151
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Casasola Balsells LA, Guerra González JC, Casasola Balsells MA, Pérez Chamorro VA. La accesibilidad de los portales web de las universidades públicas andaluzas. REVISTA ESPANOLA DE DOCUMENTACION CIENTIFICA 2017. [DOI: 10.3989/redc.2017.2.1372] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
En este trabajo se describe el análisis realizado en 2015 para la evaluación de la accesibilidad de los portales web de las universidades públicas andaluzas. Con el fin de determinar si las universidades ofrecen información accesible, se ha comprobado el cumplimiento de las Pautas de Accesibilidad de Contenidos Web (WCAG 2.0) establecidas por el Consorcio World Wide Web (W3C). Para ello, se ha diseñado una metodología de análisis que combina tres herramientas automáticas (eXaminator, accesibilidad web del MINHAP, y TAW) y un análisis manual con objeto de dotar de mayor fiabilidad y validez a los resultados. Aunque en términos generales los resultados son aceptables, un análisis detallado muestra que aún queda camino por recorrer hasta conseguir una accesibilidad completa para toda la comunidad universitaria. A este respecto, en el trabajo se sugieren mejoras en los errores comunes encontrados sobre accesibilidad que puedan servir de ayuda al diseño web de las Universidades.
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152
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Cleary JD, Ranum LP. New developments in RAN translation: insights from multiple diseases. Curr Opin Genet Dev 2017; 44:125-134. [PMID: 28365506 PMCID: PMC5951168 DOI: 10.1016/j.gde.2017.03.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 02/28/2017] [Accepted: 03/13/2017] [Indexed: 12/14/2022]
Abstract
Since the discovery of repeat-associated non-ATG (RAN) translation, and more recently its association with amyotrophic lateral sclerosis/frontotemporal dementia, there has been an intense focus to understand how this process works and the downstream effects of these novel proteins. RAN translation across several different types of repeat expansions mutations (CAG, CTG, CCG, GGGGCC, GGCCCC) results in the production of proteins in all three reading frames without an ATG initiation codon. The combination of bidirectional transcription and RAN translation has been shown to result in the accumulation of up to six mutant expansion proteins in a growing number of diseases. This process is complex mechanistically and also complex from the perspective of the downstream consequences in disease. Here we review recent developments in RAN translation and their implications on our basic understanding of neurodegenerative disease and gene expression.
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Affiliation(s)
- John Douglas Cleary
- Center for NeuroGenetics, University of Florida, Gainesville, FL, USA; Department of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA; Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Laura Pw Ranum
- Center for NeuroGenetics, University of Florida, Gainesville, FL, USA; Department of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA; Department of Neurology, University of Florida, Gainesville, FL, USA; Genetics Institute, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
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153
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Sanders DW, Brangwynne CP. Neurodegenerative disease: RNA repeats put a freeze on cells. Nature 2017; 546:215-216. [PMID: 28562583 DOI: 10.1038/nature22503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- David W Sanders
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, 08540, USA
| | - Clifford P Brangwynne
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, 08540, USA
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154
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Shahheydari H, Ragagnin A, Walker AK, Toth RP, Vidal M, Jagaraj CJ, Perri ER, Konopka A, Sultana JM, Atkin JD. Protein Quality Control and the Amyotrophic Lateral Sclerosis/Frontotemporal Dementia Continuum. Front Mol Neurosci 2017; 10:119. [PMID: 28539871 PMCID: PMC5423993 DOI: 10.3389/fnmol.2017.00119] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/10/2017] [Indexed: 12/11/2022] Open
Abstract
Protein homeostasis, or proteostasis, has an important regulatory role in cellular function. Protein quality control mechanisms, including protein folding and protein degradation processes, have a crucial function in post-mitotic neurons. Cellular protein quality control relies on multiple strategies, including molecular chaperones, autophagy, the ubiquitin proteasome system, endoplasmic reticulum (ER)-associated degradation (ERAD) and the formation of stress granules (SGs), to regulate proteostasis. Neurodegenerative diseases are characterized by the presence of misfolded protein aggregates, implying that protein quality control mechanisms are dysfunctional in these conditions. Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are neurodegenerative diseases that are now recognized to overlap clinically and pathologically, forming a continuous disease spectrum. In this review article, we detail the evidence for dysregulation of protein quality control mechanisms across the whole ALS-FTD continuum, by discussing the major proteins implicated in ALS and/or FTD. We also discuss possible ways in which protein quality mechanisms could be targeted therapeutically in these disorders and highlight promising protein quality control-based therapeutics for clinical trials.
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Affiliation(s)
- Hamideh Shahheydari
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Audrey Ragagnin
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Adam K Walker
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Reka P Toth
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Marta Vidal
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Cyril J Jagaraj
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Emma R Perri
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Anna Konopka
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Jessica M Sultana
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia
| | - Julie D Atkin
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie UniversitySydney, NSW, Australia.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe UniversityMelbourne, VIC, Australia
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155
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Moens TG, Partridge L, Isaacs AM. Genetic models of C9orf72: what is toxic? Curr Opin Genet Dev 2017; 44:92-101. [PMID: 28364657 DOI: 10.1016/j.gde.2017.01.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 01/13/2017] [Accepted: 01/18/2017] [Indexed: 12/11/2022]
Abstract
A hexanucleotide repeat expansion in the gene C9orf72 is the most common genetic cause of both amyotrophic lateral sclerosis and frontotemporal dementia. Pathogenesis may occur either due to loss of function of the C9orf72 gene, or a toxic gain of function, via the production of repetitive sense and antisense RNA and/or repetitive dipeptide repeat proteins. Recently, mouse knockouts have suggested that a loss of function of C9orf72 alone is insufficient to lead to neurodegeneration, whilst overexpression of hexanucleotide DNA is sufficient in a wide range of model systems. Additionally, models have now been created to attempt to study the effects of repetitive RNA and dipeptide proteins in isolation and thus determine their relevance to disease.
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Affiliation(s)
- Thomas G Moens
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London WC1N 3BG, UK; Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK
| | - Linda Partridge
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London WC1E 6BT, UK; Max Planck Institute for Biology of Ageing, Robert-Koch-Str. 21, 50931 Cologne, Germany
| | - Adrian M Isaacs
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London WC1N 3BG, UK.
