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Niewiadomska-Cimicka A, Fievet L, Surdyka M, Jesion E, Keime C, Singer E, Eisenmann A, Kalinowska-Poska Z, Nguyen HHP, Fiszer A, Figiel M, Trottier Y. AAV-Mediated CAG-Targeting Selectively Reduces Polyglutamine-Expanded Protein and Attenuates Disease Phenotypes in a Spinocerebellar Ataxia Mouse Model. Int J Mol Sci 2024; 25:4354. [PMID: 38673939 PMCID: PMC11050704 DOI: 10.3390/ijms25084354] [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: 03/26/2024] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Polyglutamine (polyQ)-encoding CAG repeat expansions represent a common disease-causing mutation responsible for several dominant spinocerebellar ataxias (SCAs). PolyQ-expanded SCA proteins are toxic for cerebellar neurons, with Purkinje cells (PCs) being the most vulnerable. RNA interference (RNAi) reagents targeting transcripts with expanded CAG reduce the level of various mutant SCA proteins in an allele-selective manner in vitro and represent promising universal tools for treating multiple CAG/polyQ SCAs. However, it remains unclear whether the therapeutic targeting of CAG expansion can be achieved in vivo and if it can ameliorate cerebellar functions. Here, using a mouse model of SCA7 expressing a mutant Atxn7 allele with 140 CAGs, we examined the efficacy of short hairpin RNAs (shRNAs) targeting CAG repeats expressed from PHP.eB adeno-associated virus vectors (AAVs), which were introduced into the brain via intravascular injection. We demonstrated that shRNAs carrying various mismatches with the CAG target sequence reduced the level of polyQ-expanded ATXN7 in the cerebellum, albeit with varying degrees of allele selectivity and safety profile. An shRNA named A4 potently reduced the level of polyQ-expanded ATXN7, with no effect on normal ATXN7 levels and no adverse side effects. Furthermore, A4 shRNA treatment improved a range of motor and behavioral parameters 23 weeks after AAV injection and attenuated the disease burden of PCs by preventing the downregulation of several PC-type-specific genes. Our results show the feasibility of the selective targeting of CAG expansion in the cerebellum using a blood-brain barrier-permeable vector to attenuate the disease phenotype in an SCA mouse model. Our study represents a significant advancement in developing CAG-targeting strategies as a potential therapy for SCA7 and possibly other CAG/polyQ SCAs.
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Affiliation(s)
- Anna Niewiadomska-Cimicka
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| | - Lorraine Fievet
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| | - Magdalena Surdyka
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (M.S.); (E.J.); (Z.K.-P.); (M.F.)
| | - Ewelina Jesion
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (M.S.); (E.J.); (Z.K.-P.); (M.F.)
| | - Céline Keime
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| | - Elisabeth Singer
- Centre for Rare Diseases (ZSE), University of Tuebingen, 72076 Tuebingen, Germany;
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, 72076 Tuebingen, Germany
- Department of Human Genetics, Medical Faculty, Ruhr University Bochum, 44801 Bochum, Germany;
| | - Aurélie Eisenmann
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
| | - Zaneta Kalinowska-Poska
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (M.S.); (E.J.); (Z.K.-P.); (M.F.)
| | - Hoa Huu Phuc Nguyen
- Department of Human Genetics, Medical Faculty, Ruhr University Bochum, 44801 Bochum, Germany;
| | - Agnieszka Fiszer
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland;
| | - Maciej Figiel
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland; (M.S.); (E.J.); (Z.K.-P.); (M.F.)
| | - Yvon Trottier
- Institute of Genetics and Molecular and Cellular Biology, INSERM U1258, CNRS UMR7104, University of Strasbourg, 67404 Illkirch, France; (L.F.); (C.K.); (A.E.)
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2
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Pérot JB, Niewiadomska-Cimicka A, Brouillet E, Trottier Y, Flament J. Longitudinal MRI and 1H-MRS study of SCA7 mouse forebrain reveals progressive multiregional atrophy and early brain metabolite changes indicating early neuronal and glial dysfunction. PLoS One 2024; 19:e0296790. [PMID: 38227598 PMCID: PMC10790999 DOI: 10.1371/journal.pone.0296790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 12/19/2023] [Indexed: 01/18/2024] Open
Abstract
SpinoCerebellar Ataxia type 7 (SCA7) is an inherited disorder caused by CAG triplet repeats encoding polyglutamine expansion in the ATXN7 protein, which is part of the transcriptional coactivator complex SAGA. The mutation primarily causes neurodegeneration in the cerebellum and retina, as well as several forebrain structures. The SCA7140Q/5Q knock-in mouse model recapitulates key disease features, including loss of vision and motor performance. To characterize the temporal progression of brain degeneration of this model, we performed a longitudinal study spanning from early to late symptomatic stages using high-resolution magnetic resonance imaging (MRI) and in vivo 1H-magnetic resonance spectroscopy (1H-MRS). Compared to wild-type mouse littermates, MRI analysis of SCA7 mice shows progressive atrophy of defined brain structures, with the striatum, thalamus and cortex being the first and most severely affected. The volume loss of these structures coincided with increased motor impairments in SCA7 mice, suggesting an alteration of the sensory-motor network, as observed in SCA7 patients. MRI also reveals atrophy of the hippocampus and anterior commissure at mid-symptomatic stage and the midbrain and brain stem at late stage. 1H-MRS of hippocampus, a brain region previously shown to be dysfunctional in patients, reveals early and progressive metabolic alterations in SCA7 mice. Interestingly, abnormal glutamine accumulation precedes the hippocampal atrophy and the reduction in myo-inositol and total N-acetyl-aspartate concentrations, two markers of glial and neuronal damage, respectively. Together, our results indicate that non-cerebellar alterations and glial and neuronal metabolic impairments may play a crucial role in the development of SCA7 mouse pathology, particularly at early stages of the disease. Degenerative features of forebrain structures in SCA7 mice correspond to current observations made in patients. Our study thus provides potential biomarkers that could be used for the evaluation of future therapeutic trials using the SCA7140Q/5Q model.
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Affiliation(s)
- Jean-Baptiste Pérot
- Laboratoire des Maladies Neurodégénératives, Université Paris-Saclay, Commissariat à l’Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, Molecular Imaging Research Center, Fontenay-aux-Roses, 92260, France
- Institut du Cerveau–Paris Brain Institute–ICM, Sorbonne Université, Paris, 75013, France
| | - Anna Niewiadomska-Cimicka
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch, 67404, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, 67404, France
- Université de Strasbourg, Illkirch, 67404, France
| | - Emmanuel Brouillet
- Laboratoire des Maladies Neurodégénératives, Université Paris-Saclay, Commissariat à l’Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, Molecular Imaging Research Center, Fontenay-aux-Roses, 92260, France
| | - Yvon Trottier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 67404, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7104, Illkirch, 67404, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, 67404, France
- Université de Strasbourg, Illkirch, 67404, France
| | - Julien Flament
- Laboratoire des Maladies Neurodégénératives, Université Paris-Saclay, Commissariat à l’Energie Atomique et aux Energies Alternatives, Centre National de la Recherche Scientifique, Molecular Imaging Research Center, Fontenay-aux-Roses, 92260, France
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3
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Ciancimino C, Di Pippo M, Manco GA, Romano S, Ristori G, Scuderi G, Abdolrahimzadeh S. Multimodal Ophthalmic Imaging in Spinocerebellar Ataxia Type 7. Life (Basel) 2023; 13:2169. [PMID: 38004309 PMCID: PMC10672172 DOI: 10.3390/life13112169] [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: 09/30/2023] [Revised: 10/17/2023] [Accepted: 10/30/2023] [Indexed: 11/26/2023] Open
Abstract
The aim of this case series and narrative literature review is to highlight the importance of multimodal imaging in the ophthalmological examination of patients with spinocerebellar ataxia type 7 and provide a summary of the most relevant imaging techniques. Three patients with SCA7 were included in this case series. A literature review revealed twenty-one publications regarding ocular manifestations of SCA7, and the most relevant aspects are summarized. The role of different imaging techniques in the follow-up of SCA7 patients is analyzed, including color vision testing, corneal endothelial topography, color fundus photography (CFP) and autofluorescence, near infrared reflectance imaging, spectral domain optical coherence tomography (SDOCT), visual field examination, and electrophysiological tests. SDOCT provides a rapid and non-invasive imaging evaluation of disease progression over time. Additional examination including NIR imaging can provide further information on photoreceptor alteration and subtle disruption of the RPE, which are not evident with CFP at an early stage. Electrophysiological tests provide essential results on the state of cone and rod dystrophy, which could be paramount in guiding future genetic therapies. Multimodal imaging is a valuable addition to comprehensive ophthalmological examination in the diagnosis and management of patients with SCA7.
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Affiliation(s)
- Chiara Ciancimino
- Ophthalmology Unit, Department of Neurosciences, Mental Health and Sensory Organs (NESMOS), St. Andrea Hospital, “Sapienza” University of Rome, Via di Grottarossa 1035/1039, 00189 Rome, Italy; (C.C.); (M.D.P.); (G.A.M.); (S.A.)
| | - Mariachiara Di Pippo
- Ophthalmology Unit, Department of Neurosciences, Mental Health and Sensory Organs (NESMOS), St. Andrea Hospital, “Sapienza” University of Rome, Via di Grottarossa 1035/1039, 00189 Rome, Italy; (C.C.); (M.D.P.); (G.A.M.); (S.A.)
| | - Gregorio Antonio Manco
- Ophthalmology Unit, Department of Neurosciences, Mental Health and Sensory Organs (NESMOS), St. Andrea Hospital, “Sapienza” University of Rome, Via di Grottarossa 1035/1039, 00189 Rome, Italy; (C.C.); (M.D.P.); (G.A.M.); (S.A.)
| | - Silvia Romano
- Center for Experimental Neurological Therapies (CENTERS), Department of Neurosciences, Mental Health and Sensory Organs (NESMOS), St. Andrea Hospital, “Sapienza” University of Rome, Via di Grottarossa 1035/1039, 00189 Rome, Italy; (S.R.); (G.R.)
| | - Giovanni Ristori
- Center for Experimental Neurological Therapies (CENTERS), Department of Neurosciences, Mental Health and Sensory Organs (NESMOS), St. Andrea Hospital, “Sapienza” University of Rome, Via di Grottarossa 1035/1039, 00189 Rome, Italy; (S.R.); (G.R.)
