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Costa RG, Conceição A, Matos CA, Nóbrega C. The polyglutamine protein ATXN2: from its molecular functions to its involvement in disease. Cell Death Dis 2024; 15:415. [PMID: 38877004 PMCID: PMC11178924 DOI: 10.1038/s41419-024-06812-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 06/16/2024]
Abstract
A CAG repeat sequence in the ATXN2 gene encodes a polyglutamine (polyQ) tract within the ataxin-2 (ATXN2) protein, showcasing a complex landscape of functions that have been progressively unveiled over recent decades. Despite significant progresses in the field, a comprehensive overview of the mechanisms governed by ATXN2 remains elusive. This multifaceted protein emerges as a key player in RNA metabolism, stress granules dynamics, endocytosis, calcium signaling, and the regulation of the circadian rhythm. The CAG overexpansion within the ATXN2 gene produces a protein with an extended poly(Q) tract, inducing consequential alterations in conformational dynamics which confer a toxic gain and/or partial loss of function. Although overexpanded ATXN2 is predominantly linked to spinocerebellar ataxia type 2 (SCA2), intermediate expansions are also implicated in amyotrophic lateral sclerosis (ALS) and parkinsonism. While the molecular intricacies await full elucidation, SCA2 presents ATXN2-associated pathological features, encompassing autophagy impairment, RNA-mediated toxicity, heightened oxidative stress, and disruption of calcium homeostasis. Presently, SCA2 remains incurable, with patients reliant on symptomatic and supportive treatments. In the pursuit of therapeutic solutions, various studies have explored avenues ranging from pharmacological drugs to advanced therapies, including cell or gene-based approaches. These endeavours aim to address the root causes or counteract distinct pathological features of SCA2. This review is intended to provide an updated compendium of ATXN2 functions, delineate the associated pathological mechanisms, and present current perspectives on the development of innovative therapeutic strategies.
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Affiliation(s)
- Rafael G Costa
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal.
- PhD program in Biomedical Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
| | - André Conceição
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- PhD program in Biomedical Sciences, Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
- Center for Neuroscience and Cell Biology (CNC), Coimbra, Portugal
- Champalimaud Research Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Carlos A Matos
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal
| | - Clévio Nóbrega
- Algarve Biomedical Center Research Institute (ABC-RI), Faro, Portugal.
- Faculdade de Medicina e Ciências Biomédicas, Universidade do Algarve (UAlg), Faro, Portugal.
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2
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Cole BA, Becker EBE. Modulation and Regulation of Canonical Transient Receptor Potential 3 (TRPC3) Channels. Cells 2023; 12:2215. [PMID: 37759438 PMCID: PMC10526463 DOI: 10.3390/cells12182215] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/30/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023] Open
Abstract
Canonical transient receptor potential 3 (TRPC3) channel is a non-selective cation permeable channel that plays an essential role in calcium signalling. TRPC3 is highly expressed in the brain and also found in endocrine tissues and smooth muscle cells. The channel is activated directly by binding of diacylglycerol downstream of G-protein coupled receptor activation. In addition, TRPC3 is regulated by endogenous factors including Ca2+ ions, other endogenous lipids, and interacting proteins. The molecular and structural mechanisms underlying activation and regulation of TRPC3 are incompletely understood. Recently, several high-resolution cryogenic electron microscopy structures of TRPC3 and the closely related channel TRPC6 have been resolved in different functional states and in the presence of modulators, coupled with mutagenesis studies and electrophysiological characterisation. Here, we review the recent literature which has advanced our understanding of the complex mechanisms underlying modulation of TRPC3 by both endogenous and exogenous factors. TRPC3 plays an important role in Ca2+ homeostasis and entry into cells throughout the body, and both pathological variants and downstream dysregulation of TRPC3 channels have been associated with a number of diseases. As such, TRPC3 may be a valuable therapeutic target, and understanding its regulatory mechanisms will aid future development of pharmacological modulators of the channel.
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Affiliation(s)
- Bethan A. Cole
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Esther B. E. Becker
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
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3
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Kapfhammer JP, Shimobayashi E. Viewpoint: spinocerebellar ataxias as diseases of Purkinje cell dysfunction rather than Purkinje cell loss. Front Mol Neurosci 2023; 16:1182431. [PMID: 37426070 PMCID: PMC10323145 DOI: 10.3389/fnmol.2023.1182431] [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: 03/08/2023] [Accepted: 05/22/2023] [Indexed: 07/11/2023] Open
Abstract
Spinocerebellar ataxias (SCAs) are a group of hereditary neurodegenerative diseases mostly affecting cerebellar Purkinje cells caused by a wide variety of different mutations. One subtype, SCA14, is caused by mutations of Protein Kinase C gamma (PKCγ), the dominant PKC isoform present in Purkinje cells. Mutations in the pathway in which PKCγ is active, i.e., in the regulation of calcium levels and calcium signaling in Purkinje cells, are the cause of several other variants of SCA. In SCA14, many of the observed mutations in the PKCγ gene were shown to increase the basal activity of PKCγ, raising the possibility that increased activity of PKCγ might be the cause of most forms of SCA14 and might also be involved in the pathogenesis of SCA in related subtypes. In this viewpoint and review article we will discuss the evidence for and against such a major role of PKCγ basal activity and will suggest a hypothesis of how PKCγ activity and the calcium signaling pathway may be involved in the pathogenesis of SCAs despite the different and sometimes opposing effects of mutations affecting these pathways. We will then widen the scope and propose a concept of SCA pathogenesis which is not primarily driven by cell death and loss of Purkinje cells but rather by dysfunction of Purkinje cells which are still present and alive in the cerebellum.
