1
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Ducza L, Gaál B. The Neglected Sibling: NLRP2 Inflammasome in the Nervous System. Aging Dis 2024; 15:1006-1028. [PMID: 38722788 PMCID: PMC11081174 DOI: 10.14336/ad.2023.0926-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/26/2023] [Indexed: 05/13/2024] Open
Abstract
While classical NOD-like receptor pyrin domain containing protein 1 (NLRP1) and NLRP3 inflammasomal proteins have been extensively investigated, the contribution of NLRP2 is still ill-defined in the nervous system. Given the putative significance of NLRP2 in orchestrating neuroinflammation, further inquiry is needed to gain a better understanding of its connectome, hence its specific targeting may hold a promising therapeutic implication. Therefore, bioinformatical approach for extracting information, specifically in the context of neuropathologies, is also undoubtedly preferred. To the best of our knowledge, there is no review study selectively targeting only NLRP2. Increasing, but still fragmentary evidence should encourage researchers to thoroughly investigate this inflammasome in various animal- and human models. Taken together, herein we aimed to review the current literature focusing on the role of NLRP2 inflammasome in the nervous system and more importantly, we provide an algorithm-based protein network of human NLRP2 for elucidating potentially valuable molecular partnerships that can be the beginning of a new discourse and future therapeutic considerations.
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Affiliation(s)
- László Ducza
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Hungary, Hungary
| | - Botond Gaál
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Hungary, Hungary
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2
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Rae CD, Baur JA, Borges K, Dienel G, Díaz-García CM, Douglass SR, Drew K, Duarte JMN, Duran J, Kann O, Kristian T, Lee-Liu D, Lindquist BE, McNay EC, Robinson MB, Rothman DL, Rowlands BD, Ryan TA, Scafidi J, Scafidi S, Shuttleworth CW, Swanson RA, Uruk G, Vardjan N, Zorec R, McKenna MC. Brain energy metabolism: A roadmap for future research. J Neurochem 2024; 168:910-954. [PMID: 38183680 PMCID: PMC11102343 DOI: 10.1111/jnc.16032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 11/29/2023] [Accepted: 12/05/2023] [Indexed: 01/08/2024]
Abstract
Although we have learned much about how the brain fuels its functions over the last decades, there remains much still to discover in an organ that is so complex. This article lays out major gaps in our knowledge of interrelationships between brain metabolism and brain function, including biochemical, cellular, and subcellular aspects of functional metabolism and its imaging in adult brain, as well as during development, aging, and disease. The focus is on unknowns in metabolism of major brain substrates and associated transporters, the roles of insulin and of lipid droplets, the emerging role of metabolism in microglia, mysteries about the major brain cofactor and signaling molecule NAD+, as well as unsolved problems underlying brain metabolism in pathologies such as traumatic brain injury, epilepsy, and metabolic downregulation during hibernation. It describes our current level of understanding of these facets of brain energy metabolism as well as a roadmap for future research.
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Affiliation(s)
- Caroline D. Rae
- School of Psychology, The University of New South Wales, NSW 2052 & Neuroscience Research Australia, Randwick, New South Wales, Australia
| | - Joseph A. Baur
- Department of Physiology and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Karin Borges
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, Australia
| | - Gerald Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
| | - Carlos Manlio Díaz-García
- Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | | | - Kelly Drew
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - João M. N. Duarte
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, & Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Jordi Duran
- Institut Químic de Sarrià (IQS), Universitat Ramon Llull (URL), Barcelona, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120; Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Tibor Kristian
- Veterans Affairs Maryland Health Center System, Baltimore, Maryland, USA
- Department of Anesthesiology and the Center for Shock, Trauma, and Anesthesiology Research (S.T.A.R.), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Dasfne Lee-Liu
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Región Metropolitana, Chile
| | - Britta E. Lindquist
- Department of Neurology, Division of Neurocritical Care, Gladstone Institute of Neurological Disease, University of California at San Francisco, San Francisco, California, USA
| | - Ewan C. McNay
- Behavioral Neuroscience, University at Albany, Albany, New York, USA
| | - Michael B. Robinson
- Departments of Pediatrics and System Pharmacology & Translational Therapeutics, Children’s Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Douglas L. Rothman
- Magnetic Resonance Research Center and Departments of Radiology and Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Benjamin D. Rowlands
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Timothy A. Ryan
- Department of Biochemistry, Weill Cornell Medicine, New York, New York, USA
| | - Joseph Scafidi
- Department of Neurology, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Susanna Scafidi
- Anesthesiology & Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - C. William Shuttleworth
- Department of Neurosciences, University of New Mexico School of Medicine Albuquerque, Albuquerque, New Mexico, USA
| | - Raymond A. Swanson
- Department of Neurology, University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Gökhan Uruk
- Department of Neurology, University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Nina Vardjan
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology—Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology—Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Mary C. McKenna
- Department of Pediatrics and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, USA
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3
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Brewer MK, Torres P, Ayala V, Portero-Otin M, Pamplona R, Andrés-Benito P, Ferrer I, Guinovart JJ, Duran J. Glycogen accumulation modulates life span in a mouse model of amyotrophic lateral sclerosis. J Neurochem 2024; 168:744-759. [PMID: 37401737 PMCID: PMC10764643 DOI: 10.1111/jnc.15906] [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: 02/28/2023] [Revised: 05/30/2023] [Accepted: 06/04/2023] [Indexed: 07/05/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by the progressive loss of motor neurons in the spinal cord. Glial cells, including astrocytes and microglia, have been shown to contribute to neurodegeneration in ALS, and metabolic dysfunction plays an important role in the progression of the disease. Glycogen is a soluble polymer of glucose found at low levels in the central nervous system that plays an important role in memory formation, synaptic plasticity, and the prevention of seizures. However, its accumulation in astrocytes and/or neurons is associated with pathological conditions and aging. Importantly, glycogen accumulation has been reported in the spinal cord of human ALS patients and mouse models. In the present work, using the SOD1G93A mouse model of ALS, we show that glycogen accumulates in the spinal cord and brainstem during symptomatic and end stages of the disease and that the accumulated glycogen is associated with reactive astrocytes. To study the contribution of glycogen to ALS progression, we generated SOD1G93A mice with reduced glycogen synthesis (SOD1G93A GShet mice). SOD1G93A GShet mice had a significantly longer life span than SOD1G93A mice and showed lower levels of the astrocytic pro-inflammatory cytokine Cxcl10, suggesting that the accumulation of glycogen is associated with an inflammatory response. Supporting this, inducing an increase in glycogen synthesis reduced life span in SOD1G93A mice. Altogether, these results suggest that glycogen in reactive astrocytes contributes to neurotoxicity and disease progression in ALS.