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156
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Stopford MJ, Higginbottom A, Hautbergue GM, Cooper-Knock J, Mulcahy PJ, De Vos KJ, Renton AE, Pliner H, Calvo A, Chio A, Traynor BJ, Azzouz M, Heath PR, Kirby J, Shaw PJ. C9ORF72 hexanucleotide repeat exerts toxicity in a stable, inducible motor neuronal cell model, which is rescued by partial depletion of Pten. Hum Mol Genet 2017; 26:1133-1145. [PMID: 28158451 PMCID: PMC5409131 DOI: 10.1093/hmg/ddx022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 01/02/2017] [Accepted: 01/10/2017] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating and incurable neurodegenerative disease, characterised by progressive failure of the neuromuscular system. A (G4C2)n repeat expansion in C9ORF72 is the most common genetic cause of ALS and frontotemporal dementia (FTD). To date, the balance of evidence indicates that the (G4C2)n repeat causes toxicity and neurodegeneration via a gain-of-toxic function mechanism; either through direct RNA toxicity or through the production of toxic aggregating dipeptide repeat proteins. Here, we have generated a stable and isogenic motor neuronal NSC34 cell model with inducible expression of a (G4C2)102 repeat, to investigate the gain-of-toxic function mechanisms. The expression of the (G4C2)102 repeat produces RNA foci and also undergoes RAN translation. In addition, the expression of the (G4C2)102 repeat shows cellular toxicity. Through comparison of transcriptomic data from the cellular model with laser-captured spinal motor neurons from C9ORF72-ALS cases, we also demonstrate that the PI3K/Akt cell survival signalling pathway is dysregulated in both systems. Furthermore, partial knockdown of Pten rescues the toxicity observed in the NSC34 (G4C2)102 cellular gain-of-toxic function model of C9ORF72-ALS. Our data indicate that PTEN may provide a potential therapeutic target to ameliorate toxic effects of the (G4C2)n repeat.
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Affiliation(s)
- Matthew J. Stopford
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Adrian Higginbottom
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Guillaume M. Hautbergue
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Johnathan Cooper-Knock
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Padraig J. Mulcahy
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Kurt J. De Vos
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Alan E. Renton
- Neuromuscular Diseases Research Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hannah Pliner
- Neuromuscular Diseases Research Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrea Calvo
- Department of Neuroscience, University of Turin, Turin, Italy
| | - Adriano Chio
- Department of Neuroscience, University of Turin, Turin, Italy
| | - Bryan J. Traynor
- Neuromuscular Diseases Research Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mimoun Azzouz
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Paul R. Heath
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | | | - Janine Kirby
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
| | - Pamela J. Shaw
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, UK
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157
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Mackenzie IRA. The role of dipeptide-repeat protein pathology in C9orf72 mutation cases. Neuropathol Appl Neurobiol 2017; 42:217-9. [PMID: 26577056 DOI: 10.1111/nan.12296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- I R A Mackenzie
- Department of Pathology, University of British Columbia and Vancouver General Hospital, Vancouver, British Columbia, Canada
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158
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Sellier C, Buijsen RAM, He F, Natla S, Jung L, Tropel P, Gaucherot A, Jacobs H, Meziane H, Vincent A, Champy MF, Sorg T, Pavlovic G, Wattenhofer-Donze M, Birling MC, Oulad-Abdelghani M, Eberling P, Ruffenach F, Joint M, Anheim M, Martinez-Cerdeno V, Tassone F, Willemsen R, Hukema RK, Viville S, Martinat C, Todd PK, Charlet-Berguerand N. Translation of Expanded CGG Repeats into FMRpolyG Is Pathogenic and May Contribute to Fragile X Tremor Ataxia Syndrome. Neuron 2017; 93:331-347. [PMID: 28065649 PMCID: PMC5263258 DOI: 10.1016/j.neuron.2016.12.016] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 10/06/2016] [Accepted: 12/02/2016] [Indexed: 11/26/2022]
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder caused by a limited expansion of CGG repeats in the 5′ UTR of FMR1. Two mechanisms are proposed to cause FXTAS: RNA gain-of-function, where CGG RNA sequesters specific proteins, and translation of CGG repeats into a polyglycine-containing protein, FMRpolyG. Here we developed transgenic mice expressing CGG repeat RNA with or without FMRpolyG. Expression of FMRpolyG is pathogenic, while the sole expression of CGG RNA is not. FMRpolyG interacts with the nuclear lamina protein LAP2β and disorganizes the nuclear lamina architecture in neurons differentiated from FXTAS iPS cells. Finally, expression of LAP2β rescues neuronal death induced by FMRpolyG. Overall, these results suggest that translation of expanded CGG repeats into FMRpolyG alters nuclear lamina architecture and drives pathogenesis in FXTAS. CGG repeats in the 5′ UTR of FMR1 are translated through initiation to an ACG codon Translation of CGG repeats in the polyglycine protein, FMRpolyG, is toxic in mice FMRpolyG binds and disrupts protein of the nuclear lamina
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Affiliation(s)
- Chantal Sellier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France.
| | - Ronald A M Buijsen
- Department of Clinical Genetics, Erasmus MC, 3015 Rotterdam, the Netherlands
| | - Fang He
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA; Veteran Association Health System, Ann Arbor, MI 48105, USA; Department of Biological and Health Sciences, Texas A&M University - Kingsville, Kingsville, TX 78363, USA
| | - Sam Natla
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Laura Jung
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Philippe Tropel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Angeline Gaucherot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Hugues Jacobs
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; PHENOMIN, Institut Clinique de la Souris (ICS), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Hamid Meziane
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; PHENOMIN, Institut Clinique de la Souris (ICS), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Alexandre Vincent
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Marie-France Champy
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; PHENOMIN, Institut Clinique de la Souris (ICS), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Tania Sorg
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; PHENOMIN, Institut Clinique de la Souris (ICS), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Guillaume Pavlovic
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; PHENOMIN, Institut Clinique de la Souris (ICS), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Marie Wattenhofer-Donze
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; PHENOMIN, Institut Clinique de la Souris (ICS), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Marie-Christine Birling
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; PHENOMIN, Institut Clinique de la Souris (ICS), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Mustapha Oulad-Abdelghani
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Pascal Eberling
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Frank Ruffenach
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Mathilde Joint
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France
| | - Mathieu Anheim
- Department of Neurology, University Hospital of Strasbourg, Hôpital de Hautepierre, 67200 Strasbourg, France
| | - Veronica Martinez-Cerdeno
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, CA 95817, USA; Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; M.I.N.D. Institute, University of California, Davis, Health System, Sacramento, CA 95817, USA
| | - Flora Tassone
- M.I.N.D. Institute, University of California, Davis, Health System, Sacramento, CA 95817, USA
| | - Rob Willemsen
- Department of Clinical Genetics, Erasmus MC, 3015 Rotterdam, the Netherlands
| | - Renate K Hukema
- Department of Clinical Genetics, Erasmus MC, 3015 Rotterdam, the Netherlands
| | - Stéphane Viville
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; Laboratoire de Diagnostic Génétique, UF3472 - Infertilité, Nouvel Hôpital Civil, 1 place de l'Hôpital, 67091 Strasbourg, France; IPPTS, 3 rue Koeberlé, 67000 Strasbourg, France
| | | | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA; Veteran Association Health System, Ann Arbor, MI 48105, USA
| | - Nicolas Charlet-Berguerand
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U964, CNRS UMR7104, University of Strasbourg, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Centre National de la Recherche Scientifique, UMR7104, 67400 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67400 Illkirch, France.