- Neuroimmunology Unit, IRCCS Fondazione Santa Lucia, Via Ardeatina, 306/354, 00179 Rome, Italy
| | - Gianluca Scuderi
- Ophthalmology Unit, Department of Neurosciences, Mental Health and Sensory Organs (NESMOS), St. Andrea Hospital, “Sapienza” University of Rome, Via di Grottarossa 1035/1039, 00189 Rome, Italy; (C.C.); (M.D.P.); (G.A.M.); (S.A.)
| | - Solmaz Abdolrahimzadeh
- Ophthalmology Unit, Department of Neurosciences, Mental Health and Sensory Organs (NESMOS), St. Andrea Hospital, “Sapienza” University of Rome, Via di Grottarossa 1035/1039, 00189 Rome, Italy; (C.C.); (M.D.P.); (G.A.M.); (S.A.)
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Bartelt LC, Switonski PM, Adamek G, Carvalho J, Duvick LA, Jarrah SI, McLoughlin HS, Scoles DR, Pulst SM, Orr HT, Hull C, Lowe CB, La Spada AR. Purkinje-Enriched snRNA-seq in SCA7 Cerebellum Reveals Zebrin Identity Loss as a Central Feature of Polyglutamine Ataxias. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.19.533345. [PMID: 37214832 PMCID: PMC10197555 DOI: 10.1101/2023.03.19.533345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Spinocerebellar ataxia type 7 (SCA7) is an inherited neurodegenerative disorder caused by a CAG-polyglutamine repeat expansion. SCA7 patients display a striking loss of Purkinje cell (PC) neurons with disease progression; however, PCs are rare, making them difficult to characterize. We developed a PC nuclei enrichment protocol and applied it to single-nucleus RNA-seq of a SCA7 knock-in mouse model. Our results unify prior observations into a central mechanism of cell identity loss, impacting both glia and PCs, driving accumulation of inhibitory synapses and altered PC spiking. Zebrin-II subtype dysregulation is the predominant signal in PCs, leading to complete loss of zebrin-II striping at motor symptom onset in SCA7 mice. We show this zebrin-II subtype degradation is shared across Polyglutamine Ataxia mouse models and SCA7 patients. It has been speculated that PC subtype organization is critical for cerebellar function, and our results suggest that a breakdown of zebrin-II parasagittal striping is pathological.
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Affiliation(s)
- Luke C. Bartelt
- University Program in Genetics & Genomics, Duke University Medical Center, Durham, NC 27710, USA
- Departments of Pathology & Laboratory Medicine, Neurology, Biological Chemistry, and Neurobiology & Behavior, University of California, Irvine; Irvine, CA 92697, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Pawel M. Switonski
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - Grażyna Adamek
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - Juliana Carvalho
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Lisa A. Duvick
- Institute for Translational Neuroscience, and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sabrina I. Jarrah
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Daniel R. Scoles
- Department of Neurology, University of Utah, Salt Lake City, UT 84132, USA
| | - Stefan M. Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT 84132, USA
| | - Harry T. Orr
- Institute for Translational Neuroscience, and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Court Hull
- Department of Neurobiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Craig B. Lowe
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Albert R. La Spada
- Departments of Pathology & Laboratory Medicine, Neurology, Biological Chemistry, and Neurobiology & Behavior, University of California, Irvine; Irvine, CA 92697, USA
- Department of Neurology, Duke University School of Medicine, Durham, NC 27710, USA
- UCI Center for Neurotherapeutics, University of California, Irvine; Irvine, CA 92697, USA
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5
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Rossi M, Hamed M, Rodríguez-Antigüedad J, Cornejo-Olivas M, Breza M, Lohmann K, Klein C, Rajalingam R, Marras C, van de Warrenburg BP. Genotype-Phenotype Correlations for ATX-TBP (SCA17): MDSGene Systematic Review. Mov Disord 2023; 38:368-377. [PMID: 36374860 DOI: 10.1002/mds.29278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/31/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022] Open
Abstract
Spinocerebellar ataxia type 17 or ATX-TBP is a CAG/CAA repeat expansion disorder characterized by marked clinical heterogeneity. Reports of affected carriers with subthreshold repeat expansions and of patients with Parkinson's disease (PD) with expanded repeats have cast doubt on the established cutoff values of the expansions and the phenotypic spectrum of this disorder. The objective of this systematic review was to explore the genotype-phenotype relationships for repeat expansions in TBP to delineate the ATX-TBP phenotype and reevaluate the pathological range of repeat expansions. The International Parkinson and Movement Disorder Society Genetic Mutation Database (MDSGene) standardized data extraction protocol was followed. Clinically affected carriers of reported ATX-TBP expansions were included. Publications that contained repeat sizes in screened cohorts of patients with PD and/or healthy individuals were included for a separate evaluation of cutoff values. Phenotypic and genotypic data for 346 ATX-TBP patients were curated. Overall, 97.7% of the patients had ≥41 repeats, while 99.6% of patients with PD and 99.9% of healthy individuals had ≤42 repeats, with a gray zone of reduced penetrance between 41 and 45 repeats. Pure parkinsonism was more common in ATX-TBP patients with 41 to 45 repeats than in the group with ≥46 repeats, which conversely more often presented with a complex phenotype with mixed movement disorders. An updated genotype-phenotype assessment for ATX-TBP is provided, and new repeat expansion cutoff values of reduced penetrance (41-45 expanded repeats) and full penetrance (46-66 expanded repeats) are proposed. These adjusted cutoff values will have diagnostic and counseling implications and may guide future clinical trial protocol. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Malco Rossi
- Sección de Movimientos Anormales, Departamento de Neurología, Fleni, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Moath Hamed
- New York-Presbyterian Brooklyn Methodist Hospital, Brooklyn, New York, USA
| | - Jon Rodríguez-Antigüedad
- Movement Disorders Unit, Neurology Department, Sant Pau Hospital, Barcelona, Spain
- Institut d'Investigacions Biomediques-Sant Pau, Barcelona, Spain
| | - Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
- Carrera de Medicina, Universidad Científica del Sur, Lima, Peru
| | - Marianthi Breza
- 1st Department of Neurology, School of Medicine, Eginition Hospital, National and Kapodistrian University of Athens, Athens, Greece
- Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology, The National Hospital for Neurology and Neurosurgery, London, UK
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Rajasumi Rajalingam
- Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Toronto, Ontario, Canada
| | - Connie Marras
- Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Toronto, Ontario, Canada
| | - Bart P van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition & Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
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Suárez-Sánchez R, Ávila-Avilés RD, Hernández-Hernández JM, Sánchez-Celis D, Azotla-Vilchis CN, Gómez-Macías ER, Leyva-García N, Ortega A, Magaña JJ, Cisneros B, Hernández-Hernández O. RNA Foci Formation in a Retinal Glial Model for Spinocerebellar Ataxia Type 7. LIFE (BASEL, SWITZERLAND) 2022; 13:life13010023. [PMID: 36675972 PMCID: PMC9861853 DOI: 10.3390/life13010023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/15/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Spinocerebellar ataxia type 7 (SCA7) is a neurodegenerative disorder characterized by cerebellar ataxia and retinopathy. SCA7 is caused by a CAG expansion in the ATXN7 gene, which results in an extended polyglutamine (polyQ) tract in the encoded protein, the ataxin-7. PolyQ expanded ataxin-7 elicits neurodegeneration in cerebellar Purkinje cells, however, its impact on the SCA7-associated retinopathy remains to be addressed. Since Müller glial cells play an essential role in retinal homeostasis, we generate an inducible model for SCA7, based on the glial Müller MIO-M1 cell line. The SCA7 pathogenesis has been explained by a protein gain-of-function mechanism, however, the contribution of the mutant RNA to the disease cannot be excluded. In this direction, we found nuclear and cytoplasmic foci containing mutant RNA accompanied by subtle alternative splicing defects in MIO-M1 cells. RNA foci were also observed in cells from different lineages, including peripheral mononuclear leukocytes derived from SCA7 patient, suggesting that this molecular mark could be used as a blood biomarker for SCA7. Collectively, our data showed that our glial cell model exhibits the molecular features of SCA7, which makes it a suitable model to study the RNA toxicity mechanisms, as well as to explore therapeutic strategies aiming to alleviate glial dysfunction.
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Affiliation(s)
- Rocío Suárez-Sánchez
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis, Guillermo Ibarra Ibarra, Ciudad de México 14389, Mexico
| | - Rodolfo Daniel Ávila-Avilés
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México 07360, Mexico
| | - J. Manuel Hernández-Hernández
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México 07360, Mexico
| | - Daniel Sánchez-Celis
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México 07360, Mexico
| | - Cuauhtli N. Azotla-Vilchis
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México 07360, Mexico
| | - Enue R. Gómez-Macías
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México 07360, Mexico
| | - Norberto Leyva-García
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis, Guillermo Ibarra Ibarra, Ciudad de México 14389, Mexico
| | - Arturo Ortega
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del, Instituto Politécnico Nacional, Ciudad de México 07360, Mexico
| | - Jonathan J. Magaña
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis, Guillermo Ibarra Ibarra, Ciudad de México 14389, Mexico
- Escuela de Ingeniería y Ciencias, Departamento de Bioingeniería, Tecnológico de Monterrey-Campus Ciudad de México, Ciudad de México 14380, Mexico
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México 07360, Mexico
| | - Oscar Hernández-Hernández
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación-Luis, Guillermo Ibarra Ibarra, Ciudad de México 14389, Mexico
- Correspondence: or ; Tel.: +52-(55)-5999-1000 (ext. 14710)
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7
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Biswas DD, El Haddad L, Sethi R, Huston ML, Lai E, Abdelbarr MM, Mhandire DZ, ElMallah MK. Neuro-respiratory pathology in spinocerebellar ataxia. J Neurol Sci 2022; 443:120493. [PMID: 36410186 PMCID: PMC9808489 DOI: 10.1016/j.jns.2022.120493] [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: 08/21/2022] [Revised: 10/22/2022] [Accepted: 11/09/2022] [Indexed: 11/15/2022]
Abstract
The spinocerebellar ataxias (SCA) are a heterogeneous group of neurodegenerative disorders with an autosomal dominant inheritance. Symptoms include poor coordination and balance, peripheral neuropathy, impaired vision, incontinence, respiratory insufficiency, dysphagia, and dysarthria. Although many patients with SCA have respiratory-related complications, the exact mechanism and extent of this pathology remain unclear. This review aims to provide an update on the recent clinical and preclinical scientific findings on neuropathology causing respiratory insufficiency in SCA.
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Affiliation(s)
- Debolina D Biswas
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Léa El Haddad
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Ronit Sethi
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Meredith L Huston
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Elias Lai
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Mariam M Abdelbarr
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Doreen Z Mhandire
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Mai K ElMallah
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA.
