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Skurat AV, Segvich DM, Contreras CJ, Hu YC, Hurley TD, DePaoli-Roach AA, Roach PJ. Impaired malin expression and interaction with partner proteins in Lafora disease. J Biol Chem 2024; 300:107271. [PMID: 38588813 PMCID: PMC11063907 DOI: 10.1016/j.jbc.2024.107271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
Lafora disease (LD) is an autosomal recessive myoclonus epilepsy with onset in the teenage years leading to death within a decade of onset. LD is characterized by the overaccumulation of hyperphosphorylated, poorly branched, insoluble, glycogen-like polymers called Lafora bodies. The disease is caused by mutations in either EPM2A, encoding laforin, a dual specificity phosphatase that dephosphorylates glycogen, or EMP2B, encoding malin, an E3-ubiquitin ligase. While glycogen is a widely accepted laforin substrate, substrates for malin have been difficult to identify partly due to the lack of malin antibodies able to detect malin in vivo. Here we describe a mouse model in which the malin gene is modified at the C-terminus to contain the c-myc tag sequence, making an expression of malin-myc readily detectable. Mass spectrometry analyses of immunoprecipitates using c-myc tag antibodies demonstrate that malin interacts with laforin and several glycogen-metabolizing enzymes. To investigate the role of laforin in these interactions we analyzed two additional mouse models: malin-myc/laforin knockout and malin-myc/LaforinCS, where laforin was either absent or the catalytic Cys was genomically mutated to Ser, respectively. The interaction of malin with partner proteins requires laforin but is not dependent on its catalytic activity or the presence of glycogen. Overall, the results demonstrate that laforin and malin form a complex in vivo, which stabilizes malin and enhances interaction with partner proteins to facilitate normal glycogen metabolism. They also provide insights into the development of LD and the rescue of the disease by the catalytically inactive phosphatase.
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Affiliation(s)
- Alexander V Skurat
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Dyann M Segvich
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Christopher J Contreras
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Yueh-Chiang Hu
- Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Thomas D Hurley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA.
| | - Anna A DePaoli-Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA.
| | - Peter J Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA
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2
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Żołnierkiewicz O, Rogacka D. Hyperglycemia - A culprit of podocyte pathology in the context of glycogen metabolism. Arch Biochem Biophys 2024; 753:109927. [PMID: 38350532 DOI: 10.1016/j.abb.2024.109927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/31/2024] [Accepted: 02/10/2024] [Indexed: 02/15/2024]
Abstract
Prolonged disruption in the balance of glucose can result in metabolic disorders. The kidneys play a significant role in regulating blood glucose levels. However, when exposed to chronic hyperglycemia, the kidneys' ability to handle glucose metabolism may be impaired, leading to an accumulation of glycogen. Earlier studies have shown that there can be a significant increase in glucose storage in the form of glycogen in the kidneys in diabetes. Podocytes play a crucial role in maintaining the integrity of filtration barrier. In diabetes, exposure to elevated glucose levels can lead to significant metabolic and structural changes in podocytes, contributing to kidney damage and the development of diabetic kidney disease. The accumulation of glycogen in podocytes is not a well-established phenomenon. However, a recent study has demonstrated the presence of glycogen granules in podocytes. This review delves into the intricate connections between hyperglycemia and glycogen metabolism within the context of the kidney, with special emphasis on podocytes. The aberrant storage of glycogen has the potential to detrimentally impact podocyte functionality and perturb their structural integrity. This review provides a comprehensive analysis of the alterations in cellular signaling pathways that may potentially lead to glycogen overproduction in podocytes.
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Affiliation(s)
- Olga Żołnierkiewicz
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Wita Stwosza 63, 80-308, Gdansk, Poland
| | - Dorota Rogacka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Wita Stwosza 63, 80-308, Gdansk, Poland; University of Gdansk, Faculty of Chemistry, Department of Molecular Biotechnology, Wita Stwosza 63, 80-308, Gdansk, Poland.
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3
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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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4
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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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5
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Young LEA, Conroy LR, Clarke HA, Hawkinson TR, Bolton KE, Sanders WC, Chang JE, Webb MB, Alilain WJ, Vander Kooi CW, Drake RR, Andres DA, Badgett TC, Wagner LM, Allison DB, Sun RC, Gentry MS. In situ mass spectrometry imaging reveals heterogeneous glycogen stores in human normal and cancerous tissues. EMBO Mol Med 2022; 14:e16029. [PMID: 36059248 PMCID: PMC9641418 DOI: 10.15252/emmm.202216029] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 07/25/2022] [Accepted: 08/03/2022] [Indexed: 01/19/2023] Open
Abstract
Glycogen dysregulation is a hallmark of aging, and aberrant glycogen drives metabolic reprogramming and pathogenesis in multiple diseases. However, glycogen heterogeneity in healthy and diseased tissues remains largely unknown. Herein, we describe a method to define spatial glycogen architecture in mouse and human tissues using matrix-assisted laser desorption/ionization mass spectrometry imaging. This assay provides robust and sensitive spatial glycogen quantification and architecture characterization in the brain, liver, kidney, testis, lung, bladder, and even the bone. Armed with this tool, we interrogated glycogen spatial distribution and architecture in different types of human cancers. We demonstrate that glycogen stores and architecture are heterogeneous among diseases. Additionally, we observe unique hyperphosphorylated glycogen accumulation in Ewing sarcoma, a pediatric bone cancer. Using preclinical models, we correct glycogen hyperphosphorylation in Ewing sarcoma through genetic and pharmacological interventions that ablate in vivo tumor growth, demonstrating the clinical therapeutic potential of targeting glycogen in Ewing sarcoma.
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Affiliation(s)
- Lyndsay E A Young
- Department of Molecular and Cellular Biochemistry, College of MedicineUniversity of KentuckyLexingtonKYUSA
- Markey Cancer CenterUniversity of KentuckyLexingtonKYUSA
| | - Lindsey R Conroy
- Markey Cancer CenterUniversity of KentuckyLexingtonKYUSA
- Department of Neuroscience, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Harrison A Clarke
- Department of Neuroscience, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Tara R Hawkinson
- Department of Neuroscience, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Kayli E Bolton
- Department of Molecular and Cellular Biochemistry, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - William C Sanders
- Department of Molecular and Cellular Biochemistry, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Josephine E Chang
- Department of Neuroscience, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Madison B Webb
- Department of Molecular and Cellular Biochemistry, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Warren J Alilain
- Department of Neuroscience, College of MedicineUniversity of KentuckyLexingtonKYUSA
- Spinal Cord and Brain Injury Research CenterUniversity of KentuckyLexingtonKYUSA
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of MedicineUniversity of KentuckyLexingtonKYUSA
- Markey Cancer CenterUniversity of KentuckyLexingtonKYUSA
| | - Richard R Drake
- Cell and Molecular Pharmacology and Experimental TherapeuticsMedical University of South CarolinaCharlestonSCUSA
| | - Douglas A Andres
- Department of Molecular and Cellular Biochemistry, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Tom C Badgett
- Pediatric Hematology‐Oncology, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Lars M Wagner
- Pediatric Hematology‐OncologyDuke UniversityDurhamNCUSA
| | - Derek B Allison
- Department of Pathology and Laboratory Medicine, College of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Ramon C Sun
- Markey Cancer CenterUniversity of KentuckyLexingtonKYUSA
- Department of Neuroscience, College of MedicineUniversity of KentuckyLexingtonKYUSA
- Spinal Cord and Brain Injury Research CenterUniversity of KentuckyLexingtonKYUSA
- Department of Biochemistry & Molecular Biology, College of MedicineUniversity of FloridaGainesvilleFLUSA
- Center for Advanced Spatial Biomolecule ResearchUniversity of FloridaGainesvilleFLUSA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of MedicineUniversity of KentuckyLexingtonKYUSA
- Markey Cancer CenterUniversity of KentuckyLexingtonKYUSA
- Department of Biochemistry & Molecular Biology, College of MedicineUniversity of FloridaGainesvilleFLUSA
- Center for Advanced Spatial Biomolecule ResearchUniversity of FloridaGainesvilleFLUSA
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6
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Tiwari AK, Adhikari A, Mishra LC, Srivastava A. Current Status of Our Understanding for Brain Integrated Functions and its Energetics. Neurochem Res 2022; 47:2499-2512. [PMID: 35689788 DOI: 10.1007/s11064-022-03633-w] [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: 11/30/2021] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 10/18/2022]
Abstract
Human/animal brain is a unique organ with substantially high metabolism but it contains no energy reserve that is the reason it requires continuous supply of O2 and energy fluxes through CBF. The main source of energy remains glucose as the other biomolecules do not able to cross the blood-brain barrier. The speed of glucose metabolism is heterogeneous throughout the brain. One of the major flux consumption is Neuron-astrocyte cycling of glutamate and glutamine in glutamatergic neurons (approximately 80% of glucose metabolism in brain). The quantification of cellular glucose and other related substrate in resting, activated state can be analyzed through [18 F]FDG -positron-emission tomography (studying CMRglc) and [13 C/31P -MRS: for neuroenergetics & neurotransmitter cycling &31P-MRS: for energy induction & redox state). Merging basic in vitro studies with these techniques will help to develop new treatment paradigms for human brain diseased conditions.