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Egorova PA, Marinina KS, Bezprozvanny IB. Chronic suppression of STIM1-mediated calcium signaling in Purkinje cells rescues the cerebellar pathology in spinocerebellar ataxia type 2. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119466. [PMID: 36940741 DOI: 10.1016/j.bbamcr.2023.119466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/23/2023]
Abstract
Distorted neuronal calcium signaling has been reported in many neurodegenerative disorders, including different types of spinocerebellar ataxias (SCAs). Cerebellar Purkinje cells (PCs) are primarily affected in SCAs and the disturbances in the calcium homeostasis were observed in SCA PCs. Our previous results have revealed that 3,5-dihydroxyphenylglycine (DHPG) induced greater calcium responses in SCA2-58Q PC cultures than in wild type (WT) PC cultures. Here we observed that glutamate-induced calcium release in PCs cells bodies is significantly higher in SCA2-58Q PCs from acute cerebellar slices compared to WT PCs of the same age. Recent studies have demonstrated that the stromal interaction molecule 1 (STIM1) plays an important role in the regulation of the neuronal calcium signaling in cerebellar PCs in mice. The main function of STIM1 is to regulate store-operated calcium entry through the TRPC/Orai channels formation to refill the calcium stores in the ER when it is empty. Here we demonstrated that the chronic viral-mediated expression of the small interfering RNA (siRNA) targeting STIM1 specifically in cerebellar PCs alleviates the deranged calcium signaling in SCA2-58Q PCs, rescues the spine loss in these cerebellar neurons, and also improves the motor decline in SCA2-58Q mice. Thus, our preliminary results support the important role of the altered neuronal calcium signaling in SCA2 pathology and also suggest the STIM1-mediated signaling pathway as a potential therapeutic target for treatment of SCA2 patients.
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Affiliation(s)
- Polina A Egorova
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Ksenia S Marinina
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Ilya B Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia; Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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5
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Mei X, Yin C, Pan Y, Chen L, Wu C, Li X, Feng Z. The role of ectopic P granules protein 5 homolog (EPG5) in DHPG-induced pain sensitization in mice. J Neurochem 2023; 165:196-210. [PMID: 36748629 DOI: 10.1111/jnc.15779] [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: 08/01/2022] [Revised: 01/29/2023] [Accepted: 02/01/2023] [Indexed: 02/08/2023]
Abstract
Nociplastic pain is a severe health problem, while its mechanisms are still unclear. (R, S)-3,5-Dihydroxyphenylglycine (DHPG) is a group I metabotropic glutamate receptor (mGluR) agonist that can cause central sensitization, which plays a role in nociplastic pain. In this study, after intrathecal injection of 25 nmol DHPG for three consecutive days, whole proteins were extracted from the L4~6 lumbar spinal cord of mice 2 h after intrathecal administration on the third day for proteomics analysis. Based on the results, 15 down-regulated and 20 up-regulated proteins were identified in mice. Real-time quantitative PCR (RT-qPCR) and western blotting (WB) revealed that the expression of ectopic P granules protein 5 homolog (EPG5) mRNA and protein were significantly up-regulated compared with the control group, which was consistent with the proteomics results. Originally identified in the genetic screening of Caenorhabditis elegans, EPG5 is mainly involved in regulating autophagy in the body, and in our study, it was mainly expressed in spinal neurons, as revealed by immunohistochemistry staining. After the intrathecal injection of 8 μL adeno-associated virus (AAV)-EPG5 short hairpin RNA (shRNA) to knock down spinal EPG5, the hyperalgesia caused by DHPG was relieved. Altogether, these results suggest that EPG5 plays an important role in DHPG-induced pain sensitization in mice.
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Affiliation(s)
- Xiangyang Mei
- Department of Pain Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chengyu Yin
- Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Hangzhou, China
| | - Yushuang Pan
- Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Hangzhou, China
| | - Lei Chen
- Department of Pain Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Cheng Wu
- Institute of Neuroscience, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiangyao Li
- Institute of Neuroscience, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhiying Feng
- Department of Pain Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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6
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Cendelin J, Cvetanovic M, Gandelman M, Hirai H, Orr HT, Pulst SM, Strupp M, Tichanek F, Tuma J, Manto M. Consensus Paper: Strengths and Weaknesses of Animal Models of Spinocerebellar Ataxias and Their Clinical Implications. THE CEREBELLUM 2021; 21:452-481. [PMID: 34378174 DOI: 10.1007/s12311-021-01311-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/21/2021] [Indexed: 01/02/2023]
Abstract
Spinocerebellar ataxias (SCAs) represent a large group of hereditary degenerative diseases of the nervous system, in particular the cerebellum, and other systems that manifest with a variety of progressive motor, cognitive, and behavioral deficits with the leading symptom of cerebellar ataxia. SCAs often lead to severe impairments of the patient's functioning, quality of life, and life expectancy. For SCAs, there are no proven effective pharmacotherapies that improve the symptoms or substantially delay disease progress, i.e., disease-modifying therapies. To study SCA pathogenesis and potential therapies, animal models have been widely used and are an essential part of pre-clinical research. They mainly include mice, but also other vertebrates and invertebrates. Each animal model has its strengths and weaknesses arising from model animal species, type of genetic manipulation, and similarity to human diseases. The types of murine and non-murine models of SCAs, their contribution to the investigation of SCA pathogenesis, pathological phenotype, and therapeutic approaches including their advantages and disadvantages are reviewed in this paper. There is a consensus among the panel of experts that (1) animal models represent valuable tools to improve our understanding of SCAs and discover and assess novel therapies for this group of neurological disorders characterized by diverse mechanisms and differential degenerative progressions, (2) thorough phenotypic assessment of individual animal models is required for studies addressing therapeutic approaches, (3) comparative studies are needed to bring pre-clinical research closer to clinical trials, and (4) mouse models complement cellular and invertebrate models which remain limited in terms of clinical translation for complex neurological disorders such as SCAs.
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Affiliation(s)
- Jan Cendelin
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 75, 323 00, Plzen, Czech Republic. .,Laboratory of Neurodegenerative Disorders, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, alej Svobody 75, 323 00, Plzen, Czech Republic.