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8
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Goswami R, Bello AI, Bean J, Costanzo KM, Omer B, Cornelio-Parra D, Odah R, Ahluwalia A, Allan SK, Nguyen N, Shores T, Aziz NA, Mohan RD. The Molecular Basis of Spinocerebellar Ataxia Type 7. Front Neurosci 2022; 16:818757. [PMID: 35401096 PMCID: PMC8987156 DOI: 10.3389/fnins.2022.818757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/07/2022] [Indexed: 11/19/2022] Open
Abstract
Spinocerebellar ataxia (SCA) type 7 (SCA7) is caused by a CAG trinucleotide repeat expansion in the ataxin 7 (ATXN7) gene, which results in polyglutamine expansion at the amino terminus of the ATXN7 protein. Although ATXN7 is expressed widely, the best characterized symptoms of SCA7 are remarkably tissue specific, including blindness and degeneration of the brain and spinal cord. While it is well established that ATXN7 functions as a subunit of the Spt Ada Gcn5 acetyltransferase (SAGA) chromatin modifying complex, the mechanisms underlying SCA7 remain elusive. Here, we review the symptoms of SCA7 and examine functions of ATXN7 that may provide further insights into its pathogenesis. We also examine phenotypes associated with polyglutamine expanded ATXN7 that are not considered symptoms of SCA7.
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Affiliation(s)
- Rituparna Goswami
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Abudu I. Bello
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Joe Bean
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Kara M. Costanzo
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Bwaar Omer
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Dayanne Cornelio-Parra
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Revan Odah
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Amit Ahluwalia
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Shefaa K. Allan
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Nghi Nguyen
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Taylor Shores
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
| | - N. Ahmad Aziz
- Population Health Sciences, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Ryan D. Mohan
- Division of Biological and Biomedical Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, MO, United States
- *Correspondence: Ryan D. Mohan,
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9
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Świtońska-Kurkowska K, Krist B, Delimata J, Figiel M. Juvenile Huntington's Disease and Other PolyQ Diseases, Update on Neurodevelopmental Character and Comparative Bioinformatic Review of Transcriptomic and Proteomic Data. Front Cell Dev Biol 2021; 9:642773. [PMID: 34277598 PMCID: PMC8281051 DOI: 10.3389/fcell.2021.642773] [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: 12/16/2020] [Accepted: 06/10/2021] [Indexed: 01/18/2023] Open
Abstract
Polyglutamine (PolyQ) diseases are neurodegenerative disorders caused by the CAG repeat expansion mutation in affected genes resulting in toxic proteins containing a long chain of glutamines. There are nine PolyQ diseases: Huntington’s disease (HD), spinocerebellar ataxias (types 1, 2, 3, 6, 7, and 17), dentatorubral-pallidoluysian atrophy (DRPLA), and spinal bulbar muscular atrophy (SBMA). In general, longer CAG expansions and longer glutamine tracts lead to earlier disease presentations in PolyQ patients. Rarely, cases of extremely long expansions are identified for PolyQ diseases, and they consistently lead to juvenile or sometimes very severe infantile-onset polyQ syndromes. In apparent contrast to the very long CAG tracts, shorter CAGs and PolyQs in proteins seems to be the evolutionary factor enhancing human cognition. Therefore, polyQ tracts in proteins can be modifiers of brain development and disease drivers, which contribute neurodevelopmental phenotypes in juvenile- and adult-onset PolyQ diseases. Therefore we performed a bioinformatics review of published RNAseq polyQ expression data resulting from the presence of polyQ genes in search of neurodevelopmental expression patterns and comparison between diseases. The expression data were collected from cell types reflecting stages of development such as iPSC, neuronal stem cell, neurons, but also the adult patients and models for PolyQ disease. In addition, we extended our bioinformatic transcriptomic analysis by proteomics data. We identified a group of 13 commonly downregulated genes and proteins in HD mouse models. Our comparative bioinformatic review highlighted several (neuro)developmental pathways and genes identified within PolyQ diseases and mouse models responsible for neural growth, synaptogenesis, and synaptic plasticity.
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Affiliation(s)
| | - Bart Krist
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | - Joanna Delimata
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | - Maciej Figiel
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
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10
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Fusco AF, Pucci LA, Switonski PM, Biswas DD, McCall AL, Kahn AF, Dhindsa JS, Strickland LM, La Spada AR, ElMallah MK. Respiratory dysfunction in a mouse model of spinocerebellar ataxia type 7. Dis Model Mech 2021; 14:dmm048893. [PMID: 34160002 PMCID: PMC8319550 DOI: 10.1242/dmm.048893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 06/15/2021] [Indexed: 12/13/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is an autosomal-dominant neurodegenerative disorder caused by a CAG repeat expansion in the coding region of the ataxin-7 gene. Infantile-onset SCA7 patients display extremely large repeat expansions (>200 CAGs) and exhibit progressive ataxia, dysarthria, dysphagia and retinal degeneration. Severe hypotonia, aspiration pneumonia and respiratory failure often contribute to death in affected infants. To better understand the features of respiratory and upper airway dysfunction in SCA7, we examined breathing and putative phrenic and hypoglossal neuropathology in a knock-in mouse model of early-onset SCA7 carrying an expanded allele with 266 CAG repeats. Whole-body plethysmography was used to measure awake spontaneously breathing SCA7-266Q knock-in mice at baseline in normoxia and during a hypercapnic/hypoxic respiratory challenge at 4 and 8 weeks, before and after the onset of disease. Postmortem studies included quantification of putative phrenic and hypoglossal motor neurons and microglia, and analysis of ataxin-7 aggregation at end stage. SCA7-266Q mice had profound breathing deficits during a respiratory challenge, exhibiting reduced respiratory output and a greater percentage of time in apnea. Histologically, putative phrenic and hypoglossal motor neurons of SCA7 mice exhibited a reduction in number accompanied by increased microglial activation, indicating neurodegeneration and neuroinflammation. Furthermore, intranuclear ataxin-7 accumulation was observed in cells neighboring putative phrenic and hypoglossal motor neurons in SCA7 mice. These findings reveal the importance of phrenic and hypoglossal motor neuron pathology associated with respiratory failure and upper airway dysfunction, which are observed in infantile-onset SCA7 patients and likely contribute to their early death.
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Affiliation(s)
- Anna F. Fusco
- Department of Pediatrics, School of Medicine, Duke University, Durham, NC 27708, USA
| | - Logan A. Pucci
- Department of Pediatrics, School of Medicine, Duke University, Durham, NC 27708, USA
| | - Pawel M. Switonski
- Department of Pathology & Laboratory Medicine, and Department of Neurology, School of Medicine, University of California Irvine, Irvine, CA 92697, USA
- Department of Neurology, School of Medicine, Duke University, Durham, NC 27708, USA
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14 Str., 61-704 Poznan, Poland
| | - Debolina D. Biswas
- Department of Pediatrics, School of Medicine, Duke University, Durham, NC 27708, USA
| | - Angela L. McCall
- Department of Pediatrics, School of Medicine, Duke University, Durham, NC 27708, USA
| | - Amanda F. Kahn
- Department of Pediatrics, School of Medicine, Duke University, Durham, NC 27708, USA
| | - Justin S. Dhindsa
- Department of Pediatrics, School of Medicine, Duke University, Durham, NC 27708, USA
| | - Laura M. Strickland
- Department of Pediatrics, School of Medicine, Duke University, Durham, NC 27708, USA
| | - Albert R. La Spada
- Department of Pathology & Laboratory Medicine, and Department of Neurology, School of Medicine, University of California Irvine, Irvine, CA 92697, USA
- Department of Neurology, School of Medicine, Duke University, Durham, NC 27708, USA
- UCI Institute for Neurotherapeutics, Department of Neurology, School of Medicine, University of California Irvine, Irvine, CA 92697, USA
| | - Mai K. ElMallah
- Department of Pediatrics, School of Medicine, Duke University, Durham, NC 27708, USA
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11
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Bah MG, Rodriguez D, Cazeneuve C, Mochel F, Devos D, Suppiej A, Roubertie A, Meunier I, Gitiaux C, Curie A, Klapczynski F, Allani‐Essid N, Carneiro M, Van Minkelen R, Kievit A, Fluss J, Leheup B, Ratbi L, Héron D, Gras D, Do Cao J, Pichard S, Strubi‐Villaume I, Audo I, Lesca G, Charles P, Dubois F, Comet‐Didierjean P, Capri Y, Barondiot C, Barathon M, Ewenczyk C, Durr A, Mignot C. Deciphering the natural history of SCA7 in children. Eur J Neurol 2020; 27:2267-2276. [DOI: 10.1111/ene.14405] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 06/10/2020] [Indexed: 11/30/2022]
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12
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Doxakis E. Therapeutic antisense oligonucleotides for movement disorders. Med Res Rev 2020; 41:2656-2688. [PMID: 32656818 DOI: 10.1002/med.21706] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/11/2020] [Accepted: 06/26/2020] [Indexed: 12/11/2022]
Abstract
Movement disorders are a group of neurological conditions characterized by abnormalities of movement and posture. They are broadly divided into akinetic and hyperkinetic syndromes. Until now, no effective symptomatic or disease-modifying therapies have been available. However, since many of these disorders are monogenic or have some well-defined genetic component, they represent strong candidates for antisense oligonucleotide (ASO) therapies. ASO therapies are based on the use of short synthetic single-stranded ASOs that bind to disease-related target RNAs via Watson-Crick base-pairing and pleiotropically modulate their function. With information arising from the RNA sequence alone, it is possible to design ASOs that not only alter the expression levels but also the splicing defects of any protein, far exceeding the intervention repertoire of traditional small molecule approaches. Following the regulatory approval of ASO therapies for spinal muscular atrophy and Duchenne muscular dystrophy in 2016, there has been tremendous momentum in testing such therapies for other neurological disorders. This review article initially focuses on the chemical modifications aimed at improving ASO effectiveness, the mechanisms by which ASOs can interfere with RNA function, delivery systems and pharmacokinetics, and the common set of toxicities associated with their application. It, then, describes the pathophysiology and the latest information on preclinical and clinical trials utilizing ASOs for the treatment of Parkinson's disease, Huntington's disease, and ataxias 1, 2, 3, and 7. It concludes with issues that require special attention to realize the full potential of ASO-based therapies.