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Affiliation(s)
- Anjani Kumar Tiwari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University (A Central University), 226025, Lucknow, Uttar Pradesh, India.
| | - Anupriya Adhikari
- Department of Chemistry, Babasaheb Bhimrao Ambedkar University (A Central University), 226025, Lucknow, Uttar Pradesh, India
| | - Lokesh Chandra Mishra
- Department of Zoology, Hansraj College, University of Delhi, North Campus, 110007, Delhi, India
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7
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Shahal T, Segev E, Konstantinovsky T, Marcus Y, Shefer G, Pasmanik-Chor M, Buch A, Ebenstein Y, Zimmet P, Stern N. Deconvolution of the epigenetic age discloses distinct inter-personal variability in epigenetic aging patterns. Epigenetics Chromatin 2022; 15:9. [PMID: 35255955 PMCID: PMC8900303 DOI: 10.1186/s13072-022-00441-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The epigenetic age can now be extrapolated from one of several epigenetic clocks, which are based on age-related changes in DNA methylation levels at specific multiple CpG sites. Accelerated aging, calculated from the discrepancy between the chronological age and the epigenetic age, has shown to predict morbidity and mortality rate. We assumed that deconvolution of epigenetic age to its components could shed light on the diversity of epigenetic, and by inference, on inter-individual variability in the causes of biological aging. RESULTS Using the Horvath original epigenetic clock, we identified several CpG sites linked to distinct genes that quantitatively explain much of the inter-personal variability in epigenetic aging, with CpG sites related to secretagogin and malin being the most variable. We show that equal epigenetic age in different subjects can result from variable contribution size of the same CpG sites to the total epigenetic age. In a healthy cohort, the most variable CpG sites are responsible for accelerated and decelerated epigenetic aging, relative to chronological age. CONCLUSIONS Of the 353 CpG sites that form the basis for the Horvath epigenetic age, we have found the CpG sites that are responsible for accelerated and decelerated epigenetic aging in healthy subjects. However, the relative contribution of each site to aging varies between individuals, leading to variable personal aging patterns. Our findings pave the way to form personalized aging cards allowing the identification of specific genes related to CpG sites, as aging markers, and perhaps treatment of these targets in order to hinder undesirable age drifting.
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Affiliation(s)
- Tamar Shahal
- The Sagol Center for Epigenetics of Aging and Metabolism, Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv-Sourasky Medical Center; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Elad Segev
- Department of Applied Mathematics, Holon Institute of Technology, Holon, Israel
| | - Thomas Konstantinovsky
- The Sagol Center for Epigenetics of Aging and Metabolism, Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv-Sourasky Medical Center; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Applied Mathematics, Holon Institute of Technology, Holon, Israel
| | - Yonit Marcus
- The Sagol Center for Epigenetics of Aging and Metabolism, Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv-Sourasky Medical Center; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,The Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Gabi Shefer
- The Sagol Center for Epigenetics of Aging and Metabolism, Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv-Sourasky Medical Center; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Metsada Pasmanik-Chor
- Bioinformatics Unit, The George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | - Assaf Buch
- The Sagol Center for Epigenetics of Aging and Metabolism, Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv-Sourasky Medical Center; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yuval Ebenstein
- Department of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Paul Zimmet
- Department of Diabetes, Monash University School of Medicine, Melbourne, Australia
| | - Naftali Stern
- The Sagol Center for Epigenetics of Aging and Metabolism, Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv-Sourasky Medical Center; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. .,The Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.
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8
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Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging of Glycogen In Situ. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2437:215-228. [PMID: 34902151 DOI: 10.1007/978-1-0716-2030-4_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Histopathological detection and quantitation of glycogen in situ are important for the assessment of glycogen storage diseases and different types of cancer. The current standard method for defining the regionality of glycogen rely almost exclusively on Periodic Acid-Schiff (PAS) staining, a workflow that lacks specificity and sensitivity. Herein, we describe a new and much improved workflow to detect microenvironmental glycogen in situ using enzyme-assisted matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI). This method provides superior sensitivity and can elucidate the molecular features of glycogen structure, with 50 μm spatial resolution for a next-generation histopathological assessment of glycogen.
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9
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Maly IV, Morales MJ, Pletnikov MV. Astrocyte Bioenergetics and Major Psychiatric Disorders. ADVANCES IN NEUROBIOLOGY 2021; 26:173-227. [PMID: 34888836 DOI: 10.1007/978-3-030-77375-5_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ongoing research continues to add new elements to the emerging picture of involvement of astrocyte energy metabolism in the pathophysiology of major psychiatric disorders, including schizophrenia, mood disorders, and addictions. This review outlines what is known about the energy metabolism in astrocytes, the most numerous cell type in the brain, and summarizes the recent work on how specific perturbations of astrocyte bioenergetics may contribute to the neuropsychiatric conditions. The role of astrocyte energy metabolism in mental health and disease is reviewed on the organism, organ, and cell level. Data arising from genomic, metabolomic, in vitro, and neurobehavioral studies is critically analyzed to suggest future directions in research and possible metabolism-focused therapeutic interventions.
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Affiliation(s)
- Ivan V Maly
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York, Buffalo, NY, USA
| | - Michael J Morales
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York, Buffalo, NY, USA
| | - Mikhail V Pletnikov
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York, Buffalo, NY, USA.
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10
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Han R, Liang J, Zhou B. Glucose Metabolic Dysfunction in Neurodegenerative Diseases-New Mechanistic Insights and the Potential of Hypoxia as a Prospective Therapy Targeting Metabolic Reprogramming. Int J Mol Sci 2021; 22:ijms22115887. [PMID: 34072616 PMCID: PMC8198281 DOI: 10.3390/ijms22115887] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 05/17/2021] [Accepted: 05/24/2021] [Indexed: 12/11/2022] Open
Abstract
Glucose is the main circulating energy substrate for the adult brain. Owing to the high energy demand of nerve cells, glucose is actively oxidized to produce ATP and has a synergistic effect with mitochondria in metabolic pathways. The dysfunction of glucose metabolism inevitably disturbs the normal functioning of neurons, which is widely observed in neurodegenerative disease. Understanding the mechanisms of metabolic adaptation during disease progression has become a major focus of research, and interventions in these processes may relieve the neurons from degenerative stress. In this review, we highlight evidence of mitochondrial dysfunction, decreased glucose uptake, and diminished glucose metabolism in different neurodegeneration models such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD). We also discuss how hypoxia, a metabolic reprogramming strategy linked to glucose metabolism in tumor cells and normal brain cells, and summarize the evidence for hypoxia as a putative therapy for general neurodegenerative disease.
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Affiliation(s)
- Rongrong Han
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Interdisciplinary Innovation Institute of Medicine and Engineering, Beihang University, Beijing 100191, China; (R.H.); (J.L.)
| | - Jing Liang
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Interdisciplinary Innovation Institute of Medicine and Engineering, Beihang University, Beijing 100191, China; (R.H.); (J.L.)
| | - Bing Zhou
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Interdisciplinary Innovation Institute of Medicine and Engineering, Beihang University, Beijing 100191, China; (R.H.); (J.L.)