| | - Marija Cvetanovic
- Department of Neuroscience, Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Mandi Gandelman
- Department of Neurology, University of Utah, 175 North Medical Drive East, Salt Lake City, UT, 84132, USA
| | - Hirokazu Hirai
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, 3-39-22, Gunma, 371-8511, Japan.,Viral Vector Core, Gunma University Initiative for Advanced Research (GIAR), Gunma, 371-8511, Japan
| | - Harry T Orr
- Department of Laboratory Medicine and Pathology, Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, 175 North Medical Drive East, Salt Lake City, UT, 84132, USA
| | - Michael Strupp
- Department of Neurology and German Center for Vertigo and Balance Disorders, Hospital of the Ludwig-Maximilians University, Munich, Campus Grosshadern, Marchioninistr. 15, 81377, Munich, Germany
| | - Filip Tichanek
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 75, 323 00, Plzen, Czech Republic.,Laboratory of Neurodegenerative Disorders, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, alej Svobody 75, 323 00, Plzen, Czech Republic
| | - Jan Tuma
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 75, 323 00, Plzen, Czech Republic.,The Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MC 7843, San Antonio, TX, 78229, USA
| | - Mario Manto
- Unité des Ataxies Cérébelleuses, Service de Neurologie, CHU-Charleroi, Charleroi, Belgium.,Service des Neurosciences, Université de Mons, UMons, Mons, Belgium
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7
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Scoles DR, Dansithong W, Pflieger LT, Paul S, Gandelman M, Figueroa KP, Rigo F, Bennett CF, Pulst SM. ALS-associated genes in SCA2 mouse spinal cord transcriptomes. Hum Mol Genet 2021; 29:1658-1672. [PMID: 32307524 PMCID: PMC7322574 DOI: 10.1093/hmg/ddaa072] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 04/07/2020] [Accepted: 04/09/2020] [Indexed: 12/12/2022] Open
Abstract
The spinocerebellar ataxia type 2 (SCA2) gene ATXN2 has a prominent role in the pathogenesis and treatment of amyotrophic lateral sclerosis (ALS). In addition to cerebellar ataxia, motor neuron disease is often seen in SCA2, and ATXN2 CAG repeat expansions in the long normal range increase ALS risk. Also, lowering ATXN2 expression in TDP-43 ALS mice prolongs their survival. Here we investigated the ATXN2 relationship with motor neuron dysfunction in vivo by comparing spinal cord (SC) transcriptomes reported from TDP-43 and SOD1 ALS mice and ALS patients with those from SCA2 mice. SC transcriptomes were determined using an SCA2 bacterial artificial chromosome mouse model expressing polyglutamine expanded ATXN2. SCA2 cerebellar transcriptomes were also determined, and we also investigated the modification of gene expression following treatment of SCA2 mice with an antisense oligonucleotide (ASO) lowering ATXN2 expression. Differentially expressed genes (DEGs) defined three interconnected pathways (innate immunity, fatty acid biosynthesis and cholesterol biosynthesis) in separate modules identified by weighted gene co-expression network analysis. Other key pathways included the complement system and lysosome/phagosome pathways. Of all DEGs in SC, 12.6% were also dysregulated in the cerebellum. Treatment of mice with an ATXN2 ASO also modified innate immunity, the complement system and lysosome/phagosome pathways. This study provides new insights into the underlying molecular basis of SCA2 SC phenotypes and demonstrates annotated pathways shared with TDP-43 and SOD1 ALS mice and ALS patients. It also emphasizes the importance of ATXN2 in motor neuron degeneration and confirms ATXN2 as a therapeutic target.
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Affiliation(s)
- Daniel R Scoles
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT 84132, USA
| | - Warunee Dansithong
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT 84132, USA
| | - Lance T Pflieger
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT 84132, USA.,Department of Biomedical Informatics, University of Utah, 421 Wakara Way, Salt Lake City, UT 84108, USA
| | - Sharan Paul
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT 84132, USA
| | - Mandi Gandelman
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT 84132, USA
| | - Karla P Figueroa
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT 84132, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - C Frank Bennett
- Ionis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT 84132, USA
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Paul S, Dansithong W, Figueroa KP, Gandelman M, Scoles DR, Pulst SM. Staufen1 in Human Neurodegeneration. Ann Neurol 2021; 89:1114-1128. [PMID: 33745139 DOI: 10.1002/ana.26069] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 02/10/2021] [Accepted: 03/14/2021] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Mutations in the ATXN2 gene (CAG expansions ≥32 repeats) can be a rare cause of Parkinson's disease and amyotrophic lateral sclerosis (ALS). We recently reported that the stress granule (SG) protein Staufen1 (STAU1) was overabundant in neurodegenerative disorder spinocerebellar ataxia type 2 (SCA2) patient cells, animal models, and ALS-TDP-43 fibroblasts, and provided a link between SG formation and autophagy. We aimed to test if STAU1 overabundance has a role in the pathogenesis of other neurodegenerative diseases. METHODS With multiple neurodegenerative patient-derived cell models, animal models, and human postmortem ALS tissue, we evaluate STAU1 function using biochemical and immunohistological analyses. RESULTS We demonstrate STAU1 overabundance and increased total and phosphorylated mammalian target of rapamycin (mTOR) in fibroblast cells from patients with ALS with mutations in TDP-43, patients with dementia with PSEN1 mutations, a patient with parkinsonism with MAPT mutation, Huntington's disease (HD) mutations, and SCA2 mutations. Increased STAU1 levels and mTOR activity were seen in human ALS spinal cord tissues as well as in animal models. Changes in STAU1 and mTOR protein levels were post-transcriptional. Exogenous expression of STAU1 in wildtype cells was sufficient to activate mTOR and downstream targets and form SGs. Targeting STAU1 by RNAi normalized mTOR, suggesting a potential role for therapy in diseases associated with STAU1 overabundance. INTERPRETATION STAU1 overabundance in neurodegeneration is a common phenomenon associated with hyperactive mTOR. Targeting STAU1 with ASOs or miRNA viral vectors may represent a novel, efficacious therapy for neurodegenerative diseases characterized by overabundant STAU1. ANN NEUROL 2021;89:1114-1128.
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Affiliation(s)
- Sharan Paul
- Department of Neurology, University of Utah, Salt Lake City, UT
| | | | | | - Mandi Gandelman
- Department of Neurology, University of Utah, Salt Lake City, UT
| | - Daniel R Scoles
- Department of Neurology, University of Utah, Salt Lake City, UT
| | - Stefan M Pulst
- Department of Neurology, University of Utah, Salt Lake City, UT
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Dhyani V, Gare S, Gupta RK, Swain S, Venkatesh K, Giri L. GPCR mediated control of calcium dynamics: A systems perspective. Cell Signal 2020; 74:109717. [PMID: 32711109 PMCID: PMC7375278 DOI: 10.1016/j.cellsig.2020.109717] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 02/09/2023]
Abstract
G-protein coupled receptor (GPCR) mediated calcium (Ca2+)-signaling transduction remains crucial in designing drugs for various complex diseases including neurodegeneration, chronic heart failure as well as respiratory diseases. Although there are several reviews detailing various aspects of Ca2+-signaling such as the role of IP3 receptors and Ca2+-induced-Ca2+-release, none of them provide an integrated view of the mathematical descriptions of GPCR signal transduction and investigations on dose-response curves. This article is the first study in reviewing the network structures underlying GPCR signal transduction that control downstream [Cac2+]-oscillations. The central theme of this paper is to present the biochemical pathways, as well as molecular mechanisms underlying the GPCR-mediated Ca2+-dynamics in order to facilitate a better understanding of how agonist concentration is encoded in Ca2+-signals for Gαq, Gαs, and Gαi/o signaling pathways. Moreover, we present the GPCR targeting drugs that are relevant for treating cardiac, respiratory, and neuro-diseases. The current paper presents the ODE formulation for various models along with the detailed schematics of signaling networks. To provide a systems perspective, we present the network motifs that can provide readers an insight into the complex and intriguing science of agonist-mediated Ca2+-dynamics. One of the features of this review is to pinpoint the interplay between positive and negative feedback loops that are involved in controlling intracellular [Cac2+]-oscillations. Furthermore, we review several examples of dose-response curves obtained from [Cac2+]-spiking for various GPCR pathways. This paper is expected to be useful for pharmacologists and computational biologists for designing clinical applications of GPCR targeting drugs through modulation of Ca2+-dynamics.
