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Cui ZT, Mao ZT, Yang R, Li JJ, Jia SS, Zhao JL, Zhong FT, Yu P, Dong M. Spinocerebellar ataxias: from pathogenesis to recent therapeutic advances. Front Neurosci 2024; 18:1422442. [PMID: 38894941 PMCID: PMC11185097 DOI: 10.3389/fnins.2024.1422442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 05/08/2024] [Indexed: 06/21/2024] Open
Abstract
Spinocerebellar ataxia is a phenotypically and genetically heterogeneous group of autosomal dominant-inherited degenerative disorders. The gene mutation spectrum includes dynamic expansions, point mutations, duplications, insertions, and deletions of varying lengths. Dynamic expansion is the most common form of mutation. Mutations often result in indistinguishable clinical phenotypes, thus requiring validation using multiple genetic testing techniques. Depending on the type of mutation, the pathogenesis may involve proteotoxicity, RNA toxicity, or protein loss-of-function. All of which may disrupt a range of cellular processes, such as impaired protein quality control pathways, ion channel dysfunction, mitochondrial dysfunction, transcriptional dysregulation, DNA damage, loss of nuclear integrity, and ultimately, impairment of neuronal function and integrity which causes diseases. Many disease-modifying therapies, such as gene editing technology, RNA interference, antisense oligonucleotides, stem cell technology, and pharmacological therapies are currently under clinical trials. However, the development of curative approaches for genetic diseases remains a global challenge, beset by technical, ethical, and other challenges. Therefore, the study of the pathogenesis of spinocerebellar ataxia is of great importance for the sustained development of disease-modifying molecular therapies.
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Affiliation(s)
- Zi-Ting Cui
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Zong-Tao Mao
- Department of Plastic and Reconstructive Surgery, The First Hospital of Jilin University, Changchun, China
| | - Rong Yang
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Jia-Jia Li
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Shan-Shan Jia
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Jian-Li Zhao
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Fang-Tian Zhong
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Peng Yu
- Department of Ophthalmology, the Second Hospital of Jilin University, Changchun, China
| | - Ming Dong
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
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Henriques C, Lopes MM, Silva AC, Lobo DD, Badin RA, Hantraye P, Pereira de Almeida L, Nobre RJ. Viral-based animal models in polyglutamine disorders. Brain 2024; 147:1166-1189. [PMID: 38284949 DOI: 10.1093/brain/awae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 11/26/2023] [Accepted: 12/30/2023] [Indexed: 01/30/2024] Open
Abstract
Polyglutamine disorders are a complex group of incurable neurodegenerative disorders caused by an abnormal expansion in the trinucleotide cytosine-adenine-guanine tract of the affected gene. To better understand these disorders, our dependence on animal models persists, primarily relying on transgenic models. In an effort to complement and deepen our knowledge, researchers have also developed animal models of polyglutamine disorders employing viral vectors. Viral vectors have been extensively used to deliver genes to the brain, not only for therapeutic purposes but also for the development of animal models, given their remarkable flexibility. In a time- and cost-effective manner, it is possible to use different transgenes, at varying doses, in diverse targeted tissues, at different ages, and in different species, to recreate polyglutamine pathology. This paper aims to showcase the utility of viral vectors in disease modelling, share essential considerations for developing animal models with viral vectors, and provide a comprehensive review of existing viral-based animal models for polyglutamine disorders.