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159
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Taylor JP, Brown RH, Cleveland DW. Decoding ALS: from genes to mechanism. Nature 2016; 539:197-206. [PMID: 27830784 DOI: 10.1038/nature20413] [Citation(s) in RCA: 1341] [Impact Index Per Article: 167.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 09/13/2016] [Indexed: 02/08/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive and uniformly fatal neurodegenerative disease. A plethora of genetic factors have been identified that drive the degeneration of motor neurons in ALS, increase susceptibility to the disease or influence the rate of its progression. Emerging themes include dysfunction in RNA metabolism and protein homeostasis, with specific defects in nucleocytoplasmic trafficking, the induction of stress at the endoplasmic reticulum and impaired dynamics of ribonucleoprotein bodies such as RNA granules that assemble through liquid-liquid phase separation. Extraordinary progress in understanding the biology of ALS provides new reasons for optimism that meaningful therapies will be identified.
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Affiliation(s)
- J Paul Taylor
- Howard Hughes Medical Institute and the Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Robert H Brown
- Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Don W Cleveland
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, California 92093, USA.,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA
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160
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Zhang M, Xi Z, Misquitta K, Sato C, Moreno D, Liang Y, Slow E, Rogaeva E, Tartaglia MC. C9orf72 and ATXN2 repeat expansions coexist in a family with ataxia, dementia, and parkinsonism. Mov Disord 2016; 32:158-162. [PMID: 28124431 DOI: 10.1002/mds.26841] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/09/2016] [Accepted: 09/18/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Intermediate interrupted ataxin 2 (ATXN2) alleles (27-33 CAG-repeats) increase the risk for amyotrophic lateral sclerosis and are reported as modifiers in chromosome 9 open reading frame 72 (C9orf72) carriers, rendering susceptibility to amyotrophic lateral sclerosis rather than frontotemporal lobar degeneration. The clinical presentation of C9orf72 patients with pathogenic ATXN2 alleles (≥35 CAG-repeats) is unknown. METHODS Blood samples were collected from a family affected by ataxia, dementia, and parkinsonism, but not amyotrophic lateral sclerosis. Mutation analyses of the proband included C9orf72 and 14 ataxia genes, followed by segregation analyses in family members. RESULTS Both affected siblings carry an uninterrupted 37-repeat expansion in ATXN2 and a methylated G4 C2 -repeat allele in C9orf72 that is typical of large pathogenic expansions. CONCLUSIONS The CAG-expansion in ATXN2 likely caused the ataxia, whereas the dementia may be linked to both C9orf72 and ATXN2 repeat expansions. The pathological uninterrupted ATXN2 repeat may not have the same modifying effect as intermediate interrupted alleles. © 2016 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Ming Zhang
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Zhengrui Xi
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Karen Misquitta
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Christine Sato
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Danielle Moreno
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Yan Liang
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth Slow
- Krembil Neuroscience Center, Movement Disorder's Clinic, Toronto Western Hospital, Ontario, Canada
| | - Ekaterina Rogaeva
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada.,Department of Medicine, Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Maria Carmela Tartaglia
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada.,Department of Medicine, Division of Neurology, University of Toronto, Toronto, Ontario, Canada.,Krembil Neuroscience Center, University Health Network Memory Clinic, Toronto Western Hospital, Ontario, Canada
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161
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Flores BN, Dulchavsky ME, Krans A, Sawaya MR, Paulson HL, Todd PK, Barmada SJ, Ivanova MI. Distinct C9orf72-Associated Dipeptide Repeat Structures Correlate with Neuronal Toxicity. PLoS One 2016; 11:e0165084. [PMID: 27776165 PMCID: PMC5077081 DOI: 10.1371/journal.pone.0165084] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/05/2016] [Indexed: 12/14/2022] Open
Abstract
Hexanucleotide repeat expansions in C9orf72 are the most common inherited cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The expansions elicit toxicity in part through repeat-associated non-AUG (RAN) translation of the intronic (GGGGCC)n sequence into dipeptide repeat-containing proteins (DPRs). Little is known, however, about the structural characteristics and aggregation propensities of the dipeptide units comprising DPRs. To address this question, we synthesized dipeptide units corresponding to the three sense-strand RAN translation products, analyzed their structures by circular dichroism, electron microscopy and dye binding assays, and assessed their relative toxicity when applied to primary cortical neurons. Short, glycine-arginine (GR)3 dipeptides formed spherical aggregates and selectively reduced neuronal survival compared to glycine-alanine (GA)3 and glycine-proline (GP)3 dipeptides. Doubling peptide length had little effect on the structure of GR or GP peptides, but (GA)6 peptides formed β-sheet rich aggregates that bound thioflavin T and Congo red yet lacked the typical fibrillar morphology of amyloids. Aging of (GA)6 dipeptides increased their β-sheet content and enhanced their toxicity when applied to neurons. We also observed that the relative toxicity of each tested dipeptide was proportional to peptide internalization. Our results demonstrate that different C9orf72-related dipeptides exhibit distinct structural properties that correlate with their relative toxicity.
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Affiliation(s)
- Brittany N. Flores
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Mark E. Dulchavsky
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Amy Krans
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Michael R. Sawaya
- UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles, California, United States of America
| | - Henry L. Paulson
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Peter K. Todd
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Veterans Affairs Medical Center, Ann Arbor, Michigan, United States of America
| | - Sami J. Barmada
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (MII); (SJB)
| | - Magdalena I. Ivanova
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America
- Biophysics Program, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (MII); (SJB)
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162
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Vatsavayai SC, Yoon SJ, Gardner RC, Gendron TF, Vargas JNS, Trujillo A, Pribadi M, Phillips JJ, Gaus SE, Hixson JD, Garcia PA, Rabinovici GD, Coppola G, Geschwind DH, Petrucelli L, Miller BL, Seeley WW. Timing and significance of pathological features in C9orf72 expansion-associated frontotemporal dementia. Brain 2016; 139:3202-3216. [PMID: 27797809 DOI: 10.1093/brain/aww250] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/21/2016] [Accepted: 08/16/2016] [Indexed: 12/12/2022] Open
Abstract
SEE SCABER AND TALBOT DOI101093/AWW264 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: A GGGGCC repeat expansion in C9orf72 leads to frontotemporal dementia and/or amyotrophic lateral sclerosis. Diverse pathological features have been identified, and their disease relevance remains much debated. Here, we describe two illuminating patients with frontotemporal dementia due to the C9orf72 repeat expansion. Case 1 was a 65-year-old female with behavioural variant frontotemporal dementia accompanied by focal degeneration in subgenual anterior cingulate cortex, amygdala, and medial pulvinar thalamus. At autopsy, widespread RNA foci and dipeptide repeat protein inclusions were observed, but TDP-43 pathology was nearly absent, even in degenerating brain regions. Case 2 was a 74-year-old female with atypical frontotemporal dementia-motor neuron disease who underwent temporal lobe resection for epilepsy 5 years prior to her first frontotemporal dementia symptoms. Archival surgical resection tissue contained RNA foci, dipeptide repeat protein inclusions, and loss of nuclear TDP-43 but no TDP-43 inclusions despite florid TDP-43 inclusions at autopsy 8 years after first symptoms. These findings suggest that C9orf72-specific phenomena may impact brain structure and function and emerge before first symptoms and TDP-43 aggregation.