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Affiliation(s)
- Epaminondas Doxakis
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Athens, Greece
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13
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Metabolic and Organelle Morphology Defects in Mice and Human Patients Define Spinocerebellar Ataxia Type 7 as a Mitochondrial Disease. Cell Rep 2020; 26:1189-1202.e6. [PMID: 30699348 PMCID: PMC6420346 DOI: 10.1016/j.celrep.2019.01.028] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/14/2018] [Accepted: 01/08/2019] [Indexed: 12/17/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is a retinal-cerebellar degenerative disorder caused by CAG-polyglutamine (polyQ) repeat expansions in the ataxin-7 gene. As many SCA7 clinical phenotypes occur in mitochondrial disorders, and magnetic resonance spectroscopy of patients revealed altered energy metabolism, we considered a role for mitochondrial dysfunction. Studies of SCA7 mice uncovered marked impairments in oxygen consumption and respiratory exchange. When we examined cerebellar Purkinje cells in mice, we observed mitochondrial network abnormalities, with enlarged mitochondria upon ultrastructural analysis. We developed stem cell models from patients and created stem cell knockout rescue systems, documenting mitochondrial morphology defects, impaired oxidative metabolism, and reduced expression of nicotinamide adenine dinucleotide (NAD+) production enzymes in SCA7 models. We observed NAD+ reductions in mitochondria of SCA7 patient NPCs using ratiometric fluorescent sensors and documented alterations in tryptophan-kynurenine metabolism in patients. Our results indicate that mitochondrial dysfunction, stemming from decreased NAD+, is a defining feature of SCA7.
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14
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Nambo-Venegas R, Valdez-Vargas C, Cisneros B, Palacios-González B, Vela-Amieva M, Ibarra-González I, Cerecedo-Zapata CM, Martínez-Cruz E, Cortés H, Reyes-Grajeda JP, Magaña JJ. Altered Plasma Acylcarnitines and Amino Acids Profile in Spinocerebellar Ataxia Type 7. Biomolecules 2020; 10:biom10030390. [PMID: 32138195 PMCID: PMC7175318 DOI: 10.3390/biom10030390] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 12/19/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7), a neurodegenerative disease characterized by cerebellar ataxia and retinal degeneration, is caused by an abnormal CAG repeat expansion in the ATXN7 gene coding region. The onset and severity of SCA7 are highly variable between patients, thus identification of sensitive biomarkers that accurately diagnose the disease and monitoring its progression are needed. With the aim of identified SCA7-specific metabolites with clinical relevance, we report for the first time, to the best of our knowledge, a metabolomics profiling of circulating acylcarnitines and amino acids in SCA7 patients. We identified 21 metabolites with altered levels in SCA7 patients and determined two different sets of metabolites with diagnostic power. The first signature of metabolites (Valine, Leucine, and Tyrosine) has the ability to discriminate between SCA7 patients and healthy controls, while the second one (Methionine, 3-hydroxytetradecanoyl-carnitine, and 3-hydroxyoctadecanoyl-carnitine) possess the capability to differentiate between early-onset and adult-onset patients, as shown by the multivariate model and ROC analyses. Furthermore, enrichment analyses of metabolic pathways suggest alterations in mitochondrial function, energy metabolism, and fatty acid beta-oxidation in SCA7 patients. In summary, circulating SCA7-specific metabolites identified in this study could serve as effective predictors of SCA7 progression in the clinics, as they are sampled in accessible biofluid and assessed by a relatively simple biochemical assay.
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Affiliation(s)
- Rafael Nambo-Venegas
- Laboratory of Chronic Diseases Biochemistry, National Genomics Medicine Institute (INMEGEN), Mexico City 14610, Mexico;
| | - Claudia Valdez-Vargas
- Laboratory of Genomic Medicine, Department of Genetics, National Rehabilitation Institute (INR-LGII), Mexico City 14389, Mexico; (C.V.-V.); (H.C.)
- Department of Genetics and Molecular Biology, Center of Research and Advanced Studies (CINVESTAV-IPN), Mexico City 07360, Mexico;
| | - Bulmaro Cisneros
- Department of Genetics and Molecular Biology, Center of Research and Advanced Studies (CINVESTAV-IPN), Mexico City 07360, Mexico;
| | | | - Marcela Vela-Amieva
- Laboratory of Inborn errors of metabolism, National Pediatrics Institute (INP), Mexico City 04530, Mexico;
| | | | - César M. Cerecedo-Zapata
- Rehabilitation and Special Education Center of Veracruz (CRISVER-DIF), Xalapa 91097, Veracruz, Mexico; (C.M.C.-Z.)
| | - Emilio Martínez-Cruz
- Rehabilitation and Special Education Center of Veracruz (CRISVER-DIF), Xalapa 91097, Veracruz, Mexico; (C.M.C.-Z.)
| | - Hernán Cortés
- Laboratory of Genomic Medicine, Department of Genetics, National Rehabilitation Institute (INR-LGII), Mexico City 14389, Mexico; (C.V.-V.); (H.C.)
| | - Juan P. Reyes-Grajeda
- Laboratory of Chronic Diseases Biochemistry, National Genomics Medicine Institute (INMEGEN), Mexico City 14610, Mexico;
- Correspondence: (J.P.R.-G.); or (J.J.M.); Tel.: +52-55-5350-1900 (ext. 1192) (J.P.R.-G.); +52-55- 5999-1000 (ext. 14708) (J.J.M.)
| | - Jonathan J. Magaña
- Laboratory of Genomic Medicine, Department of Genetics, National Rehabilitation Institute (INR-LGII), Mexico City 14389, Mexico; (C.V.-V.); (H.C.)
- Correspondence: (J.P.R.-G.); or (J.J.M.); Tel.: +52-55-5350-1900 (ext. 1192) (J.P.R.-G.); +52-55- 5999-1000 (ext. 14708) (J.J.M.)
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15
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Niewiadomska-Cimicka A, Trottier Y. Molecular Targets and Therapeutic Strategies in Spinocerebellar Ataxia Type 7. Neurotherapeutics 2019; 16:1074-1096. [PMID: 31432449 PMCID: PMC6985300 DOI: 10.1007/s13311-019-00778-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is a rare autosomal dominant neurodegenerative disorder characterized by progressive neuronal loss in the cerebellum, brainstem, and retina, leading to cerebellar ataxia and blindness as major symptoms. SCA7 is due to the expansion of a CAG triplet repeat that is translated into a polyglutamine tract in ATXN7. Larger SCA7 expansions are associated with earlier onset of symptoms and more severe and rapid disease progression. Here, we summarize the pathological and genetic aspects of SCA7, compile the current knowledge about ATXN7 functions, and then focus on recent advances in understanding the pathogenesis and in developing biomarkers and therapeutic strategies. ATXN7 is a bona fide subunit of the multiprotein SAGA complex, a transcriptional coactivator harboring chromatin remodeling activities, and plays a role in the differentiation of photoreceptors and Purkinje neurons, two highly vulnerable neuronal cell types in SCA7. Polyglutamine expansion in ATXN7 causes its misfolding and intranuclear accumulation, leading to changes in interactions with native partners and/or partners sequestration in insoluble nuclear inclusions. Studies of cellular and animal models of SCA7 have been crucial to unveil pathomechanistic aspects of the disease, including gene deregulation, mitochondrial and metabolic dysfunctions, cell and non-cell autonomous protein toxicity, loss of neuronal identity, and cell death mechanisms. However, a better understanding of the principal molecular mechanisms by which mutant ATXN7 elicits neurotoxicity, and how interconnected pathogenic cascades lead to neurodegeneration is needed for the development of effective therapies. At present, therapeutic strategies using nucleic acid-based molecules to silence mutant ATXN7 gene expression are under development for SCA7.
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Affiliation(s)
- Anna Niewiadomska-Cimicka
- Institute of Genetic and Molecular and Cellular Biology (IGBMC), Centre National de la Recherche Scientifique (UMR7104), Institut National de la Santé et de la Recherche Médicale (U1258), University of Strasbourg, Illkirch, France
| | - Yvon Trottier
- Institute of Genetic and Molecular and Cellular Biology (IGBMC), Centre National de la Recherche Scientifique (UMR7104), Institut National de la Santé et de la Recherche Médicale (U1258), University of Strasbourg, Illkirch, France.
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16
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Verma AK, Khan E, Bhagwat SR, Kumar A. Exploring the Potential of Small Molecule-Based Therapeutic Approaches for Targeting Trinucleotide Repeat Disorders. Mol Neurobiol 2019; 57:566-584. [DOI: 10.1007/s12035-019-01724-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/29/2019] [Indexed: 12/18/2022]
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17
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Szpisjak L, Zadori D, Klivenyi P, Vecsei L. Clinical Characteristics and Possible Drug Targets in Autosomal Dominant Spinocerebellar Ataxias. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2019; 18:279-293. [DOI: 10.2174/1871527318666190311155846] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/10/2018] [Accepted: 01/31/2019] [Indexed: 12/28/2022]
Abstract
Background & Objective:
The autosomal dominant spinocerebellar ataxias (SCAs) belong
to a large and expanding group of neurodegenerative disorders. SCAs comprise more than 40 subtypes
characterized by progressive ataxia as a common feature. The most prevalent diseases among SCAs
are caused by CAG repeat expansions in the coding-region of the causative gene resulting in polyglutamine
(polyQ) tract formation in the encoded protein. Unfortunately, there is no approved therapy to
treat cerebellar motor dysfunction in SCA patients. In recent years, several studies have been conducted
to recognize the clinical and pathophysiological aspects of the polyQ SCAs more accurately.
This scientific progress has provided new opportunities to develop promising gene therapies, including
RNA interference and antisense oligonucleotides.
Conclusion:
The aim of the current work is to give a brief summary of the clinical features of SCAs
and to review the cardinal points of pathomechanisms of the most common polyQ SCAs. In addition,
we review the last few year’s promising gene suppression therapies of the most frequent polyQ SCAs
in animal models, on the basis of which human trials may be initiated in the near future.
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Affiliation(s)
- Laszlo Szpisjak
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Denes Zadori
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Peter Klivenyi
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Laszlo Vecsei
- Department of Neurology, University of Szeged, Szeged, Hungary
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18
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Oxidative Stress in Spinocerebellar Ataxia Type 7 Is Associated with Disease Severity. THE CEREBELLUM 2019; 17:601-609. [PMID: 29876803 DOI: 10.1007/s12311-018-0947-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Spinocerebellar ataxia type 7 is a neurodegenerative inherited disease caused by a CAG expansion in the coding region of the ATXN7 gene, which results in the synthesis of polyglutamine-containing ataxin-7. Expression of mutant ataxin-7 disturbs different cell processes, including transcriptional regulation, protein conformation and clearance, autophagy, and glutamate transport; however, mechanisms underlying neurodegeneration in SCA7 are still unknown. Implication of oxidative stress in the pathogenesis of various neurodegenerative diseases, including polyglutamine disorders, has recently emerged. We perform a cross-sectional study to determine for the first time pheripheral levels of different oxidative stress markers in 29 SCA7 patients and 28 age- and sex-matched healthy subjects. Patients with SCA7 exhibit oxidative damage to lipids (high levels of lipid hydroperoxides and malondialdehyde) and proteins (elevated levels of advanced oxidation protein products and protein carbonyls). Furthermore, SCA7 patients showed enhanced activity of various anti-oxidant enzymes (glutathione reductase, glutathione peroxidase, and paraoxonase) as well as increased total anti-oxidant capacity, which suggest that activation of the antioxidant defense system might occur to counteract oxidant damage. Strikingly, we found positive correlation between some altered oxidative stress markers and disease severity, as determined by different clinical scales, with early-onset patients showing a more severe disturbance of the redox system than adult-onset patients. In summay, our results suggest that oxidative stress might contribute to SCA7 pathogenesis. Furthermore, oxidative stress biomarkers that were found relevant to SCA7 in this study could be useful to follow disease progression and monitor therapeutic intervention.