- School of Engineering Medicine, Beihang University, Beijing 100191, China
- Correspondence:
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11
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An N, Bassil K, Al Jowf GI, Steinbusch HWM, Rothermel M, de Nijs L, Rutten BPF. Dual-specificity phosphatases in mental and neurological disorders. Prog Neurobiol 2020; 198:101906. [PMID: 32905807 DOI: 10.1016/j.pneurobio.2020.101906] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 08/26/2020] [Accepted: 09/01/2020] [Indexed: 01/01/2023]
Abstract
The dual-specificity phosphatase (DUSP) family includes a heterogeneous group of protein phosphatases that dephosphorylate both phospho-tyrosine and phospho-serine/phospho-threonine residues within a single substrate. These protein phosphatases have many substrates and modulate diverse neural functions, such as neurogenesis, differentiation, and apoptosis. DUSP genes have furthermore been associated with mental disorders such as depression and neurological disorders such as Alzheimer's disease. Herein, we review the current literature on the DUSP family of genes concerning mental and neurological disorders. This review i) outlines the structure and general functions of DUSP genes, and ii) overviews the literature on DUSP genes concerning mental and neurological disorders, including model systems, while furthermore providing perspectives for future research.
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Affiliation(s)
- Ning An
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; European Graduate School of Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Katherine Bassil
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; European Graduate School of Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Ghazi I Al Jowf
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; College of Applied Medical Sciences, Department of Public Health, King Faisal University, Al-Ahsa, Saudi Arabia; European Graduate School of Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Harry W M Steinbusch
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; European Graduate School of Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Markus Rothermel
- European Graduate School of Neuroscience, Maastricht University, Maastricht, the Netherlands; Department of Chemosensation - AG Neuromodulation, RWTH Aachen University, Aachen, Germany
| | - Laurence de Nijs
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; European Graduate School of Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Bart P F Rutten
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; European Graduate School of Neuroscience, Maastricht University, Maastricht, the Netherlands.
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12
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Taneja K, Ganesh S. Dendritic spine abnormalities correlate with behavioral and cognitive deficits in mouse models of Lafora disease. J Comp Neurol 2020; 529:1099-1120. [DOI: 10.1002/cne.25006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 06/20/2020] [Accepted: 08/04/2020] [Indexed: 01/03/2023]
Affiliation(s)
- Komal Taneja
- Department of Biological Sciences and Bioengineering Indian Institute of Technology Kanpur Kanpur Uttar Pradesh India
| | - Subramaniam Ganesh
- Department of Biological Sciences and Bioengineering Indian Institute of Technology Kanpur Kanpur Uttar Pradesh India
- The Mehta Family Centre for Engineering in Medicine Indian Institute of Technology Kanpur Kanpur Uttar Pradesh India
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13
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Sullivan MA, Nitschke S, Skwara EP, Wang P, Zhao X, Pan XS, Chown EE, Wang T, Perri AM, Lee JPY, Vilaplana F, Minassian BA, Nitschke F. Skeletal Muscle Glycogen Chain Length Correlates with Insolubility in Mouse Models of Polyglucosan-Associated Neurodegenerative Diseases. Cell Rep 2020; 27:1334-1344.e6. [PMID: 31042462 DOI: 10.1016/j.celrep.2019.04.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/29/2019] [Accepted: 04/02/2019] [Indexed: 01/31/2023] Open
Abstract
Lafora disease (LD) and adult polyglucosan body disease (APBD) are glycogen storage diseases characterized by a pathogenic buildup of insoluble glycogen. Mechanisms causing glycogen insolubility are poorly understood. Here, in two mouse models of LD (Epm2a-/- and Epm2b-/-) and one of APBD (Gbe1ys/ys), the separation of soluble and insoluble muscle glycogen is described, enabling separate analysis of each fraction. Total glycogen is increased in LD and APBD mice, which, together with abnormal chain length and molecule size distributions, is largely if not fully attributed to insoluble glycogen. Soluble glycogen consists of molecules with distinct chain length distributions and differential corresponding solubility, providing a mechanistic link between soluble and insoluble glycogen in vivo. Phosphorylation states differ across glycogen fractions and mouse models, demonstrating that hyperphosphorylation is not a basic feature of insoluble glycogen. Lastly, model-specific variances in protein and activity levels of key glycogen synthesis enzymes suggest uninvestigated regulatory mechanisms.
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Affiliation(s)
- Mitchell A Sullivan
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada; Glycation and Diabetes, Translational Research Institute, Mater Research Institute - University of Queensland, Brisbane, QLD 4102, Australia
| | - Silvia Nitschke
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Evan P Skwara
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Peixiang Wang
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Xiaochu Zhao
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Xiao S Pan
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Erin E Chown
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Travis Wang
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Ami M Perri
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Jennifer P Y Lee
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Francisco Vilaplana
- Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm 10691, Sweden
| | - Berge A Minassian
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A8, Canada; Division of Neurology, Department of Pediatrics, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Felix Nitschke
- Program in Genetics and Genome Biology, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada.
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14
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Besford QA, Cavalieri F, Caruso F. Glycogen as a Building Block for Advanced Biological Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904625. [PMID: 31617264 DOI: 10.1002/adma.201904625] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/15/2019] [Indexed: 06/10/2023]
Abstract
Biological nanoparticles found in living systems possess distinct molecular architectures and diverse functions. Glycogen is a unique biological polysaccharide nanoparticle fabricated by nature through a bottom-up approach. The biocatalytic synthesis of glycogen has evolved over time to form a nanometer-sized dendrimer-like structure (20-150 nm) with a highly branched surface and a dense core. This makes glycogen markedly different from other natural linear or branched polysaccharides and particularly attractive as a platform for biomedical applications. Glycogen is inherently biodegradable, nontoxic, and can be functionalized with diverse surface and internal motifs for enhanced biofunctional properties. Recently, there has been growing interest in glycogen as a natural alternative to synthetic polymers and nanoparticles in a range of applications. Herein, the recent literature on glycogen in the material-based sciences, including its use as a constituent in biodegradable hydrogels and fibers, drug delivery vectors, tumor targeting and penetrating nanoparticles, immunomodulators, vaccine adjuvants, and contrast agents, is reviewed. The various methods of chemical functionalization and physical assembly of glycogen nanoparticles into multicomponent nanodevices, which advance glycogen toward a functional therapeutic nanoparticle from nature and back again, are discussed in detail.
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Affiliation(s)
- Quinn A Besford
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Francesca Cavalieri
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
- Dipartimento di Scienze e Tecnologie Chimiche, Università degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - Frank Caruso
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
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15
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Tang B, Frasinyuk MS, Chikwana VM, Mahalingan KK, Morgan CA, Segvich DM, Bondarenko SP, Mrug GP, Wyrebek P, Watt DS, DePaoli-Roach AA, Roach PJ, Hurley TD. Discovery and Development of Small-Molecule Inhibitors of Glycogen Synthase. J Med Chem 2020; 63:3538-3551. [PMID: 32134266 DOI: 10.1021/acs.jmedchem.9b01851] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The overaccumulation of glycogen appears as a hallmark in various glycogen storage diseases (GSDs), including Pompe, Cori, Andersen, and Lafora disease. Accumulating evidence suggests that suppression of glycogen accumulation represents a potential therapeutic approach for treating these GSDs. Using a fluorescence polarization assay designed to screen for inhibitors of the key glycogen synthetic enzyme, glycogen synthase (GS), we identified a substituted imidazole, (rac)-2-methoxy-4-(1-(2-(1-methylpyrrolidin-2-yl)ethyl)-4-phenyl-1H-imidazol-5-yl)phenol (H23), as a first-in-class inhibitor for yeast GS 2 (yGsy2p). Data from X-ray crystallography at 2.85 Å, as well as kinetic data, revealed that H23 bound within the uridine diphosphate glucose binding pocket of yGsy2p. The high conservation of residues between human and yeast GS in direct contact with H23 informed the development of around 500 H23 analogs. These analogs produced a structure-activity relationship profile that led to the identification of a substituted pyrazole, 4-(4-(4-hydroxyphenyl)-3-(trifluoromethyl)-1H-pyrazol-5-yl)pyrogallol, with a 300-fold improved potency against human GS. These substituted pyrazoles possess a promising scaffold for drug development efforts targeting GS activity in GSDs associated with excess glycogen accumulation.
