiratory Medicine, Birmingham Women's and Children's Hospital NHS Foundation Trust, Birmingham B15 2TG, UK
| | - Jeanne Amiel
- Département de Génétique, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris (AP-HP), Paris 75015, France
- Laboratory of Embryology and Genetics of Human Malformations, INSERM UMR 1163, Institut Imagine, Université de Paris, Paris 75015, France
| | - Giacomo Maria Bacci
- Pediatric Ophthalmology Unit, Meyer Children's Hospital IRCCS, Florence 50139, Italy
| | - Claudia Calogero
- Pediatric Pulmonary Unit, Meyer Children's Hospital IRCCS, Florence 50139, Italy
| | - Viviana Palazzo
- Medical Genetics Unit, Meyer Children's Hospital IRCCS, Florence 50139, Italy
| | - Lucia Tiberi
- Medical Genetics Unit, Meyer Children's Hospital IRCCS, Florence 50139, Italy
| | | | - Andrew Rogers
- Respiratory Paediatrics, Royal Brompton Hospital, London SW3 6NP, UK
| | - Jennifer A Wambach
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Daniel J Wegner
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Anne B Fulton
- Department of Ophthalmology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Margaret Kenna
- Department of Otolaryngology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Margaret Rosenfeld
- Department of Pediatrics, University of Washington School of Medicine and Seattle Children's Research Institute, Seattle, WA 98015, USA
| | - Ingrid A Holm
- Division of Genetics and Genomics and the Manton Center for Orphan Diseases Research, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA 02115 USA
| | - Alan Quigley
- Department of Paediatric Radiology, Royal Hospital for Children and Young People, Edinburgh EH16 4TJ, UK
| | - Emma A Hall
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Laura C Murphy
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Diane M Cassidy
- Respiratory Research Group, Molecular and Cellular Medicine, University of Dundee, Dundee DD1 9SY, UK
| | - Alex von Kriegsheim
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Jean-François Papon
- ENT Department, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris-Saclay University, Le Kremlin-Bicêtre 94270, France
| | - Laurent Pasquier
- Medical Genetics Department, CHU Pontchaillou, Rennes 35033, France
| | - Marlène S Murris
- Department of Pulmonology, Transplantation, and Cystic Fibrosis Centre, Larrey Hospital, Toulouse 31400, France
| | - James D Chalmers
- Respiratory Research Group, Molecular and Cellular Medicine, University of Dundee, Dundee DD1 9SY, UK
| | - Claire Hogg
- Respiratory Paediatrics, Royal Brompton Hospital, London SW3 6NP, UK
| | - Kenneth A Macleod
- Department of Paediatric Respiratory and Sleep Medicine, Royal Hospital for Children and Young People, Edinburgh EH16 4TJ, UK
| | - Don S Urquhart
- Department of Paediatric Respiratory and Sleep Medicine, Royal Hospital for Children and Young People, Edinburgh EH16 4TJ, UK
- Department of Child Life and Health, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Stefan Unger
- Department of Paediatric Respiratory and Sleep Medicine, Royal Hospital for Children and Young People, Edinburgh EH16 4TJ, UK
- Department of Child Life and Health, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Timothy J Aitman
- Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Serge Amselem
- Molecular Genetics Laboratory, Sorbonne Université, Assistance Publique - Hôpitaux de Paris (AP-HP), Hôpital Armand Trousseau, Paris 75012, France
- Sorbonne Université, INSERM, Childhood Genetic Disorders, Paris 75012, France
| | - Margaret W Leigh
- Department of Pediatrics, Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7248, USA
| | - Michael R Knowles
- Department of Medicine, Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7248, USA
| | - Heymut Omran
- Department of General Pediatrics, University Children's Hospital Münster, Münster 48149, Germany
| | - Hannah M Mitchison
- Genetics and Genomic Medicine Department, UCL Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Alan Brown
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Joseph A Marsh
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Julie P I Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Shih-Chieh Ti
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Amjad Horani
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63130, USA
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology, INSERM UMR_1163, Institute of Genetic Diseases, Institut Imagine, Université de Paris, Paris 75015, France
| | - Isabelle Perrault
- Laboratory of Genetics in Ophthalmology, INSERM UMR_1163, Institute of Genetic Diseases, Institut Imagine, Université de Paris, Paris 75015, France
| | - Pleasantine Mill
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
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Schijven D, Soheili-Nezhad S, Fisher SE, Francks C. Exome-wide analysis implicates rare protein-altering variants in human handedness. Nat Commun 2024; 15:2632. [PMID: 38565598 PMCID: PMC10987538 DOI: 10.1038/s41467-024-46277-w] [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: 07/21/2023] [Accepted: 02/20/2024] [Indexed: 04/04/2024] Open
Abstract
Handedness is a manifestation of brain hemispheric specialization. Left-handedness occurs at increased rates in neurodevelopmental disorders. Genome-wide association studies have identified common genetic effects on handedness or brain asymmetry, which mostly involve variants outside protein-coding regions and may affect gene expression. Implicated genes include several that encode tubulins (microtubule components) or microtubule-associated proteins. Here we examine whether left-handedness is also influenced by rare coding variants (frequencies ≤ 1%), using exome data from 38,043 left-handed and 313,271 right-handed individuals from the UK Biobank. The beta-tubulin gene TUBB4B shows exome-wide significant association, with a rate of rare coding variants 2.7 times higher in left-handers than right-handers. The TUBB4B variants are mostly heterozygous missense changes, but include two frameshifts found only in left-handers. Other TUBB4B variants have been linked to sensorineural and/or ciliopathic disorders, but not the variants found here. Among genes previously implicated in autism or schizophrenia by exome screening, DSCAM and FOXP1 show evidence for rare coding variant association with left-handedness. The exome-wide heritability of left-handedness due to rare coding variants was 0.91%. This study reveals a role for rare, protein-altering variants in left-handedness, providing further evidence for the involvement of microtubules and disorder-relevant genes.
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Affiliation(s)
- Dick Schijven
- Language & Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Sourena Soheili-Nezhad
- Language & Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
| | - Simon E Fisher
- Language & Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Clyde Francks
- Language & Genetics Department, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands.
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.
- Department of Cognitive Neuroscience, Radboud University Medical Center, Nijmegen, The Netherlands.