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Affiliation(s)
- Carina Henriques
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Miguel M Lopes
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
| | - Ana C Silva
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
| | - Diana D Lobo
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
| | - Romina Aron Badin
- CEA, DRF, Institute of Biology François Jacob, Molecular Imaging Research Center (MIRCen), 92265 Fontenay-aux-Roses, France
- CNRS, CEA, Paris-Sud University, Université Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), 92265 Fontenay-aux-Roses, France
| | - Philippe Hantraye
- CEA, DRF, Institute of Biology François Jacob, Molecular Imaging Research Center (MIRCen), 92265 Fontenay-aux-Roses, France
- CNRS, CEA, Paris-Sud University, Université Paris-Saclay, Neurodegenerative Diseases Laboratory (UMR9199), 92265 Fontenay-aux-Roses, France
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Rui Jorge Nobre
- Center for Neuroscience and Cell Biology (CNC), Gene and Stem Cell Therapies for the Brain Group, University of Coimbra, 3004-504 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), Vectors, Gene and Cell Therapy Group, University of Coimbra, 3004-504 Coimbra, Portugal
- ViraVector-Viral Vector for Gene Transfer Core Facility, University of Coimbra, 3004-504 Coimbra, Portugal
- Institute for Interdisciplinary Research (III), University of Coimbra, 3030-789 Coimbra, Portugal
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Felício D, du Mérac TR, Amorim A, Martins S. Functional implications of paralog genes in polyglutamine spinocerebellar ataxias. Hum Genet 2023; 142:1651-1676. [PMID: 37845370 PMCID: PMC10676324 DOI: 10.1007/s00439-023-02607-4] [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: 07/10/2023] [Accepted: 09/22/2023] [Indexed: 10/18/2023]
Abstract
Polyglutamine (polyQ) spinocerebellar ataxias (SCAs) comprise a group of autosomal dominant neurodegenerative disorders caused by (CAG/CAA)n expansions. The elongated stretches of adjacent glutamines alter the conformation of the native proteins inducing neurotoxicity, and subsequent motor and neurological symptoms. Although the etiology and neuropathology of most polyQ SCAs have been extensively studied, only a limited selection of therapies is available. Previous studies on SCA1 demonstrated that ATXN1L, a human duplicated gene of the disease-associated ATXN1, alleviated neuropathology in mice models. Other SCA-associated genes have paralogs (i.e., copies at different chromosomal locations derived from duplication of the parental gene), but their functional relevance and potential role in disease pathogenesis remain unexplored. Here, we review the protein homology, expression pattern, and molecular functions of paralogs in seven polyQ dominant ataxias-SCA1, SCA2, MJD/SCA3, SCA6, SCA7, SCA17, and DRPLA. Besides ATXN1L, we highlight ATXN2L, ATXN3L, CACNA1B, ATXN7L1, ATXN7L2, TBPL2, and RERE as promising functional candidates to play a role in the neuropathology of the respective SCA, along with the parental gene. Although most of these duplicates lack the (CAG/CAA)n region, if functionally redundant, they may compensate for a partial loss-of-function or dysfunction of the wild-type genes in SCAs. We aim to draw attention to the hypothesis that paralogs of disease-associated genes may underlie the complex neuropathology of dominant ataxias and potentiate new therapeutic strategies.
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Affiliation(s)
- Daniela Felício
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Instituto Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313, Porto, Portugal
| | - Tanguy Rubat du Mérac
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Faculty of Science, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands
| | - António Amorim
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal
| | - Sandra Martins
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal.
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OUP accepted manuscript. Brain 2022; 145:3022-3034. [DOI: 10.1093/brain/awac154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/14/2022] [Accepted: 04/03/2022] [Indexed: 11/12/2022] Open
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McIntosh CS, Li D, Wilton SD, Aung-Htut MT. Polyglutamine Ataxias: Our Current Molecular Understanding and What the Future Holds for Antisense Therapies. Biomedicines 2021; 9:1499. [PMID: 34829728 PMCID: PMC8615177 DOI: 10.3390/biomedicines9111499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 02/07/2023] Open
Abstract
Polyglutamine (polyQ) ataxias are a heterogenous group of neurological disorders all caused by an expanded CAG trinucleotide repeat located in the coding region of each unique causative gene. To date, polyQ ataxias encompass six disorders: spinocerebellar ataxia types 1, 2, 3, 6, 7, and 17 and account for a larger group of disorders simply known as polyglutamine disorders, which also includes Huntington's disease. These diseases are typically characterised by progressive ataxia, speech and swallowing difficulties, lack of coordination and gait, and are unfortunately fatal in nature, with the exception of SCA6. All the polyQ spinocerebellar ataxias have a hallmark feature of neuronal aggregations and share many common pathogenic mechanisms, such as mitochondrial dysfunction, impaired proteasomal function, and autophagy impairment. Currently, therapeutic options are limited, with no available treatments that slow or halt disease progression. Here, we discuss the common molecular and clinical presentations of polyQ spinocerebellar ataxias. We will also discuss the promising antisense oligonucleotide therapeutics being developed as treatments for these devastating diseases. With recent advancements and therapeutic approvals of various antisense therapies, it is envisioned that some of the studies reviewed may progress into clinical trials and beyond.
