1
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Neoh GKS, Tan X, Chen S, Roura E, Dong X, Gilbert RG. Glycogen metabolism and structure: A review. Carbohydr Polym 2024; 346:122631. [PMID: 39245499 DOI: 10.1016/j.carbpol.2024.122631] [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: 07/15/2024] [Revised: 08/15/2024] [Accepted: 08/16/2024] [Indexed: 09/10/2024]
Abstract
Glycogen is a glucose polymer that plays a crucial role in glucose homeostasis by functioning as a short-term energy storage reservoir in animals and bacteria. Abnormalities in its metabolism and structure can cause several problems, including diabetes, glycogen storage diseases (GSDs) and muscular disorders. Defects in the enzymes involved in glycogen synthesis or breakdown, resulting in either excessive accumulation or insufficient availability of glycogen in cells seem to account for the most common pathogenesis. This review discusses glycogen metabolism and structure, including molecular architecture, branching dynamics, and the role of associated components within the granules. The review also discusses GSD type XV and Lafora disease, illustrating the broader implications of aberrant glycogen metabolism and structure. These conditions also impart information on important regulatory mechanisms of glycogen, which hint at potential therapeutic targets. Knowledge gaps and potential future research directions are identified.
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Affiliation(s)
- Galex K S Neoh
- School of Medicine, Shanghai University, Shanghai 200444, China.
| | - Xinle Tan
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia; Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Si Chen
- School of Medicine, Shanghai University, Shanghai 200444, China.
| | - Eugeni Roura
- Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Xin Dong
- School of Medicine, Shanghai University, Shanghai 200444, China.
| | - Robert G Gilbert
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia; Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou 225009, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
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2
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Krishnan V, Wu J, Mazumder AG, Kamen JL, Schirmer C, Adhyapak N, Bass JS, Lee SC, Maheshwari A, Molinaro G, Gibson JR, Huber KM, Minassian BA. Clinicopathologic Dissociation: Robust Lafora Body Accumulation in Malin KO Mice Without Observable Changes in Home-Cage Behavior. J Comp Neurol 2024; 532:e25660. [PMID: 39039998 PMCID: PMC11370821 DOI: 10.1002/cne.25660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 07/03/2024] [Accepted: 07/09/2024] [Indexed: 07/24/2024]
Abstract
Lafora disease (LD) is a syndrome of progressive myoclonic epilepsy and cumulative neurocognitive deterioration caused by recessively inherited genetic lesions of EPM2A (laforin) or NHLRC1 (malin). Neuropsychiatric symptomatology in LD is thought to be directly downstream of neuronal and astrocytic polyglucosan aggregates, termed Lafora bodies (LBs), which faithfully accumulate in an age-dependent manner in all mouse models of LD. In this study, we applied home-cage monitoring to examine the extent of neurobehavioral deterioration in a model of malin-deficient LD as a means to identify robust preclinical endpoints that may guide the selection of novel genetic treatments. At 6 weeks, ∼6-7 months, and ∼12 months of age, malin-deficient mice ("KO") and wild-type (WT) littermates underwent a standardized home-cage behavioral assessment designed to non-obtrusively appraise features of rest/arousal, consumptive behaviors, risk aversion, and voluntary wheel-running. At all timepoints, and over a range of metrics that we report transparently, WT and KO mice were essentially indistinguishable. In contrast, within WT mice compared across the same timepoints, we identified age-related nocturnal hypoactivity, diminished sucrose preference, and reduced wheel-running. Neuropathological examinations in subsets of the same mice revealed expected age-dependent LB accumulation, gliosis, and microglial activation in cortical and subcortical brain regions. At 12 months of age, despite the burden of neocortical LBs, we did not identify spontaneous seizures during an electroencephalographic (EEG) survey, and KO and WT mice exhibited similar spectral EEG features. However, in an in vitro assay of neocortical function, paroxysmal bursts of network activity (UP states) in KO slices were more prolonged at 3 and 6 months of age, but similar to WT at 12 months. KO mice displayed a distinct response to pentylenetetrazole, with a greater incidence of clonic seizures and a more pronounced postictal suppression of movement, feeding, and drinking behavior. Together, these results highlight the clinicopathologic dissociation in a mouse model of LD, where the accrual of LBs may latently modify cortical circuit function and seizure threshold without clinically meaningful changes in home-cage behavior. Our findings allude to a delay between LB accumulation and neurobehavioral decline in LD: one that may provide a window for treatment, and whose precise duration may be difficult to ascertain within the typical lifespan of a laboratory mouse.