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Sewell MT, Legué E, Liem KF. Tubb4b is required for multi-ciliogenesis in the mouse. Development 2024; 151:dev201819. [PMID: 38031972 PMCID: PMC10820790 DOI: 10.1242/dev.201819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 11/23/2023] [Indexed: 12/01/2023]
Abstract
Cilia are microtubule (MT)-based organelles present on the surface of nearly all vertebrate cells. MTs are polymers of α- and β-tubulins that are each encoded by multiple, individual isotype genes. Tubulin isotype composition is thought to influence MT behaviors. Ciliary MTs differ from other MTs in the cell in terms of organization, stability and post-translational modifications. However, little is known about the tubulin isotypes that build ciliary MTs and the functional requirements for tubulin isotypes in cilia have not been examined in vertebrates. Here, we have tested the role of the β-tubulin isotype genes in the mouse that harbor a conserved amino acid motif associated with ciliated organisms. We found that Tubb4b localizes to cilia in multi-ciliated cells (MCCs) specifically. In respiratory and oviduct MCCs, Tubb4b is asymmetrically localized within multi-cilia, indicating that the tubulin isotype composition changes along the length of the ciliary axonemal MTs. Deletion of Tubb4b resulted in striking structural defects within the axonemes of multi-cilia, without affecting primary cilia. These studies show that Tubb4b is essential for the formation of a specific MT-based subcellular organelle and sheds light on the requirements of tubulin isotypes in cilia.
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Affiliation(s)
- Mycah T. Sewell
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Emilie Legué
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Karel F. Liem
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
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McFadden JR, Tolete CDP, Huang Y, Macnamara E, Sept D, Nesterova G, Gahl WA, Sackett DL, Malicdan MCV. Clinical, genetic, and structural characterization of a novel TUBB4B tubulinopathy. Mol Genet Metab Rep 2023; 36:100990. [PMID: 37448631 PMCID: PMC10336574 DOI: 10.1016/j.ymgmr.2023.100990] [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: 06/24/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023] Open
Abstract
Microtubules are cytoskeletal polymers of ⍺/β-tubulin heterodimers essential for a wide range of cellular processes. Pathogenic variations in microtubule-encoding genes (e.g., TUBB4B, which encodes the β-4B tubulin isotype) are responsible for a wide spectrum of cerebral malformations, collectively referred to as "tubulinopathies." The phenotypic manifestation of TUBB4B-associated tubulinopathy is Leber congenital amaurosis with early-onset deafness (LCAEOD), an autosomal dominant syndrome characterized by photoreceptor and cochlear cell loss; all known patients have pathogenic variations in amino acid R391. We present the clinical and molecular genetics findings of a 16-year-old female with a de novo missense variant in exon 1 of TUBB4B, c.32 A > G (p.Gln11Arg; Q11R). In addition to hearing loss and hyperopia without retinal abnormalities, our proband presented with two phenotypes of unknown genetic etiology, i.e., renal tubular Fanconi Syndrome (FS) and hypophosphatemic rickets (HR). The Q11R variant expands the genetic basis of early sensory hearing loss; its consequences with respect to microtubule structure are described. A mechanistic explanation for the FS and rickets, involving microtubule-mediated translocation of transporter proteins to and from the apical membrane of renal proximal tubular cells, is proposed.
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Affiliation(s)
- Jason R. McFadden
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Christina Deanne P. Tolete
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Yan Huang
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Ellen Macnamara
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - David Sept
- Departments of Biomedical Engineering and Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Galina Nesterova
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - William A. Gahl
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
- Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892-1851, USA
| | - Dan L. Sackett
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | - May Christine V. Malicdan
- NIH Undiagnosed Diseases Program, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
- Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892-1851, USA
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6
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Tantry MSA, Santhakumar K. Insights on the Role of α- and β-Tubulin Isotypes in Early Brain Development. Mol Neurobiol 2023; 60:3803-3823. [PMID: 36943622 DOI: 10.1007/s12035-023-03302-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 03/05/2023] [Indexed: 03/23/2023]
Abstract
Tubulins are the highly conserved subunit of microtubules which involve in various fundamental functions including brain development. Microtubules help in neuronal proliferation, migration, differentiation, cargo transport along the axons, synapse formation, and many more. Tubulin gene family consisting of multiple isotypes, their differential expression and varied post translational modifications create a whole new level of complexity and diversity in accomplishing manifold neuronal functions. The studies on the relation between tubulin genes and brain development opened a new avenue to understand the role of each tubulin isotype in neurodevelopment. Mutations in tubulin genes are reported to cause brain development defects especially cortical malformations, referred as tubulinopathies. There is an increased need to understand the molecular correlation between various tubulin mutations and the associated brain pathology. Recently, mutations in tubulin isotypes (TUBA1A, TUBB, TUBB1, TUBB2A, TUBB2B, TUBB3, and TUBG1) have been linked to cause various neurodevelopmental defects like lissencephaly, microcephaly, cortical dysplasia, polymicrogyria, schizencephaly, subcortical band heterotopia, periventricular heterotopia, corpus callosum agenesis, and cerebellar hypoplasia. This review summarizes on the microtubule dynamics, their role in neurodevelopment, tubulin isotypes, post translational modifications, and the role of tubulin mutations in causing specific neurodevelopmental defects. A comprehensive list containing all the reported tubulin pathogenic variants associated with brain developmental defects has been prepared to give a bird's eye view on the broad range of tubulin functions.
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Affiliation(s)
- M S Ananthakrishna Tantry
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, 603203, India
| | - Kirankumar Santhakumar
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, 603203, India.
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7
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Cushion TD, Leca I, Keays DA. MAPping tubulin mutations. Front Cell Dev Biol 2023; 11:1136699. [PMID: 36875768 PMCID: PMC9975266 DOI: 10.3389/fcell.2023.1136699] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/02/2023] [Indexed: 02/17/2023] Open
Abstract
Microtubules are filamentous structures that play a critical role in a diverse array of cellular functions including, mitosis, nuclear translocation, trafficking of organelles and cell shape. They are composed of α/β-tubulin heterodimers which are encoded by a large multigene family that has been implicated in an umbrella of disease states collectively known as the tubulinopathies. De novo mutations in different tubulin genes are known to cause lissencephaly, microcephaly, polymicrogyria, motor neuron disease, and female infertility. The diverse clinical features associated with these maladies have been attributed to the expression pattern of individual tubulin genes, as well as their distinct Functional repertoire. Recent studies, however, have highlighted the impact of tubulin mutations on microtubule-associated proteins (MAPs). MAPs can be classified according to their effect on microtubules and include polymer stabilizers (e.g., tau, MAP2, doublecortin), destabilizers (e.g., spastin, katanin), plus-end binding proteins (e.g., EB1-3, XMAP215, CLASPs) and motor proteins (e.g., dyneins, kinesins). In this review we analyse mutation-specific disease mechanisms that influence MAP binding and their phenotypic consequences, and discuss methods by which we can exploit genetic variation to identify novel MAPs.