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Affiliation(s)
- Craig S. McIntosh
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Dunhui Li
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - Steve D. Wilton
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
| | - May T. Aung-Htut
- Molecular Therapy Laboratory, Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute Murdoch University, Discovery Way, Murdoch, WA 6150, Australia; (C.S.M.); (D.L.); (S.D.W.)
- Perron Institute for Neurological and Translational Science, Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA 6009, Australia
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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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Wernick AI, Walton RL, Soto-Beasley AI, Koga S, Heckman MG, Valentino RR, Milanowski LM, Hoffman-Zacharska D, Koziorowski D, Hassan A, Uitti RJ, Cheshire WP, Singer W, Wszolek ZK, Dickson DW, Low PA, Ross OA. Frequency of spinocerebellar ataxia mutations in patients with multiple system atrophy. Clin Auton Res 2021; 31:117-125. [PMID: 33502644 DOI: 10.1007/s10286-020-00759-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/18/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE Investigate single nucleotide variants and short tandem repeats in 39 genes related to spinocerebellar ataxia in clinical and pathologically defined cohorts of multiple system atrophy. METHODS Exome sequencing was conducted in 28 clinical multiple system atrophy patients to identify single nucleotide variants in spinocerebellar ataxia-related genes. Novel variants were validated in two independent disease cohorts: 86 clinically diagnosed multiple system atrophy patients and 166 pathological multiple system atrophy cases. Expanded repeat alleles in spinocerebellar ataxia genes were evaluated in 36 clinically diagnosed multiple system atrophy patients, and CAG/CAA repeats in TATA-Box Binding Protein (TBP, causative of SCA17) were screened in 216 clinical and pathological multiple system atrophy patients and 346 controls. RESULTS No known pathogenic spinocerebellar ataxia single nucleotide variants or pathogenic range expanded repeat alleles of ATXN1, ATXN2, ATXN3, CACNA1A, AXTN7, ATXN8OS, ATXN10, PPP2R2B, and TBP were detected in any clinical multiple system atrophy patients. However, four novel variants were identified in four spinocerebellar ataxia-related genes across three multiple system atrophy patients. Additionally, four multiple system atrophy patients (1.6%) and one control (0.3%) carried an intermediate length 41 TBP CAG/CAA repeat allele (OR = 4.11, P = 0.21). There was a significant association between the occurrence of a repeat length of longer alleles (> 38 repeats) and an increased risk of multiple system atrophy (OR = 1.64, P = 0.03). CONCLUSION Occurrence of TBP CAG/CAA repeat length of longer alleles (> 38 repeats) is significantly associated with increased multiple system atrophy risk. This discovery warrants further investigation and supports a possible genetic overlap of multiple system atrophy with SCA17.
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Affiliation(s)
- Anna I Wernick
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- School of Biological Sciences, University of Manchester, Manchester, UK
- Queen Square Institute of Neurology, University College London, London, UK
| | - Ronald L Walton
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Alexandra I Soto-Beasley
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Shunsuke Koga
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Michael G Heckman
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Jacksonville, FL, USA
| | - Rebecca R Valentino
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Lukasz M Milanowski
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
- Department of Neurology, Faculty of Health Science, Medical University of Warsaw, Warsaw, Poland
| | | | - Dariusz Koziorowski
- Department of Neurology, Faculty of Health Science, Medical University of Warsaw, Warsaw, Poland
| | - Anhar Hassan
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Ryan J Uitti
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | | | | | | | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Phillip A Low
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Owen A Ross
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
- Mayo Graduate School, Neuroscience Track, Mayo Clinic, Jacksonville, FL, USA.
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, USA.