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Affiliation(s)
- M. Kathryn Brewer
- Institute for Research in Biomedicine of Barcelona (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Pascual Torres
- Metabolic Pathophysiology Research Group, Department of Experimental Medicine, University of Lleida-IRB Lleida, Lleida, Spain
| | - Victòria Ayala
- Metabolic Pathophysiology Research Group, Department of Experimental Medicine, University of Lleida-IRB Lleida, Lleida, Spain
| | - Manuel Portero-Otin
- Metabolic Pathophysiology Research Group, Department of Experimental Medicine, University of Lleida-IRB Lleida, Lleida, Spain
| | - Reinald Pamplona
- Metabolic Pathophysiology Research Group, Department of Experimental Medicine, University of Lleida-IRB Lleida, Lleida, Spain
| | - Pol Andrés-Benito
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Hospitalet de Llobregat, Spain
| | - Isidro Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Hospitalet de Llobregat, Spain
- Biomedical Network Research Center on Neurodegenerative Diseases (CIBERNED), Institute Carlos III, Hospitalet de Llobregat, Spain
| | - Joan J. Guinovart
- Institute for Research in Biomedicine of Barcelona (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Barcelona, Spain
| | - Jordi Duran
- Institute for Research in Biomedicine of Barcelona (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
- Institut Químic de Sarrià (IQS), Universitat Ramon Llull (URL), Barcelona, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain
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4
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Markussen KH, Corti M, Byrne BJ, Kooi CWV, Sun RC, Gentry MS. The multifaceted roles of the brain glycogen. J Neurochem 2024; 168:728-743. [PMID: 37554056 PMCID: PMC10901277 DOI: 10.1111/jnc.15926] [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: 04/17/2023] [Revised: 07/04/2023] [Accepted: 07/07/2023] [Indexed: 08/10/2023]
Abstract
Glycogen is a biologically essential macromolecule that is directly involved in multiple human diseases. While its primary role in carbohydrate storage and energy metabolism in the liver and muscle is well characterized, recent research has highlighted critical metabolic and non-metabolic roles for glycogen in the brain. In this review, the emerging roles of glycogen homeostasis in the healthy and diseased brain are discussed with a focus on advancing our understanding of the role of glycogen in the brain. Innovative technologies that have led to novel insights into glycogen functions are detailed. Key insights into how cellular localization impacts neuronal and glial function are discussed. Perturbed glycogen functions are observed in multiple disorders of the brain, including where it serves as a disease driver in the emerging category of neurological glycogen storage diseases (n-GSDs). n-GSDs include Lafora disease (LD), adult polyglucosan body disease (APBD), Cori disease, Glucose transporter type 1 deficiency syndrome (G1D), GSD0b, and late-onset Pompe disease (PD). They are neurogenetic disorders characterized by aberrant glycogen which results in devastating neurological and systemic symptoms. In the most severe cases, rapid neurodegeneration coupled with dementia results in death soon after diagnosis. Finally, we discuss current treatment strategies that are currently being developed and have the potential to be of great benefit to patients with n-GSD. Taken together, novel technologies and biological insights have resulted in a renaissance in brain glycogen that dramatically advanced our understanding of both biology and disease. Future studies are needed to expand our understanding and the multifaceted roles of glycogen and effectively apply these insights to human disease.
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Affiliation(s)
- Kia H. Markussen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, USA
| | - Manuela Corti
- Department of Pediatrics, Powell Gene Therapy Center, College of Medicine, University of Florida, USA
| | - Barry J. Byrne
- Department of Pediatrics, Powell Gene Therapy Center, College of Medicine, University of Florida, USA
| | - Craig W. Vander Kooi
- Department of Biochemistry & Molecular Biology, College of Medicine, University of Florida, USA
- Center for Advanced Spatial Biomolecule Research, University of Florida
- Lafora Epilepsy Cure Initiative
| | - Ramon C. Sun
- Department of Biochemistry & Molecular Biology, College of Medicine, University of Florida, USA
- Center for Advanced Spatial Biomolecule Research, University of Florida
- Lafora Epilepsy Cure Initiative
| | - Matthew S. Gentry
- Department of Biochemistry & Molecular Biology, College of Medicine, University of Florida, USA
- Center for Advanced Spatial Biomolecule Research, University of Florida
- Lafora Epilepsy Cure Initiative
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5
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Mitra S, Chen B, Shelton JM, Nitschke S, Wu J, Covington L, Dear M, Lynn T, Verma M, Nitschke F, Fuseya Y, Iwai K, Evers BM, Minassian BA. Myofiber-type-dependent 'boulder' or 'multitudinous pebble' formations across distinct amylopectinoses. Acta Neuropathol 2024; 147:46. [PMID: 38411740 DOI: 10.1007/s00401-024-02698-x] [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: 11/23/2023] [Revised: 01/13/2024] [Accepted: 01/24/2024] [Indexed: 02/28/2024]
Abstract
At least five enzymes including three E3 ubiquitin ligases are dedicated to glycogen's spherical structure. Absence of any reverts glycogen to a structure resembling amylopectin of the plant kingdom. This amylopectinosis (polyglucosan body formation) causes fatal neurological diseases including adult polyglucosan body disease (APBD) due to glycogen branching enzyme deficiency, Lafora disease (LD) due to deficiencies of the laforin glycogen phosphatase or the malin E3 ubiquitin ligase and type 1 polyglucosan body myopathy (PGBM1) due to RBCK1 E3 ubiquitin ligase deficiency. Little is known about these enzymes' functions in glycogen structuring. Toward understanding these functions, we undertake a comparative murine study of the amylopectinoses of APBD, LD and PGBM1. We discover that in skeletal muscle, polyglucosan bodies form as two main types, small and multitudinous ('pebbles') or giant and single ('boulders'), and that this is primarily determined by the myofiber types in which they form, 'pebbles' in glycolytic and 'boulders' in oxidative fibers. This pattern recapitulates what is known in the brain in LD, innumerable dust-like in astrocytes and single giant sized in neurons. We also show that oxidative myofibers are relatively protected against amylopectinosis, in part through highly increased glycogen branching enzyme expression. We present evidence of polyglucosan body size-dependent cell necrosis. We show that sex influences amylopectinosis in genotype, brain region and myofiber-type-specific fashion. RBCK1 is a component of the linear ubiquitin chain assembly complex (LUBAC), the only known cellular machinery for head-to-tail linear ubiquitination critical to numerous cellular pathways. We show that the amylopectinosis of RBCK1 deficiency is not due to loss of linear ubiquitination, and that another function of RBCK1 or LUBAC must exist and operate in the shaping of glycogen. This work opens multiple new avenues toward understanding the structural determinants of the mammalian carbohydrate reservoir critical to neurologic and neuromuscular function and disease.