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Affiliation(s)
- Thomas D Cushion
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Ines Leca
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - David A Keays
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria.,Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, Munich, Germany
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8
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Attard TJ, Welburn JPI, Marsh JA. Understanding molecular mechanisms and predicting phenotypic effects of pathogenic tubulin mutations. PLoS Comput Biol 2022; 18:e1010611. [PMID: 36206299 PMCID: PMC9581425 DOI: 10.1371/journal.pcbi.1010611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/19/2022] [Accepted: 09/28/2022] [Indexed: 11/21/2022] Open
Abstract
Cells rely heavily on microtubules for several processes, including cell division and molecular trafficking. Mutations in the different tubulin-α and -β proteins that comprise microtubules have been associated with various diseases and are often dominant, sporadic and congenital. While the earliest reported tubulin mutations affect neurodevelopment, mutations are also associated with other disorders such as bleeding disorders and infertility. We performed a systematic survey of tubulin mutations across all isotypes in order to improve our understanding of how they cause disease, and increase our ability to predict their phenotypic effects. Both protein structural analyses and computational variant effect predictors were very limited in their utility for differentiating between pathogenic and benign mutations. This was even worse for those genes associated with non-neurodevelopmental disorders. We selected tubulin-α and -β disease mutations that were most poorly predicted for experimental characterisation. These mutants co-localise to the mitotic spindle in HeLa cells, suggesting they may exert dominant-negative effects by altering microtubule properties. Our results show that tubulin mutations represent a blind spot for current computational approaches, being much more poorly predicted than mutations in most human disease genes. We suggest that this is likely due to their strong association with dominant-negative and gain-of-function mechanisms.
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Affiliation(s)
- Thomas J. Attard
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Julie P. I. Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Joseph A. Marsh
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
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9
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Abstract
The microtubule cytoskeleton is assembled from the α- and β-tubulin subunits of the canonical tubulin heterodimer, which polymerizes into microtubules, and a small number of other family members, such as γ-tubulin, with specialized functions. Overall, microtubule function involves the collective action of multiple α- and β-tubulin isotypes. However, despite 40 years of awareness that most eukaryotes harbor multiple tubulin isotypes, their role in the microtubule cytoskeleton has remained relatively unclear. Various model organisms offer specific advantages for gaining insight into the role of tubulin isotypes. Whereas simple unicellular organisms such as yeast provide experimental tractability that can facilitate deeper access to mechanistic details, more complex organisms, such as the fruit fly, nematode and mouse, can be used to discern potential specialized functions of tissue- and structure-specific isotypes. Here, we review the role of α- and β-tubulin isotypes in microtubule function and in associated tubulinopathies with an emphasis on the advances gained using model organisms. Overall, we argue that studying tubulin isotypes in a range of organisms can reveal the fundamental mechanisms by which they mediate microtubule function. It will also provide valuable perspectives on how these mechanisms underlie the functional and biological diversity of the cytoskeleton.
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Affiliation(s)
- Emmanuel T Nsamba
- Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Mohan L Gupta
- Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011, USA
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10
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Maasz A, Hadzsiev K, Ripszam R, Zsigmond A, Maka E, Knezy K, Lesch B, Nemeth A, Bene J, Galik B, Gyenesei A, Melegh B. TUBB4B gene mutation in Leber phenotype of congenital amaurosis syndrome associated with early-onset deafness. Eur J Med Genet 2022; 65:104471. [PMID: 35240325 DOI: 10.1016/j.ejmg.2022.104471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 02/16/2022] [Accepted: 02/25/2022] [Indexed: 11/30/2022]
Abstract
Beta-tubulin 4B isotype is one of the subunits of microtubules encoded by TUBB4B gene on chromosome 9, which is responsible for the maintenance of microtubule stability. In humans, mutations in microtubule-encoding genes have been associated with several tubulinopathies with very heterogeneous symptoms. So far, only two missense mutations in TUBB4B gene have been found to have pathological implications in this disorder. Here we report a Hungarian family with three affected members, mother and her 12- and 14-year-old children, who suffer from ophthalmologic and hearing impairments probably due to c.1171C > T missense variant in the TUBB4B gene. The presented case is the second report, and unique in the literature because of three affected family members carrying the same mutation and the family provides evidence for a quite similar but not identical phenotype of LCAEOD in subjects carrying this mutation.
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Affiliation(s)
- Anita Maasz
- Department of Medical Genetics, Hungary; Szentagothai Research Centre, Clinical Genetics and Genomics Research Group, Hungary.
| | - Kinga Hadzsiev
- Department of Medical Genetics, Hungary; Szentagothai Research Centre, Clinical Genetics and Genomics Research Group, Hungary
| | - Reka Ripszam
- Department of Medical Genetics, Hungary; Szentagothai Research Centre, Clinical Genetics and Genomics Research Group, Hungary
| | - Anna Zsigmond
- Department of Medical Genetics, Hungary; Szentagothai Research Centre, Clinical Genetics and Genomics Research Group, Hungary
| | - Erika Maka
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Krisztina Knezy
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Balazs Lesch
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Adrienn Nemeth
- Department of Otorhinolaryngology, Clinical Centre and Medical School, Hungary
| | - Judit Bene
- Department of Medical Genetics, Hungary; Szentagothai Research Centre, Clinical Genetics and Genomics Research Group, Hungary
| | - Bence Galik
- Bioinformatics Research Group, Genomics and Bioinformatics Core Facility, University of Pecs, Pecs, H-7624, Hungary
| | - Attila Gyenesei
- Bioinformatics Research Group, Genomics and Bioinformatics Core Facility, University of Pecs, Pecs, H-7624, Hungary
| | - Bela Melegh
- Department of Medical Genetics, Hungary; Szentagothai Research Centre, Clinical Genetics and Genomics Research Group, Hungary
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11
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Fertuzinhos S, Legué E, Li D, Liem KF. A dominant tubulin mutation causes cerebellar neurodegeneration in a genetic model of tubulinopathy. SCIENCE ADVANCES 2022; 8:eabf7262. [PMID: 35171680 PMCID: PMC8849301 DOI: 10.1126/sciadv.abf7262] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Mutations in tubulins cause distinct neurodevelopmental and degenerative diseases termed "tubulinopathies"; however, little is known about the functional requirements of tubulins or how mutations cause cell-specific pathologies. Here, we identify a mutation in the gene Tubb4a that causes degeneration of cerebellar granule neurons and myelination defects. We show that the neural phenotypes result from a cell type-specific enrichment of a dominant mutant form of Tubb4a relative to the expression other β-tubulin isotypes. Loss of Tubb4a function does not underlie cellular pathology but is compensated by the transcriptional up-regulation of related tubulin genes in a cell type-specific manner. This work establishes that the expression of a primary tubulin mutation in mature neurons is sufficient to promote cell-autonomous cell death, consistent with a causative association of microtubule dysfunction with neurodegenerative diseases. These studies provide evidence that mutations in tubulins cause specific phenotypes based on expression ratios of tubulin isotype genes.