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Baizabal-Carvallo JF, Cardoso F. Chorea in children: etiology, diagnostic approach and management. J Neural Transm (Vienna) 2020; 127:1323-1342. [DOI: 10.1007/s00702-020-02238-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/01/2020] [Indexed: 01/07/2023]
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New Synthetic 3-Benzoyl-5-Hydroxy-2 H-Chromen-2-One (LM-031) Inhibits Polyglutamine Aggregation and Promotes Neurite Outgrowth through Enhancement of CREB, NRF2, and Reduction of AMPK α in SCA17 Cell Models. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:3129497. [PMID: 32377295 PMCID: PMC7195640 DOI: 10.1155/2020/3129497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 03/25/2020] [Accepted: 04/02/2020] [Indexed: 12/31/2022]
Abstract
Spinocerebellar ataxia type 17 (SCA17) is caused by a CAG/CAA expansion mutation encoding an expanded polyglutamine (polyQ) tract in TATA-box binding protein (TBP), a general transcription initiation factor. Suppression of cAMP-responsive element binding protein- (CREB-) dependent transcription, impaired nuclear factor erythroid 2-related factor 2 (NRF2) signaling, and interaction of AMP-activated protein kinase (AMPK) with increased oxidative stress have been implicated to be involved in pathogenic mechanisms of polyQ-mediated diseases. In this study, we demonstrated decreased pCREB and NRF2 and activated AMPK contributing to neurotoxicity in SCA17 SH-SY5Y cells. We also showed that licochalcone A and the related in-house derivative compound 3-benzoyl-5-hydroxy-2H-chromen-2-one (LM-031) exhibited antiaggregation, antioxidative, antiapoptosis, and neuroprotective effects in TBP/Q79-GFP-expressing cell models. LM-031 and licochalcone A exerted neuroprotective effects by upregulating pCREB and its downstream genes, BCL2 and GADD45B, and enhancing NRF2. Furthermore, LM-031, but not licochalcone A, reduced activated AMPKα. Knockdown of CREB and NRF2 and treatment of AICAR (5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside), an AMPK activator, attenuated the aggregation-inhibiting and neurite outgrowth promoting effects of LM-031 on TBP/Q79 SH-SY5Y cells. The study results suggest the LM-031 as potential therapeutics for SCA17 and probable other polyQ diseases.
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Chen CM, Chen WL, Hung CT, Lin TH, Lee MC, Chen IC, Lin CH, Chao CY, Wu YR, Chang KH, Hsieh-Li HM, Lee-Chen GJ. Shaoyao Gancao Tang (SG-Tang), a formulated Chinese medicine, reduces aggregation and exerts neuroprotection in spinocerebellar ataxia type 17 (SCA17) cell and mouse models. Aging (Albany NY) 2020; 11:986-1007. [PMID: 30760647 PMCID: PMC6382417 DOI: 10.18632/aging.101804] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 01/24/2019] [Indexed: 12/22/2022]
Abstract
Spinocerebellar ataxia (SCA) type 17 is an autosomal dominant ataxia caused by expanded polyglutamine (polyQ) tract in the TATA-box binding protein (TBP). Substantial studies have shown involvement of compromised mitochondria biogenesis regulator peroxisome proliferator-activated receptor gamma-coactivator 1 alpha (PGC-1α), nuclear factor erythroid 2-related factor 2 (NRF2), nuclear factor-Y subunit A (NFYA), and their downstream target genes in the pathogenesis of polyQ-expansion diseases. The extracts of Paeonia lactiflora (P. lactiflora) and Glycyrrhiza uralensis (G. uralensis) have long been used as a Chinese herbal medicine (CHM). Shaoyao Gancao Tang (SG-Tang) is a formulated CHM made of P. lactiflora and G. uralensis at a 1:1 ratio. In the present study, we demonstrated the aggregate-inhibitory and anti-oxidative effect of SG-Tang in 293 TBP/Q79 cells. We then showed that SG-Tang reduced the aggregates and ameliorated the neurite outgrowth deficits in TBP/Q79 SH-SY5Y cells. SG-Tang upregulated expression levels of NFYA, PGC-1α, NRF2, and their downstream target genes in TBP/Q79 SH-SY5Y cells. Knock down of NFYA, PGC-1α, and NRF2 attenuated the neurite outgrowth promoting effect of SG-Tang on TBP/Q79 SH-SY5Y cells. Furthermore, SG-Tang inhibited aggregation and rescued motor-deficits in SCA17 mouse model. The study results suggest the potential of SG-Tang in treating SCA17 and probable other polyQ diseases.