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Affiliation(s)
- Vaibhav Dhyani
- Department of Chemical Engineering, Indian Institute of Technology Hyderabad, Sangareddy, Telangana, India
| | - Suman Gare
- Department of Chemical Engineering, Indian Institute of Technology Hyderabad, Sangareddy, Telangana, India
| | - Rishikesh Kumar Gupta
- Department of Chemical Engineering, Indian Institute of Technology Hyderabad, Sangareddy, Telangana, India
| | - Sarpras Swain
- Department of Chemical Engineering, Indian Institute of Technology Hyderabad, Sangareddy, Telangana, India
| | - K.V. Venkatesh
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
| | - Lopamudra Giri
- Department of Chemical Engineering, Indian Institute of Technology Hyderabad, Sangareddy, Telangana, India.
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10
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Robinson KJ, Watchon M, Laird AS. Aberrant Cerebellar Circuitry in the Spinocerebellar Ataxias. Front Neurosci 2020; 14:707. [PMID: 32765211 PMCID: PMC7378801 DOI: 10.3389/fnins.2020.00707] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/11/2020] [Indexed: 12/11/2022] Open
Abstract
The spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative diseases that share convergent disease features. A common symptom of these diseases is development of ataxia, involving impaired balance and motor coordination, usually stemming from cerebellar dysfunction and neurodegeneration. For most spinocerebellar ataxias, pathology can be attributed to an underlying gene mutation and the impaired function of the encoded protein through loss or gain-of-function effects. Strikingly, despite vast heterogeneity in the structure and function of disease-causing genes across the SCAs and the cellular processes affected, the downstream effects have considerable overlap, including alterations in cerebellar circuitry. Interestingly, aberrant function and degeneration of Purkinje cells, the major output neuronal population present within the cerebellum, precedes abnormalities in other neuronal populations within many SCAs, suggesting that Purkinje cells have increased vulnerability to cellular perturbations. Factors that are known to contribute to perturbed Purkinje cell function in spinocerebellar ataxias include altered gene expression resulting in altered expression or functionality of proteins and channels that modulate membrane potential, downstream impairments in intracellular calcium homeostasis and changes in glutamatergic input received from synapsing climbing or parallel fibers. This review will explore this enhanced vulnerability and the aberrant cerebellar circuitry linked with it in many forms of SCA. It is critical to understand why Purkinje cells are vulnerable to such insults and what overlapping pathogenic mechanisms are occurring across multiple SCAs, despite different underlying genetic mutations. Enhanced understanding of disease mechanisms will facilitate the development of treatments to prevent or slow progression of the underlying neurodegenerative processes, cerebellar atrophy and ataxic symptoms.
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Affiliation(s)
| | | | - Angela S. Laird
- Centre for Motor Neuron Disease Research, Department of Biomedical Science, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
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11
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Egorova PA, Gavrilova AV, Bezprozvanny IB. Ataxic Symptoms in Huntington's Disease Transgenic Mouse Model Are Alleviated by Chlorzoxazone. Front Neurosci 2020; 14:279. [PMID: 32317916 PMCID: PMC7147686 DOI: 10.3389/fnins.2020.00279] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 03/11/2020] [Indexed: 12/11/2022] Open
Abstract
Huntington’s disease (HD) is a hereditary neurodegenerative disease caused by a polyglutamine expansion in the huntingtin protein, Striatum atrophy in HD leads to a progressive disturbance of psychiatric, motor, and cognitive function. Recent studies of HD patients revealed that the degeneration of cerebellum is also observed independently from the striatal atrophy during early HD stage and may contribute to the motor impairment and ataxia observed in HD. Cerebellar Purkinje cells (PCs) are responsible for the proper cerebellar pathways functioning and motor control. Recent studies on mouse models of HD have shown that the abnormality of the biochemical functions of PCs are observed in HD, suggesting the contribution of PC dysfunction and death to the impaired movement coordination observed in HD. To investigate ataxic symptoms in HD we performed a series of experiments with the yeast artificial chromosome transgenic mouse model of HD (YAC128). Using extracellular single-unit recording method we found that the portion of the cerebellar PCs with bursting and irregular patterns of spontaneous activity drastically rises in aged YAC128 HD mice when compared with wild type littermates. Previous studies demonstrated that SK channels are responsible for the cerebellar PC pacemaker activity and that positive modulation of SK channel activity exerted beneficial effects in different ataxic mouse models. Here we studied effects of the SK channels modulator chlorzoxazone (CHZ) on the motor behavior of YAC128 HD mice and also on the electrophysiological activity and neuroanatomy of the cerebellar PCs from these mice. We determined that the long-term intraperitoneal injections of CHZ alleviated the progressive impairment in the firing pattern of YAC128 PCs. We also demonstrated that treatment with CHZ rescued age-dependent motor incoordination and improved the cerebellar morphology in YAC128 mice. We propose that abnormal changes in the PC firing patterns might be a one of the possible causes of ataxic symptoms in HD and in other polyglutamine disorders and that the pharmacological activation of SK channels may serve as a potential way to improve the activity of cerebellar PCs and relieve the ataxic phenotype in HD patients.