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Affiliation(s)
- Sharmistha Mitra
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA.
| | - Baozhi Chen
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - John M Shelton
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9148, USA
| | - Silvia Nitschke
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Lindsay Covington
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9148, USA
| | - Mathew Dear
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Tori Lynn
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Mayank Verma
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Felix Nitschke
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA
| | - Yasuhiro Fuseya
- Department of Molecular and Cellular Physiology, Kyoto University School of Medicine, Kyoto, 606-8501, Japan
| | - Kazuhiro Iwai
- Department of Molecular and Cellular Physiology, Kyoto University School of Medicine, Kyoto, 606-8501, Japan
| | - Bret M Evers
- Departments of Pathology and Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9073, USA
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-9063, USA.
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Donohue KJ, Fitzsimmons B, Bruntz RC, Markussen KH, Young LEA, Clarke HA, Coburn PT, Griffith LE, Sanders W, Klier J, Burke SN, Maurer AP, Minassian BA, Sun RC, Kordasiewisz HB, Gentry MS. Gys1 Antisense Therapy Prevents Disease-Driving Aggregates and Epileptiform Discharges in a Lafora Disease Mouse Model. Neurotherapeutics 2023; 20:1808-1819. [PMID: 37700152 PMCID: PMC10684475 DOI: 10.1007/s13311-023-01434-9] [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] [Accepted: 08/22/2023] [Indexed: 09/14/2023] Open
Abstract
Patients with Lafora disease have a mutation in EPM2A or EPM2B, resulting in dysregulation of glycogen metabolism throughout the body and aberrant glycogen molecules that aggregate into Lafora bodies. Lafora bodies are particularly damaging in the brain, where the aggregation drives seizures with increasing severity and frequency, coupled with neurodegeneration. Previous work employed mouse genetic models to reduce glycogen synthesis by approximately 50%, and this strategy significantly reduced Lafora body formation and disease phenotypes. Therefore, an antisense oligonucleotide (ASO) was developed to reduce glycogen synthesis in the brain by targeting glycogen synthase 1 (Gys1). To test the distribution and efficacy of this drug, the Gys1-ASO was administered to Epm2b-/- mice via intracerebroventricular administration at 4, 7, and 10 months. The mice were then sacrificed at 13 months and their brains analyzed for Gys1 expression, glycogen aggregation, and neuronal excitability. The mice treated with Gys1-ASO exhibited decreased Gys1 protein levels, decreased glycogen aggregation, and reduced epileptiform discharges compared to untreated Epm2b-/- mice. This work provides proof of concept that a Gys1-ASO halts disease progression of EPM2B mutations of Lafora disease.
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Affiliation(s)
- Katherine J Donohue
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Bethany Fitzsimmons
- Department of Antisense Drug Discovery, Ionis Pharmaceuticals, Carlsbad, CA, 92010, USA
| | - Ronald C Bruntz
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Kia H Markussen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Lyndsay E A Young
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Harrison A Clarke
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, 32610, USA
| | - Peyton T Coburn
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Laiken E Griffith
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - William Sanders
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Jack Klier
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | - Sara N Burke
- Department of Neuroscience and Center for Cognitive Aging and Memory, University of Florida, Gainesville, FL, 32610, USA
| | - Andrew P Maurer
- Department of Neuroscience and Center for Cognitive Aging and Memory, University of Florida, Gainesville, FL, 32610, USA
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ramon C Sun
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, 32610, USA
| | - Holly B Kordasiewisz
- Department of Antisense Drug Discovery, Ionis Pharmaceuticals, Carlsbad, CA, 92010, USA
| | - Matthew S Gentry
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, 32610, USA.