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Affiliation(s)
- Sarat C Vatsavayai
- 1 Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94158, USA
| | - Soo Jin Yoon
- 2 Department of Neurology, Eulji University Hospital, Eulji University School of Medicine, Daejeon 35233, South Korea
| | - Raquel C Gardner
- 1 Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94158, USA
| | - Tania F Gendron
- 3 Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224, USA
| | - Jose Norberto S Vargas
- 1 Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94158, USA
| | - Andrew Trujillo
- 1 Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94158, USA
| | - Mochtar Pribadi
- 4 Department of Neurology and Department of Psychiatry, Semel Institute for Neuroscience and Human Behaviour, University of California, Los Angeles, CA 90095, USA
| | - Joanna J Phillips
- 5 Department of Pathology and Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Stephanie E Gaus
- 1 Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94158, USA
| | - John D Hixson
- 6 Epilepsy Center, Department of Neurology, University of California San Francisco, CA 94143, USA
| | - Paul A Garcia
- 6 Epilepsy Center, Department of Neurology, University of California San Francisco, CA 94143, USA
| | - Gil D Rabinovici
- 1 Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94158, USA
| | - Giovanni Coppola
- 4 Department of Neurology and Department of Psychiatry, Semel Institute for Neuroscience and Human Behaviour, University of California, Los Angeles, CA 90095, USA
| | - Daniel H Geschwind
- 4 Department of Neurology and Department of Psychiatry, Semel Institute for Neuroscience and Human Behaviour, University of California, Los Angeles, CA 90095, USA
| | - Leonard Petrucelli
- 3 Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224, USA
| | - Bruce L Miller
- 1 Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94158, USA
| | - William W Seeley
- 1 Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA 94158, USA .,7 Department of Pathology, University of California, San Francisco, CA 94143, USA
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163
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Wen X, Westergard T, Pasinelli P, Trotti D. Pathogenic determinants and mechanisms of ALS/FTD linked to hexanucleotide repeat expansions in the C9orf72 gene. Neurosci Lett 2016; 636:16-26. [PMID: 27619540 DOI: 10.1016/j.neulet.2016.09.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 07/12/2016] [Accepted: 09/06/2016] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are two apparently distinct neurodegenerative diseases, the former characterized by selective loss of motor neurons in the brain and spinal cord and the latter characterized by selective atrophy of frontal and temporal lobes. Over the years, however, growing evidence from clinical, pathological and genetic findings has suggested that ALS and FTD belong to the same clinic-pathological spectrum disorder. This concept has been further supported by the identification of the most common genetic cause for both diseases, an aberrantly expanded hexanucleotide repeat GGGGCC/ CCCCGG sequence located in a non-coding region of the gene C9orf72. Three hypotheses have been proposed to explain how this repeats expansion causes diseases: 1) C9orf72 haploinsufficiency-expanded repeats interfere with transcription or translation of the gene, leading to decreased expression of the C9orf72 protein; 2) RNA gain of function-RNA foci formed by sense and antisense transcripts of expanded repeats interact and sequester essential RNA binding proteins, causing neurotoxicity; 3) Repeat associated non-ATG initiated (RAN) translation of expanded sense GGGGCC and antisense CCCCGG repeats produces potential toxic dipeptide repeat protein (DPR). In this review, we assess current evidence supporting or arguing against each proposed mechanism in C9 ALS/FTD disease pathogenesis. Additionally, controversial findings are also discussed. Lastly, we discuss the possibility that the three pathogenic mechanisms are not mutually exclusive and all three might be involved in disease.
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Affiliation(s)
- Xinmei Wen
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - Thomas Westergard
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Piera Pasinelli
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Davide Trotti
- Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA 19107, USA
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164
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Ferguson R, Serafeimidou-Pouliou E, Subramanian V. Dynamic expression of the mouse orthologue of the human amyotropic lateral sclerosis associated gene C9orf72 during central nervous system development and neuronal differentiation. J Anat 2016; 229:871-891. [PMID: 27476503 DOI: 10.1111/joa.12526] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2016] [Indexed: 12/12/2022] Open
Abstract
The hexanucleotide repeat in the first intron of the C9orf72 gene is the most significant cause of amyotropic lateral sclerosis as well as some forms of fronto-temporal dementia. The C9orf72 protein has been previously reported to be expressed in post-mortem human brain as well as in late embryonic and some postnatal stages in mice. Herein, we present a detailed study of the distribution of C9orf72 protein in the embryonic, postnatal and adult mouse brain, spinal cord as well as during the differentiation of P19 embryonal carcinoma cells to neurons including motor neurons. We show that the expression levels of the C9orf72 transcripts in the developing and adult mouse brain as well as in differentiating neurons, are dynamic. Besides the strong expression in the cerebellum and motor cortex reported previously, we show for the first time that C9orf72 is expressed strongly in the olfactory bulb and also in the hippocampus. Our immunostaining data also reveal a hitherto unreported switch in the cellular distribution of C9orf72 from a predominantly cytoplasmic to a nucleo-cytoplasmic distribution during corticogenesis. This switch in distribution was also observed during differentiation of the pluripotent embryonal carcinoma P19 cell line to mature neurons. Our findings have implications for interpreting the pathophysiology caused by the repeat expansions in C9orf72 in mouse models.
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Affiliation(s)
- Ross Ferguson
- Department of Biology and Biochemistry, University of Bath, BA2 7AY, Bath, UK
| | | | - Vasanta Subramanian
- Department of Biology and Biochemistry, University of Bath, BA2 7AY, Bath, UK
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165
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Jovičić A, Paul JW, Gitler AD. Nuclear transport dysfunction: a common theme in amyotrophic lateral sclerosis and frontotemporal dementia. J Neurochem 2016; 138 Suppl 1:134-44. [PMID: 27087014 DOI: 10.1111/jnc.13642] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/03/2016] [Accepted: 04/08/2016] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are neurodegenerative diseases with overlapping genetic factors and pathology. On the cellular level, a majority of ALS and FTD cases are characterized by nuclear clearance and cytoplasmic aggregation of otherwise nuclear proteins, TAR DNA-binding protein 43 (TDP-43), or fused in sarcoma. Recent studies investigating cellular pathways perturbed by genetic risk factors for ALS/FTD converge on nucleocytoplasmic transport dysfunction as a mechanism leading to disease pathophysiology. We propose that mutations in FUS and hexanucleotide expansions in C9orf72 and aging all converge on the impairment of nucleocytoplasmic transport, which results in the hallmark pathological feature of ALS/FTD - cytoplasmic aggregation of TDP-43 or FUS.