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19
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Buijsen RAM, Toonen LJA, Gardiner SL, van Roon-Mom WMC. Genetics, Mechanisms, and Therapeutic Progress in Polyglutamine Spinocerebellar Ataxias. Neurotherapeutics 2019; 16:263-286. [PMID: 30607747 PMCID: PMC6554265 DOI: 10.1007/s13311-018-00696-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Autosomal dominant cerebellar ataxias (ADCAs) are a group of neurodegenerative disorders characterized by degeneration of the cerebellum and its connections. All ADCAs have progressive ataxia as their main clinical feature, frequently accompanied by dysarthria and oculomotor deficits. The most common spinocerebellar ataxias (SCAs) are 6 polyglutamine (polyQ) SCAs. These diseases are all caused by a CAG repeat expansion in the coding region of a gene. Currently, no curative treatment is available for any of the polyQ SCAs, but increasing knowledge on the genetics and the pathological mechanisms of these polyQ SCAs has provided promising therapeutic targets to potentially slow disease progression. Potential treatments can be divided into pharmacological and gene therapies that target the toxic downstream effects, gene therapies that target the polyQ SCA genes, and stem cell replacement therapies. Here, we will provide a review on the genetics, mechanisms, and therapeutic progress in polyglutamine spinocerebellar ataxias.
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Affiliation(s)
- Ronald A M Buijsen
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.
| | - Lodewijk J A Toonen
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Sarah L Gardiner
- Department of Human Genetics, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
- Department of Neurology, LUMC, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
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20
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Wide Profiling of Circulating MicroRNAs in Spinocerebellar Ataxia Type 7. Mol Neurobiol 2019; 56:6106-6120. [PMID: 30721448 DOI: 10.1007/s12035-019-1480-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/10/2019] [Indexed: 12/28/2022]
Abstract
Spinocerebellar ataxia type 7 (SCA7), a neurodegenerative disease characterized by cerebellar ataxia and retinal degeneration, is caused by a CAG repeat expansion in the ATXN7 gene coding region. Disease onset and progression are highly variable between patients, thus identification of specific/sensitive biomarkers that can improve the monitoring of disease progression is an immediate need. Because altered expression of circulating microRNAs (miRNAs) has been shown in various neurological diseases, they could be useful biomarkers for SCA7. In this study, we showed, to our knowledge for the first time, the expression profile of circulating miRNAs in SCA7. Using the TaqMan profiling low density array (TLDA), we found 71 differentially expressed miRNAs in the plasma of SCA7 patients, compared with healthy controls. The reliability of TLDA data was validated independently by quantitative real-time polymerase chain reaction in an independent cohort of patients and controls. We identified four validated miRNAs that possesses the diagnostic value to discriminate between healthy controls and patients (hsa-let-7a-5p, hsa-let7e-5p, hsa-miR-18a-5p, and hsa-miR-30b-5p). The target genes of these four miRNAs were significantly enriched in cellular processes that are relevant to central nervous system function, including Fas-mediated cell-death, heparansulfate biosynthesis, and soluble-N-ethylmaleimide-sensitive factor activating protein receptor pathways. Finally, we identify a signature of four miRNAs associated with disease severity that discriminate between early onset and adult onset, highlighting their potential utility to surveillance disease progression. In summary, circulating miRNAs might provide accessible biomarkers for disease stage and progression and help to identify novel cellular processes involved in SCA7.
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Marinello M, Werner A, Giannone M, Tahiri K, Alves S, Tesson C, den Dunnen W, Seeler JS, Brice A, Sittler A. SUMOylation by SUMO2 is implicated in the degradation of misfolded ataxin-7 via RNF4 in SCA7 models. Dis Model Mech 2019; 12:dmm.036145. [PMID: 30559154 PMCID: PMC6361149 DOI: 10.1242/dmm.036145] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 12/04/2018] [Indexed: 01/10/2023] Open
Abstract
Perturbation of protein homeostasis and aggregation of misfolded proteins is a major cause of many human diseases. A hallmark of the neurodegenerative disease spinocerebellar ataxia type 7 (SCA7) is the intranuclear accumulation of mutant, misfolded ataxin-7 (polyQ-ATXN7). Here, we show that endogenous ATXN7 is modified by SUMO proteins, thus also suggesting a physiological role for this modification under conditions of proteotoxic stress caused by the accumulation of polyQ-ATXN7. Co-immunoprecipitation experiments, immunofluorescence microscopy and proximity ligation assays confirmed the colocalization and interaction of polyQ-ATXN7 with SUMO2 in cells. Moreover, upon inhibition of the proteasome, both endogenous SUMO2/3 and the RNF4 ubiquitin ligase surround large polyQ-ATXN7 intranuclear inclusions. Overexpression of RNF4 and/or SUMO2 significantly decreased levels of polyQ-ATXN7 and, upon proteasomal inhibition, led to a marked increase in the polyubiquitination of polyQ-ATXN7. This provides a mechanism for the clearance of polyQ-ATXN7 from affected cells that involves the recruitment of RNF4 by SUMO2/3-modified polyQ-ATXN7, thus leading to its ubiquitination and proteasomal degradation. In a SCA7 knock-in mouse model, we similarly observed colocalization of SUMO2/3 with polyQ-ATXN7 inclusions in the cerebellum and retina. Furthermore, we detected accumulation of SUMO2/3 high-molecular-mass species in the cerebellum of SCA7 knock-in mice, compared with their wild-type littermates, and changes in SUMO-related transcripts. Immunohistochemical analysis showed the accumulation of SUMO proteins and RNF4 in the cerebellum of SCA7 patients. Taken together, our results show that the SUMO pathway contributes to the clearance of aggregated ATXN7 and suggest that its deregulation might be associated with SCA7 disease progression.
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Affiliation(s)
- Martina Marinello
- Sorbonne Universités, UPMC, Univ Paris 06 UMRS 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013 Paris, France.,Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres (PSL) Research University, Neurogenetics Group, 75013 Paris, France
| | - Andreas Werner
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Mariagiovanna Giannone
- Sorbonne Universités, UPMC, Univ Paris 06 UMRS 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013 Paris, France.,Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres (PSL) Research University, Neurogenetics Group, 75013 Paris, France
| | - Khadija Tahiri
- Sorbonne Universités, UPMC, Univ Paris 06 UMRS 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013 Paris, France
| | - Sandro Alves
- Sorbonne Universités, UPMC, Univ Paris 06 UMRS 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013 Paris, France
| | - Christelle Tesson
- Sorbonne Universités, UPMC, Univ Paris 06 UMRS 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013 Paris, France.,Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres (PSL) Research University, Neurogenetics Group, 75013 Paris, France
| | - Wilfred den Dunnen
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands
| | - Jacob-S Seeler
- Nuclear Organization and Oncogenesis Unit, INSERM U.993, Department of Cell Biology and Infection, Institut Pasteur, F-75015 Paris, France
| | - Alexis Brice
- Sorbonne Universités, UPMC, Univ Paris 06 UMRS 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013 Paris, France.,AP-HP, Genetic Department, Pitié-Salpêtrière University Hospital, F-75013 Paris, France
| | - Annie Sittler
- Sorbonne Universités, UPMC, Univ Paris 06 UMRS 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital, 75013 Paris, France
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22
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Cagnoli C, Brussino A, Mancini C, Ferrone M, Orsi L, Salmin P, Pappi P, Giorgio E, Pozzi E, Cavalieri S, Di Gregorio E, Ferrero M, Filla A, De Michele G, Gellera C, Mariotti C, Nethisinghe S, Giunti P, Stevanin G, Brusco A. Spinocerebellar Ataxia Tethering PCR: A Rapid Genetic Test for the Diagnosis of Spinocerebellar Ataxia Types 1, 2, 3, 6, and 7 by PCR and Capillary Electrophoresis. J Mol Diagn 2018; 20:289-297. [PMID: 29462666 DOI: 10.1016/j.jmoldx.2017.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/17/2017] [Accepted: 12/19/2017] [Indexed: 12/14/2022] Open
Abstract
Spinocerebellar ataxia (SCA) types 1, 2, 3, 6, and 7, associated with a (CAG)n repeat expansion in coding sequences, are the most prevalent autosomal dominant ataxias worldwide (approximately 60% of the cases). In addition, the phenotype of SCA2 expansions has been now extended to Parkinson disease and amyotrophic lateral sclerosis. Their diagnosis is currently based on a PCR to identify small expanded alleles, followed by a second-level test whenever a false normal homozygous or a CAT interruption in SCA1 needs to be verified. Next-generation sequencing still does not allow efficient detection of these repeats. Here, we show the efficacy of a novel, rapid, and cost-effective method to identify and size pathogenic expansions in SCA1, 2, 3, 6, and 7 and recognize large alleles or interruptions without a second-level test. Twenty-five healthy controls and 33 expansion carriers were analyzed: alleles migrated consistently in different PCRs and capillary runs, and homozygous individuals were always distinguishable from heterozygous carriers of both common and large (>100 repeats) pathogenic CAG expansions. Repeat number could be calculated counting the number of peaks, except for the largest SCA2 and SCA7 alleles. Interruptions in SCA1 were always visible. Overall, our method allows a simpler, cost-effective, and sensibly faster SCA diagnostic protocol compared with the standard technique and to the still unadapted next-generation sequencing.