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7
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Murphy RD, Troublefield CA, Miracle JS, Young LEA, Brizzee CO, Dhara A, Sun RC, Vander Kooi CW, Gentry MS, Sinai AP. TgLaforin, a glucan phosphatase, reveals the dynamic role of storage polysaccharides in Toxoplasma gondii tachyzoites and bradyzoites. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.29.560185. [PMID: 37808860 PMCID: PMC10557770 DOI: 10.1101/2023.09.29.560185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The asexual stages of Toxoplasma gondii are defined by the rapidly growing tachyzoite during the acute infection and by the slow growing bradyzoite housed within tissue cysts during the chronic infection. These stages represent unique physiological states, each with distinct glucans reflecting differing metabolic needs. A defining feature of T. gondii bradyzoites is the presence of insoluble storage glucans known as amylopectin granules (AGs) that are believed to play a role in reactivation, but their functions during the chronic infection remain largely unexplored. More recently, the presence of storage glucans has been recognized in tachyzoites where their precise function and architecture have yet to be fully defined. Importantly, the T. gondii genome encodes activities needed for glucan turnover: a glucan phosphatase (TgLaforin; TGME49_205290) and a glucan kinase (TgGWD; TGME49_214260) that catalyze a cycle of reversible glucan phosphorylation required for glucan degradation by amylases. The expression of these enzymes in tachyzoites supports the existence of a storage glucan, evidence that is corroborated by specific labeling with the anti-glycogen antibody IV58B6. Disruption of reversible glucan phosphorylation via a CRISPR/Cas9 knockout (KO) of TgLaforin revealed no growth defects under nutrient-replete conditions in tachyzoites. However, the growth of TgLaforin-KO tachyzoites was severely stunted when starved of glutamine, even under glucose replete conditions. The loss of TgLaforin also resulted in the attenuation of acute virulence in mice accompanied by a lower cyst burden. Defective cyst formation due to profound changes in AG morphology was also observed in TgLaforin-KO parasites, both in vitro and in vivo. Together, these data demonstrate the importance of glucan turnover across the T. gondii asexual cycle. These findings, alongside our previously identified class of small molecules that inhibit TgLaforin, implicate reversible glucan phosphorylation as a legitimate target for the development of new drugs against chronic T. gondii infections.
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Affiliation(s)
- Robert D Murphy
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Cortni A Troublefield
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky
| | - Joy S Miracle
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky
| | - Lyndsay E A Young
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Corey O Brizzee
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Animesh Dhara
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky
| | - Ramon C Sun
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
| | - Anthony P Sinai
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky
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8
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Krishnan V, Wu J, Mazumder AG, Kamen JL, Schirmer C, Adhyapak N, Bass JS, Lee SC, Maheshwari A, Molinaro G, Gibson JR, Huber KM, Minassian BA. Clinicopathologic Dissociation: Robust Lafora Body Accumulation in Malin KO Mice Without Observable Changes in Home-cage Behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.11.557226. [PMID: 37745312 PMCID: PMC10515855 DOI: 10.1101/2023.09.11.557226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Lafora Disease (LD) is a syndrome of progressive myoclonic epilepsy and cumulative neurocognitive deterioration caused by recessively inherited genetic lesions of EPM2A (laforin) or NHLRC1 (malin). Neuropsychiatric symptomatology in LD is thought to be directly downstream of neuronal and astrocytic polyglucosan aggregates, termed Lafora bodies (LBs), which faithfully accumulate in an age-dependent manner in all mouse models of LD. In this study, we applied home-cage monitoring to examine the extent of neurobehavioral deterioration in a model of malin-deficient LD, as a means to identify robust preclinical endpoints that may guide the selection of novel genetic treatments. At 6 weeks, ~6-7 months and ~12 months of age, malin deficient mice ("KO") and wild type (WT) littermates underwent a standardized home-cage behavioral assessment designed to non-obtrusively appraise features of rest/arousal, consumptive behaviors, risk aversion and voluntary wheel-running. At all timepoints, and over a range of metrics that we report transparently, WT and KO mice were essentially indistinguishable. In contrast, within WT mice compared across timepoints, we identified age-related nocturnal hypoactivity, diminished sucrose preference and reduced wheel-running. Neuropathological examinations in subsets of the same mice revealed expected age dependent LB accumulation, gliosis and microglial activation in cortical and subcortical brain regions. At 12 months of age, despite the burden of neocortical LBs, we did not identify spontaneous seizures during an electroencephalographic (EEG) survey, and KO and WT mice exhibited similar spectral EEG features. Using an in vitro assay of neocortical function, paroxysmal increases in network activity (UP states) in KO slices were more prolonged at 3 and 6 months of age, but were similar to WT at 12 months. KO mice displayed a distinct response to pentylenetetrazole, with a greater incidence of clonic seizures and a more pronounced post-ictal suppression of movement, feeding and drinking behavior. Together, these results highlight a stark clinicopathologic dissociation in a mouse model of LD, where LBs accrue substantially without clinically meaningful changes in overall wellbeing. Our findings allude to a delay between LB accumulation and neurobehavioral decline: one that may provide a window for treatment, and whose precise duration may be difficult to ascertain within the typical lifespan of a laboratory mouse.
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Affiliation(s)
- Vaishnav Krishnan
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Arindam Ghosh Mazumder
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Jessica L. Kamen
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Catharina Schirmer
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Nandani Adhyapak
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - John Samuel Bass
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Samuel C. Lee
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Atul Maheshwari
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Gemma Molinaro
- Department of Neuroscience University of Texas Southwestern Medical Center, Dallas, TX
| | - Jay R. Gibson
- Department of Neuroscience University of Texas Southwestern Medical Center, Dallas, TX
| | - Kimberly M. Huber
- Department of Neuroscience University of Texas Southwestern Medical Center, Dallas, TX
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
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9
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Lindquist BE, Timbie C, Voskobiynyk Y, Paz JT. Thalamocortical circuits in generalized epilepsy: Pathophysiologic mechanisms and therapeutic targets. Neurobiol Dis 2023; 181:106094. [PMID: 36990364 PMCID: PMC10192143 DOI: 10.1016/j.nbd.2023.106094] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/02/2023] [Accepted: 03/19/2023] [Indexed: 03/29/2023] Open
Abstract
Generalized epilepsy affects 24 million people globally; at least 25% of cases remain medically refractory. The thalamus, with widespread connections throughout the brain, plays a critical role in generalized epilepsy. The intrinsic properties of thalamic neurons and the synaptic connections between populations of neurons in the nucleus reticularis thalami and thalamocortical relay nuclei help generate different firing patterns that influence brain states. In particular, transitions from tonic firing to highly synchronized burst firing mode in thalamic neurons can cause seizures that rapidly generalize and cause altered awareness and unconsciousness. Here, we review the most recent advances in our understanding of how thalamic activity is regulated and discuss the gaps in our understanding of the mechanisms of generalized epilepsy syndromes. Elucidating the role of the thalamus in generalized epilepsy syndromes may lead to new opportunities to better treat pharmaco-resistant generalized epilepsy by thalamic modulation and dietary therapy.