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Affiliation(s)
- Buyun Tang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202, Indiana, United States
| | - Mykhaylo S Frasinyuk
- V. P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry, NAS of Ukraine, Kyiv 02094, Ukraine.,National University of Food Technologies, Kyiv 01601, Ukraine
| | - Vimbai M Chikwana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202, Indiana, United States
| | - Krishna K Mahalingan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202, Indiana, United States
| | - Cynthia A Morgan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202, Indiana, United States
| | - Dyann M Segvich
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202, Indiana, United States
| | | | - Galyna P Mrug
- V. P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry, NAS of Ukraine, Kyiv 02094, Ukraine.,National University of Food Technologies, Kyiv 01601, Ukraine
| | - Przemyslaw Wyrebek
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington 40506, Kentucky, United States.,Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington 40536, Kentucky, United States
| | - David S Watt
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington 40506, Kentucky, United States.,Center for Pharmaceutical Research and Innovation, College of Pharmacy, University of Kentucky, Lexington 40536, Kentucky, United States.,Lucille Parker Markey Cancer Center, University of Kentucky, Lexington 40536, Kentucky, United States
| | - Anna A DePaoli-Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202, Indiana, United States
| | - Peter J Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202, Indiana, United States
| | - Thomas D Hurley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis 46202, Indiana, United States
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16
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Young LE, Brizzee CO, Macedo JKA, Murphy RD, Contreras CJ, DePaoli-Roach AA, Roach PJ, Gentry MS, Sun RC. Accurate and sensitive quantitation of glucose and glucose phosphates derived from storage carbohydrates by mass spectrometry. Carbohydr Polym 2020; 230:115651. [PMID: 31887930 PMCID: PMC7018519 DOI: 10.1016/j.carbpol.2019.115651] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/13/2019] [Accepted: 11/19/2019] [Indexed: 01/30/2023]
Abstract
The addition of phosphate groups into glycogen modulates its branching pattern and solubility which all impact its accessibility to glycogen interacting enzymes. As glycogen architecture modulates its metabolism, it is essential to accurately evaluate and quantify its phosphate content. Simultaneous direct quantitation of glucose and its phosphate esters requires an assay with high sensitivity and a robust dynamic range. Herein, we describe a highly-sensitive method for the accurate detection of both glycogen-derived glucose and glucose-phosphate esters utilizing gas-chromatography coupled mass spectrometry. Using this method, we observed higher glycogen levels in the liver compared to skeletal muscle, but skeletal muscle contained many more phosphate esters. Importantly, this method can detect femtomole levels of glucose and glucose phosphate esters within an extremely robust dynamic range with excellent accuracy and reproducibility. The method can also be easily adapted for the quantification of plant starch, amylopectin or other biopolymers.
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Affiliation(s)
- Lyndsay E.A. Young
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Corey O. Brizzee
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Jessica K. A. Macedo
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Robert D. Murphy
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Christopher J. Contreras
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202,Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Anna A. DePaoli-Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202,Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Peter J. Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202,Lafora Epilepsy Cure Initiative, 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,University of Kentucky Epilepsy & Brain Metabolism Alliance, University of Kentucky College of Medicine, Lexington, KY 40536, USA,Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, KY 40536, USA,Markey Cancer Center, Lexington, KY 40536, USA
| | - Ramon C. Sun
- Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY 40536, USA,Markey Cancer Center, Lexington, KY 40536, USA,To whom correspondence should be addressed: Ramon Sun: Department of Neuroscience BBSRB B179, University of Kentucky, Lexington, KY, 40536-0509 USA; ; Tel. +1 (859)562-2298 Fax. +1 (859)323-5505
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17
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Abstract
Lafora disease is a severe, autosomal recessive, progressive myoclonus epilepsy. The disease usually manifests in previously healthy adolescents, and death commonly occurs within 10 years of symptom onset. Lafora disease is caused by loss-of-function mutations in EPM2A or NHLRC1, which encode laforin and malin, respectively. The absence of either protein results in poorly branched, hyperphosphorylated glycogen, which precipitates, aggregates and accumulates into Lafora bodies. Evidence from Lafora disease genetic mouse models indicates that these intracellular inclusions are a principal driver of neurodegeneration and neurological disease. The integration of current knowledge on the function of laforin-malin as an interacting complex suggests that laforin recruits malin to parts of glycogen molecules where overly long glucose chains are forming, so as to counteract further chain extension. In the absence of either laforin or malin function, long glucose chains in specific glycogen molecules extrude water, form double helices and drive precipitation of those molecules, which over time accumulate into Lafora bodies. In this article, we review the genetic, clinical, pathological and molecular aspects of Lafora disease. We also discuss traditional antiseizure treatments for this condition, as well as exciting therapeutic advances based on the downregulation of brain glycogen synthesis and disease gene replacement.
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18
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Ducommun S, Deak M, Zeigerer A, Göransson O, Seitz S, Collodet C, Madsen AB, Jensen TE, Viollet B, Foretz M, Gut P, Sumpton D, Sakamoto K. Chemical genetic screen identifies Gapex-5/GAPVD1 and STBD1 as novel AMPK substrates. Cell Signal 2019; 57:45-57. [PMID: 30772465 DOI: 10.1016/j.cellsig.2019.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 02/06/2023]
Abstract
AMP-activated protein kinase (AMPK) is a key regulator of cellular energy homeostasis, acting as a sensor of energy and nutrient status. As such, AMPK is considered a promising drug target for treatment of medical conditions particularly associated with metabolic dysfunctions. To better understand the downstream effectors and physiological consequences of AMPK activation, we have employed a chemical genetic screen in mouse primary hepatocytes in an attempt to identify novel AMPK targets. Treatment of hepatocytes with a potent and specific AMPK activator 991 resulted in identification of 65 proteins phosphorylated upon AMPK activation, which are involved in a variety of cellular processes such as lipid/glycogen metabolism, vesicle trafficking, and cytoskeleton organisation. Further characterisation and validation using mass spectrometry followed by immunoblotting analysis with phosphorylation site-specific antibodies identified AMPK-dependent phosphorylation of Gapex-5 (also known as GTPase-activating protein and VPS9 domain-containing protein 1 (GAPVD1)) on Ser902 in hepatocytes and starch-binding domain 1 (STBD1) on Ser175 in multiple cells/tissues. As new promising roles of AMPK as a key metabolic regulator continue to emerge, the substrates we identified could provide new mechanistic and therapeutic insights into AMPK-activating drugs in the liver.
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Affiliation(s)
- Serge Ducommun
- Nestlé Research, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, bâtiment G, 1015 Lausanne, Switzerland; School of Life Sciences, EPFL, 1015 Lausanne, Switzerland
| | - Maria Deak
- Nestlé Research, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, bâtiment G, 1015 Lausanne, Switzerland
| | - Anja Zeigerer
- Institute for Diabetes and Cancer, Helmholtz Center for Environmental Health, 85764 Neuherberg, Germany; Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine 1, Heidelberg University Hospital, Heidelberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Olga Göransson
- Department of Experimental Medical Sciences, Lund University, 221 84 Lund, Sweden
| | - Susanne Seitz
- Institute for Diabetes and Cancer, Helmholtz Center for Environmental Health, 85764 Neuherberg, Germany; Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine 1, Heidelberg University Hospital, Heidelberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Caterina Collodet
- Nestlé Research, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, bâtiment G, 1015 Lausanne, Switzerland; School of Life Sciences, EPFL, 1015 Lausanne, Switzerland
| | - Agnete B Madsen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Jensen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Benoit Viollet
- Inserm, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris cité, Paris, France
| | - Marc Foretz
- Inserm, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris cité, Paris, France
| | - Philipp Gut
- Nestlé Research, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, bâtiment G, 1015 Lausanne, Switzerland
| | - David Sumpton
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, UK
| | - Kei Sakamoto
- Nestlé Research, École Polytechnique Fédérale de Lausanne (EPFL) Innovation Park, bâtiment G, 1015 Lausanne, Switzerland; School of Life Sciences, EPFL, 1015 Lausanne, Switzerland.