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Affiliation(s)
- Polina A Egorova
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Aleksandra V Gavrilova
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Ilya B Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia.,Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
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12
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Binda F, Pernaci C, Saxena S. Cerebellar Development and Circuit Maturation: A Common Framework for Spinocerebellar Ataxias. Front Neurosci 2020; 14:293. [PMID: 32300292 PMCID: PMC7145357 DOI: 10.3389/fnins.2020.00293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 03/13/2020] [Indexed: 01/24/2023] Open
Abstract
Spinocerebellar ataxias (SCAs) affect the cerebellum and its afferent and efferent systems that degenerate during disease progression. In the cerebellum, Purkinje cells (PCs) are the most vulnerable and their prominent loss in the late phase of the pathology is the main characteristic of these neurodegenerative diseases. Despite the constant advancement in the discovery of affected molecules and cellular pathways, a comprehensive description of the events leading to the development of motor impairment and degeneration is still lacking. However, in the last years the possible causal role for altered cerebellar development and neuronal circuit wiring in SCAs has been emerging. Not only wiring and synaptic transmission deficits are a common trait of SCAs, but also preventing the expression of the mutant protein during cerebellar development seems to exert a protective role. By discussing this tight relationship between cerebellar development and SCAs, in this review, we aim to highlight the importance of cerebellar circuitry for the investigation of SCAs.
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Affiliation(s)
- Francesca Binda
- Department of Neurology, Center for Experimental Neurology, University Hospital of Bern, Bern, Switzerland.,Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Carla Pernaci
- Department of Neurology, Center for Experimental Neurology, University Hospital of Bern, Bern, Switzerland.,Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Switzerland
| | - Smita Saxena
- Department of Neurology, Center for Experimental Neurology, University Hospital of Bern, Bern, Switzerland.,Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
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13
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Prestori F, Moccia F, D’Angelo E. Disrupted Calcium Signaling in Animal Models of Human Spinocerebellar Ataxia (SCA). Int J Mol Sci 2019; 21:ijms21010216. [PMID: 31892274 PMCID: PMC6981692 DOI: 10.3390/ijms21010216] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/22/2019] [Accepted: 12/24/2019] [Indexed: 12/12/2022] Open
Abstract
Spinocerebellar ataxias (SCAs) constitute a heterogeneous group of more than 40 autosomal-dominant genetic and neurodegenerative diseases characterized by loss of balance and motor coordination due to dysfunction of the cerebellum and its efferent connections. Despite a well-described clinical and pathological phenotype, the molecular and cellular events that underlie neurodegeneration are still poorly undaerstood. Emerging research suggests that mutations in SCA genes cause disruptions in multiple cellular pathways but the characteristic SCA pathogenesis does not begin until calcium signaling pathways are disrupted in cerebellar Purkinje cells. Ca2+ signaling in Purkinje cells is important for normal cellular function as these neurons express a variety of Ca2+ channels, Ca2+-dependent kinases and phosphatases, and Ca2+-binding proteins to tightly maintain Ca2+ homeostasis and regulate physiological Ca2+-dependent processes. Abnormal Ca2+ levels can activate toxic cascades leading to characteristic death of Purkinje cells, cerebellar atrophy, and ataxia that occur in many SCAs. The output of the cerebellar cortex is conveyed to the deep cerebellar nuclei (DCN) by Purkinje cells via inhibitory signals; thus, Purkinje cell dysfunction or degeneration would partially or completely impair the cerebellar output in SCAs. In the absence of the inhibitory signal emanating from Purkinje cells, DCN will become more excitable, thereby affecting the motor areas receiving DCN input and resulting in uncoordinated movements. An outstanding advantage in studying the pathogenesis of SCAs is represented by the availability of a large number of animal models which mimic the phenotype observed in humans. By mainly focusing on mouse models displaying mutations or deletions in genes which encode for Ca2+ signaling-related proteins, in this review we will discuss the several pathogenic mechanisms related to deranged Ca2+ homeostasis that leads to significant Purkinje cell degeneration and dysfunction.
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Affiliation(s)
- Francesca Prestori
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- Correspondence:
| | - Francesco Moccia
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy;
| | - Egidio D’Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- IRCCS Mondino Foundation, 27100 Pavia, Italy
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14
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Egorova PA, Bezprozvanny IB. Molecular Mechanisms and Therapeutics for Spinocerebellar Ataxia Type 2. Neurotherapeutics 2019; 16:1050-1073. [PMID: 31435879 PMCID: PMC6985344 DOI: 10.1007/s13311-019-00777-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The effective therapeutic treatment and the disease-modifying therapy for spinocerebellar ataxia type 2 (SCA2) (a progressive hereditary disease caused by an expansion of polyglutamine in the ataxin-2 protein) is not available yet. At present, only symptomatic treatment and methods of palliative care are prescribed to the patients. Many attempts were made to study the physiological, molecular, and biochemical changes in SCA2 patients and in a variety of the model systems to find new therapeutic targets for SCA2 treatment. A better understanding of the uncovered molecular mechanisms of the disease allowed the scientific community to develop strategies of potential therapy and helped to create some promising therapeutic approaches for SCA2 treatment. Recent progress in this field will be discussed in this review article.
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Affiliation(s)
- Polina A Egorova
- Laboratory of Molecular Neurodegeneration, Peter the Great St.Petersburg Polytechnic University, St. Petersburg, 195251, Russia
| | - Ilya B Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Peter the Great St.Petersburg Polytechnic University, St. Petersburg, 195251, Russia.
- Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, ND12.200, Dallas, Texas, 75390, USA.