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Affiliation(s)
- Claudia Cagnoli
- Department of Medical Sciences, University of Turin, Turin, Italy
| | | | - Cecilia Mancini
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Marina Ferrone
- Department of Medical Sciences, University of Turin, Turin, Italy; Medical Genetics Unit, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - Laura Orsi
- Department of Laboratory Medicine, and the Neurologic Division I, Department of Neuroscience and Mental Health, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - Paola Salmin
- Medical Genetics Unit, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - Patrizia Pappi
- Medical Genetics Unit, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - Elisa Giorgio
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Elisa Pozzi
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Simona Cavalieri
- Department of Medical Sciences, University of Turin, Turin, Italy
| | | | - Marta Ferrero
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Alessandro Filla
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Giuseppe De Michele
- Department of Neurosciences, Odontostomatological and Reproductive Sciences, University Federico II, Naples, Italy
| | - Cinzia Gellera
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Carlo Besta Neurological Institute, Milan, Italy
| | - Caterina Mariotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Carlo Besta Neurological Institute, Milan, Italy
| | - Suran Nethisinghe
- Ataxia Centre, Department of Molecular Neuroscience, Institute of Neurology, University College London, London, United Kingdom
| | - Paola Giunti
- Ataxia Centre, Department of Molecular Neuroscience, Institute of Neurology, University College London, London, United Kingdom
| | - Giovanni Stevanin
- INSERM, U 1127, Institut du Cerveau et de la Moelle epinière, Paris, France; Centre National de la Recherche Scientifique UMR 7225, Paris, France; UMRS 1127, Université Pierre et Marie Curie (Paris 06), Sorbonne Universités, Paris, France; Ecole Pratique des Hautes Etudes, PSL Research University, Paris, France; Centre de Référence de Neurogénétique, Hôpital de la Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Alfredo Brusco
- Department of Medical Sciences, University of Turin, Turin, Italy; Medical Genetics Unit, Città della Salute e della Scienza University Hospital, Turin, Italy.
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23
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Karam A, Trottier Y. Molecular Mechanisms and Therapeutic Strategies in Spinocerebellar Ataxia Type 7. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:197-218. [DOI: 10.1007/978-3-319-71779-1_9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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24
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Klein JL, Lemmon ME, Northington FJ, Boltshauser E, Huisman TAGM, Poretti A. Clinical and neuroimaging features as diagnostic guides in neonatal neurology diseases with cerebellar involvement. CEREBELLUM & ATAXIAS 2016; 3:1. [PMID: 26770813 PMCID: PMC4712469 DOI: 10.1186/s40673-016-0039-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/10/2015] [Indexed: 02/07/2023]
Abstract
Cerebellar abnormalities are encountered in a high number of neurological diseases that present in the neonatal period. These disorders can be categorized broadly as inherited (e.g. malformations, inborn errors of metabolism) or acquired (e.g. hemorrhages, infections, stroke). In some disorders such as Dandy-Walker malformation or Joubert syndrome, the main abnormalities are located within the cerebellum and brainstem. In other disorders such as Krabbe disease or sulfite oxidase deficiency, the main abnormalities are found within the supratentorial brain, but the cerebellar involvement may be helpful for diagnostic purposes. In In this article, we review neurological disorders with onset in the neonatal period and cerebellar involvement with a focus on how characterization of cerebellar involvement can facilitate accurate diagnosis and improved accuracy of neuro-functional prognosis.
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Affiliation(s)
- Jessica L Klein
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD USA ; Neurosciences Intensive Care Nursery Program, The Johns Hopkins University School of Medicine, Baltimore, MD USA ; Department of Pediatrics, Medical University of South Carolina, Charleston, SC USA
| | - Monica E Lemmon
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD USA ; Neurosciences Intensive Care Nursery Program, The Johns Hopkins University School of Medicine, Baltimore, MD USA ; Division of Pediatric Neurology, Department of Pediatrics, Duke University School of Medicine, Durham, NC USA
| | - Frances J Northington
- Neurosciences Intensive Care Nursery Program, The Johns Hopkins University School of Medicine, Baltimore, MD USA ; Division of Neonatology, Department of Pediatrics, The Johns Hopkins University School of Medicine, Baltimore, MD USA
| | - Eugen Boltshauser
- Division of Pediatric Neurology, University Children's Hospital, Zurich, Switzerland
| | - Thierry A G M Huisman
- Neurosciences Intensive Care Nursery Program, The Johns Hopkins University School of Medicine, Baltimore, MD USA ; Section of Pediatric Neuroradiology, Division of Pediatric Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center, Sheikh Zayed Tower, Room 4174, 1800 Orleans Street, Baltimore, MD USA
| | - Andrea Poretti
- Neurosciences Intensive Care Nursery Program, The Johns Hopkins University School of Medicine, Baltimore, MD USA ; Division of Pediatric Neurology, University Children's Hospital, Zurich, Switzerland ; Section of Pediatric Neuroradiology, Division of Pediatric Radiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center, Sheikh Zayed Tower, Room 4174, 1800 Orleans Street, Baltimore, MD USA
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25
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Mohan RD, Workman JL, Abmayr SM. Drosophila models reveal novel insights into mechanisms underlying neurodegeneration. Fly (Austin) 2015; 8:148-52. [PMID: 25483136 PMCID: PMC4594482 DOI: 10.4161/19336934.2014.969150] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The SAGA chromatin modifying complex functions as a transcriptional coactivator for a large number of genes, and SAGA dysfunction has been linked to carcinogenesis and neurodegenerative disease. The protein complex is comprised of approximately 20 subunits, arranged in a modular fashion, and includes 2 enzymatic subunits: the Gcn5 acetyltransferase and the Non-stop deubiquitinase. As we learn more about SAGA, it becomes evident that this complex functions through sophisticated mechanisms that support very precise regulation of gene expression. Here we describe recent findings in which a Drosophila loss-of-function model revealed novel mechanisms for regulation of SAGA-mediated histone H2B deubiquitination. This model also yielded novel and surprising insights into mechanisms that underlie progressive neurodegenerative disease. Lastly, we comment on the utility of Drosophila as a model for neurodegenerative disease through which crucial and conserved mechanisms may be revealed.
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Affiliation(s)
- Ryan D Mohan
- a Stowers Institute for Medical Research ; Kansas City , MO USA
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26
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Donis KC, Mattos EP, Silva AA, Furtado GV, Saraiva-Pereira ML, Jardim LB, Saute JA. Infantile spinocerebellar ataxia type 7: Case report and a review of the literature. J Neurol Sci 2015; 354:118-21. [PMID: 25972113 DOI: 10.1016/j.jns.2015.04.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 10/23/2022]
Affiliation(s)
- Karina Carvalho Donis
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil; Post Graduate Program in Children and Adolescent Health, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Eduardo Preusser Mattos
- Post-Graduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - André Anjos Silva
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil
| | - Gabriel Vasata Furtado
- Post-Graduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Maria Luiza Saraiva-Pereira
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil; Post-Graduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Laura Bannach Jardim
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil; Post-Graduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Department of Internal Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Jonas Alex Saute
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil.
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27
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Somatic instability of expanded CAG repeats of ATXN7 in Japanese patients with spinocerebellar ataxia type 7. Doc Ophthalmol 2015; 130:189-95. [DOI: 10.1007/s10633-015-9488-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Accepted: 01/28/2015] [Indexed: 11/30/2022]
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28
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Mohan RD, Abmayr SM, Workman JL. The expanding role for chromatin and transcription in polyglutamine disease. Curr Opin Genet Dev 2014; 26:96-104. [PMID: 25108806 DOI: 10.1016/j.gde.2014.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 06/22/2014] [Accepted: 06/25/2014] [Indexed: 11/28/2022]
Abstract
Nine genetic diseases arise from expansion of CAG repeats in seemingly unrelated genes. They are referred to as polyglutamine (polyQ) diseases due to the presence of elongated glutamine tracts in the corresponding proteins. The pathologic consequences of polyQ expansion include progressive spinal, cerebellar, and neural degeneration. These pathologies are not identical, however, suggesting that disruption of protein-specific functions is crucial to establish and maintain each disease. A closer examination of protein function reveals that several act as regulators of gene expression. Here we examine the roles these proteins play in regulating gene expression, discuss how polyQ expansion may disrupt these functions to cause disease, and speculate on the neural specificity of perturbing ubiquitous gene regulators.
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Affiliation(s)
- Ryan D Mohan
- Stowers Institute for Medical Research, 1000 E 50th St., Kansas City, MO 64110, USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research, 1000 E 50th St., Kansas City, MO 64110, USA.
| | - Jerry L Workman
- Stowers Institute for Medical Research, 1000 E 50th St., Kansas City, MO 64110, USA.
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29
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Mohan RD, Abmayr SM, Workman JL. Pulling complexes out of complex diseases: Spinocerebellar Ataxia 7. Rare Dis 2014; 2:e28859. [PMID: 25054097 PMCID: PMC4091419 DOI: 10.4161/rdis.28859] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/06/2014] [Accepted: 04/11/2014] [Indexed: 11/19/2022] Open
Abstract
Spinocerebellar ataxia 7 (SCA7) is an incurable disease caused by expansion of CAG trinucleotide sequences within the Ataxin-7 gene. This elongated CAG tract results in an Ataxin-7 protein bearing an expanded polyglutamine (PolyQ) repeat. SCA7 disease is characterized by progressive neural and retinal degeneration leading to ataxia and blindness. Evidence gathered from investigating SCA7 and other PolyQ diseases strongly suggest that misregulation of gene expression contributes to neurodegeneration. In fact, Ataxin-7 is a subunit of the essential Spt-Ada-Gcn5-Acetltransferase (SAGA) chromatin modifying complex that regulates expression of a large number of genes. Here we discuss recent insights into Ataxin-7 function and, considering these findings, propose a model for how polyglutamine expansion of Ataxin-7 may affect Ataxin-7 function to alter chromatin modifications and gene expression.
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Affiliation(s)
- Ryan D Mohan
- Stowers Institute for Medical Research; Kansas City, MO USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research; Kansas City, MO USA
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30
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Neuhann T, Rautenstrauss B. Genetic and phenotypic variability of optic neuropathies. Expert Rev Neurother 2013; 13:357-67. [PMID: 23545052 DOI: 10.1586/ern.13.19] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hereditary optic neuropathies comprise a group of clinically and genetically heterogeneous disorders. Two subgroups can be formed: isolated hereditary optic atrophies and optic neuropathy as part of complex disorders. In group 1 of hereditary optic neuropathies, optic nerve dysfunction is typically the only manifestation of the disease. This group comprises autosomal dominant, autosomal recessive and X-linked recessive optic atrophy and the maternally inherited Leber's hereditary optic neuropathy. Among the autosomal-dominant forms of optic atrophy, Kjer's disease is most frequently observed. In the second group of complex disorders, various neurologic and other systemic abnormalities are regularly observed. Most frequent in this group are mtDNA mutations, inherited peripheral neuropathies, Charcot-Marie-Tooth disorders (CMT2A2, CMTX5), hereditary sensory neuropathy type 3 (HSAN3), Friedreich's ataxia, leukodystrophies, sphingolipidoses, ceroid-lipofuscinoses and neurodegeneration with brain iron accumulation. We review current knowledge about the underlying genetic predispositions, the most urgent open questions and how this may affect our management of this heterogeneous group of disorders in the future.