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Affiliation(s)
- Sofia Fertuzinhos
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Emilie Legué
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Davis Li
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Karel F. Liem
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
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12
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Bieniussa L, Jain I, Bosch Grau M, Juergens L, Hagen R, Janke C, Rak K. Microtubule and auditory function - an underestimated connection. Semin Cell Dev Biol 2022; 137:74-86. [PMID: 35144861 DOI: 10.1016/j.semcdb.2022.02.004] [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: 07/01/2021] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 10/19/2022]
Abstract
The organ of Corti, located in the cochlea within the inner ear is the receptor organ for hearing. It converts auditory signals into neuronal action potentials that are transmitted to the brain for further processing. The mature organ of Corti consists of a variety of highly differentiated sensory cells that fulfil unique tasks in the processing of auditory signals. The actin and microtubule cytoskeleton play essential function in hearing, however so far, more attention has been paid to the role of actin. Microtubules play important roles in maintaining cellular structure and intracellular transport in virtually all eukaryotic cells. Their functions are controlled by interactions with a large variety of microtubule-associated proteins (MAPs) and molecular motors. Current advances show that tubulin posttranslational modifications, as well as tubulin isotypes could play key roles in modulating microtubule properties and functions in cells. These mechanisms could have various effects on the stability and functions of microtubules in the highly specialised cells of the cochlea. Here, we review the current understanding of the role of microtubule-regulating mechanisms in the function of the cochlea and their implications for hearing, which highlights the importance of microtubules in the field of hearing research.
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Affiliation(s)
- Linda Bieniussa
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Germany
| | - Ipsa Jain
- Institute of Stem cell Biology and Regenerative Medicine, Bangalore, India
| | - Montserrat Bosch Grau
- Genetics and Physiology of Hearing Laboratory, Institute Pasteur, 75015 Paris, France
| | - Lukas Juergens
- Department of Ophthalmology, University of Duesseldorf, Germany
| | - Rudolf Hagen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Germany
| | - Carsten Janke
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France; Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Kristen Rak
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Germany.
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13
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Medina G, Perry J, Oza A, Kenna M. Hiding in plain sight: genetic deaf-blindness is not always Usher syndrome. Cold Spring Harb Mol Case Stud 2021; 7:mcs.a006088. [PMID: 34021019 PMCID: PMC8327880 DOI: 10.1101/mcs.a006088] [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: 01/27/2021] [Accepted: 05/03/2021] [Indexed: 11/25/2022] Open
Abstract
Hearing loss (HL) is the most common congenital sensory impairment. Usher syndrome (USH) is the leading genetic etiology of congenital deafness combined with progressive vision loss, and individuals presenting with these symptoms are often assumed to have USH. This can be an erroneous assumption, as there are additional genetic causes of deaf-blindness. Our objective is to describe and accurately diagnose non-USH genetic causes of deaf-blindness. We present three children with hearing and vision loss with clinical and genetic findings suggestive of USH. However, ongoing clinical assessment did not completely support an USH diagnosis, and exome analysis was pursued for all three individuals. Updated genetic testing showed pathogenic variants in ALMS1 in the first individual and TUBB4B in the second and third. Although HL in all three was consistent with USH type 2, vision impairment with retinal changes was noted by age 2 yr, which is unusual for USH. In all three the updated genotype more accurately fit the clinical phenotype. Because USH is the most common form of genetic deaf-blindness, individuals with HL, early vision impairment, and retinal dysfunction are often assumed to have USH. However, additional genes associated with HL and retinal impairment include ALMS1, TUBB4B, CEP78, ABHD12, and PRPS1. Accurate genetic diagnosis is critical to these individuals’ understanding of their genetic conditions, prognosis, vision and hearing loss management, and future access to molecular therapies. If clinically or genetically USH seems uncertain, updated genetic testing for non-USH genes is essential.
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Affiliation(s)
- Genevieve Medina
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Julia Perry
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, Boston, Massachusetts 02115, USA
| | - Andrea Oza
- Laboratory for Molecular Medicine, Partners HealthCare Personalized Medicine, Cambridge, Massachusetts 02139, USA.,Invitae, San Francisco, California 94103, USA
| | - Margaret Kenna
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts 02115, USA
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14
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Sánchez-Bellver L, Toulis V, Marfany G. On the Wrong Track: Alterations of Ciliary Transport in Inherited Retinal Dystrophies. Front Cell Dev Biol 2021; 9:623734. [PMID: 33748110 PMCID: PMC7973215 DOI: 10.3389/fcell.2021.623734] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/09/2021] [Indexed: 01/14/2023] Open
Abstract
Ciliopathies are a group of heterogeneous inherited disorders associated with dysfunction of the cilium, a ubiquitous microtubule-based organelle involved in a broad range of cellular functions. Most ciliopathies are syndromic, since several organs whose cells produce a cilium, such as the retina, cochlea or kidney, are affected by mutations in ciliary-related genes. In the retina, photoreceptor cells present a highly specialized neurosensory cilium, the outer segment, stacked with membranous disks where photoreception and phototransduction occurs. The daily renewal of the more distal disks is a unique characteristic of photoreceptor outer segments, resulting in an elevated protein demand. All components necessary for outer segment formation, maintenance and function have to be transported from the photoreceptor inner segment, where synthesis occurs, to the cilium. Therefore, efficient transport of selected proteins is critical for photoreceptor ciliogenesis and function, and any alteration in either cargo delivery to the cilium or intraciliary trafficking compromises photoreceptor survival and leads to retinal degeneration. To date, mutations in more than 100 ciliary genes have been associated with retinal dystrophies, accounting for almost 25% of these inherited rare diseases. Interestingly, not all mutations in ciliary genes that cause retinal degeneration are also involved in pleiotropic pathologies in other ciliated organs. Depending on the mutation, the same gene can cause syndromic or non-syndromic retinopathies, thus emphasizing the highly refined specialization of the photoreceptor neurosensory cilia, and raising the possibility of photoreceptor-specific molecular mechanisms underlying common ciliary functions such as ciliary transport. In this review, we will focus on ciliary transport in photoreceptor cells and discuss the molecular complexity underpinning retinal ciliopathies, with a special emphasis on ciliary genes that, when mutated, cause either syndromic or non-syndromic retinal ciliopathies.