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15
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Scoles DR, Pulst SM. Antisense therapies for movement disorders. Mov Disord 2019; 34:1112-1119. [PMID: 31283857 DOI: 10.1002/mds.27782] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 05/10/2019] [Accepted: 06/06/2019] [Indexed: 12/12/2022] Open
Abstract
Currently, few disease-modifying therapies exist for degenerative movement disorders. Antisense oligonucleotides are small DNA oligonucleotides, usually encompassing ∼20 base pairs, that can potentially target any messenger RNA of interest. Antisense oligonucleotides often contain modifications to the phosphate backbone, the sugar moiety, and the nucleotide base. The development of antisense oligonucleotide therapies spinal muscular atrophy and Duchenne muscular dystrophy suggest potentially wide-ranging therapeutic applications for antisense oligonucleotides in neurology. Successes with these two diseases have heightened interest in academia and the pharmaceutical industry to develop antisense oligonucleotides for several movement disorders, including, spinocerebellar ataxias, Huntington's disease, and Parkinson's disease. Compared to small molecules, antisense oligonucleotide-based therapies have an advantage because the target disease gene sequence is the immediate path to identifying the therapeutically effective complementary antisense oligonucleotide. In this review we describe the different types of antisense oligonucleotide chemistries and their potential use for the treatment of human movement disorders. © 2019 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Daniel R Scoles
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, Utah, USA
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16
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Scoles DR, Minikel EV, Pulst SM. Antisense oligonucleotides: A primer. NEUROLOGY-GENETICS 2019; 5:e323. [PMID: 31119194 PMCID: PMC6501637 DOI: 10.1212/nxg.0000000000000323] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/14/2019] [Indexed: 12/13/2022]
Abstract
There are few disease-modifying therapeutics for neurodegenerative diseases, but successes on the development of antisense oligonucleotide (ASO) therapeutics for spinal muscular atrophy and Duchenne muscular dystrophy predict a robust future for ASOs in medicine. Indeed, existing pipelines for the development of ASO therapies for spinocerebellar ataxias, Huntington disease, Alzheimer disease, amyotrophic lateral sclerosis, Parkinson disease, and others, and increased focus by the pharmaceutical industry on ASO development, strengthen the outlook for using ASOs for neurodegenerative diseases. Perhaps the most significant advantage to ASO therapeutics over other small molecule approaches is that acquisition of the target sequence provides immediate knowledge of putative complementary oligonucleotide therapeutics. In this review, we describe the various types of ASOs, how they are used therapeutically, and the present efforts to develop new ASO therapies that will contribute to a forthcoming toolkit for treating multiple neurodegenerative diseases.
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Affiliation(s)
- Daniel R Scoles
- Department of Neurology (D.R.S., S.M.P.), University of Utah, Salt Lake City, UT; and Center for the Science of Therapeutics (E.V.M.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Eric V Minikel
- Department of Neurology (D.R.S., S.M.P.), University of Utah, Salt Lake City, UT; and Center for the Science of Therapeutics (E.V.M.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Stefan M Pulst
- Department of Neurology (D.R.S., S.M.P.), University of Utah, Salt Lake City, UT; and Center for the Science of Therapeutics (E.V.M.), Broad Institute of MIT and Harvard, Cambridge, MA
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17
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MTSS1/Src family kinase dysregulation underlies multiple inherited ataxias. Proc Natl Acad Sci U S A 2018; 115:E12407-E12416. [PMID: 30530649 DOI: 10.1073/pnas.1816177115] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The genetically heterogeneous spinocerebellar ataxias (SCAs) are caused by Purkinje neuron dysfunction and degeneration, but their underlying pathological mechanisms remain elusive. The Src family of nonreceptor tyrosine kinases (SFK) are essential for nervous system homeostasis and are increasingly implicated in degenerative disease. Here we reveal that the SFK suppressor Missing-in-metastasis (MTSS1) is an ataxia locus that links multiple SCAs. MTSS1 loss results in increased SFK activity, reduced Purkinje neuron arborization, and low basal firing rates, followed by cell death. Surprisingly, mouse models for SCA1, SCA2, and SCA5 show elevated SFK activity, with SCA1 and SCA2 displaying dramatically reduced MTSS1 protein levels through reduced gene expression and protein translation, respectively. Treatment of each SCA model with a clinically approved Src inhibitor corrects Purkinje neuron basal firing and delays ataxia progression in MTSS1 mutants. Our results identify a common SCA therapeutic target and demonstrate a key role for MTSS1/SFK in Purkinje neuron survival and ataxia progression.
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18
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Suvrathan A, Raymond JL. Depressed by Learning-Heterogeneity of the Plasticity Rules at Parallel Fiber Synapses onto Purkinje Cells. CEREBELLUM (LONDON, ENGLAND) 2018; 17:747-755. [PMID: 30069835 PMCID: PMC6550343 DOI: 10.1007/s12311-018-0968-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Climbing fiber-driven long-term depression (LTD) of parallel fiber synapses onto cerebellar Purkinje cells has long been investigated as a putative mechanism of motor learning. We recently discovered that the rules governing the induction of LTD at these synapses vary across different regions of the cerebellum. Here, we discuss the design of LTD induction protocols in light of this heterogeneity in plasticity rules. The analytical advantages of the cerebellum provide an opportunity to develop a deeper understanding of how the specific plasticity rules at synapses support the implementation of learning.
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Affiliation(s)
- Aparna Suvrathan
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Department of Pediatrics, Brain Repair and Integrative Neuroscience Program, the Research Institute of the McGill University Health Centre, McGill University, Montréal General Hospital, Montréal, Quebec, H3G 1A4, Canada
| | - Jennifer L Raymond
- Department of Neurobiology, Stanford University, Stanford, CA, 94305, USA.
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19
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Perkins EM, Clarkson YL, Suminaite D, Lyndon AR, Tanaka K, Rothstein JD, Skehel PA, Wyllie DJA, Jackson M. Loss of cerebellar glutamate transporters EAAT4 and GLAST differentially affects the spontaneous firing pattern and survival of Purkinje cells. Hum Mol Genet 2018; 27:2614-2627. [PMID: 29741614 PMCID: PMC6049029 DOI: 10.1093/hmg/ddy169] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 12/20/2022] Open
Abstract
Loss of excitatory amino acid transporters (EAATs) has been implicated in a number of human diseases including spinocerebellar ataxias, Alzhiemer's disease and motor neuron disease. EAAT4 and GLAST/EAAT1 are the two predominant EAATs responsible for maintaining low extracellular glutamate levels and preventing neurotoxicity in the cerebellum, the brain region essential for motor control. Here using genetically modified mice we identify new critical roles for EAAT4 and GLAST/EAAT1 as modulators of Purkinje cell (PC) spontaneous firing patterns. We show high EAAT4 levels, by limiting mGluR1 signalling, are essential in constraining inherently heterogeneous firing of zebrin-positive PCs. Moreover mGluR1 antagonists were found to restore regular spontaneous PC activity and motor behaviour in EAAT4 knockout mice. In contrast, GLAST/EAAT1 expression is required to sustain normal spontaneous simple spike activity in low EAAT4 expressing (zebrin-negative) PCs by restricting NMDA receptor activation. Blockade of NMDA receptor activity restores spontaneous activity in zebrin-negative PCs of GLAST knockout mice and furthermore alleviates motor deficits. In addition both transporters have differential effects on PC survival, with zebrin-negative PCs more vulnerable to loss of GLAST/EAAT1 and zebrin-positive PCs more vulnerable to loss of EAAT4. These findings reveal that glutamate transporter dysfunction through elevated extracellular glutamate and the aberrant activation of extrasynaptic receptors can disrupt cerebellar output by altering spontaneous PC firing. This expands our understanding of disease mechanisms in cerebellar ataxias and establishes EAATs as targets for restoring homeostasis in a variety of neurological diseases where altered cerebellar output is now thought to play a key role in pathogenesis.