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Affiliation(s)
- Britta E Lindquist
- UCSF Department of Neurology, Division of Neurocritical Care, United States of America; UCSF Department of Neurology, Division of Pediatric Epilepsy, United States of America; UCSF Department of Neurology, United States of America
| | - Clare Timbie
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, Division of Pediatric Epilepsy, United States of America; UCSF Department of Neurology, United States of America
| | - Yuliya Voskobiynyk
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, United States of America
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, United States of America; UCSF Department of Neurology, United States of America; Kavli Institute for Fundamental Neuroscience, UCSF, United States of America.
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10
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Juras JA, Webb MB, Young LE, Markussen KH, Hawkinson TR, Buoncristiani MD, Bolton KE, Coburn PT, Williams MI, Sun LP, Sanders WC, Bruntz RC, Conroy LR, Wang C, Gentry MS, Smith BN, Sun RC. In situ microwave fixation provides an instantaneous snapshot of the brain metabolome. CELL REPORTS METHODS 2023; 3:100455. [PMID: 37159672 PMCID: PMC10163000 DOI: 10.1016/j.crmeth.2023.100455] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 02/14/2023] [Accepted: 03/27/2023] [Indexed: 05/11/2023]
Abstract
Brain glucose metabolism is highly heterogeneous among brain regions and continues postmortem. In particular, we demonstrate exhaustion of glycogen and glucose and an increase in lactate production during conventional rapid brain resection and preservation by liquid nitrogen. In contrast, we show that these postmortem changes are not observed with simultaneous animal sacrifice and in situ fixation with focused, high-power microwave. We further employ microwave fixation to define brain glucose metabolism in the mouse model of streptozotocin-induced type 1 diabetes. Using both total pool and isotope tracing analyses, we identified global glucose hypometabolism in multiple brain regions, evidenced by reduced 13C enrichment into glycogen, glycolysis, and the tricarboxylic acid (TCA) cycle. Reduced glucose metabolism correlated with a marked decrease in GLUT2 expression and several metabolic enzymes in unique brain regions. In conclusion, our study supports the incorporation of microwave fixation for more accurate studies of brain metabolism in rodent models.
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Affiliation(s)
- Jelena A. Juras
- Department of Neuroscience, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Madison B. Webb
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Lyndsay E.A. Young
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Kia H. Markussen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Tara R. Hawkinson
- Department of Neuroscience, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL 32611, USA
| | - Michael D. Buoncristiani
- Department of Neuroscience, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Kayli E. Bolton
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Peyton T. Coburn
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Meredith I. Williams
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Lisa P.Y. Sun
- Department of Neuroscience, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - William C. Sanders
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Ronald C. Bruntz
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Lindsey R. Conroy
- Department of Neuroscience, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Chi Wang
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
- Division of Biostatics, Department of Internal Medicine, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
| | - Matthew S. Gentry
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL 32611, USA
- Center for Advanced Spatial Biomolecule Research, University of Florida, College of Medicine, Gainesville, FL 32611, USA
| | - Bret N. Smith
- Department of Neuroscience, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Ramon C. Sun
- Department of Neuroscience, University of Kentucky, College of Medicine, Lexington, KY 40536, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
- Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL 32611, USA
- Center for Advanced Spatial Biomolecule Research, University of Florida, College of Medicine, Gainesville, FL 32611, USA
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11
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Duran J. Role of Astrocytes in the Pathophysiology of Lafora Disease and Other Glycogen Storage Disorders. Cells 2023; 12:cells12050722. [PMID: 36899857 PMCID: PMC10000527 DOI: 10.3390/cells12050722] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/05/2023] [Accepted: 02/22/2023] [Indexed: 03/12/2023] Open
Abstract
Lafora disease is a rare disorder caused by loss of function mutations in either the EPM2A or NHLRC1 gene. The initial symptoms of this condition are most commonly epileptic seizures, but the disease progresses rapidly with dementia, neuropsychiatric symptoms, and cognitive deterioration and has a fatal outcome within 5-10 years after onset. The hallmark of the disease is the accumulation of poorly branched glycogen in the form of aggregates known as Lafora bodies in the brain and other tissues. Several reports have demonstrated that the accumulation of this abnormal glycogen underlies all the pathologic traits of the disease. For decades, Lafora bodies were thought to accumulate exclusively in neurons. However, it was recently identified that most of these glycogen aggregates are present in astrocytes. Importantly, astrocytic Lafora bodies have been shown to contribute to pathology in Lafora disease. These results identify a primary role of astrocytes in the pathophysiology of Lafora disease and have important implications for other conditions in which glycogen abnormally accumulates in astrocytes, such as Adult Polyglucosan Body disease and the buildup of Corpora amylacea in aged brains.