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Affiliation(s)
- Laura Sánchez-Bellver
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
| | - Vasileios Toulis
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Marfany
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
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15
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Perrault I, Hanein S, Gérard X, Mounguengue N, Bouyakoub R, Zarhrate M, Fourrage C, Jabot-Hanin F, Bocquet B, Meunier I, Zanlonghi X, Kaplan J, Rozet JM. Whole Locus Sequencing Identifies a Prevalent Founder Deep Intronic RPGRIP1 Pathologic Variant in the French Leber Congenital Amaurosis Cohort. Genes (Basel) 2021; 12:genes12020287. [PMID: 33670832 PMCID: PMC7922592 DOI: 10.3390/genes12020287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/10/2021] [Accepted: 02/16/2021] [Indexed: 01/04/2023] Open
Abstract
Leber congenital amaurosis (LCA) encompasses the earliest and most severe retinal dystrophies and can occur as a non-syndromic or a syndromic disease. Molecular diagnosis in LCA is of particular importance in clinical decision-making and patient care since it can provide ocular and extraocular prognostics and identify patients eligible to develop gene-specific therapies. Routine high-throughput molecular testing in LCA yields 70%–80% of genetic diagnosis. In this study, we aimed to investigate the non-coding regions of one non-syndromic LCA gene, RPGRIP1, in a series of six families displaying one single disease allele after a gene-panel screening of 722 LCA families which identified 26 biallelic RPGRIP1 families. Using trio-based high-throughput whole locus sequencing (WLS) for second disease alleles, we identified a founder deep intronic mutation (NM_020366.3:c.1468-128T>G) in 3/6 families. We employed Sanger sequencing to search for the pathologic variant in unresolved LCA cases (106/722) and identified three additional families (two homozygous and one compound heterozygous with the NM_020366.3:c.930+77A>G deep intronic change). This makes the c.1468-128T>G the most frequent RPGRIP1 disease allele (8/60, 13%) in our cohort. Studying patient lymphoblasts, we show that the pathologic variant creates a donor splice-site and leads to the insertion of the pseudo-exon in the mRNA, which we were able to hamper using splice-switching antisense oligonucleotides (AONs), paving the way to therapies.
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Affiliation(s)
- Isabelle Perrault
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
- Correspondence:
| | - Sylvain Hanein
- Translational Genetics, Institute of Genetic Diseases, INSERM UMR1163, Imagine and Paris Descartes University, 75015 Paris, France;
| | - Xavier Gérard
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Nelson Mounguengue
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Ryme Bouyakoub
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Mohammed Zarhrate
- Genomics Platform, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France;
| | - Cécile Fourrage
- Bioinformatic Platform, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (C.F.); (F.J.-H.)
| | - Fabienne Jabot-Hanin
- Bioinformatic Platform, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (C.F.); (F.J.-H.)
- Bioinformatics Core Facility, Université Paris Descartes-Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, 75015 Paris, France
| | - Béatrice Bocquet
- Centre de Référence des Affections Sensorielles Génétiques, Institut des Neurosciences de Montpellier, CHU-Saint Eloi Montpellier, 34091 Montpellier, France; (B.B.); (I.M.)
| | - Isabelle Meunier
- Centre de Référence des Affections Sensorielles Génétiques, Institut des Neurosciences de Montpellier, CHU-Saint Eloi Montpellier, 34091 Montpellier, France; (B.B.); (I.M.)
- National Reference Centre for Inherited Sensory Diseases, Univ Montpellier, CHU, 34091 Montpellier, France
| | - Xavier Zanlonghi
- Eye Clinic Jules Verne, 44300 Nantes, France;
- CHU, 35000 Rennes, France
| | - Josseline Kaplan
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
- Ophthalmology Department, University Hospital Henri Mondor, APHP, 94000 Créteil, France
| | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
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16
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Ambrosio L, Hansen RM, Moskowitz A, Oza A, Barrett D, Manganella J, Medina G, Kawai K, Fulton AB, Kenna M. Dark-adapted threshold and electroretinogram for diagnosis of Usher syndrome. Doc Ophthalmol 2021; 143:39-51. [PMID: 33511521 DOI: 10.1007/s10633-021-09818-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 01/07/2021] [Indexed: 12/21/2022]
Abstract
PURPOSE To determine the utility of ophthalmology evaluation, dark-adapted threshold, and full-field electroretinogram for early detection of Usher syndrome in young patients with bilateral sensorineural hearing loss. METHODS We identified 39 patients with secure genetic diagnoses of Usher Syndrome. Visual acuity, spherical equivalent, fundus appearance, dark-adapted threshold, and full-field electroretinogram results were summarized and compared to those in a group of healthy controls with normal hearing. In those Usher patients with repeated measures, regression analysis was done to evaluate for change in visual acuity and dark-adapted threshold with age. Spherical equivalent and full-field electroretinogram responses from dark- and light-adapted eyes were evaluated as a function of age. RESULTS The majority of initial visual acuity and spherical equivalent results were within normal limits for age. Visual acuity and dark-adapted threshold worsened significantly with age in Usher type 1 but not in Usher type 2. At initial test, full-field electroretinogram responses from dark- and light-adapted eyes were abnormal in 53% of patients. Remarkably, nearly half of our patients (17% of Usher type 1 and 30% of Usher type 2) would have been missed by tests of retinal function alone if evaluated before age 10. CONCLUSIONS Although there is an association of abnormal dark-adapted threshold and full-field electroretinogram at young ages in Usher patients, it appears that a small but important proportion of patients would not be detected by tests of retinal function alone. Thus, genetic testing is needed to secure a diagnosis of Usher syndrome.
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Affiliation(s)
- Lucia Ambrosio
- Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA. .,Department of Ophthalmology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA.
| | - Ronald M Hansen
- Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Ophthalmology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Anne Moskowitz
- Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Ophthalmology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Andrea Oza
- Laboratory for Molecular Medicine, Partners HealthCare Personalized Medicine, 65 Landsdowne Street, Cambridge, MA, 02139, USA
| | - Devon Barrett
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Juliana Manganella
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Genevieve Medina
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Kosuke Kawai
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Otolaryngology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Anne B Fulton
- Department of Ophthalmology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Ophthalmology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Margaret Kenna
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.,Department of Otolaryngology, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
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17
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Lee HMT, Sayegh NY, Gayek AS, Jao SLJ, Chalfie M, Zheng C. Epistatic, synthetic, and balancing interactions among tubulin missense mutations affecting neurite growth in Caenorhabditis elegans. Mol Biol Cell 2020; 32:331-347. [PMID: 33378215 PMCID: PMC8098816 DOI: 10.1091/mbc.e20-07-0492] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mutations in tubulins affect microtubule (MT) dynamics and functions during neuronal differentiation and their genetic interaction provides insights into the regulation of MT functions. We previously used Caenorhabditis elegans touch receptor neurons to analyze the cellular impact of tubulin mutations and reported the phenotypes of 67 tubulin missense mutations, categorized into three classes: loss-of-function (lf), antimorphic (anti), and neomorphic (neo) alleles. In this study, we isolated 54 additional tubulin alleles through suppressor screens in sensitized backgrounds that caused excessive neurite growth. These alleles included 32 missense mutations not analyzed before, bringing the total number of mutations in our collection to 99. Phenotypic characterization of these newly isolated mutations identified three new types of alleles: partial lf and weak neo alleles of mec-7/β-tubulin that had subtle effects and strong anti alleles of mec-12/α-tubulin. We also discovered complex genetic interactions among the tubulin mutations, including the suppression of neo mutations by intragenic lf and anti alleles, additive and synthetic effects between mec-7 neo alleles, and unexpected epistasis, in which weaker neo alleles masked the effects of stronger neo alleles in inducing ectopic neurite growth. We also observed balancing between neo and anti alleles, whose respective MT-hyperstablizing and -destabilizing effects neutralized each other.