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19
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Abstract
Glucose is the long-established, obligatory fuel for brain that fulfills many critical functions, including ATP production, oxidative stress management, and synthesis of neurotransmitters, neuromodulators, and structural components. Neuronal glucose oxidation exceeds that in astrocytes, but both rates increase in direct proportion to excitatory neurotransmission; signaling and metabolism are closely coupled at the local level. Exact details of neuron-astrocyte glutamate-glutamine cycling remain to be established, and the specific roles of glucose and lactate in the cellular energetics of these processes are debated. Glycolysis is preferentially upregulated during brain activation even though oxygen availability is sufficient (aerobic glycolysis). Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in excess of oxygen, and adrenergic regulation of aerobic glycolysis draws attention to astrocytic metabolism, particularly glycogen turnover, which has a high impact on the oxygen-carbohydrate mismatch. Aerobic glycolysis is proposed to be predominant in young children and specific brain regions, but re-evaluation of data is necessary. Shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation, neurotransmission, and memory consolidation are controversial topics for which alternative mechanisms are proposed. Nutritional therapy and vagus nerve stimulation are translational bridges from metabolism to clinical treatment of diverse brain disorders.
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Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences , Little Rock, Arkansas ; and Department of Cell Biology and Physiology, University of New Mexico , Albuquerque, New Mexico
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20
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Desdentado L, Espert R, Sanz P, Tirapu-Ustarroz J. [Lafora disease: a review of the literature]. Rev Neurol 2019; 68:66-74. [PMID: 30638256 PMCID: PMC6531605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
INTRODUCTION Lafora disease is autosomal recessive progressive myoclonus epilepsy with late childhood-to teenage-onset caused by loss-of-function mutations in either EPM2A or EPM2B genes encoding laforin or malin, respectively. DEVELOPMENT The main symptoms of Lafora disease, which worsen progressively, are: myoclonus, occipital seizures, generalized tonic-clonic seizures, cognitive decline, neuropsychiatric syptoms and ataxia with a fatal outcome. Pathologically, Lafora disease is characterized by the presence of polyglucosans deposits (named Lafora bodies), in the brain, liver, muscle and sweat glands. Diagnosis of Lafora disease is made through clinical, electrophysiological, histological and genetic findings. Currently, there is no treatment to cure or prevent the development of the disease. Traditionally, antiepileptic drugs are used for the management of myoclonus and seizures. However, patients become drug-resistant after the initial stage. CONCLUSIONS Lafora disease is a rare pathology that has serious consequences for patients and their caregivers despite its low prevalence. Therefore, continuing research in order to clarify the underlying mechanisms and hopefully developing new palliative and curative treatments for the disease is necessary.
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Affiliation(s)
- L Desdentado
- Hospital Clinico Universitario de Valencia, 46010 Valencia, Espana
| | - R Espert
- Hospital Clinico Universitario de Valencia, 46010 Valencia, Espana
- Universidad de Valencia, 46071 Valencia, Espana
| | - P Sanz
- Instituto de Biomedicina de Valencia, 46010 Valencia, Venezuela
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21
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Pederson BA. Structure and Regulation of Glycogen Synthase in the Brain. ADVANCES IN NEUROBIOLOGY 2019; 23:83-123. [PMID: 31667806 DOI: 10.1007/978-3-030-27480-1_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Brain glycogen synthesis is a regulated, multi-step process that begins with glucose transport across the blood brain barrier and culminates with the actions of glycogen synthase and the glycogen branching enzyme to elongate glucose chains and introduce branch points in a growing glycogen molecule. This review focuses on the synthesis of glycogen in the brain, with an emphasis on glycogen synthase, but draws on salient studies in mammalian muscle and liver as well as baker's yeast, with the goal of providing a more comprehensive view of glycogen synthesis and highlighting potential areas for further study in the brain. In addition, deficiencies in the glycogen biosynthetic enzymes which lead to glycogen storage diseases in humans are discussed, highlighting effects on the brain and discussing findings in genetically modified animal models that recapitulate these diseases. Finally, implications of glycogen synthesis in neurodegenerative and other diseases that impact the brain are presented.
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22
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The Structure and the Regulation of Glycogen Phosphorylases in Brain. ADVANCES IN NEUROBIOLOGY 2019; 23:125-145. [DOI: 10.1007/978-3-030-27480-1_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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23
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Glycophagy: An emerging target in pathology. Clin Chim Acta 2018; 484:298-303. [DOI: 10.1016/j.cca.2018.06.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/08/2018] [Accepted: 06/08/2018] [Indexed: 12/14/2022]
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24
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Augé E, Pelegrí C, Manich G, Cabezón I, Guinovart JJ, Duran J, Vilaplana J. Astrocytes and neurons produce distinct types of polyglucosan bodies in Lafora disease. Glia 2018; 66:2094-2107. [PMID: 30152044 DOI: 10.1002/glia.23463] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 05/10/2018] [Accepted: 05/10/2018] [Indexed: 01/07/2023]
Abstract
Lafora disease (LD), the most devastating adolescence-onset epilepsy, is caused by mutations in the EPM2A or EPM2B genes, which encode the proteins laforin and malin, respectively. Loss of function of one of these proteins, which are involved in the regulation of glycogen synthesis, induces the accumulation of polyglucosan bodies (PGBs)-known as Lafora bodies (LBs) and associated with neurons-in the brain. Ageing and some neurodegenerative conditions lead to the appearance of another type of PGB called corpora amylacea, which are associated with astrocytes and contain neo-epitopes that can be recognized by natural antibodies. Here we studied the PGBs in the cerebral cortex and hippocampus of malin knockout mice, a mouse model of LD. These animals presented not only LBs associated with neurons but also a significant number of PGBs associated with astrocytes. These astrocytic PGBs were also increased in mice from senescence-accelerated mouse-prone 8 (SAMP8) strain and mice with overexpression of Protein Targeting to Glycogen (PTGOE ), indicating that they are not exclusive of LD. The astrocytic PGBs, but not neuronal LBs, contained neo-epitopes that are recognized by natural antibodies. The astrocytic PGBs appeared predominantly in the hippocampus but were also present in some cortical brain regions, while neuronal LBs were found mainly in the brain cortex and the pyramidal layer of hippocampal regions CA2 and CA3. Our results indicate that astrocytes, contrary to current belief, are involved in the etiopathogenesis of LD.