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Affiliation(s)
- Jordi Duran
- Institut Químic de Sarrià (IQS), Universitat Ramon Llull (URL), 08017 Barcelona, Spain;
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
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12
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Active Glycogen Synthase in the Liver Prevents High-Fat Diet-Induced Glucose Intolerance, Decreases Food Intake, and Lowers Body Weight. Int J Mol Sci 2023; 24:ijms24032574. [PMID: 36768897 PMCID: PMC9917303 DOI: 10.3390/ijms24032574] [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: 12/29/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
Many lines of evidence demonstrate a correlation between liver glycogen content and food intake. We previously demonstrated that mice overexpressing protein targeting to glycogen (PTG) specifically in the liver-which have increased glycogen content in this organ-are protected from high-fat diet (HFD)-induced obesity by reduced food intake. However, the use of PTG to increase liver glycogen implies certain limitations. PTG stimulates glycogen synthesis but also inhibits the enzyme responsible for glycogen degradation. Furthermore, as PTG is a regulatory subunit of protein phosphatase 1 (PP1), which regulates many cellular functions, its overexpression could have side effects beyond the regulation of glycogen metabolism. Therefore, it is necessary to determine whether the direct activation of glycogen synthesis, without affecting its degradation or other cellular functions, has the same effects. To this end, we generated mice overexpressing a non-inactivatable form of glycogen synthase (GS) specifically in the liver (9A-MGSAlb mice). Control and 9a-MGSAlb mice were fed a standard diet (SD) or HFD for 16 weeks. Glucose tolerance and feeding behavior were analyzed. 9A-MGSAlb mice showed an increase in hepatic glycogen in fed and fasting conditions. When fed an HFD, these animals preserved their hepatic energy state, had a reduced food intake, and presented a lower body weight and fat mass than control animals, without changes in energy expenditure. Furthermore, 9A-MGSAlb animals showed improved glucose tolerance when fed an SD or HFD. Moreover, liver triacylglycerol levels that were increased after HFD feeding were lower in these mice. These results confirm that increased liver glycogen stores contribute to decreased appetite and improve glucose tolerance in mice fed an HFD. On the basis of our findings, strategies to preserve hepatic glycogen stores emerge as potential treatments for obesity and hyperglycemia.
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13
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Della Vecchia S, Marchese M, Santorelli FM. Glial Contributions to Lafora Disease: A Systematic Review. Biomedicines 2022; 10:biomedicines10123103. [PMID: 36551859 PMCID: PMC9776290 DOI: 10.3390/biomedicines10123103] [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: 11/02/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Lafora disease (LD) is a neurodegenerative condition characterized by the accumulation of polyglucosan bodies (PBs) throughout the brain. Alongside metabolic and molecular alterations, neuroinflammation has emerged as another key histopathological feature of LD. METHODS To investigate the role of astrocytes and microglia in LD, we performed a systematic review according to the PRISMA statement. PubMed, Scopus, and Web-of-Science database searches were performed independently by two reviewers. RESULTS Thirty-five studies analyzing the relationship of astrocytes and microglia with LD and/or the effects of anti-inflammatory treatments in LD animal models were identified and included in the review. Although LD has long been dominated by a neuronocentric view, a growing body of evidence suggests a role of glial cells in the disease, starting with the finding that these cells accumulate PBs. We discuss the potential meaning of glial PB accumulations, the likely factors activating glial cells, and the possible contribution of glial cells to LD neurodegeneration and epilepsy. CONCLUSIONS Given the evidence for the role of neuroinflammation in LD, future studies should consider glial cells as a potential therapeutic target for modifying/delaying LD progression; however, it should be kept in mind that these cells can potentially assume multiple reactive phenotypes, which could influence the therapeutic response.
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Affiliation(s)
- Stefania Della Vecchia
- Molecular Medicine and Neurogenetics, IRCCS Stella Maris Foundation, Calambrone, 56128 Pisa, Italy
- Correspondence: (S.D.V.); (F.M.S.)
| | - Maria Marchese
- Neurobiology, IRCCS Stella Maris Foundation, Calambrone, 56128 Pisa, Italy
| | - Filippo Maria Santorelli
- Molecular Medicine and Neurogenetics, IRCCS Stella Maris Foundation, Calambrone, 56128 Pisa, Italy
- Neurobiology, IRCCS Stella Maris Foundation, Calambrone, 56128 Pisa, Italy
- Correspondence: (S.D.V.); (F.M.S.)
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14
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Hawkinson TR, Clarke HA, Young LEA, Conroy LR, Markussen KH, Kerch KM, Johnson LA, Nelson PT, Wang C, Allison DB, Gentry MS, Sun RC. In situ spatial glycomic imaging of mouse and human Alzheimer's disease brains. Alzheimers Dement 2022; 18:1721-1735. [PMID: 34908231 PMCID: PMC9198106 DOI: 10.1002/alz.12523] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 10/06/2021] [Accepted: 10/10/2021] [Indexed: 01/28/2023]
Abstract
N-linked protein glycosylation in the brain is an understudied facet of glucose utilization that impacts a myriad of cellular processes including resting membrane potential, axon firing, and synaptic vesicle trafficking. Currently, a spatial map of N-linked glycans within the normal and Alzheimer's disease (AD) human brain does not exist. A comprehensive analysis of the spatial N-linked glycome would improve our understanding of brain energy metabolism, linking metabolism to signaling events perturbed during AD progression, and could illuminate new therapeutic strategies. Herein we report an optimized in situ workflow for enzyme-assisted, matrix-assisted laser desorption and ionization (MALDI) mass spectrometry imaging (MSI) of brain N-linked glycans. Using this workflow, we spatially interrogated N-linked glycan heterogeneity in both mouse and human AD brains and their respective age-matched controls. We identified robust regional-specific N-linked glycan changes associated with AD in mice and humans. These data suggest that N-linked glycan dysregulation could be an underpinning of AD pathologies.