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Affiliation(s)
- Emma M Perkins
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - Yvonne L Clarkson
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - Daumante Suminaite
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - Alastair R Lyndon
- School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, John Muir Building, Riccarton, Edinburgh, UK
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-Ku, Tokyo, Japan
| | - Jeffrey D Rothstein
- Department of Neurology and Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Paul A Skehel
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
| | - David J A Wyllie
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
- Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India
| | - Mandy Jackson
- The Centre for Discovery Brain Sciences, The University of Edinburgh, Hugh Robson Building, Edinburgh, UK
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20
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Ca 2+ signaling and spinocerebellar ataxia. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1733-1744. [PMID: 29777722 DOI: 10.1016/j.bbamcr.2018.05.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/07/2018] [Accepted: 05/09/2018] [Indexed: 11/22/2022]
Abstract
Spinocerebellar ataxia (SCA) is a neural disorder, which is caused by degenerative changes in the cerebellum. SCA is primarily characterized by gait ataxia, and additional clinical features include nystagmus, dysarthria, tremors and cerebellar atrophy. Forty-four hereditary SCAs have been identified to date, along with >35 SCA-associated genes. Despite the great diversity and distinct functionalities of the SCA-related genes, accumulating evidence supports the occurrence of a common pathophysiological event among several hereditary SCAs. Altered calcium (Ca2+) homeostasis in the Purkinje cells (PCs) of the cerebellum has been proposed as a possible pathological SCA trigger. In support of this, signaling events that are initiated from or lead to aberrant Ca2+ release from the type 1 inositol 1,4,5-trisphosphate receptor (IP3R1), which is highly expressed in cerebellar PCs, seem to be closely associated with the pathogenesis of several SCA types. In this review, we summarize the current research on pathological hereditary SCA events, which involve altered Ca2+ homeostasis in PCs, through IP3R1 signaling.
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21
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Hoxha E, Balbo I, Miniaci MC, Tempia F. Purkinje Cell Signaling Deficits in Animal Models of Ataxia. Front Synaptic Neurosci 2018; 10:6. [PMID: 29760657 PMCID: PMC5937225 DOI: 10.3389/fnsyn.2018.00006] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 04/09/2018] [Indexed: 12/19/2022] Open
Abstract
Purkinje cell (PC) dysfunction or degeneration is the most frequent finding in animal models with ataxic symptoms. Mutations affecting intrinsic membrane properties can lead to ataxia by altering the firing rate of PCs or their firing pattern. However, the relationship between specific firing alterations and motor symptoms is not yet clear, and in some cases PC dysfunction precedes the onset of ataxic signs. Moreover, a great variety of ionic and synaptic mechanisms can affect PC signaling, resulting in different features of motor dysfunction. Mutations affecting Na+ channels (NaV1.1, NaV1.6, NaVβ4, Fgf14 or Rer1) reduce the firing rate of PCs, mainly via an impairment of the Na+ resurgent current. Mutations that reduce Kv3 currents limit the firing rate frequency range. Mutations of Kv1 channels act mainly on inhibitory interneurons, generating excessive GABAergic signaling onto PCs, resulting in episodic ataxia. Kv4.3 mutations are responsible for a complex syndrome with several neurologic dysfunctions including ataxia. Mutations of either Cav or BK channels have similar consequences, consisting in a disruption of the firing pattern of PCs, with loss of precision, leading to ataxia. Another category of pathogenic mechanisms of ataxia regards alterations of synaptic signals arriving at the PC. At the parallel fiber (PF)-PC synapse, mutations of glutamate delta-2 (GluD2) or its ligand Crbl1 are responsible for the loss of synaptic contacts, abolishment of long-term depression (LTD) and motor deficits. At the same synapse, a correct function of metabotropic glutamate receptor 1 (mGlu1) receptors is necessary to avoid ataxia. Failure of climbing fiber (CF) maturation and establishment of PC mono-innervation occurs in a great number of mutant mice, including mGlu1 and its transduction pathway, GluD2, semaphorins and their receptors. All these models have in common the alteration of PC output signals, due to a variety of mechanisms affecting incoming synaptic signals or the way they are processed by the repertoire of ionic channels responsible for intrinsic membrane properties. Although the PC is a final common pathway of ataxia, the link between specific firing alterations and neurologic symptoms has not yet been systematically studied and the alterations of the cerebellar contribution to motor signals are still unknown.
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Affiliation(s)
- Eriola Hoxha
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Turin, Italy.,Department of Neuroscience, University of Torino, Turin, Italy
| | - Ilaria Balbo
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Turin, Italy.,Department of Neuroscience, University of Torino, Turin, Italy
| | - Maria Concetta Miniaci
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Filippo Tempia
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Turin, Italy.,Department of Neuroscience, University of Torino, Turin, Italy.,National Institute of Neuroscience (INN), Turin, Italy
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22
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Bushart DD, Chopra R, Singh V, Murphy GG, Wulff H, Shakkottai VG. Targeting potassium channels to treat cerebellar ataxia. Ann Clin Transl Neurol 2018; 5:297-314. [PMID: 29560375 PMCID: PMC5846455 DOI: 10.1002/acn3.527] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/14/2017] [Accepted: 12/18/2017] [Indexed: 12/22/2022] Open
Abstract
Objective Purkinje neuron dysfunction is associated with cerebellar ataxia. In a mouse model of spinocerebellar ataxia type 1 (SCA1), reduced potassium channel function contributes to altered membrane excitability resulting in impaired Purkinje neuron spiking. We sought to determine the relationship between altered membrane excitability and motor dysfunction in SCA1 mice. Methods Patch-clamp recordings in acute cerebellar slices and motor phenotype testing were used to identify pharmacologic agents which improve Purkinje neuron physiology and motor performance in SCA1 mice. Additionally, we retrospectively reviewed records of patients with SCA1 and other autosomal-dominant SCAs with prominent Purkinje neuron involvement to determine whether currently approved potassium channel activators were tolerated. Results Activating calcium-activated and subthreshold-activated potassium channels improved Purkinje neuron spiking impairment in SCA1 mice (P < 0.05). Additionally, dendritic hyperexcitability was improved by activating subthreshold-activated potassium channels but not calcium-activated potassium channels (P < 0.01). Improving spiking and dendritic hyperexcitability through a combination of chlorzoxazone and baclofen produced sustained improvements in motor dysfunction in SCA1 mice (P < 0.01). Retrospective review of SCA patient records suggests that co-treatment with chlorzoxazone and baclofen is tolerated. Interpretation Targeting both altered spiking and dendritic membrane excitability is associated with sustained improvements in motor performance in SCA1 mice, while targeting altered spiking alone produces only short-term improvements in motor dysfunction. Potassium channel activators currently in clinical use are well tolerated and may provide benefit in SCA patients. Future clinical trials with potassium channel activators are warranted in cerebellar ataxia.