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Affiliation(s)
- Elisabet Augé
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Universitat de Barcelona, Barcelona, Spain.,Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Carme Pelegrí
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Universitat de Barcelona, Barcelona, Spain.,Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain.,Centros de Biomedicina en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Gemma Manich
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Universitat de Barcelona, Barcelona, Spain
| | - Itsaso Cabezón
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Universitat de Barcelona, Barcelona, Spain.,Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Joan J Guinovart
- Institute for Research in Biomedicine (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.,Departament de Bioquímica i Biomedicina Molecular, Universitat de Barcelona, Barcelona, Spain
| | - Jordi Duran
- Institute for Research in Biomedicine (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
| | - Jordi Vilaplana
- Secció de Fisiologia, Departament de Bioquímica i Fisiologia, Universitat de Barcelona, Barcelona, Spain.,Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain.,Centros de Biomedicina en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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25
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Garcia-Gimeno MA, Rodilla-Ramirez PN, Viana R, Salas-Puig X, Brewer MK, Gentry MS, Sanz P. A novel EPM2A mutation yields a slow progression form of Lafora disease. Epilepsy Res 2018; 145:169-177. [PMID: 30041081 DOI: 10.1016/j.eplepsyres.2018.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/11/2018] [Accepted: 07/13/2018] [Indexed: 12/19/2022]
Abstract
Lafora disease (LD, OMIM 254780) is a rare disorder characterized by epilepsy and neurodegeneration leading patients to a vegetative state and death, usually within the first decade from the onset of the first symptoms. In the vast majority of cases LD is related to mutations in either the EPM2A gene (encoding the glucan phosphatase laforin) or the EPM2B gene (encoding the E3-ubiquitin ligase malin). In this work, we characterize the mutations present in the EPM2A gene in a patient displaying a slow progression form of the disease. The patient is compound heterozygous with Y112X and N163D mutations in the corresponding alleles. In primary fibroblasts obtained from the patient, we analyzed the expression of the mutated alleles by quantitative real time PCR and found slightly lower levels of expression of the EPM2A gene respect to control cells. However, by Western blotting we were unable to detect endogenous levels of the protein in crude extracts from patient fibroblasts. The Y112X mutation would render a truncated protein lacking the phosphatase domain and likely degraded. Since minute amounts of laforin-N163D might still play a role in cell physiology, we analyzed the biochemical characteristics of the N163D mutation. We found that recombinant laforin N163D protein was as stable as wild type and exhibited near wild type phosphatase activity towards biologically relevant substrates. On the contrary, it showed a severe impairment in the interaction profile with previously identified laforin binding partners. These results lead us to conclude that the slow progression of the disease present in this patient could be either due to the specific biochemical properties of laforin N163D or to the presence of alternative genetic modifying factors separate from pathogenicity.
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Affiliation(s)
| | | | - Rosa Viana
- IBV-CSIC. Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Xavier Salas-Puig
- Epilepsy Unit, Neurology Dept., Hospital Vall Hebron, Barcelona, Spain
| | - M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, USA; Lafora Epilepsy Cure Initiative, USA
| | - Pascual Sanz
- IBV-CSIC. Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain; CIBERER. Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain; Lafora Epilepsy Cure Initiative, USA.
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Rai A, Mishra R, Ganesh S. Suppression of leptin signaling reduces polyglucosan inclusions and seizure susceptibility in a mouse model for Lafora disease. Hum Mol Genet 2018; 26:4778-4785. [PMID: 28973665 DOI: 10.1093/hmg/ddx357] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 09/12/2017] [Indexed: 01/10/2023] Open
Abstract
Lafora disease (LD) represents a fatal form of neurodegenerative disorder characterized by the presence of abnormally large number of polyglucosan bodies-called the Lafora bodies-in neurons and other tissues of the affected patients. The disease is caused by defects in the EPM2A gene coding for a protein phosphatase (laforin) or the NHLRC1 gene coding for an ubiquitin ligase (malin). Studies have shown that inhibition of glycogen synthesis in the brain could prevent the formation of Lafora bodies in the neurons and reduce seizure susceptibility in laforin-deficient mouse, an established animal model for LD. Since increased glucose uptake is thought to underlie increased glycogen in LD, and since the adipocyte hormone leptin is known to positively regulate the glucose uptake in neurons, we reasoned that blocking leptin signaling might reduce the neuronal glucose uptake and ameliorate the LD pathology. We demonstrate here that mice that were deficient for both laforin and leptin receptor showed a reduction in the glycogen level, Lafora bodies and gliosis in the brain, and displayed reduced susceptibility to induced seizures as compared to animals that were deficient only for laforin. Thus, blocking leptin signaling could be a one of the effective therapeutic strategies in LD.
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Affiliation(s)
- Anupama Rai
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Rohit Mishra
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Subramaniam Ganesh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
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Parihar R, Rai A, Ganesh S. Lafora disease: from genotype to phenotype. J Genet 2018; 97:611-624. [PMID: 30027899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The progressive myoclonic epilepsy of Lafora or Lafora disease (LD) is a neurodegenerative disorder characterized by recurrent seizures and cognitive deficits. With typical onset in the late childhood or early adolescence, the patients show progressive worsening of the disease symptoms, leading to death in about 10 years. It is an autosomal recessive disorder caused by the loss-of-function mutations in the EPM2A gene, coding for a protein phosphatase (laforin) or the NHLRC1 gene coding for an E3 ubiquitin ligase (malin). LD is characterized by the presence of abnormally branched water insoluble glycogen inclusions known as Lafora bodies in the neurons and other tissues, suggesting a role for laforin and malin in glycogen metabolic pathways. Mouse models of LD, developed by targeted disruption of the Epm2a or Nhlrc1 gene, recapitulated most of the symptoms and pathological features as seen in humans, and have offered insight into the pathomechanisms. Besides the formation of Lafora bodies in the neurons in the presymptomatic stage, the animal models have also demonstrated perturbations in the proteolytic pathways, such as ubiquitin proteasome system and autophagy, and inflammatory response. This review attempts to provide a comprehensive coverage on the genetic defects leading to the LD in humans, on the functional properties of the laforin and malin proteins, and on how defects in any one of these two proteins result in a clinically similar phenotype. We also discuss the disease pathologies as revealed by the studies on the animal models and, finally, on the progress with therapeutic attempts albeit in the animal models.
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Affiliation(s)
- Rashmi Parihar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208 016, India.
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Nitschke F, Sullivan MA, Wang P, Zhao X, Chown EE, Perri AM, Israelian L, Juana-López L, Bovolenta P, Rodríguez de Córdoba S, Steup M, Minassian BA. Abnormal glycogen chain length pattern, not hyperphosphorylation, is critical in Lafora disease. EMBO Mol Med 2018; 9:906-917. [PMID: 28536304 PMCID: PMC5494504 DOI: 10.15252/emmm.201707608] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Lafora disease (LD) is a fatal progressive epilepsy essentially caused by loss-of-function mutations in the glycogen phosphatase laforin or the ubiquitin E3 ligase malin. Glycogen in LD is hyperphosphorylated and poorly hydrosoluble. It precipitates and accumulates into neurotoxic Lafora bodies (LBs). The leading LD hypothesis that hyperphosphorylation causes the insolubility was recently challenged by the observation that phosphatase-inactive laforin rescues the laforin-deficient LD mouse model, apparently through correction of a general autophagy impairment. We were for the first time able to quantify brain glycogen phosphate. We also measured glycogen content and chain lengths, LBs, and autophagy markers in several laforin- or malin-deficient mouse lines expressing phosphatase-inactive laforin. We find that: (i) in laforin-deficient mice, phosphatase-inactive laforin corrects glycogen chain lengths, and not hyperphosphorylation, which leads to correction of glycogen amounts and prevention of LBs; (ii) in malin-deficient mice, phosphatase-inactive laforin confers no correction; (iii) general impairment of autophagy is not necessary in LD We conclude that laforin's principle function is to control glycogen chain lengths, in a malin-dependent fashion, and that loss of this control underlies LD.
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Affiliation(s)
- Felix Nitschke
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - Mitchell A Sullivan
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada.,Glycation and Diabetes, Mater Research Institute, Translational Research Institute, The University of Queensland, Brisbane, Qld, Australia
| | - Peixiang Wang
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - Xiaochu Zhao
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - Erin E Chown
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Ami M Perri
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - Lori Israelian
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Lucia Juana-López
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas and Ciber de Enfermedades Raras, Madrid, Spain
| | - Paola Bovolenta
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM and Ciber de Enfermedades Raras, Universidad Autónoma de Madrid, Madrid, Spain
| | - Santiago Rodríguez de Córdoba
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas and Ciber de Enfermedades Raras, Madrid, Spain
| | - Martin Steup
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - Berge A Minassian
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON, Canada .,Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Division of Neurology, Department of Pediatrics, University of Texas Southwestern, Dallas, TX, USA
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Gentry MS, Guinovart JJ, Minassian BA, Roach PJ, Serratosa JM. Lafora disease offers a unique window into neuronal glycogen metabolism. J Biol Chem 2018; 293:7117-7125. [PMID: 29483193 DOI: 10.1074/jbc.r117.803064] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Lafora disease (LD) is a fatal, autosomal recessive, glycogen-storage disorder that manifests as severe epilepsy. LD results from mutations in the gene encoding either the glycogen phosphatase laforin or the E3 ubiquitin ligase malin. Individuals with LD develop cytoplasmic, aberrant glycogen inclusions in nearly all tissues that more closely resemble plant starch than human glycogen. This Minireview discusses the unique window into glycogen metabolism that LD research offers. It also highlights recent discoveries, including that glycogen contains covalently bound phosphate and that neurons synthesize glycogen and express both glycogen synthase and glycogen phosphorylase.