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Affiliation(s)
- Tara R. Hawkinson
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Harrison A. Clarke
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Lyndsay E. A. Young
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
| | - Lindsey R. Conroy
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Kia H. Markussen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Kayla M. Kerch
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Lance A. Johnson
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Peter T. Nelson
- Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Chi Wang
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
- Department of Biostatistics, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Derek B. Allison
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
- Department of Pathology and Laboratory Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Matthew S. Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
| | - Ramon C. Sun
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
- Markey Cancer Center, University of Kentucky, Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
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15
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Varea O, Guinovart JJ, Duran J. Malin restoration as proof of concept for gene therapy for Lafora disease. Brain Commun 2022; 4:fcac168. [PMID: 35813879 PMCID: PMC9260307 DOI: 10.1093/braincomms/fcac168] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 05/03/2022] [Accepted: 06/21/2022] [Indexed: 11/25/2022] Open
Abstract
Lafora disease is a fatal neurodegenerative childhood dementia caused by loss-of-function mutations in either the laforin or malin gene. The hallmark of the disease is the accumulation of abnormal glycogen aggregates known as Lafora bodies (LBs) in the brain and other tissues. These aggregates are responsible for the pathological features of the disease. As a monogenic disorder, Lafora disease is a good candidate for gene therapy-based approaches. However, most patients are diagnosed after the appearance of the first symptoms and thus when LBs are already present in the brain. In this context, it was not clear whether the restoration of a normal copy of the defective gene (either laforin or malin) would prove effective. Here we evaluated the effect of restoring malin in a malin-deficient mouse model of Lafora disease as a proof of concept for gene replacement therapy. To this end, we generated a malin-deficient mouse in which malin expression can be induced at a certain time. Our results reveal that malin restoration at an advanced stage of the disease arrests the accumulation of LBs in brain and muscle, induces the degradation of laforin and glycogen synthase bound to the aggregates, and ameliorates neuroinflammation. These results identify malin restoration as the first therapeutic strategy to show effectiveness when applied at advanced stages of Lafora disease.
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Affiliation(s)
- Olga Varea
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology , Barcelona 08028 , Spain
| | - Joan J Guinovart
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology , Barcelona 08028 , Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM) , Madrid 28029 , Spain
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona , Barcelona 08028 , Spain
| | - Jordi Duran
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology , Barcelona 08028 , Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM) , Madrid 28029 , Spain
- Institut Químic de Sarrià (IQS), Universitat Ramon Llull (URL) , Barcelona 08017 , Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology , Barcelona 08028 , Spain
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16
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Murphy RD, Chen T, Lin J, He R, Wu L, Pearson CR, Sharma S, Vander Kooi CD, Sinai AP, Zhang ZY, Vander Kooi CW, Gentry MS. The Toxoplasma glucan phosphatase TgLaforin utilizes a distinct functional mechanism that can be exploited by therapeutic inhibitors. J Biol Chem 2022; 298:102089. [PMID: 35640720 PMCID: PMC9254107 DOI: 10.1016/j.jbc.2022.102089] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 01/19/2023] Open
Abstract
Toxoplasma gondii is an intracellular parasite that generates amylopectin granules (AGs), a polysaccharide associated with bradyzoites that define chronic T. gondii infection. AGs are postulated to act as an essential energy storage molecule that enable bradyzoite persistence, transmission, and reactivation. Importantly, reactivation can result in the life-threatening symptoms of toxoplasmosis. T. gondii encodes glucan dikinase and glucan phosphatase enzymes that are homologous to the plant and animal enzymes involved in reversible glucan phosphorylation and which are required for efficient polysaccharide degradation and utilization. However, the structural determinants that regulate reversible glucan phosphorylation in T. gondii are unclear. Herein, we define key functional aspects of the T. gondii glucan phosphatase TgLaforin (TGME49_205290). We demonstrate that TgLaforin possesses an atypical split carbohydrate-binding-module domain. AlphaFold2 modeling combined with hydrogen-deuterium exchange mass spectrometry and differential scanning fluorimetry also demonstrate the unique structural dynamics of TgLaforin with regard to glucan binding. Moreover, we show that TgLaforin forms a dual specificity phosphatase domain-mediated dimer. Finally, the distinct properties of the glucan phosphatase catalytic domain were exploited to identify a small molecule inhibitor of TgLaforin catalytic activity. Together, these studies define a distinct mechanism of TgLaforin activity, opening up a new avenue of T. gondii bradyzoite biology as a therapeutic target.
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Affiliation(s)
- Robert D Murphy
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA; Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Tiantian Chen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Jianping Lin
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Rongjun He
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Li Wu
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Caden R Pearson
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Savita Sharma
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Carl D Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Anthony P Sinai
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Zhong-Yin Zhang
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA.
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA.
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA.
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17
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Trehalose Treatment in Zebrafish Model of Lafora Disease. Int J Mol Sci 2022; 23:ijms23126874. [PMID: 35743315 PMCID: PMC9224929 DOI: 10.3390/ijms23126874] [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: 05/24/2022] [Revised: 06/15/2022] [Accepted: 06/17/2022] [Indexed: 01/18/2023] Open
Abstract
Mutations in the EPM2A gene encoding laforin cause Lafora disease (LD), a progressive myoclonic epilepsy characterized by drug-resistant seizures and progressive neurological impairment. To date, rodents are the only available models for studying LD; however, their use for drug screening is limited by regulatory restrictions and high breeding costs. To investigate the role of laforin loss of function in early neurodevelopment, and to screen for possible new compounds for treating the disorder, we developed a zebrafish model of LD. Our results showed the epm2a−/− zebrafish to be a faithful model of LD, exhibiting the main disease features, namely motor impairment and neuronal hyperexcitability with spontaneous seizures. The model also showed increased inflammatory response and apoptotic death, as well as an altered autophagy pathway that occurs early in development and likely contributes to the disease progression. Early administration of trehalose was found to be effective for rescuing motor impairment and neuronal hyperexcitability associated with seizures. Our study adds a new tool for investigating LD and might help to identify new treatment opportunities.