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Affiliation(s)
- Chiung-Mei Chen
- Department of Neurology, Chang-Gung Memorial Hospital, Chang-Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Wan-Ling Chen
- Department of Neurology, Chang-Gung Memorial Hospital, Chang-Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Chen-Ting Hung
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Te-Hsien Lin
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | | | - I-Cheng Chen
- Department of Neurology, Chang-Gung Memorial Hospital, Chang-Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Chih-Hsin Lin
- Department of Neurology, Chang-Gung Memorial Hospital, Chang-Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Chih-Ying Chao
- Department of Neurology, Chang-Gung Memorial Hospital, Chang-Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Yih-Ru Wu
- Department of Neurology, Chang-Gung Memorial Hospital, Chang-Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Kuo-Hsuan Chang
- Department of Neurology, Chang-Gung Memorial Hospital, Chang-Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Hsiu Mei Hsieh-Li
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Guey-Jen Lee-Chen
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
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Abstract
The spinocerebellar ataxias (SCAs) are a genetically heterogeneous group of autosomal dominantly inherited progressive disorders, the clinical hallmark of which is loss of balance and coordination accompanied by slurred speech; onset is most often in adult life. Genetically, SCAs are grouped as repeat expansion SCAs, such as SCA3/Machado-Joseph disease (MJD), and rare SCAs that are caused by non-repeat mutations, such as SCA5. Most SCA mutations cause prominent damage to cerebellar Purkinje neurons with consecutive cerebellar atrophy, although Purkinje neurons are only mildly affected in some SCAs. Furthermore, other parts of the nervous system, such as the spinal cord, basal ganglia and pontine nuclei in the brainstem, can be involved. As there is currently no treatment to slow or halt SCAs (many SCAs lead to premature death), the clinical care of patients with SCA focuses on managing the symptoms through physiotherapy, occupational therapy and speech therapy. Intense research has greatly expanded our understanding of the pathobiology of many SCAs, revealing that they occur via interrelated mechanisms (including proteotoxicity, RNA toxicity and ion channel dysfunction), and has led to the identification of new targets for treatment development. However, the development of effective therapies is hampered by the heterogeneity of the SCAs; specific therapeutic approaches may be required for each disease.
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Jin W, Qazi TJ, Quan Z, Li N, Qing H. Dysregulation of Transcription Factors: A Key Culprit Behind Neurodegenerative Disorders. Neuroscientist 2018; 25:548-565. [PMID: 30484370 DOI: 10.1177/1073858418811787] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neurodegenerative diseases (NDs) are considered heterogeneous disorders characterized by progressive pathological changes in neuronal systems. Transcription factors are protein molecules that are important in regulating the expression of genes. Although the clinical manifestations of NDs vary, the pathological processes appear similar with regard to neuroinflammation, oxidative stress, and proteostasis, to which, as numerous studies have discovered, transcription factors are closely linked. In this review, we summarized and reviewed the roles of transcription factors in NDs, and then we elucidated their functions during pathological processes, and finally we discussed their therapeutic values in NDs.
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Affiliation(s)
- Wei Jin
- Beijing Key Laboratory of Separation and Analysis in Biomedical and Pharmaceuticals, Department of Biomedical Engineering, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
| | - Talal Jamil Qazi
- Beijing Key Laboratory of Separation and Analysis in Biomedical and Pharmaceuticals, Department of Biomedical Engineering, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
| | - Zhenzhen Quan
- Beijing Key Laboratory of Separation and Analysis in Biomedical and Pharmaceuticals, Department of Biomedical Engineering, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
| | - Nuomin Li
- Beijing Key Laboratory of Separation and Analysis in Biomedical and Pharmaceuticals, Department of Biomedical Engineering, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
| | - Hong Qing
- Beijing Key Laboratory of Separation and Analysis in Biomedical and Pharmaceuticals, Department of Biomedical Engineering, School of Life Science, Beijing Institute of Technology, Haidian District, Beijing, China
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13
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Abstract
Spinocerebellar ataxia (SCA) is a heterogeneous group of neurodegenerative ataxic disorders with autosomal dominant inheritance. We aim to provide an update on the recent clinical and scientific progresses in SCA where numerous novel genes have been identified with next-generation sequencing techniques. The main disease mechanisms of these SCAs include toxic RNA gain-of-function, mitochondrial dysfunction, channelopathies, autophagy and transcription dysregulation. Recent studies have also demonstrated the importance of DNA repair pathways in modifying SCA with CAG expansions. In addition, we summarise the latest technological advances in detecting known and novel repeat expansion in SCA. Finally, we discuss the roles of antisense oligonucleotides and RNA-based therapy as potential treatments.