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Affiliation(s)
- Matthew S Gentry
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Department of Biochemistry and Molecular Biology, Lexington, Kentucky 40503; University of Kentucky Epilepsy Research Center (EpiC), University of Kentucky, Lexington, Kentucky 40503.
| | - Joan J Guinovart
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Spain; Biomedical Research Networking Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), 28029 Madrid, Spain; Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain
| | - Berge A Minassian
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Department of Pediatrics and Dallas Children's Medical Center, University of Texas Southwestern, Dallas, Texas 75390-9063; Department of Pediatrics, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario M5G 0A4, Canada
| | - Peter J Roach
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Department of Biochemistry and Molecular Biology, Center for Diabetes and Metabolic Diseases and Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Jose M Serratosa
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Laboratory of Neurology, IIS-Jimenez Diaz Foundation, UAM, 28045 Madrid, Spain; Biomedical Research Networking Center on Rare Diseases (CIBERER), 28029 Madrid, Spain
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Abstract
The key regulatory enzymes of glycogenolysis are phosphorylase kinase, a hetero-oligomer with four different types of subunits, and glycogen phosphorylase, a homodimer. Both enzymes are activated by phosphorylation and small ligands, and both enzymes have distinct isoforms that are predominantly expressed in muscle, liver, or brain; however, whole-transcriptome high-throughput sequencing analyses show that in brain both of these enzymes are likely composed of subunit isoforms representing all three tissues. This Minireview examines the regulatory properties of the isoforms of these two enzymes expressed in the three tissues, focusing on their potential regulatory similarities and differences. Additionally, the activity, structure, and regulation of the remaining enzyme necessary for glycogenolysis, glycogen-debranching enzyme, are also reviewed.
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Affiliation(s)
- Owen W Nadeau
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160-7421
| | - Joseph D Fontes
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160-7421
| | - Gerald M Carlson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160-7421.
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Carrillo JB, Gomez-Casati DF, Martín M, Busi MV. Identification and analysis of OsttaDSP, a phosphoglucan phosphatase from Ostreococcus tauri. PLoS One 2018; 13:e0191621. [PMID: 29360855 PMCID: PMC5779698 DOI: 10.1371/journal.pone.0191621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/08/2018] [Indexed: 11/18/2022] Open
Abstract
Ostreococcus tauri, the smallest free-living (non-symbiotic) eukaryote yet described, is a unicellular green alga of the Prasinophyceae family. It has a very simple cellular organization and presents a unique starch granule and chloroplast. However, its starch metabolism exhibits a complexity comparable to higher plants, with multiple enzyme forms for each metabolic reaction. Glucan phosphatases, a family of enzymes functionally conserved in animals and plants, are essential for normal starch or glycogen degradation in plants and mammals, respectively. Despite the importance of O. tauri microalgae in evolution, there is no information available concerning the enzymes involved in reversible phosphorylation of starch. Here, we report the molecular cloning and heterologous expression of the gene coding for a dual specific phosphatase from O. tauri (OsttaDSP), homologous to Arabidopsis thaliana LSF2. The recombinant enzyme was purified to electrophoretic homogeneity to characterize its oligomeric and kinetic properties accurately. OsttaDSP is a homodimer of 54.5 kDa that binds and dephosphorylates amylopectin. Also, we also determined that residue C162 is involved in catalysis and possibly also in structural stability of the enzyme. Our results could contribute to better understand the role of glucan phosphatases in the metabolism of starch in green algae.
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Affiliation(s)
- Julieta B. Carrillo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Diego F. Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Mariana Martín
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
- * E-mail: (MM); (MVB)
| | - Maria V. Busi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
- * E-mail: (MM); (MVB)
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Kakhlon O. Pharmacological approaches for treating glycogen storage disorders involving polyglucosan body accumulation. Expert Opin Orphan Drugs 2017. [DOI: 10.1080/21678707.2017.1405804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Or Kakhlon
- Department of Neurology, Hadassah Medical Association, Ein Kerem, Jerusalem, Israel
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A novel image-based high-throughput screening assay discovers therapeutic candidates for adult polyglucosan body disease. Biochem J 2017; 474:3403-3420. [PMID: 28827282 DOI: 10.1042/bcj20170469] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 07/20/2017] [Accepted: 08/17/2017] [Indexed: 01/26/2023]
Abstract
Glycogen storage disorders (GSDs) are caused by excessive accumulation of glycogen. Some GSDs [adult polyglucosan (PG) body disease (APBD), and Tarui and Lafora diseases] are caused by intracellular accumulation of insoluble inclusions, called PG bodies (PBs), which are chiefly composed of malconstructed glycogen. We developed an APBD patient skin fibroblast cell-based assay for PB identification, where the bodies are identified as amylase-resistant periodic acid-Schiff's-stained structures, and quantified. We screened the DIVERSet CL 10 084 compound library using this assay in high-throughput format and discovered 11 dose-dependent and 8 non-dose-dependent PB-reducing hits. Approximately 70% of the hits appear to act through reducing glycogen synthase (GS) activity, which can elongate glycogen chains and presumably promote PB generation. Some of these GS inhibiting hits were also computationally predicted to be similar to drugs interacting with the GS activator protein phosphatase 1. Our work paves the way to discovering medications for the treatment of PB-involving GSD, which are extremely severe or fatal disorders.
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Pathogenesis of Lafora Disease: Transition of Soluble Glycogen to Insoluble Polyglucosan. Int J Mol Sci 2017; 18:ijms18081743. [PMID: 28800070 PMCID: PMC5578133 DOI: 10.3390/ijms18081743] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 08/04/2017] [Accepted: 08/06/2017] [Indexed: 02/07/2023] Open
Abstract
Lafora disease (LD, OMIM #254780) is a rare, recessively inherited neurodegenerative disease with adolescent onset, resulting in progressive myoclonus epilepsy which is fatal usually within ten years of symptom onset. The disease is caused by loss-of-function mutations in either of the two genes EPM2A (laforin) or EPM2B (malin). It characteristically involves the accumulation of insoluble glycogen-derived particles, named Lafora bodies (LBs), which are considered neurotoxic and causative of the disease. The pathogenesis of LD is therefore centred on the question of how insoluble LBs emerge from soluble glycogen. Recent data clearly show that an abnormal glycogen chain length distribution, but neither hyperphosphorylation nor impairment of general autophagy, strictly correlates with glycogen accumulation and the presence of LBs. This review summarizes results obtained with patients, mouse models, and cell lines and consolidates apparent paradoxes in the LD literature. Based on the growing body of evidence, it proposes that LD is predominantly caused by an impairment in chain-length regulation affecting only a small proportion of the cellular glycogen. A better grasp of LD pathogenesis will further develop our understanding of glycogen metabolism and structure. It will also facilitate the development of clinical interventions that appropriately target the underlying cause of LD.
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Carrillo JB, Gomez-Casati DF, Busi MV, Martín M. Development of fast and simple chromogenic methods for glucan phosphatases in-gel activity assays. Anal Biochem 2017; 517:36-39. [PMID: 27836260 DOI: 10.1016/j.ab.2016.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/03/2016] [Accepted: 11/07/2016] [Indexed: 10/20/2022]
Abstract
Glucan phosphatases are essential for normal starch degradation in plants and glycogen metabolism in mammals. Here we develop two chromogenic methods for the detection of glucan phosphatase activity in situ after non denaturing poliacrylamide gel electrophoresis; one method uses pNPP and the second one applies BCIP/NBT. The assays are sensitive, fast, simple, reliable and cost-effective preventing the use of radioactive or fluorogenic compounds. Taking advantage of an efficient separation method combined with the reported assays it is possible to obtain information about oligomeric state of the active enzymes as well as to simultaneously detect glucan substrate binding and phosphatase activity.