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18
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Gentry MS, Markussen KH, Donohue KJ. Two Diseases-One Preclinical Treatment Targeting Glycogen Synthesis. Neurotherapeutics 2022; 19:977-981. [PMID: 35460010 PMCID: PMC9294113 DOI: 10.1007/s13311-022-01240-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2022] [Indexed: 01/30/2023] Open
Affiliation(s)
- Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA.
| | - Kia H Markussen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Katherine J Donohue
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
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19
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Pellegrini P, Hervera A, Varea O, Brewer MK, López-Soldado I, Guitart A, Aguilera M, Prats N, del Río JA, Guinovart JJ, Duran J. Lack of p62 Impairs Glycogen Aggregation and Exacerbates Pathology in a Mouse Model of Myoclonic Epilepsy of Lafora. Mol Neurobiol 2021; 59:1214-1229. [PMID: 34962634 PMCID: PMC8857170 DOI: 10.1007/s12035-021-02682-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/04/2021] [Indexed: 01/06/2023]
Abstract
Lafora disease (LD) is a fatal childhood-onset dementia characterized by the extensive accumulation of glycogen aggregates—the so-called Lafora Bodies (LBs)—in several organs. The accumulation of LBs in the brain underlies the neurological phenotype of the disease. LBs are composed of abnormal glycogen and various associated proteins, including p62, an autophagy adaptor that participates in the aggregation and clearance of misfolded proteins. To study the role of p62 in the formation of LBs and its participation in the pathology of LD, we generated a mouse model of the disease (malinKO) lacking p62. Deletion of p62 prevented LB accumulation in skeletal muscle and cardiac tissue. In the brain, the absence of p62 altered LB morphology and increased susceptibility to epilepsy. These results demonstrate that p62 participates in the formation of LBs and suggest that the sequestration of abnormal glycogen into LBs is a protective mechanism through which it reduces the deleterious consequences of its accumulation in the brain.
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Affiliation(s)
- Pasquale Pellegrini
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Arnau Hervera
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, 08028 Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, 08028 Barcelona, Spain
| | - Olga Varea
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - M. Kathryn Brewer
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Iliana López-Soldado
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Anna Guitart
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Mònica Aguilera
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Neus Prats
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - José Antonio del Río
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain
- Department of Cell Biology, Physiology and Immunology, Universitat de Barcelona, 08028 Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, 08028 Barcelona, Spain
| | - Joan J. Guinovart
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain
| | - Jordi Duran
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
- Institut Químic de Sarrià, University Ramon Llull, 08017 Barcelona, Spain
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Mitra S, Gumusgoz E, Minassian BA. Lafora disease: Current biology and therapeutic approaches. Rev Neurol (Paris) 2021; 178:315-325. [PMID: 34301405 DOI: 10.1016/j.neurol.2021.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/21/2021] [Accepted: 06/16/2021] [Indexed: 12/19/2022]
Abstract
The ubiquitin system impacts most cellular processes and is altered in numerous neurodegenerative diseases. However, little is known about its role in neurodegenerative diseases due to disturbances of glycogen metabolism such as Lafora disease (LD). In LD, insufficiently branched and long-chained glycogen forms and precipitates into insoluble polyglucosan bodies (Lafora bodies), which drive neuroinflammation, neurodegeneration and epilepsy. LD is caused by mutations in the gene encoding the glycogen phosphatase laforin or the gene coding for the laforin interacting partner ubiquitin E3 ligase malin. The role of the malin-laforin complex in regulating glycogen structure remains with full of gaps. In this review we bring together the disparate body of data on these two proteins and propose a mechanistic hypothesis of the disease in which malin-laforin's role to monitor and prevent over-elongation of glycogen branch chains, which drive glycogen molecules to precipitate and accumulate into Lafora bodies. We also review proposed connections between Lafora bodies and the ensuing neuroinflammation, neurodegeneration and intractable epilepsy. Finally, we review the exciting activities in developing therapies for Lafora disease based on replacing the missing genes, slowing the enzyme - glycogen synthase - that over-elongates glycogen branches, and introducing enzymes that can digest Lafora bodies. Much more work is needed to fill the gaps in glycogen metabolism in which laforin and malin operate. However, knowledge appears already adequate to advance disease course altering therapies for this catastrophic fatal disease.
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Affiliation(s)
- S Mitra
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - E Gumusgoz
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - B A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
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21
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Canine Lafora Disease: An Unstable Repeat Expansion Disorder. Life (Basel) 2021; 11:life11070689. [PMID: 34357061 PMCID: PMC8304204 DOI: 10.3390/life11070689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 11/17/2022] Open
Abstract
Canine Lafora disease is a recessively inherited, rapidly progressing neurodegenerative disease caused by the accumulation of abnormally constructed insoluble glycogen Lafora bodies in the brain and other tissues due to the loss of NHL repeat containing E3 ubiquitin protein ligase 1 (NHLRC1). Dogs have a dodecamer repeat sequence within the NHLRC1 gene, which is prone to unstable (dynamic) expansion and loss of function. Progressive signs of Lafora disease include hypnic jerks, reflex and spontaneous myoclonus, seizures, vision loss, ataxia and decreased cognitive function. We studied five dogs (one Chihuahua, two French Bulldogs, one Griffon Bruxellois, one mixed breed) with clinical signs associated with canine Lafora disease. Identification of polyglucosan bodies (Lafora bodies) in myocytes supported diagnosis in the French Bulldogs; muscle areas close to the myotendinous junction and the myofascial union segment had the highest yield of inclusions. Postmortem examination of one of the French Bulldogs revealed brain Lafora bodies. Genetic testing for the known canine NHLRC1 mutation confirmed the presence of a homozygous mutation associated with canine Lafora disease. Our results show that Lafora disease extends beyond previous known breeds to the French Bulldog, Griffon Bruxellois and even mixed-breed dogs, emphasizing the likely species-wide nature of this genetic problem. It also establishes these breeds as animal models for the devastating human disease. Genetic testing should be used when designing breeding strategies to determine the frequency of the NHLRC1 mutation in affected breeds. Lafora diseases should be suspected in any older dog presenting with myoclonus, hypnic jerks or photoconvulsions.
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