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14
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The indole compound NC009-1 inhibits aggregation and promotes neurite outgrowth through enhancement of HSPB1 in SCA17 cells and ameliorates the behavioral deficits in SCA17 mice. Neurotoxicology 2018; 67:259-269. [PMID: 29936316 DOI: 10.1016/j.neuro.2018.06.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 06/14/2018] [Accepted: 06/14/2018] [Indexed: 12/18/2022]
Abstract
Spinocerebellar ataxia type 17 (SCA17) is caused by the expansion of translated CAG repeat in the TATA box binding protein (TBP) gene encoding a long polyglutamine (polyQ) tract in the TBP protein, which leads to intracellular accumulation of aggregated TBP and cell death. The molecular chaperones act in preventing protein aggregation to ameliorate downstream harmful events. In this study, we used Tet-On cells with inducible SCA17 TBP/Q79-GFP expression to test five in-house NC009 indole compounds for neuroprotection. We found that both aggregation and polyQ-induced reactive oxygen species can be significantly prohibited by the tested NC009 compounds in Tet-On TBP/Q79 293 cells. Among the five indole compounds, NC009-1 up-regulated expression of heat shock protein family B (small) member 1 (HSPB1) chaperone to reduce polyQ aggregation and promote neurite outgrowth in neuronal differentiated TBP/Q79 SH-SY5Y cells. The increased HSPB1 thus ameliorated the increased BH3 interacting domain death agonist (BID), cytochrome c (CYCS) release, and caspase 3 (CASP3) activation which result in apoptosis. Knock down of HSPB1 attenuated the effects of NC009-1 on TBP/Q79 SH-SY5Y cells, suggesting that HSPB1 might be one of the major pathways involved for NC009-1 effects. NC009-1 further reduced polyQ aggregation in Purkinje cells and ameliorated behavioral deficits in SCA17 TBP/Q109 transgenic mice. Our results suggest that NC009-1 has a neuroprotective effect on SCA17 cell and mouse models to support its therapeutic potential in SCA17 treatment.
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Huang M, Verbeek DS. Why do so many genetic insults lead to Purkinje Cell degeneration and spinocerebellar ataxia? Neurosci Lett 2018; 688:49-57. [PMID: 29421540 DOI: 10.1016/j.neulet.2018.02.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/02/2018] [Indexed: 12/29/2022]
Abstract
The genetically heterozygous spinocerebellar ataxias are all characterized by cerebellar atrophy and pervasive Purkinje Cell degeneration. Up to date, more than 35 functionally diverse spinocerebellar ataxia genes have been identified. The main question that remains yet unsolved is why do some many genetic insults lead to Purkinje Cell degeneration and spinocerebellar ataxia? To address this question it is important to identify intrinsic pathways important for Purkinje Cell function and survival. In this review, we discuss the current consensus on shared mechanisms underlying the pervasive Purkinje Cell loss in spinocerebellar ataxia. Additionally, using recently published cell type specific expression data, we identified several Purkinje Cell-specific genes and discuss how the corresponding pathways might underlie the vulnerability of Purkinje Cells in response to the diverse genetic insults causing spinocerebellar ataxia.
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Affiliation(s)
- Miaozhen Huang
- University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, The Netherlands
| | - Dineke S Verbeek
- University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, The Netherlands.