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Affiliation(s)
- Ana Jovičić
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Joseph W Paul
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
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166
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Todd TW, Petrucelli L. Insights into the pathogenic mechanisms of Chromosome 9 open reading frame 72 (C9orf72) repeat expansions. J Neurochem 2016; 138 Suppl 1:145-62. [PMID: 27016280 DOI: 10.1111/jnc.13623] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/04/2016] [Accepted: 03/21/2016] [Indexed: 12/12/2022]
Abstract
The identification of a hexanucleotide repeat expansion in a non-coding region of C9orf72 as a major cause of both frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) drastically changed the field of research on both of these conditions. Yet, despite the vast amount of work aimed at elucidating the molecular mechanisms underlying the role of this repeat in disease, the exact pathomechanisms are still unclear. A reduction in the expression of the C9orf72 gene is observed in patients, but a gain-of-function model is now preferred. The hexanucleotide repeat expansion forms RNA foci in the central nervous system (CNS) of repeat-positive FTD and ALS patients, and these foci are believed to sequester RNA-binding proteins (RBPs) and impair their function in RNA processing. At the same time, the repeat undergoes repeat-associated non-ATG translation to produce dipeptide repeat proteins that also form inclusions in the patient CNS. Studies from cells and flies suggest that these proteins may also be an important factor in the disease. Finally, the hexanucleotide repeat also induces the mislocalization and aggregation of TAR DNA-binding protein 43 (TDP-43) through an as yet unknown mechanism. This review covers the different potential pathogenic factors that have been put forth for C9orf72-repeat-associated FTD and ALS (C9-FTD/ALS), while highlighting some remaining questions. A repeat expansion in C9orf72 is a common cause of both frontal temporal dementia and amyotrophic lateral sclerosis. Although there is a decrease in C9orf72 expression in patients, this repeat is believed to induce disease primarily through an unknown gain-of-function mechanism involving the RNA, repeat-associated non-AUG translation, or both. This review summarizes and discusses current knowledge on C9orf72 repeat-associated pathophysiology. This article is part of the Frontotemporal Dementia special issue.
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Affiliation(s)
- Tiffany W Todd
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
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167
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Mackenzie IRA, Neumann M. Molecular neuropathology of frontotemporal dementia: insights into disease mechanisms from postmortem studies. J Neurochem 2016; 138 Suppl 1:54-70. [PMID: 27306735 DOI: 10.1111/jnc.13588] [Citation(s) in RCA: 221] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/12/2016] [Accepted: 02/16/2016] [Indexed: 12/13/2022]
Abstract
Frontotemporal dementia (FTD) is a clinical syndrome with a heterogeneous molecular basis. The past decade has seen the discovery of several new FTD-causing genetic mutations and the identification of many of the relevant pathological proteins. The current neuropathological classification is based on the predominant protein abnormality and allows most cases of FTD to be placed into one of three broad molecular subgroups; frontotemporal lobar degeneration with tau, TDP-43 or FET protein accumulation. This review will describe our current understanding of the molecular basis of FTD, focusing on insights gained from the study of human postmortem tissue, as well as some of the current controversies. Most cases of FTD can be subclassified into one of three broad molecular subgroups based on the predominant protein that accumulates as pathological cellular inclusions. Understanding the associated pathogenic mechanisms and recognizing these FTD molecular subtypes in vivo will likely be crucial for the development and use of targeted therapies. This article is part of the Frontotemporal Dementia special issue.
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Affiliation(s)
- Ian R A Mackenzie
- Department of Pathology, University of British Columbia and Vancouver General Hospital, Vancouver, Canada
| | - Manuela Neumann
- Department of Neuropathology, University of Tübingen and German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
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168
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Tsai RM, Boxer AL. Therapy and clinical trials in frontotemporal dementia: past, present, and future. J Neurochem 2016; 138 Suppl 1:211-21. [PMID: 27306957 DOI: 10.1111/jnc.13640] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/06/2016] [Accepted: 04/08/2016] [Indexed: 12/12/2022]
Abstract
Frontotemporal dementia (FTD) is a common form of dementia with heterogeneous clinical presentations and distinct clinical syndromes. This article will review currently available therapies for FTD, its related disorders and their clinical evidence. It will also discuss recent advancements in FTD pathophysiology, treatment development, biomarker advancement and their relation to recently completed or currently ongoing clinical trials as well as future implications. Frontotemporal dementia (FTD) is a type of dementia with distinct clinical syndromes. Current treatments involve off-label use of medications for symptomatic management and cannot modify disease course. Advancements in FTD pathophysiology, genetics, and biomarkers have led to development of small molecules targeting the underlying pathology in hopes of achieving a disease-modifying effect. This article will review current therapies for FTD, discuss advancements in FTD pathophysiology, therapy development, biomarker advancement, their relation to recent clinical trials and future implications. This article is part of the Frontotemporal Dementia special issue.
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Affiliation(s)
- Richard M Tsai
- Assistant Adjunct Professor of Neurology, University of California San Francisco Department of Neurology, San Francisco, California, USA
| | - Adam L Boxer
- Associate Professor of Neurology, University of California San Francisco Department of Neurology, San Francisco, California, USA
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169
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Alsultan AA, Waller R, Heath PR, Kirby J. The genetics of amyotrophic lateral sclerosis: current insights. Degener Neurol Neuromuscul Dis 2016; 6:49-64. [PMID: 30050368 PMCID: PMC6053097 DOI: 10.2147/dnnd.s84956] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that results in loss of the upper and lower motor neurons from motor cortex, brainstem, and spinal cord. While the majority of cases are sporadic, approximately 10% show familial inheritance. ALS is usually inherited in an autosomal dominant manner, although autosomal recessive and X-linked inheritance do occur. To date, 24 of the genes at 26 loci have been identified; these include loci linked to ALS and to frontotemporal dementia-ALS, where family pedigrees contain individuals with frontotemporal dementia with/without ALS. The most commonly established genetic causes of familial ALS (FALS) to date are the presence of a hexanucleotide repeat expansion in the C9ORF72 gene (39.3% FALS) and mutation of SOD1, TARDBP, and FUS, with frequencies of 12%-23.5%, 5%, and 4.1%, respectively. However, with the increasing use of next-generation sequencing of small family pedigrees, this has led to an increasing number of genes being associated with ALS. This review provides a comprehensive review on the genetics of ALS and an update of the pathogenic mechanisms associated with these genes. Commonly implicated pathways have been established, including RNA processing, the protein degradation pathways of autophagy and ubiquitin-proteasome system, as well as protein trafficking and cytoskeletal function. Elucidating the role genetics plays in both FALS and sporadic ALS is essential for understanding the subsequent cellular dysregulation that leads to motor neuron loss, in order to develop future effective therapeutic strategies.