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Affiliation(s)
- David D Bushart
- Department of Molecular & Integrative Physiology University of Michigan Ann Arbor Michigan
| | - Ravi Chopra
- Department of Neurology University of Michigan Ann Arbor Michigan
| | - Vikrant Singh
- Department of Pharmacology University of California Davis California
| | - Geoffrey G Murphy
- Department of Molecular & Integrative Physiology University of Michigan Ann Arbor Michigan.,Molecular & Behavioral Neuroscience Institute University of Michigan Ann Arbor Michigan
| | - Heike Wulff
- Department of Pharmacology University of California Davis California
| | - Vikram G Shakkottai
- Department of Molecular & Integrative Physiology University of Michigan Ann Arbor Michigan.,Department of Neurology University of Michigan Ann Arbor Michigan
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23
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Scoles DR, Pulst SM. Spinocerebellar Ataxia Type 2. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:175-195. [PMID: 29427103 DOI: 10.1007/978-3-319-71779-1_8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Spinocerebellar ataxia type 2 (SCA2) is autosomal dominantly inherited and caused by CAG repeat expansion in the ATXN2 gene. Because the CAG repeat expansion is localized to an encoded region of ATXN2, the result is an expanded polyglutamine (polyQ) tract in the ATXN2 protein. SCA2 is characterized by progressive ataxia, and slow saccades. No treatment for SCA2 exists. ATXN2 mutation causes gains of new or toxic functions for the ATXN2 protein, resulting in abnormally slow Purkinje cell (PC) firing frequency and ultimately PC loss. This chapter describes the characteristics of SCA2 patients briefly, and reviews ATXN2 molecular features and progress toward the identification of a treatment for SCA2.
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Affiliation(s)
- Daniel R Scoles
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT, 84132, USA
| | - Stefan M Pulst
- Department of Neurology, University of Utah, 175 North Medical Drive East, 5th Floor, Salt Lake City, UT, 84132, USA.
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24
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Bossi S, Musante I, Bonfiglio T, Bonifacino T, Emionite L, Cerminara M, Cervetto C, Marcoli M, Bonanno G, Ravazzolo R, Pittaluga A, Puliti A. Genetic inactivation of mGlu5 receptor improves motor coordination in the Grm1 crv4 mouse model of SCAR13 ataxia. Neurobiol Dis 2017; 109:44-53. [PMID: 28982591 DOI: 10.1016/j.nbd.2017.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/13/2017] [Accepted: 10/01/2017] [Indexed: 01/29/2023] Open
Abstract
Deleterious mutations in the glutamate receptor metabotropic 1 gene (GRM1) cause a recessive form of cerebellar ataxia, SCAR13. GRM1 and GRM5 code for the metabotropic glutamate type 1 (mGlu1) and type 5 (mGlu5) receptors, respectively. Their different expression profiles suggest they could have distinct functional roles. In a previous study, homozygous mice lacking mGlu1 receptors (Grm1crv4/crv4) and exhibiting ataxia presented cerebellar overexpression of mGlu5 receptors, that was proposed to contribute to the mouse phenotype. To test this hypothesis, we here crossed Grm1crv4 and Grm5ko mice to generate double mutants (Grm1crv4/crv4Grm5ko/ko) lacking both mGlu1 and mGlu5 receptors. Double mutants and control mice were analyzed for spontaneous behavior and for motor activity by rotarod and footprint analyses. In the same mice, the release of glutamate from cerebellar nerve endings (synaptosomes) elicited by 12mM KCl or by α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) was also evaluated. Motor coordination resulted improved in double mutants when compared to Grm1crv4/crv4 mice. Furthermore, in in vitro studies, glutamate release elicited by both KCl depolarization and activation of AMPA autoreceptors resulted reduced in Grm1crv4/crv4 mice compared to wild type mice, while it presented normal levels in double mutants. Moreover, we found that Grm1crv4/crv4 mice showed reduced expression of GluA2/3 AMPA receptor subunits in cerebellar synaptosomes, while it resulted restored to wild type level in double mutants. To conclude, blocking of mGlu5 receptor reduced the dysregulation of glutamate transmission and improved motor coordination in the Grm1crv4 mouse model of SCAR13, thus suggesting the possible usefulness of pharmacological therapies based on modulation of mGlu5 receptor activity for the treatment of this type of ataxia.
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Affiliation(s)
- Simone Bossi
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy
| | - Ilaria Musante
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy
| | - Tommaso Bonfiglio
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy
| | - Tiziana Bonifacino
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy
| | - Laura Emionite
- Animal Facility, IRCCS A.U.O. San Martino-IST, Largo Rosanna Benzi 10, Genoa, Italy
| | - Maria Cerminara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy
| | - Chiara Cervetto
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy
| | - Manuela Marcoli
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy
| | - Giambattista Bonanno
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy
| | - Roberto Ravazzolo
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy; Medical Genetics Unit, Istituto Giannina Gaslini, via Gaslini 5, 16148 Genoa, Italy
| | - Anna Pittaluga
- Department of Pharmacy, Pharmacology and Toxicology Unit, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy
| | - Aldamaria Puliti
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), University of Genoa, via Gaslini 5, 16148 Genoa, Italy; Centre of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV 9, 16132 Genoa, Italy; Medical Genetics Unit, Istituto Giannina Gaslini, via Gaslini 5, 16148 Genoa, Italy.
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