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16
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Bushart DD, Shakkottai VG. Ion channel dysfunction in cerebellar ataxia. Neurosci Lett 2018; 688:41-48. [PMID: 29421541 DOI: 10.1016/j.neulet.2018.02.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 02/02/2018] [Indexed: 12/31/2022]
Abstract
Cerebellar ataxias constitute a heterogeneous group of disorders that result in impaired speech, uncoordinated limb movements, and impaired balance, often ultimately resulting in wheelchair confinement. Motor dysfunction in ataxia can be attributed to dysfunction and degeneration of neurons in the cerebellum and its associated pathways. Recent work has suggested the importance of cerebellar neuronal dysfunction resulting from mutations in specific ion-channels that regulate membrane excitability in the pathogenesis of cerebellar ataxia in humans. Importantly, even in ataxias not directly due to ion-channel mutations, transcriptional changes resulting in ion-channel dysfunction are tied to motor dysfunction and degeneration in models of disease. In this review, we describe the role that ion-channel dysfunction plays in a variety of cerebellar ataxias, and postulate that a potential therapeutic strategy that targets specific ion-channels exists for cerebellar ataxia.
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Affiliation(s)
- David D Bushart
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor MI, USA
| | - Vikram G Shakkottai
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor MI, USA; Department of Neurology, University of Michigan, 4009 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109, USA.
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17
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Guo J, Cui Y, Liu Q, Yang Y, Li Y, Weng L, Tang B, Jin P, Li XJ, Yang S, Li S. Piperine ameliorates SCA17 neuropathology by reducing ER stress. Mol Neurodegener 2018; 13:4. [PMID: 29378605 PMCID: PMC5789626 DOI: 10.1186/s13024-018-0236-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 01/17/2018] [Indexed: 12/15/2022] Open
Abstract
Background Spinocerebellar ataxia 17 (SCA17) belongs to the family of neurodegenerative diseases caused by polyglutamine (polyQ) expansion. In SCA17, polyQ expansion occurs in the TATA box binding protein (TBP) and leads to the misfolding of TBP and the preferential degeneration in the cerebellar Purkinje neurons. Currently there is no effective treatment for SCA17. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a recently identified neurotrophic factor, and increasing MANF expression ameliorated SCA17 neuropathology in TBP-105Q knock-in (KI) mouse model, indicating that MANF could be a therapeutic target for treating SCA17. Methods In this study, we screened a collection of 2000 FDA-approved chemicals using a stable cell line expressing luciferase reporter, which is driven by MANF promoter. We identified several potential candidates that can induce the expression of MANF. Of these inducers, piperine is an agent that potently induces the luciferase expression or MANF expression. Results Addition of piperine in both cellular and mouse models of SCA17 alleviated toxicity caused by mutant TBP. Although mutant TBP is primarily localized in the nuclei, the polyQ expansion in TBP is able to induce ER stress, suggesting that nuclear misfolded proteins can also elicit ER stress as cytoplasmic misfolded proteins do. Moreover, piperine plays its protective role by reducing toxicity caused by the ER stress. Conclusion Our study established piperine as a MANF-based therapeutic agent for ER stress-related neuropathology in SCA17.
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Affiliation(s)
- Jifeng Guo
- Department of Neurology and National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.,Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Yiting Cui
- Department of Neurology and National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.,Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Qiong Liu
- Department of Neurology and National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.,Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Yang Yang
- Department of Neurology and National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.,Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Yujing Li
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Ling Weng
- Department of Neurology and National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Beisha Tang
- Department of Neurology and National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Xiao-Jiang Li
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA.,GHM Institute of CNS Regeneration, Jinan University, Guangzhou, 510631, China
| | - Su Yang
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA.
| | - Shihua Li
- Department of Neurology and National Clinical Research Center for Geriatric Disorder, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China. .,Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA, 30322, USA.
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18
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Paulson HL, Shakkottai VG, Clark HB, Orr HT. Polyglutamine spinocerebellar ataxias - from genes to potential treatments. Nat Rev Neurosci 2017; 18:613-626. [PMID: 28855740 PMCID: PMC6420820 DOI: 10.1038/nrn.2017.92] [Citation(s) in RCA: 220] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The dominantly inherited spinocerebellar ataxias (SCAs) are a large and diverse group of neurodegenerative diseases. The most prevalent SCAs (SCA1, SCA2, SCA3, SCA6 and SCA7) are caused by expansion of a glutamine-encoding CAG repeat in the affected gene. These SCAs represent a substantial portion of the polyglutamine neurodegenerative disorders and provide insight into this class of diseases as a whole. Recent years have seen considerable progress in deciphering the clinical, pathological, physiological and molecular aspects of the polyglutamine SCAs, with these advances establishing a solid base from which to pursue potential therapeutic approaches.