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Affiliation(s)
- Afnan A Alsultan
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK,
| | - Rachel Waller
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK,
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK,
| | - Janine Kirby
- Sheffield Institute for Translational Neuroscience (SITraN), Department of Neuroscience, University of Sheffield, Sheffield, UK,
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170
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Richards RI, Robertson SA, O'Keefe LV, Fornarino D, Scott A, Lardelli M, Baune BT. The Enemy within: Innate Surveillance-Mediated Cell Death, the Common Mechanism of Neurodegenerative Disease. Front Neurosci 2016; 10:193. [PMID: 27242399 PMCID: PMC4862319 DOI: 10.3389/fnins.2016.00193] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 04/18/2016] [Indexed: 12/16/2022] Open
Abstract
Neurodegenerative diseases comprise an array of progressive neurological disorders all characterized by the selective death of neurons in the central nervous system. Although, rare (familial) and common (sporadic) forms can occur for the same disease, it is unclear whether this reflects several distinct pathogenic pathways or the convergence of different causes into a common form of nerve cell death. Remarkably, neurodegenerative diseases are increasingly found to be accompanied by activation of the innate immune surveillance system normally associated with pathogen recognition and response. Innate surveillance is the cell's quality control system for the purpose of detecting such danger signals and responding in an appropriate manner. Innate surveillance is an "intelligent system," in that the manner of response is relevant to the magnitude and duration of the threat. If possible, the threat is dealt with within the cell in which it is detected, by degrading the danger signal(s) and restoring homeostasis. If this is not successful then an inflammatory response is instigated that is aimed at restricting the spread of the threat by elevating degradative pathways, sensitizing neighboring cells, and recruiting specialized cell types to the site. If the danger signal persists, then the ultimate response can include not only the programmed cell death of the original cell, but the contents of this dead cell can also bring about the death of adjacent sensitized cells. These responses are clearly aimed at destroying the ability of the detected pathogen to propagate and spread. Innate surveillance comprises intracellular, extracellular, non-cell autonomous and systemic processes. Recent studies have revealed how multiple steps in these processes involve proteins that, through their mutation, have been linked to many familial forms of neurodegenerative disease. This suggests that individuals harboring these mutations may have an amplified response to innate-mediated damage in neural tissues, and renders innate surveillance mediated cell death a plausible common pathogenic pathway responsible for neurodegenerative diseases, in both familial and sporadic forms. Here we have assembled evidence in favor of the hypothesis that neurodegenerative disease is the cumulative result of chronic activation of the innate surveillance pathway, triggered by endogenous or environmental danger or damage associated molecular patterns in a progressively expanding cascade of inflammation, tissue damage and cell death.
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Affiliation(s)
- Robert I Richards
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Sarah A Robertson
- School of Paediatrics and Reproductive Health, Robinson Research Institute, The University of Adelaide Adelaide, SA, Australia
| | - Louise V O'Keefe
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Dani Fornarino
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Andrew Scott
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Michael Lardelli
- Department of Genetics and Evolution, Centre for Molecular Pathology, School of Biological Sciences, The University of Adelaide Adelaide, SA, Australia
| | - Bernhard T Baune
- School of Medicine, Discipline of Psychiatry, The University of Adelaide Adelaide, SA, Australia
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171
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Jiang J, Zhu Q, Gendron TF, Saberi S, McAlonis-Downes M, Seelman A, Stauffer JE, Jafar-Nejad P, Drenner K, Schulte D, Chun S, Sun S, Ling SC, Myers B, Engelhardt J, Katz M, Baughn M, Platoshyn O, Marsala M, Watt A, Heyser CJ, Ard MC, De Muynck L, Daughrity LM, Swing DA, Tessarollo L, Jung CJ, Delpoux A, Utzschneider DT, Hedrick SM, de Jong PJ, Edbauer D, Van Damme P, Petrucelli L, Shaw CE, Bennett CF, Da Cruz S, Ravits J, Rigo F, Cleveland DW, Lagier-Tourenne C. Gain of Toxicity from ALS/FTD-Linked Repeat Expansions in C9ORF72 Is Alleviated by Antisense Oligonucleotides Targeting GGGGCC-Containing RNAs. Neuron 2016; 90:535-50. [PMID: 27112497 PMCID: PMC4860075 DOI: 10.1016/j.neuron.2016.04.006] [Citation(s) in RCA: 384] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/29/2016] [Accepted: 04/04/2016] [Indexed: 12/13/2022]
Abstract
Hexanucleotide expansions in C9ORF72 are the most frequent genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Disease mechanisms were evaluated in mice expressing C9ORF72 RNAs with up to 450 GGGGCC repeats or with one or both C9orf72 alleles inactivated. Chronic 50% reduction of C9ORF72 did not provoke disease, while its absence produced splenomegaly, enlarged lymph nodes, and mild social interaction deficits, but not motor dysfunction. Hexanucleotide expansions caused age-, repeat-length-, and expression-level-dependent accumulation of RNA foci and dipeptide-repeat proteins synthesized by AUG-independent translation, accompanied by loss of hippocampal neurons, increased anxiety, and impaired cognitive function. Single-dose injection of antisense oligonucleotides (ASOs) that target repeat-containing RNAs but preserve levels of mRNAs encoding C9ORF72 produced sustained reductions in RNA foci and dipeptide-repeat proteins, and ameliorated behavioral deficits. These efforts identify gain of toxicity as a central disease mechanism caused by repeat-expanded C9ORF72 and establish the feasibility of ASO-mediated therapy.
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Affiliation(s)
- Jie Jiang
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Qiang Zhu
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Tania F Gendron
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Shahram Saberi
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Melissa McAlonis-Downes
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Amanda Seelman
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jennifer E Stauffer
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Kevin Drenner
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Derek Schulte
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Seung Chun
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Shuying Sun
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shuo-Chien Ling
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Physiology, National University of Singapore, 12 Science Drive 2, Singapore 117549, Singapore
| | - Brian Myers
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Melanie Katz
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Michael Baughn
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Oleksandr Platoshyn
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA; Neuroregeneration Laboratory, Sanford Consortium for Regenerative Medicine, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA
| | - Martin Marsala
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA; Neuroregeneration Laboratory, Sanford Consortium for Regenerative Medicine, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA; Institute of Neurobiology, Slovak Academy of Sciences, Soltesovej 9, 04001 Kosice, Slovakia
| | - Andy Watt
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Charles J Heyser
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - M Colin Ard
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Louis De Muynck
- Laboratory of Neurobiology, Vesalius Research Center, Experimental Neurology, Department of Neurosciences, KU Leuven/VIB, 3000 Leuven, Belgium; Department of Neurology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Lillian M Daughrity
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Deborah A Swing
- Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Lino Tessarollo
- Mouse Cancer Genetics Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Chris J Jung
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way, Oakland, CA 94609, USA
| | - Arnaud Delpoux
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel T Utzschneider
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stephen M Hedrick
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Pieter J de Jong
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way, Oakland, CA 94609, USA
| | - Dieter Edbauer
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Maximilians University and Munich Cluster of Systems Neurology (SyNergy), Feodor-Lynen Strasse 17, 81377 Munich, Germany
| | - Philip Van Damme
- Laboratory of Neurobiology, Vesalius Research Center, Experimental Neurology, Department of Neurosciences, KU Leuven/VIB, 3000 Leuven, Belgium; Department of Neurology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | | | - C Frank Bennett
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Sandrine Da Cruz
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - John Ravits
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Don W Cleveland
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Clotilde Lagier-Tourenne
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.