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Affiliation(s)
- Teresa Neuhann
- Medizinisch Genetisches Zentrum, Munich, Bayerstrasse 3-5, Munich 80335, Germany.
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31
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Rüb U, Schöls L, Paulson H, Auburger G, Kermer P, Jen JC, Seidel K, Korf HW, Deller T. Clinical features, neurogenetics and neuropathology of the polyglutamine spinocerebellar ataxias type 1, 2, 3, 6 and 7. Prog Neurobiol 2013; 104:38-66. [PMID: 23438480 DOI: 10.1016/j.pneurobio.2013.01.001] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 01/22/2013] [Accepted: 01/31/2013] [Indexed: 12/18/2022]
Abstract
The spinocerebellar ataxias type 1 (SCA1), 2 (SCA2), 3 (SCA3), 6 (SCA6) and 7 (SCA7) are genetically defined autosomal dominantly inherited progressive cerebellar ataxias (ADCAs). They belong to the group of CAG-repeat or polyglutamine diseases and share pathologically expanded and meiotically unstable glutamine-encoding CAG-repeats at distinct gene loci encoding elongated polyglutamine stretches in the disease proteins. In recent years, progress has been made in the understanding of the pathogenesis of these currently incurable diseases: Identification of underlying genetic mechanisms made it possible to classify the different ADCAs and to define their clinical and pathological features. Furthermore, advances in molecular biology yielded new insights into the physiological and pathophysiological role of the gene products of SCA1, SCA2, SCA3, SCA6 and SCA7 (i.e. ataxin-1, ataxin-2, ataxin-3, α-1A subunit of the P/Q type voltage-dependent calcium channel, ataxin-7). In the present review we summarize our current knowledge about the polyglutamine ataxias SCA1, SCA2, SCA3, SCA6 and SCA7 and compare their clinical and electrophysiological features, genetic and molecular biological background, as well as their brain pathologies. Furthermore, we provide an overview of the structure, interactions and functions of the different disease proteins. On the basis of these comprehensive data, similarities, differences and possible disease mechanisms are discussed.
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Affiliation(s)
- Udo Rüb
- Dr. Senckenberg Chronomedical Institute, Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt/Main, Germany.
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32
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Yanicostas C, Barbieri E, Hibi M, Brice A, Stevanin G, Soussi-Yanicostas N. Requirement for zebrafish ataxin-7 in differentiation of photoreceptors and cerebellar neurons. PLoS One 2012; 7:e50705. [PMID: 23226359 PMCID: PMC3511343 DOI: 10.1371/journal.pone.0050705] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 10/24/2012] [Indexed: 11/25/2022] Open
Abstract
The expansion of a polyglutamine (polyQ) tract in the N-terminal region of ataxin-7 (atxn7) is the causative event in spinocerebellar ataxia type 7 (SCA7), an autosomal dominant neurodegenerative disorder mainly characterized by progressive, selective loss of rod-cone photoreceptors and cerebellar Purkinje and granule cells. The molecular and cellular processes underlying this restricted neuronal vulnerability, which contrasts with the broad expression pattern of atxn7, remains one of the most enigmatic features of SCA7, and more generally of all polyQ disorders. To gain insight into this specific neuronal vulnerability and achieve a better understanding of atxn7 function, we carried out a functional analysis of this protein in the teleost fish Danio rerio. We characterized the zebrafish atxn7 gene and its transcription pattern, and by making use of morpholino-oligonucleotide-mediated gene inactivation, we analysed the phenotypes induced following mild or severe zebrafish atxn7 depletion. Severe or nearly complete zebrafish atxn7 loss-of-function markedly impaired embryonic development, leading to both early embryonic lethality and severely deformed embryos. More importantly, in relation to SCA7, moderate depletion of the protein specifically, albeit partially, prevented the differentiation of both retina photoreceptors and cerebellar Purkinje and granule cells. In addition, [1–232] human atxn7 fragment rescued these phenotypes showing strong function conservation of this protein through evolution. The specific requirement for zebrafish atxn7 in the proper differentiation of cerebellar neurons provides, to our knowledge, the first in vivo evidence of a direct functional relationship between atxn7 and the differentiation of Purkinje and granule cells, the most crucial neurons affected in SCA7 and most other polyQ-mediated SCAs. These findings further suggest that altered protein function may play a role in the pathophysiology of the disease, an important step toward the development of future therapeutic strategies.
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Affiliation(s)
- Constantin Yanicostas
- INSERM, U676, Hôpital Robert Debré, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Elisa Barbieri
- INSERM, U676, Hôpital Robert Debré, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- INSERM, U975, Paris, France
- Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UMR_S975, GHU Pitié-Salpêtrière, Paris, France
- CNRS, UMR7225, Paris, France
| | - Masahiko Hibi
- Laboratory for Vertebrate Axis Formation, RIKEN Center for Developmental Biology, Kobe, Hyogo, Japan
- Bioscience and Biotechnology Center, Nagoya University, Nagoya, Japan
| | - Alexis Brice
- INSERM, U975, Paris, France
- Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UMR_S975, GHU Pitié-Salpêtrière, Paris, France
- CNRS, UMR7225, Paris, France
| | - Giovanni Stevanin
- INSERM, U975, Paris, France
- Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UMR_S975, GHU Pitié-Salpêtrière, Paris, France
- CNRS, UMR7225, Paris, France
- Ecole Pratique des Hautes Etudes, Paris, France
| | - Nadia Soussi-Yanicostas
- INSERM, U676, Hôpital Robert Debré, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- * E-mail:
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Abstract
Spinocerebellar ataxia type 7 (SCA7) is associated with progressive blindness, dominant transmission, and marked anticipation. SCA7 represents one of the polyglutamine expansion diseases with increase of CAG repeats. The gene maps to chromosome 3p12-p21.1. Normal values of CAG repeats range from 4 to 18. The SCA7 gene encodes a protein of largely unknown function, called ataxin-7. SCA7 is reported in many countries and ethnic groups. Its phenotypic expression depends on the number of expanded repeats. The infantile phenotype is very severe, with more than 100 repeats. The classic type has 50 to 55 repeats and is characterized by a combination of visual and ataxic disturbances lasting for 20-40 years.When the number of CAG repeats is between 36 and 43, the evolution is much slower, with few or no retinal abnormalities. A CAG repeat number from 18 to 35 is asymptomatic but predisposes to the development of the disorder when expanding to the pathological range through transmission. The diagnosis is made by molecular genetics. The neuropathology of the disorder includes atrophy of the spinocerebellar pathways, pyramidal tracts, and motor nuclei in the brainstem and spinal cord, a cone-rod sytrophy of the retina, and ataxin-7 immunoreactive neuronal intranuclear inclusions. The neuropathological features vary as a function of the number of CAG repeats. Present research deals mainly with the study of ataxin-7 in transfected neural cells and transgenic mouse models.
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Yamada M, Sato T, Tsuji S, Takahashi H. CAG repeat disorder models and human neuropathology: similarities and differences. Acta Neuropathol 2008; 115:71-86. [PMID: 17786457 DOI: 10.1007/s00401-007-0287-5] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Revised: 08/15/2007] [Accepted: 08/16/2007] [Indexed: 11/24/2022]
Abstract
CAG repeat diseases are hereditary neurodegenerative disorders caused by expansion of a polyglutamine tract in each respective disease protein. They include at least nine disorders, including Huntington's disease (HD), dentatorubral pallidoluysian atrophy (DRPLA), spinal and bulbar muscular atrophy (SBMA), and the spinocerebellar ataxias SCA1, SCA2, SCA3 (also known as Machado-Joseph disease), SCA6, SCA7, and SCA17. It is thought that a gain of toxic function resulting from the protein mutation plays important and common roles in the pathogenesis of these diseases. Recent studies have disclosed that, in addition to the presence of clinical phenotypes and conventional neuropathology in each disease, human brains affected by CAG repeat diseases share several polyglutamine-related changes in their neuronal nuclei and cytoplasm including the formation of intranuclear inclusions. Although these novel pathologic changes also show a distribution pattern characteristic to each disease, they are generally present beyond the lesion distribution of neuronal loss, suggesting that neurons are affected much more widely than has been recognized previously. Various mouse models of CAG repeat diseases have revealed that CAG repeat lengths, which are responsible for polyglutamine diseases in humans, are not sufficient for creating the conditions characteristic of each disease in mice. Although high expression of mutant proteins in mice results in the successful generation of polyglutamine-related changes in the brain, there are still some differences from human pathology in the lesion distribution or cell types that are affected. In addition, no model has yet successfully reproduced the specific neuronal loss observed in humans. Although there are no models that fully represent the neuropathologic changes present in humans, the data obtained have provided evidence that clinical onset is not clearly associated with neuronal cell death, but depends on intranuclear accumulation of mutant proteins in neurons.
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Affiliation(s)
- Mitsunori Yamada
- Department of Pathology, Brain Research Institute, Niigata University, 1 Asahimachi, Niigata, 951-8585, Japan.
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35
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Spinocerebellar ataxia type 7 presenting as Stargardt's disease. J Neurol 2007; 255:456-8. [PMID: 18080847 DOI: 10.1007/s00415-007-0740-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 08/15/2007] [Accepted: 09/10/2007] [Indexed: 10/22/2022]
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36
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Whitney A, Lim M, Kanabar D, Lin JP. Massive SCA7 expansion detected in a 7-month-old male with hypotonia, cardiomegaly, and renal compromise. Dev Med Child Neurol 2007; 49:140-3. [PMID: 17254003 DOI: 10.1111/j.1469-8749.2007.00140.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infantile spinocerebellar ataxia type 7 (SCA7) is phenotypically different from the child-onset and adult-onset cases, presenting as a multisystem disorder associated with pathologically large CAG trinucleotide repeat sequences. We describe a case study of a male who presented at 5 months of age with marked motor delay, failure to thrive, and a patent ductus arteriosus. He later developed renal failure of uncertain aetiology. The infant became progressively hypotonic, and cardiac and renal function deteriorated further; he died at the age of 11 months of multisystem failure. Family history revealed a diagnosis of SCA7 in the infant's father, paternal grandfather, and aunt. DNA analysis confirmed an expanded trinucleotide repeat in the SCA7 locus of about 240 repeats, suggesting a diagnosis of infantile SCA7. Striking anticipation is seen in SCA7, particularly with paternal transmission. The underlying pathophysiological processes seem to involve alteration in transcriptional regulation and a selective neuronal vulnerability to the widely distributed abnormal protein product. This case report reviews the current literature relating to infantile SCA7 and raises awareness of this rare but important phenotype.