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Affiliation(s)
- Henry L Paulson
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Vikram G Shakkottai
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - H Brent Clark
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota, 55455, USA
| | - Harry T Orr
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota, 55455, USA
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota, 55455, USA
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MANF regulates hypothalamic control of food intake and body weight. Nat Commun 2017; 8:579. [PMID: 28924165 PMCID: PMC5603516 DOI: 10.1038/s41467-017-00750-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 07/25/2017] [Indexed: 12/30/2022] Open
Abstract
The hypothalamus has a vital role in controlling food intake and energy homeostasis; its activity is modulated by neuropeptides and endocrine factors. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a neurotrophic factor that is also localized in the endoplasmic reticulum (ER) in neurons. Here we show that MANF is highly enriched in distinct nuclei of the mouse hypothalamus, and that MANF expression in the hypothalamus is upregulated in response to fasting. Increasing or decreasing hypothalamic MANF protein levels causes hyperphagia or hypophagia, respectively. Moreover, MANF triggers hypothalamic insulin resistance by enhancing the ER localization and activity of PIP4k2b, a kinase known to regulate insulin signaling. Our findings indicate that MANF influences food intake and body weight by modulating hypothalamic insulin signaling.MANF is a neurotrophic factor that is secreted but also mediates the unfolded protein response acting intracellularly. Here, the authors show that MANF expression in the brain is influenced by nutritional cues, and hypothalamic MANF influences food intake and systemic energy homeostasis.
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20
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Synergistic Toxicity of Polyglutamine-Expanded TATA-Binding Protein in Glia and Neuronal Cells: Therapeutic Implications for Spinocerebellar Ataxia 17. J Neurosci 2017; 37:9101-9115. [PMID: 28821675 DOI: 10.1523/jneurosci.0111-17.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 07/09/2017] [Accepted: 07/24/2017] [Indexed: 01/12/2023] Open
Abstract
Spinocerebellar ataxia 17 (SCA17) is caused by polyglutamine (polyQ) repeat expansion in the TATA-binding protein (TBP) and is among a family of neurodegenerative diseases in which polyQ expansion leads to preferential neuronal loss in the brain. Although previous studies have demonstrated that expression of polyQ-expanded proteins in glial cells can cause neuronal injury via noncell-autonomous mechanisms, these studies investigated animal models that overexpress transgenic mutant proteins. Since glial cells are particularly reactive to overexpressed mutant proteins, it is important to investigate the in vivo role of glial dysfunction in neurodegeneration when mutant polyQ proteins are endogenously expressed. In the current study, we generated two conditional TBP-105Q knock-in mouse models that specifically express mutant TBP at the endogenous level in neurons or in astrocytes. We found that mutant TBP expression in neuronal cells or astrocytes alone only caused mild neurodegeneration, whereas severe neuronal toxicity requires the expression of mutant TBP in both neuronal and glial cells. Coculture of neurons and astrocytes further validated that mutant TBP in astrocytes promoted neuronal injury. We identified activated inflammatory signaling pathways in mutant TBP-expressing astrocytes, and blocking nuclear factor κB (NF-κB) signaling in astrocytes ameliorated neurodegeneration. Our results indicate that the synergistic toxicity of mutant TBP in neuronal and glial cells plays a critical role in SCA17 pathogenesis and that targeting glial inflammation could be a potential therapeutic approach for SCA17 treatment.SIGNIFICANCE STATEMENT Mutant TBP with polyglutamine expansion preferentially affects neuronal viability in SCA17 patients. Whether glia, the cells that support and protect neurons, contribute to neurodegeneration in SCA17 remains mostly unexplored. In this study, we provide both in vivo and in vitro evidence arguing that endogenous expression of mutant TBP in neurons and glia synergistically impacts neuronal survival. Hyperactivated inflammatory signaling pathways, particularly the NF-κB pathway, underlie glia-mediated neurotoxicity. Moreover, blocking NF-κB activity with small chemical inhibitors alleviated such neurotoxicity. Our study establishes glial dysfunction as an important component of SCA17 pathogenesis and suggests targeting glial inflammation as a potential therapeutic approach for SCA17 treatment.
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