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172
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Zhang YJ, Gendron TF, Grima JC, Sasaguri H, Jansen-West K, Xu YF, Katzman RB, Gass J, Murray ME, Shinohara M, Lin WL, Garrett A, Stankowski JN, Daughrity L, Tong J, Perkerson EA, Yue M, Chew J, Castanedes-Casey M, Kurti A, Wang ZS, Liesinger AM, Baker JD, Jiang J, Lagier-Tourenne C, Edbauer D, Cleveland DW, Rademakers R, Boylan KB, Bu G, Link CD, Dickey CA, Rothstein JD, Dickson DW, Fryer JD, Petrucelli L. C9ORF72 poly(GA) aggregates sequester and impair HR23 and nucleocytoplasmic transport proteins. Nat Neurosci 2016; 19:668-677. [PMID: 26998601 PMCID: PMC5138863 DOI: 10.1038/nn.4272] [Citation(s) in RCA: 241] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 02/17/2016] [Indexed: 12/13/2022]
Abstract
Neuronal inclusions of poly(GA), a protein unconventionally translated from G4C2 repeat expansions in C9ORF72, are abundant in patients with frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) caused by this mutation. To investigate poly(GA) toxicity, we generated mice that exhibit poly(GA) pathology, neurodegeneration and behavioral abnormalities reminiscent of FTD and ALS. These phenotypes occurred in the absence of TDP-43 pathology and required poly(GA) aggregation. HR23 proteins involved in proteasomal degradation and proteins involved in nucleocytoplasmic transport were sequestered by poly(GA) in these mice. HR23A and HR23B similarly colocalized to poly(GA) inclusions in C9ORF72 expansion carriers. Sequestration was accompanied by an accumulation of ubiquitinated proteins and decreased xeroderma pigmentosum C (XPC) levels in mice, indicative of HR23A and HR23B dysfunction. Restoring HR23B levels attenuated poly(GA) aggregation and rescued poly(GA)-induced toxicity in neuronal cultures. These data demonstrate that sequestration and impairment of nuclear HR23 and nucleocytoplasmic transport proteins is an outcome of, and a contributor to, poly(GA) pathology.
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Affiliation(s)
- Yong-Jie Zhang
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Tania F Gendron
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Jonathan C Grima
- Department of Neurology, School of Medicine, Johns Hopkins University, Maryland, USA
- Brain Science Institute, School of Medicine, Johns Hopkins University, Maryland, USA
- Department of Neuroscience, School of Medicine, Johns Hopkins University, Maryland, USA
| | - Hiroki Sasaguri
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | | | - Ya-Fei Xu
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | | | - Jennifer Gass
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Melissa E Murray
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | | | - Wen-Lang Lin
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Aliesha Garrett
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | | | | | - Jimei Tong
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | | | - Mei Yue
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Jeannie Chew
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
- Neurobiology of Disease Graduate Program, Mayo Graduate School, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | | | - Aishe Kurti
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Zizhao S Wang
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | | | - Jeremy D Baker
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, Florida, USA
| | - Jie Jiang
- Ludwig Institute, University of California at San Diego, La Jolla, California, USA
| | | | - Dieter Edbauer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Institute for Metabolic Biochemistry, Ludwig Maximilians University Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Don W Cleveland
- Ludwig Institute, University of California at San Diego, La Jolla, California, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California, USA
| | - Rosa Rademakers
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Kevin B Boylan
- Department of Neurology, Mayo Clinic, Jacksonville, Florida, USA
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - Christopher D Link
- Integrative Physiology, Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado, USA
| | - Chad A Dickey
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, Florida, USA
| | - Jeffrey D Rothstein
- Department of Neurology, School of Medicine, Johns Hopkins University, Maryland, USA
- Brain Science Institute, School of Medicine, Johns Hopkins University, Maryland, USA
- Department of Neuroscience, School of Medicine, Johns Hopkins University, Maryland, USA
| | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
| | - John D Fryer
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA
- Neurobiology of Disease Graduate Program, Mayo Graduate School, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
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173
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Chi S, Jiang T, Tan L, Yu JT. Distinct neurological disorders with C9orf72 mutations: genetics, pathogenesis, and therapy. Neurosci Biobehav Rev 2016; 66:127-42. [PMID: 27139021 DOI: 10.1016/j.neubiorev.2016.03.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 03/24/2016] [Accepted: 03/25/2016] [Indexed: 12/12/2022]
Abstract
The G4C2 repeat expansion within C9orf72 has been recently identified as the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. This mutation has also been detected in a variety of other neurological diseases with distinct clinical manifestations. The exact mechanisms of how this mutation leads to the wide spectrum of clinical syndromes remain unknown. A series of molecular changes together with some potential modifiers may play a key role. Nucleolar stress, nucleocytoplasmic transport defect, oxidative damage, inhibited stress granules assembly, activated endoplasmic reticulum stress, and inhibited proteasome activity are mechanisms that contribute to the pathogenesis of these diseases. Additional mutations, epigenetic modifiers, and repeat size are potential modifiers that modulate specific phenotypes on the basis of the molecular changes. Here, we summarize distinct C9orf72-related neurological disorders and their corresponding neuropathological changes. Then, we elucidate the existing molecular knowledge and the potential modifiers. Finally, we detail the main target of treatment aiming at controlling expanded RNA transcripts.
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Affiliation(s)
- Song Chi
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, Shandong, China; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China
| | - Teng Jiang
- Department of Neurology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China.
| | - Jin-Tai Yu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China.
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174
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Green KM, Linsalata AE, Todd PK. RAN translation-What makes it run? Brain Res 2016; 1647:30-42. [PMID: 27060770 DOI: 10.1016/j.brainres.2016.04.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/24/2016] [Accepted: 04/01/2016] [Indexed: 12/14/2022]
Abstract
Nucleotide-repeat expansions underlie a heterogeneous group of neurodegenerative and neuromuscular disorders for which there are currently no effective therapies. Recently, it was discovered that such repetitive RNA motifs can support translation initiation in the absence of an AUG start codon across a wide variety of sequence contexts, and that the products of these atypical translation initiation events contribute to neuronal toxicity. This review examines what we currently know and do not know about repeat associated non-AUG (RAN) translation in the context of established canonical and non-canonical mechanisms of translation initiation. We highlight recent findings related to RAN translation in three repeat expansion disorders: CGG repeats in fragile X-associated tremor ataxia syndrome (FXTAS), GGGGCC repeats in C9orf72 associated amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) and CAG repeats in Huntington disease. These studies suggest that mechanistic differences may exist for RAN translation dependent on repeat type, repeat reading frame, and the surrounding sequence context, but that for at least some repeats, RAN translation retains a dependence on some of the canonical translational initiation machinery. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease.