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Affiliation(s)
- Andrea Whitney
- Paediatric Neurosciences, Guy's & St Thomas' NHS Foundation Trust, London, UK
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37
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Cagnoli C, Stevanin G, Michielotto C, Gerbino Promis G, Brussino A, Pappi P, Durr A, Dragone E, Viemont M, Gellera C, Brice A, Migone N, Brusco A. Large pathogenic expansions in the SCA2 and SCA7 genes can be detected by fluorescent repeat-primed polymerase chain reaction assay. J Mol Diagn 2006; 8:128-32. [PMID: 16436644 PMCID: PMC1867568 DOI: 10.2353/jmoldx.2006.050043] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Large expansions in the SCA2 and SCA7 genes (>100 CAG repeats) have been associated with juvenile and infantile forms of cerebellar ataxias that cannot be detected using standard polymerase chain reaction (PCR). Here, we describe a successful application of the fluorescent short tandem repeat-primed PCR method for accurate identification of these expanded repeats. The test is robust, reliable, and inexpensive and can be used to screen large series of patients, although it cannot give a precise evaluation of the size of the expansion. This test may be of practical value in prenatal diagnoses offered to affected or pre-symptomatic at-risk parents, in which a very large expansion inherited from one of the parents can be missed in the fetus by standard PCR.
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Affiliation(s)
- Claudia Cagnoli
- Dipartimento di Genetica Biologia e Biochimica, Università degli Studi di Torino, via Santena 19, 10126, Torino, Italy
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Infante J, Combarros O, Volpini V, Corral J, Llorca J, Berciano J. Autosomal dominant cerebellar ataxias in Spain: molecular and clinical correlations, prevalence estimation and survival analysis. Acta Neurol Scand 2005; 111:391-9. [PMID: 15876341 DOI: 10.1111/j.1600-0404.2005.00400.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION The genetic and clinical profile of autosomal dominant cerebellar ataxias (ADCA) displays marked geographical and ethnical variability. MATERIALS AND METHODS We have analysed the molecular and clinical correlations in an ethnically homogeneous sample of 30 Spanish ADCA kindreds. Minimal point prevalence for the region of Cantabria was estimated. RESULTS Seventy per cent of the families harboured known mutations. Areflexia, slow saccades and hypopallesthesia predominated in SCA2; nystagmus, pyramidal signs or areflexia restricted to the legs in SCA 3; and retinal degeneration, pyramidal signs and slow saccades in SCA 7. Anticipation and intergenerational instability were greater in SCA 7. Length of expansions and age at onset were inversely correlated in all SCA subtypes. Larger expansions correlated with areflexia in SCA 2, with pyramidal signs in SCA 3 and with early visual impairment in SCA 7. Survival was similar among the different SCA subtypes. Prevalence of ADCA in Cantabria was 1.6 cases per 100,000 population. CONCLUSIONS This report shows the epidemiological, clinical and genetic profile of ADCA in Spain, providing additional data regarding the broad clinical heterogeneity of these disorders and the variability of the genotype-phenotype correlations.
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Affiliation(s)
- J Infante
- Neurology Service, Marqués de Valdecilla University Hospital, University of Cantabria, Santander, Spain.
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39
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Bowman AB, Yoo SY, Dantuma NP, Zoghbi HY. Neuronal dysfunction in a polyglutamine disease model occurs in the absence of ubiquitin-proteasome system impairment and inversely correlates with the degree of nuclear inclusion formation. Hum Mol Genet 2005; 14:679-91. [PMID: 15661755 DOI: 10.1093/hmg/ddi064] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The accumulation of protein deposits in neurons, in vitro proteasome assays and over-expression studies suggest that impairment of the ubiquitin-proteasome system (UPS) may be a common mechanism of pathogenesis in polyglutamine diseases such as Huntington disease and spinocerebellar ataxias (SCAs). Using a knock-in mouse model that recapitulates the clinical features of human SCA7, including selective neuronal dysfunction, we assessed the UPS at cellular resolution using transgenic mice that express a green fluorescent protein (GFP)-based reporter substrate (Ub(G76V)-GFP) of the UPS. The levels of the reporter remained low during the initial phase of disease, suggesting that neuronal dysfunction occurs in the presence of a functional UPS. Late in disease, we observed a significant increase in reporter levels specific to the most vulnerable neurons. Surprisingly, the basis for the increase in Ub(G76V)-GFP protein can be explained by a corresponding increase in Ub(G76V)-GFP mRNA in the vulnerable neurons. An in vitro assay also showed normal proteasome proteolytic activity in the vulnerable neurons. Thus, no evidence for general UPS impairment or reduction of proteasome activity was seen. The differential increase of Ub(G76V)-GFP among individual neurons directly correlated with the down-regulation of a marker of selective pathology and neuronal dysfunction in SCA7. Furthermore, we observed a striking inverse correlation between the neuropathology revealed by this reporter and ataxin-7 nuclear inclusions in the vulnerable neurons. Altogether, these data show a protective role against neuronal dysfunction for polyglutamine nuclear inclusions and exclude significant impairment of the UPS as a necessary step for polyglutamine neuropathology.
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Affiliation(s)
- Aaron B Bowman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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40
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Ansorge O, Giunti P, Michalik A, Van Broeckhoven C, Harding B, Wood N, Scaravilli F. Ataxin-7 aggregation and ubiquitination in infantile SCA7 with 180 CAG repeats. Ann Neurol 2004; 56:448-52. [PMID: 15349877 DOI: 10.1002/ana.20230] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Extremely long (>150) CAG repeats are often used to create models of polyglutamine diseases yet are very rare in humans where they manifest as pediatric multisystem syndromes of little specificity. Here, we describe an infant with 180 CAG repeats in the spinocerebellar ataxia type 7 gene and focus on systemic ataxin-7 aggregation. This was found in many organs, including the cardiovascular system. In the brain, the hippocampus emerged as a principal site of ataxin-7 aggregation without cell loss. We note differential ubiquitination of aggregates and discuss how this may relate to selective vulnerability.
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Affiliation(s)
- Olaf Ansorge
- Division of Neuropathology, Institute of Neurology, Queen Square, London, United Kingdom.
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41
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Viau M, Boulanger Y. Characterization of ataxias with magnetic resonance imaging and spectroscopy. Parkinsonism Relat Disord 2004; 10:335-51. [PMID: 15261875 DOI: 10.1016/j.parkreldis.2004.02.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2003] [Revised: 02/17/2004] [Accepted: 02/26/2004] [Indexed: 11/19/2022]
Abstract
A wide variety of autosomal transmitted ataxias exist and their ultimate characterization requires genetic testing. Common clinical characteristics among different ataxia types complicate the choice of the appropriate genetic test. Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) generally show cerebellar or cerebral atrophy and perturbed metabolite levels which differ between ataxias. In order to help the clinician accurately identify the ataxia type, reported MRI and MRS data in different brain regions are summarized for more than 60 different types of autosomal inherited and sporadic ataxias.
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Affiliation(s)
- Martin Viau
- Département de Radiologie, Hôpital Saint-Luc, Centre Hospitalier de l'Université de Montréal, 1058 St-Denis, Montréal, Québec, Canada H2X 3J4
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Michalik A, Martin JJ, Van Broeckhoven C. Spinocerebellar ataxia type 7 associated with pigmentary retinal dystrophy. Eur J Hum Genet 2003; 12:2-15. [PMID: 14571264 DOI: 10.1038/sj.ejhg.5201108] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Spinocerebellar ataxia type 7 (SCA7) is an autosomal-dominant, late-onset, slowly progressive disorder, primarily characterized by gradual loss of motor coordination, resulting from dysfunction and degeneration of the cerebellum and its connecting pathways. The disease is caused by expansion of a CAG trinucleotide repeat within the SCA7 gene, which encodes a polyglutamine tract within a novel protein, termed ataxin-7. The expansion of polyglutamine-encoding CAG repeats in dissimilar genes underlies eight neurodegenerative conditions besides SCA7, including a number of dominant ataxias related to SCA7. Although elongated polyglutamine itself can initiate neuronal dysfunction and death, its toxicity is modulated by the context of the disease proteins, as evidenced by the differing clinical and pathological presentation of the various disorders. In this respect, it is exciting that SCA7 constitutes the only polyglutamine disorder, in which the photoreceptors of the retina are also severely affected, leading to retinal degeneration and blindness. Since the discovery of the SCA7 mutation, numerous studies attempted to pinpoint the molecular mechanisms underlying the unique features of SCA7, particularly the retinal involvement. Here we summarize the clinical, pathological, and genetic aspects of SCA7, and review the current understanding of the pathogenesis of this disorder.
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Affiliation(s)
- A Michalik
- Department of Molecular Genetics, Neurogenetics Group, Flanders Interuniversity Institute for Biotechnology, Antwerpen, Belgium
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43
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Abstract
Many genetic conditions can result in ataxia. Careful clinical, radiologic, and genetic evaluation permits the specific diagnosis of many of these conditions, which in turn facilitates medical care for the patient and genetic counseling for the patient and family. Predictive, prenatal, and carrier testing are possible for some conditions, but the use of gene tests in these clinical situations requires detailed genetic counseling that may be best left to genetics specialists.
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Affiliation(s)
- Martha A Nance
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA
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44
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Yoo SY, Pennesi ME, Weeber EJ, Xu B, Atkinson R, Chen S, Armstrong DL, Wu SM, Sweatt JD, Zoghbi HY. SCA7 knockin mice model human SCA7 and reveal gradual accumulation of mutant ataxin-7 in neurons and abnormalities in short-term plasticity. Neuron 2003; 37:383-401. [PMID: 12575948 DOI: 10.1016/s0896-6273(02)01190-x] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We targeted 266 CAG repeats (a number that causes infantile-onset disease) into the mouse Sca7 locus to generate an authentic model of spinocerebellar ataxia type 7 (SCA7). These mice reproduced features of infantile SCA7 (ataxia, visual impairments, and premature death) and showed impaired short-term synaptic potentiation; downregulation of photoreceptor-specific genes, despite apparently normal CRX activity, led to shortening of photoreceptor outer segments. Wild-type ataxin-7 was barely detectable, as was mutant ataxin-7 in young animals; with increasing age, however, ataxin-7 staining became more pronounced. Neurons that appeared most vulnerable had relatively high levels of mutant ataxin-7; it is interesting, however, that marked dysfunction occurred in these neurons weeks prior to the appearance of nuclear inclusions. These data demonstrate that glutamine expansion stabilizes mutant ataxin-7, provide an explanation for selective neuronal vulnerability, and show that mutant ataxin-7 impairs posttetanic potentiation (PTP).
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Affiliation(s)
- Seung Yun Yoo
- Division of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
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