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Affiliation(s)
- Ho Ming Terence Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | | | - A Sophia Gayek
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | | | - Martin Chalfie
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Chaogu Zheng
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
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18
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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.
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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.
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19
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Tatour Y, Ben-Yosef T. Syndromic Inherited Retinal Diseases: Genetic, Clinical and Diagnostic Aspects. Diagnostics (Basel) 2020; 10:diagnostics10100779. [PMID: 33023209 PMCID: PMC7600643 DOI: 10.3390/diagnostics10100779] [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: 09/09/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 02/06/2023] Open
Abstract
Inherited retinal diseases (IRDs), which are among the most common genetic diseases in humans, define a clinically and genetically heterogeneous group of disorders. Over 80 forms of syndromic IRDs have been described. Approximately 200 genes are associated with these syndromes. The majority of syndromic IRDs are recessively inherited and rare. Many, although not all, syndromic IRDs can be classified into one of two major disease groups: inborn errors of metabolism and ciliopathies. Besides the retina, the systems and organs most commonly involved in syndromic IRDs are the central nervous system, ophthalmic extra-retinal tissues, ear, skeleton, kidney and the cardiovascular system. Due to the high degree of phenotypic variability and phenotypic overlap found in syndromic IRDs, correct diagnosis based on phenotypic features alone may be challenging and sometimes misleading. Therefore, genetic testing has become the benchmark for the diagnosis and management of patients with these conditions, as it complements the clinical findings and facilitates an accurate clinical diagnosis and treatment.
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20
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Bolz HJ. Usher syndrome: diagnostic approach, differential diagnoses and proposal of an updated function-based genetic classification. MED GENET-BERLIN 2020. [DOI: 10.1515/medgen-2020-2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Abstract
Usher syndrome (USH) manifests with congenital and apparently isolated hearing loss, followed by retinal degeneration in later life. Therefore, and because of its high prevalence in the congenitally hearing-impaired population, USH is one of the most relevant deafness syndromes. Next-generation sequencing (NGS)-based testing can now provide most analyzed USH patients with a molecular diagnosis, based on mutations in 11 genes. Given the availability of several excellent articles on the clinical and biochemical basis of USH, this short review focuses on critical assessment of new genes announced as USH genes, clinical and genetic differential diagnoses and therapeutic developments. Because obsolete loci, disproved USH genes and the inclusion of genes whose mutations cause similar phenotypes have increasingly blurred genetic classification, a revision based on phenotype restricted to genes related to the Usher protein complex is proposed.
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Affiliation(s)
- Hanno J. Bolz
- Senckenberg Centre for Human Genetics , Weismüllerstr. 50 , Frankfurt am Main , Germany
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21
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Lopez-Juarez A, Gonzalez-Vega A, Kleinert-Altamirano A, Piazza V, Garduno-Robles A, Alata M, Villaseñor-Mora C, Eguibar JR, Cortes C, Padierna LC, Hernandez VH. Auditory impairment in H-ABC tubulinopathy. J Comp Neurol 2020; 529:957-968. [PMID: 32681585 DOI: 10.1002/cne.24990] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/12/2020] [Accepted: 07/10/2020] [Indexed: 12/20/2022]
Abstract
Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a neurodegenerative disease due to mutations in TUBB4A. Patients suffer from extrapyramidal movements, spasticity, ataxia, and cognitive deficits. Magnetic resonance imaging features are hypomyelination and atrophy of the striatum and cerebellum. A correlation between the mutations and their cellular, tissue and organic effects is largely missing. The effects of these mutations on sensory functions have not been described so far. We have previously reported a rat carrying a TUBB4A (A302T) mutation and sharing most of the clinical and radiological signs with H-ABC patients. Here, for the first time, we did a comparative study of the hearing function in an H-ABC patient and in this mutant model. By analyzing hearing function, we found that there are no significant differences in the auditory brainstem response (ABR) thresholds between mutant rats and WT controls. Nevertheless, ABRs show longer latencies in central waves (II-IV) that in some cases disappear when compared to WT. The patient also shows abnormal AEPs presenting only Waves I and II. Distortion product of otoacoustic emissions and immunohistochemistry in the rat show that the peripheral hearing function and morphology of the organ of Corti are normal. We conclude that the tubulin mutation severely impairs the central hearing pathway most probably by progressive central white matter degeneration. Hearing function might be affected in a significant fraction of patients with H-ABC; therefore, screening for auditory function should be done on patients with tubulinopathies to evaluate hearing support therapies.
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Affiliation(s)
| | - Arturo Gonzalez-Vega
- Division of Sciences and Engineering, University of Guanajuato, Guanajuato, Mexico
| | | | | | - Angeles Garduno-Robles
- Division of Sciences and Engineering, University of Guanajuato, Guanajuato, Mexico.,Center of Research in Optics, Leon, Mexico
| | | | | | - Jose R Eguibar
- Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico.,Vicerrectoría de Investigación y Estudios de Posgrado, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Carmen Cortes
- Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Luis Carlos Padierna
- Division of Sciences and Engineering, University of Guanajuato, Guanajuato, Mexico
| | - Victor H Hernandez
- Division of Sciences and Engineering, University of Guanajuato, Guanajuato, Mexico
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22
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Wang S, Wen H, Fei W, Zhao Y, Feng Y, Kuang L, Wang M, Wu M. Two engineered site-specific antibody-drug conjugates, HLmD4 and HLvM4, have potent therapeutic activity in two DLL4-positive tumour xenograft models. Am J Cancer Res 2020; 10:2387-2408. [PMID: 32905508 PMCID: PMC7471348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023] Open
Abstract
The humanized Delta-like 4 (DLL4) monoclonal antibody H3L2 with a quite high affinity for hrDLL4 inhibits the DLL4-mediated human umbilical vein endothelial cell (HUVEC) phenotype, inducing dysfunctional angiogenesis and tumour cell apoptosis, which effectively arrests breast cancer cell growth in vivo. To develop a more effective therapy, an engineered cysteine residue at alanine 121 (Kabat numbering) on each H3L2 heavy chain or at valine 207 (Kabat numbering) on each H3L2 light chain was established by site-directed mutagenesis. Three engineered antibodies, THL4, TH2 and TL2, were identified, and the specific-site antibody-drug conjugates (ADCs) THL4-mpeoDM1 (named HLmD4), TH2-mpeoDM1 (named HmD2), TL2-mpeoDM1 (named LmD2) and THL4-vcMMAE (named HLvM4), were produced, which exhibit much more potent antitumour activity than the naked antibody. The engineered ADCs can be directed against DLL4 and effectively internalized, followed by the release of small molecule cytotoxic agents, e.g., DM1 or MMAE, into the cytosol, which inhibit the synthesis of microtubules and induce G2/M phase growth arrest and cell death through the induction of apoptosis. ADC-conjugated DM1 was highly potent against DLL4-expressing cells in vitro. We systematically compared the in vitro potency and the in vivo preclinical efficacy and safety profiles of the heterogeneous conventional ADC, H3L2-mpeoDM1 (named JmD4) with that of the homogeneous engineered conjugate HLmD4. The engineered anti-DLL4 ADCs, particularly HLmD4, showed more potent antitumour activity than Docetaxel and superior safety compared with JmD4 in two xenograft tumour models. Our findings indicate that engineered ADCs have promising potential as effective preclinical therapies for cancers.