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Affiliation(s)
- Katelyn M Green
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States; Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Alexander E Linsalata
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States; Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Peter K Todd
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States; Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI, United States; Veterans Affairs Medical Center, Ann Arbor, MI, United States.
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175
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Gitler AD, Tsuiji H. There has been an awakening: Emerging mechanisms of C9orf72 mutations in FTD/ALS. Brain Res 2016; 1647:19-29. [PMID: 27059391 DOI: 10.1016/j.brainres.2016.04.004] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 03/30/2016] [Accepted: 04/03/2016] [Indexed: 12/13/2022]
Abstract
The discovery of C9orf72 mutations as the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) has awakened a surge of interest in deciphering how mutations in this mysterious gene cause disease and what can be done to stop it. C9orf72 harbors a hexanucleotide repeat, GGGGCC, in a non-coding region of the gene and a massive expansion of this repeat causes ALS, FTD, or both (FTD/ALS). Many questions lie ahead. What does this gene normally do? What is the consequence of an enormous GGGGCC repeat expansion on that gene's function? Could that hexanucleotide repeat expansion have additional pathological actions unrelated to C9orf72 function? There has been tremendous progress on all fronts in the quest to define how C9orf72 mutations cause disease. Many new experimental models have been constructed and unleashed in powerful genetic screens. Studies in mouse and human patient samples, including iPS-derived neurons, have provided unprecedented insights into pathogenic mechanisms. Three major hypotheses have emerged and are still being hotly debated in the field. These include (1) loss of function owing to decrease in the abundance of C9orf72 protein and its ability to carryout its still unknown cellular role; (2) RNA toxicity from bidirectionally transcribed sense (GGGGCC) and antisense (GGCCCC) transcripts that accumulate in RNA foci and might sequester critical RNA-binding proteins; (3) proteotoxicity from dipeptide repeat proteins produced by an unconventional form of translation from the expanded nucleotide repeats. Here we review the evidence in favor and against each of these three hypotheses. We also suggest additional experiments and considerations that we propose will help clarify which mechanism(s) are most important for driving disease and therefore most critical for considering during the development of therapeutic interventions. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease.
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Affiliation(s)
- Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, 300 Pasteur Drive, M322 Alway Building, Stanford, CA 94305, USA.
| | - Hitomi Tsuiji
- Department of Biomedical Science, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori, Mizuhoku, Nagoya, Aichi 467-8603, Japan.
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176
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Davidson Y, Robinson AC, Liu X, Wu D, Troakes C, Rollinson S, Masuda-Suzukake M, Suzuki G, Nonaka T, Shi J, Tian J, Hamdalla H, Ealing J, Richardson A, Jones M, Pickering-Brown S, Snowden JS, Hasegawa M, Mann DMA. Neurodegeneration in frontotemporal lobar degeneration and motor neurone disease associated with expansions in C9orf72 is linked to TDP-43 pathology and not associated with aggregated forms of dipeptide repeat proteins. Neuropathol Appl Neurobiol 2015; 42:242-54. [PMID: 26538301 PMCID: PMC4832296 DOI: 10.1111/nan.12292] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 10/26/2015] [Accepted: 10/26/2015] [Indexed: 12/13/2022]
Abstract
Aims A hexanucleotide expansion in C9orf72 is the major genetic cause of inherited behavioural variant Frontotemporal dementia (bvFTD) and motor neurone disease (MND), although the pathological mechanism(s) underlying disease remains uncertain. Methods Using antibodies to poly‐GA, poly‐GP, poly‐GR, poly‐AP and poly‐PR proteins, we examined sections of cerebral cortex, hippocampus, thalamus, cerebellum and spinal cord, from 20 patients with bvFTD and/or MND bearing an expansion in C9orf72 for aggregated deposits of dipeptide repeat proteins (DPR). Results Antibodies to poly‐GA, poly‐GP and poly‐GR detected numerous rounded cytoplasmic inclusions (NCI) within granule cells of hippocampal dentate gyrus and those of the cerebellum, as well as ‘star‐burst’ shaped NCI in pyramidal neurones of CA3/4 region of hippocampus. NCI were uncommon in Purkinje cells, and only very rarely seen in anterior horn cells. Poly‐PA antibody detected occasional NCI within CA3/4 neurones alone, whereas poly‐PR antibody did not identify any NCI but immunostained the nucleus of anterior horn cells, CA3/4 neurones and Purkinje cells, in patients with or without expansion in C9orf72, as well as in normal controls. Poly‐GA antibody generally detected more DPR than poly‐GP, which in turn was greater than poly‐GR. All patients with bvFTD + MND or MND showed plentiful p62/TDP‐43 positive inclusions in remaining anterior horn cells. Conclusion Degeneration and loss of anterior horn cells associated with expansions in C9orf72 occurs in the absence of DPR, and implies that changes involving loss of nuclear staining for and a cytoplasmic aggregation of TDP‐43 are more likely to be the cause of this.
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Affiliation(s)
- Y Davidson
- Clinical and Cognitive Sciences Research Group, Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford, UK
| | - A C Robinson
- Clinical and Cognitive Sciences Research Group, Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford, UK
| | - X Liu
- Clinical and Cognitive Sciences Research Group, Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford, UK.,Beijing University of Chinese Medicine, Dongzhimen Hospital, Beijing, China
| | - D Wu
- Clinical and Cognitive Sciences Research Group, Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford, UK.,Beijing University of Chinese Medicine, Dongzhimen Hospital, Beijing, China
| | - C Troakes
- London Neurodegenerative Diseases Brain Bank, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - S Rollinson
- Clinical and Cognitive Sciences Research Group, Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
| | - M Masuda-Suzukake
- Department of Neuropathology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - G Suzuki
- Department of Neuropathology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - T Nonaka
- Department of Neuropathology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - J Shi
- Beijing University of Chinese Medicine, Dongzhimen Hospital, Beijing, China
| | - J Tian
- Beijing University of Chinese Medicine, Dongzhimen Hospital, Beijing, China
| | - H Hamdalla
- Manchester MND Care Centre, Salford Royal Hospital, Manchester, UK
| | - J Ealing
- Manchester MND Care Centre, Salford Royal Hospital, Manchester, UK
| | - A Richardson
- Cerebral Function Unit, Salford Royal Hospital, Manchester, UK
| | - M Jones
- Cerebral Function Unit, Salford Royal Hospital, Manchester, UK
| | - S Pickering-Brown
- Clinical and Cognitive Sciences Research Group, Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
| | - J S Snowden
- Clinical and Cognitive Sciences Research Group, Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford, UK.,Cerebral Function Unit, Salford Royal Hospital, Manchester, UK
| | - M Hasegawa
- Department of Neuropathology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - D M A Mann
- Clinical and Cognitive Sciences Research Group, Institute of Brain, Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, Salford Royal Hospital, Salford, UK
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177
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Neurodegenerative disease: C9orf72 repeats compromise nucleocytoplasmic transport. Nat Rev Neurol 2015; 11:670-2. [PMID: 26526532 DOI: 10.1038/nrneurol.2015.219] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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