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Affiliation(s)
- Julieta B Carrillo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000 Rosario, Santa Fe, Argentina
| | - Diego F Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000 Rosario, Santa Fe, Argentina
| | - Maria V Busi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000 Rosario, Santa Fe, Argentina.
| | - Mariana Martín
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000 Rosario, Santa Fe, Argentina.
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Contreras CJ, Segvich DM, Mahalingan K, Chikwana VM, Kirley TL, Hurley TD, DePaoli-Roach AA, Roach PJ. Incorporation of phosphate into glycogen by glycogen synthase. Arch Biochem Biophys 2016; 597:21-9. [PMID: 27036853 DOI: 10.1016/j.abb.2016.03.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 03/23/2016] [Indexed: 01/27/2023]
Abstract
The storage polymer glycogen normally contains small amounts of covalently attached phosphate as phosphomonoesters at C2, C3 and C6 atoms of glucose residues. In the absence of the laforin phosphatase, as in the rare childhood epilepsy Lafora disease, the phosphorylation level is elevated and is associated with abnormal glycogen structure that contributes to the pathology. Laforin therefore likely functions in vivo as a glycogen phosphatase. The mechanism of glycogen phosphorylation is less well-understood. We have reported that glycogen synthase incorporates phosphate into glycogen via a rare side reaction in which glucose-phosphate rather than glucose is transferred to a growing polyglucose chain (Tagliabracci et al. (2011) Cell Metab13, 274-282). We proposed a mechanism to account for phosphorylation at C2 and possibly at C3. Our results have since been challenged (Nitschke et al. (2013) Cell Metab17, 756-767). Here we extend the evidence supporting our conclusion, validating the assay used for the detection of glycogen phosphorylation, measurement of the transfer of (32)P from [β-(32)P]UDP-glucose to glycogen by glycogen synthase. The (32)P associated with the glycogen fraction was stable to ethanol precipitation, SDS-PAGE and gel filtration on Sephadex G50. The (32)P-signal was not affected by inclusion of excess unlabeled UDP before analysis or by treatment with a UDPase, arguing against the signal being due to contaminating [β-(32)P]UDP generated in the reaction. Furthermore, [(32)P]UDP did not bind non-covalently to glycogen. The (32)P associated with glycogen was released by laforin treatment, suggesting that it was present as a phosphomonoester. The conclusion is that glycogen synthase can mediate the introduction of phosphate into glycogen, thereby providing a possible mechanism for C2, and perhaps C3, phosphorylation.
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Affiliation(s)
- Christopher J Contreras
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Dyann M Segvich
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Krishna Mahalingan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Vimbai M Chikwana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA; Dow AgroSciences LLC, 9630 Zionsville Road, Indianapolis, IN 46268, USA
| | - Terence L Kirley
- Department of Pharmacology and Cell Biophysics, College of Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267, USA
| | - Thomas D Hurley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Anna A DePaoli-Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Peter J Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
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Meekins DA, Vander Kooi CW, Gentry MS. Structural mechanisms of plant glucan phosphatases in starch metabolism. FEBS J 2016; 283:2427-47. [PMID: 26934589 DOI: 10.1111/febs.13703] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 01/31/2016] [Accepted: 02/29/2016] [Indexed: 01/12/2023]
Abstract
Glucan phosphatases are a recently discovered class of enzymes that dephosphorylate starch and glycogen, thereby regulating energy metabolism. Plant genomes encode two glucan phosphatases, called Starch EXcess4 (SEX4) and Like Sex Four2 (LSF2), that regulate starch metabolism by selectively dephosphorylating glucose moieties within starch glucan chains. Recently, the structures of both SEX4 and LSF2 were determined, with and without phosphoglucan products bound, revealing the mechanism for their unique activities. This review explores the structural and enzymatic features of the plant glucan phosphatases, and outlines how they are uniquely adapted to perform their cellular functions. We outline the physical mechanisms used by SEX4 and LSF2 to interact with starch glucans: SEX4 binds glucan chains via a continuous glucan-binding platform comprising its dual-specificity phosphatase domain and carbohydrate-binding module, while LSF2 utilizes surface binding sites. SEX4 and LSF2 both contain a unique network of aromatic residues in their catalytic dual-specificity phosphatase domains that serve as glucan engagement platforms and are unique to the glucan phosphatases. We also discuss the phosphoglucan substrate specificities inherent to SEX4 and LSF2, and outline structural features within the active site that govern glucan orientation. This review defines the structural mechanism of the plant glucan phosphatases with respect to phosphatases, starch metabolism and protein-glucan interaction, thereby providing a framework for their application in both agricultural and industrial settings.
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Affiliation(s)
- David A Meekins
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY, USA.,Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY, USA
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Liver glycogen in type 2 diabetic mice is randomly branched as enlarged aggregates with blunted glucose release. Glycoconj J 2015; 33:41-51. [PMID: 26521055 DOI: 10.1007/s10719-015-9631-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 12/28/2022]
Abstract
Glycogen is a vital highly branched polymer of glucose that is essential for blood glucose homeostasis. In this article, the structure of liver glycogen from mice is investigated with respect to size distributions, degradation kinetics, and branching structure, complemented by a comparison of normal and diabetic liver glycogen. This is done to screen for differences that may result from disease. Glycogen α-particle (diameter ∼ 150 nm) and β-particle (diameter ∼ 25 nm) size distributions are reported, along with in vitro γ-amylase degradation experiments, and a small angle X-ray scattering analysis of mouse β-particles. Type 2 diabetic liver glycogen upon extraction was found to be present as large loosely bound, aggregates, not present in normal livers. Liver glycogen was found to aggregate in vitro over a period of 20 h, and particle size is shown to be related to rate of glucose release, allowing a structure-function relationship to be inferred for the tissue specific distribution of particle types. Application of branching theories to small angle X-ray scattering data for mouse β-particles revealed these particles to be randomly branched polymers, not fractal polymers. Together, this article shows that type 2 diabetic liver glycogen is present as large aggregates in mice, which may contribute to the inflexibility of interconversion between glucose and glycogen in type 2 diabetes, and further that glycogen particles are randomly branched with a size that is related to the rate of glucose release.
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Duran J, Guinovart JJ. Brain glycogen in health and disease. Mol Aspects Med 2015; 46:70-7. [PMID: 26344371 DOI: 10.1016/j.mam.2015.08.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 08/21/2015] [Indexed: 12/18/2022]
Abstract
Glycogen is present in the brain at much lower concentrations than in muscle or liver. However, by characterizing an animal depleted of brain glycogen, we have shown that the polysaccharide plays a key role in learning capacity and in activity-dependent changes in hippocampal synapse strength. Since glycogen is essentially found in astrocytes, the diverse roles proposed for this polysaccharide in the brain have been attributed exclusively to these cells. However, we have demonstrated that neurons have an active glycogen metabolism that contributes to tolerance to hypoxia. However, these cells can store only minute amounts of glycogen, since the progressive accumulation of this molecule leads to neuronal loss. Loss-of-function mutations in laforin and malin cause Lafora disease. This condition is characterized by the presence of high numbers of insoluble polyglucosan bodies, known as Lafora bodies, in neuronal cells. Our findings reveal that the accumulation of this aberrant glycogen accounts for the neurodegeneration and functional consequences, as well as the impaired autophagy, observed in models of this disease. Similarly glycogen synthase is responsible for the accumulation of corpora amylacea, which are polysaccharide-based aggregates present in the neurons of aged human brains. Our findings change the current view of the role of glycogen in the brain and reveal that endogenous neuronal glycogen metabolism is important under stress conditions and that neuronal glycogen accumulation contributes to neurodegenerative diseases and to aging-related corpora amylacea formation.
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Affiliation(s)
- Jordi Duran
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain
| | - Joan J Guinovart
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Spain; Department of Biochemistry and Molecular Biology, University of Barcelona, Barcelona, Spain.
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