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Affiliation(s)
- Shijing Wang
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University Nanjing 210009, China
| | - Hui Wen
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University Nanjing 210009, China
| | - Wenyi Fei
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University Nanjing 210009, China
| | - Yuhong Zhao
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University Nanjing 210009, China
| | - Yuqi Feng
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University Nanjing 210009, China
| | - Lu Kuang
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University Nanjing 210009, China
| | - Min Wang
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University Nanjing 210009, China
| | - Min Wu
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University Nanjing 210009, China
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23
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Mechaussier S, Almoallem B, Zeitz C, Van Schil K, Jeddawi L, Van Dorpe J, Dueñas Rey A, Condroyer C, Pelle O, Polak M, Boddaert N, Bahi-Buisson N, Cavallin M, Bacquet JL, Mouallem-Bézière A, Zambrowski O, Sahel JA, Audo I, Kaplan J, Rozet JM, De Baere E, Perrault I. Loss of Function of RIMS2 Causes a Syndromic Congenital Cone-Rod Synaptic Disease with Neurodevelopmental and Pancreatic Involvement. Am J Hum Genet 2020; 106:859-871. [PMID: 32470375 PMCID: PMC7273530 DOI: 10.1016/j.ajhg.2020.04.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 04/29/2020] [Indexed: 12/13/2022] Open
Abstract
Congenital cone-rod synaptic disorder (CRSD), also known as incomplete congenital stationary night blindness (iCSNB), is a non-progressive inherited retinal disease (IRD) characterized by night blindness, photophobia, and nystagmus, and distinctive electroretinographic features. Here, we report bi-allelic RIMS2 variants in seven CRSD-affected individuals from four unrelated families. Apart from CRSD, neurodevelopmental disease was observed in all affected individuals, and abnormal glucose homeostasis was observed in the eldest affected individual. RIMS2 regulates synaptic membrane exocytosis. Data mining of human adult bulk and single-cell retinal transcriptional datasets revealed predominant expression in rod photoreceptors, and immunostaining demonstrated RIMS2 localization in the human retinal outer plexiform layer, Purkinje cells, and pancreatic islets. Additionally, nonsense variants were shown to result in truncated RIMS2 and decreased insulin secretion in mammalian cells. The identification of a syndromic stationary congenital IRD has a major impact on the differential diagnosis of syndromic congenital IRD, which has previously been exclusively linked with degenerative IRD.
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Affiliation(s)
- Sabrina Mechaussier
- Laboratory of Genetics in Ophthalmology, INSERM UMR 1163, Institute of Genetic Diseases, Imagine and Paris University, 75015 Paris, France
| | - Basamat Almoallem
- Center for Medical Genetics and Department of Biomolecular Medicine, Ghent University and Ghent University Hospital, 9000 Ghent, Belgium; Department of Ophthalmology, King Abdul-Aziz University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Christina Zeitz
- Sorbonne Université, INSERM, Centre National de la Recherche Scientifique, Institut de la Vision, 75012 Paris, France
| | - Kristof Van Schil
- Center for Medical Genetics and Department of Biomolecular Medicine, Ghent University and Ghent University Hospital, 9000 Ghent, Belgium
| | - Laila Jeddawi
- Pediatric Ophthalmology Division, Dhahran Eye Specialist Hospital, Dhahran 34257, Saudi Arabia
| | - Jo Van Dorpe
- Department of Pathology, Ghent University and Ghent University Hospital, 9000 Ghent, Belgium
| | - Alfredo Dueñas Rey
- Center for Medical Genetics and Department of Biomolecular Medicine, Ghent University and Ghent University Hospital, 9000 Ghent, Belgium
| | - Christel Condroyer
- Sorbonne Université, INSERM, Centre National de la Recherche Scientifique, Institut de la Vision, 75012 Paris, France
| | - Olivier Pelle
- Cell Sorting Facility, INSERM UMR 1163, Institute of Genetic Diseases, Imagine and Paris University, 75015 Paris, France
| | - Michel Polak
- Endocrinology, Gynecology, and Pediatric Diabetology Department, University Hospital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France
| | - Nathalie Boddaert
- Department of Pediatric Radiology, University Hospital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France
| | - Nadia Bahi-Buisson
- Pediatric Neurology Department, University Hospital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France
| | - Mara Cavallin
- Laboratory of Embryology and Genetics of Human Malformation, INSERM UMR 1163, Institute of Genetic Diseases, Imagine and Paris University, 75015 Paris, France
| | - Jean-Louis Bacquet
- Service d'Ophtalmologie, Centre Hospitalier Intercommunal de Créteil, Assistance Publique-Hôpitaux de Paris, 94000 Créteil, France
| | - Alexandra Mouallem-Bézière
- Service d'Ophtalmologie, Centre Hospitalier Intercommunal de Créteil, Assistance Publique-Hôpitaux de Paris, 94000 Créteil, France
| | - Olivia Zambrowski
- Service d'Ophtalmologie, Centre Hospitalier Intercommunal de Créteil, Assistance Publique-Hôpitaux de Paris, 94000 Créteil, France; Ophthalmology Department, University Hospital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France
| | - José Alain Sahel
- Sorbonne Université, INSERM, Centre National de la Recherche Scientifique, Institut de la Vision, 75012 Paris, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM, Direction de l'Hospitalisation et de l'Organisation des Soins (DHOS), Centres d'Investigations Cliniques (CIC) 1423, 75012 Paris, France; Fondation Ophtalmologique Adolphe de Rothschild, 75019 Paris, France; Académie des Sciences, Institut de France, 75006 Paris, France; Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, PA 15213, USA
| | - Isabelle Audo
- Sorbonne Université, INSERM, Centre National de la Recherche Scientifique, Institut de la Vision, 75012 Paris, France; Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM, Direction de l'Hospitalisation et de l'Organisation des Soins (DHOS), Centres d'Investigations Cliniques (CIC) 1423, 75012 Paris, France; Institute of Ophthalmology, University College of London, London EC1V 9EL, UK
| | - Josseline Kaplan
- Laboratory of Genetics in Ophthalmology, INSERM UMR 1163, Institute of Genetic Diseases, Imagine and Paris University, 75015 Paris, France; Service d'Ophtalmologie, Centre Hospitalier Intercommunal de Créteil, Assistance Publique-Hôpitaux de Paris, 94000 Créteil, France
| | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology, INSERM UMR 1163, Institute of Genetic Diseases, Imagine and Paris University, 75015 Paris, France
| | - Elfride De Baere
- Center for Medical Genetics and Department of Biomolecular Medicine, Ghent University and Ghent University Hospital, 9000 Ghent, Belgium.
| | - Isabelle Perrault
- Laboratory of Genetics in Ophthalmology, INSERM UMR 1163, Institute of Genetic Diseases, Imagine and Paris University, 75015 Paris, France.
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24
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Genetic Deciphering of Early-Onset and Severe Retinal Dystrophy Associated with Sensorineural Hearing Loss. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1185:233-238. [PMID: 31884617 DOI: 10.1007/978-3-030-27378-1_38] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The specific association of Leber congenital amaurosis (LCA) or early-onset severe retinal dystrophy (LCA-like) with sensorineural hearing loss (SHL) is uncommon. Recently, we ascribed some of these distinctive associations to dominant and de novo mutations in the β-tubulin 4B isotype-encoding gene (TUBB4B), providing a link between a sensorineural disease and anomalies in microtubules behavior. Here, we report 12 sporadic cases with LCA/SHL or LCA-like/SHL and no TUBB4B mutation. Trio-based whole exome sequencing (WES) identified disease-causing mutations in 5/12 cases. Four out of five carried biallelic mutations in PEX1 (1/4) or PEX6 (3/4), involved in peroxisome biogenesis disorders from Zellweger syndrome characterized by severe neurologic and neurosensory dysfunctions, craniofacial abnormalities, and liver dysfunction to Heimler syndrome associating SHL, enamel hypoplasia of the secondary dentition, nail abnormalities, and occasional retinal disease. Upon reexamination, the index case carrying PEX1 mutations, a 4-year-old girl, presented additional symptoms consistent with Zellweger syndrome. Reexamination of individuals with PEX6 mutations (1/3 unavailable) revealed normal nails but enamel hypoplasia affecting one primary teeth in a 4-year-old girl and severe enamel hypoplasia of primary teeth hidden by dental prosthesis in a 50-year-old male, describing a novel PEX6-associated disease of the Zellweger/Heimler spectrum. Finally, hemizygosity for a CACNA1F mutation was identified in an 18-year-old male addressed for LCA/SHL, redirecting the retinal diagnosis to congenital stationary night blindness (CSNB2A). Consistent with the pure CSNB2A retinal involvement, SHL was ascribed to biallelic mutations in another gene, STRC, involved in nonprogressive DFNB16 deafness.
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25
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Much More Than a Scaffold: Cytoskeletal Proteins in Neurological Disorders. Cells 2020; 9:cells9020358. [PMID: 32033020 PMCID: PMC7072452 DOI: 10.3390/cells9020358] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 02/08/2023] Open
Abstract
Recent observations related to the structure of the cytoskeleton in neurons and novel cytoskeletal abnormalities involved in the pathophysiology of some neurological diseases are changing our view on the function of the cytoskeletal proteins in the nervous system. These efforts allow a better understanding of the molecular mechanisms underlying neurological diseases and allow us to see beyond our current knowledge for the development of new treatments. The neuronal cytoskeleton can be described as an organelle formed by the three-dimensional lattice of the three main families of filaments: actin filaments, microtubules, and neurofilaments. This organelle organizes well-defined structures within neurons (cell bodies and axons), which allow their proper development and function through life. Here, we will provide an overview of both the basic and novel concepts related to those cytoskeletal proteins, which are emerging as potential targets in the study of the pathophysiological mechanisms underlying neurological disorders.
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26
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Gao LL, Xu F, Jin Z, Ying XY, Liu JW. Microtubule‑severing protein Katanin p60 ATPase‑containing subunit A‑like 1 is involved in pole‑based spindle organization during mouse oocyte meiosis. Mol Med Rep 2019; 20:3573-3582. [PMID: 31485656 DOI: 10.3892/mmr.2019.10605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 05/31/2019] [Indexed: 11/05/2022] Open
Abstract
Microtubule‑severing proteins (MTSPs) are a group of microtubule‑associated proteins essential for multiple microtubule‑related processes, including mitosis and meiosis. Katanin p60 ATPase‑containing subunit A‑like 1 (p60 katanin‑like 1) is an MTSP that maintains the density of spindle microtubules at the poles in mitotic cells; however, to date, there have been no studies about its role in female meiosis. Using in vitro‑matured (IVM) oocytes as a model, it was first revealed that p60 katanin‑like 1 was predominant in the ovaries and oocytes, indicating its essential roles in oocyte meiosis. It was also revealed that p60 katanin‑like 1 was concentrated at the spindle poles and co‑localized and interacted with γ‑tubulin, indicating that it may be involved in pole organization. Next, specific siRNA was used to deplete p60 katanin‑like 1; the spindle organization was severely disrupted and characterized by an abnormal width:length ratio, multipolarity and extra aster microtubules out of the main spindles. Finally, it was determined that p60 katanin‑like 1 knockdown retarded oocyte meiosis, reduced fertilization, and caused abnormal mitochondrial distribution. Collectively, these results indicated that p60 katanin‑like 1 is essential for oocyte meiosis by ensuring the integrity of the spindle poles.
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Affiliation(s)
- Lei-Lei Gao
- Department of Gynecology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Fei Xu
- Department of Gynecology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Zhen Jin
- Reproductive Genetic Center, Suzhou Municipal Hospital, Suzhou Hospital of Nanjing, Nanjing, Jiangsu 215000, P.R. China
| | - Xiao-Yan Ying
- Department of Gynecology, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu 210011, P.R. China
| | - Jin-Wei Liu
- Department of Gynecology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
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27
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Drug repositioning and biomarkers in low-grade glioma via bioinformatics approach. INFORMATICS IN MEDICINE UNLOCKED 2019. [DOI: 10.1016/j.imu.2019.100250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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