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Affiliation(s)
- Vaishnav Krishnan
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Arindam Ghosh Mazumder
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Jessica L. Kamen
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Catharina Schirmer
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Nandani Adhyapak
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - John Samuel Bass
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Samuel C. Lee
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Atul Maheshwari
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Gemma Molinaro
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX
| | - Jay R. Gibson
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX
| | - Kimberly M. Huber
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
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3
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Aisyah R, Ohshima N, Watanabe D, Nakagawa Y, Sakuma T, Nitschke F, Nakamura M, Sato K, Nakahata K, Yokoyama C, Marchioni CR, Kumrungsee T, Shimizu T, Sotomaru Y, Takeo T, Nakagata N, Izumi T, Miura S, Minassian BA, Yamamoto T, Wada M, Yanaka N. GDE5/Gpcpd1 activity determines phosphatidylcholine composition in skeletal muscle and regulates contractile force in mice. Commun Biol 2024; 7:604. [PMID: 38769369 PMCID: PMC11106330 DOI: 10.1038/s42003-024-06298-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 05/07/2024] [Indexed: 05/22/2024] Open
Abstract
Glycerophosphocholine (GPC) is an important precursor for intracellular choline supply in phosphatidylcholine (PC) metabolism. GDE5/Gpcpd1 hydrolyzes GPC into choline and glycerol 3-phosphate; this study aimed to elucidate its physiological function in vivo. Heterozygous whole-body GDE5-deficient mice reveal a significant GPC accumulation across tissues, while homozygous whole-body knockout results in embryonic lethality. Skeletal muscle-specific GDE5 deletion (Gde5 skKO) exhibits reduced passive force and improved fatigue resistance in electrically stimulated gastrocnemius muscles in vivo. GDE5 deficiency also results in higher glycolytic metabolites and glycogen levels, and glycerophospholipids alteration, including reduced levels of phospholipids that bind polyunsaturated fatty acids (PUFAs), such as DHA. Interestingly, this PC fatty acid compositional change is similar to that observed in skeletal muscles of denervated and Duchenne muscular dystrophy mouse models. These are accompanied by decrease of GDE5 expression, suggesting a regulatory role of GDE5 activity for glycerophospholipid profiles. Furthermore, a DHA-rich diet enhances contractile force and lowers fatigue resistance, suggesting a functional relationship between PC fatty acid composition and muscle function. Finally, skinned fiber experiments show that GDE5 loss increases the probability of the ryanodine receptor opening and lowers the maximum Ca2+-activated force. Collectively, GDE5 activity plays roles in PC and glucose/glycogen metabolism in skeletal muscle.
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Affiliation(s)
- Rahmawati Aisyah
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | | | - Daiki Watanabe
- Graduate School of Humanities and Social Sciences, Hiroshima University, Hiroshima, Japan
- Graduate School of Sport and Health Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan
| | - Yoshiko Nakagawa
- Center for Animal Resources and Development (CARD), Kumamoto University, Kumamoto, Japan
| | - Tetsushi Sakuma
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Felix Nitschke
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Minako Nakamura
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Koji Sato
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Kaori Nakahata
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Chihiro Yokoyama
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Charlotte R Marchioni
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Takahiko Shimizu
- Aging Stress Response Research Project Team, National Center for Geriatrics and Gerontology, Aichi, Japan
| | - Yusuke Sotomaru
- Natural Science Center for Basic Research and Development, Hiroshima University, Hiroshima, Japan
| | - Toru Takeo
- Center for Animal Resources and Development (CARD), Kumamoto University, Kumamoto, Japan
| | - Naomi Nakagata
- Center for Animal Resources and Development (CARD), Kumamoto University, Kumamoto, Japan
| | - Takashi Izumi
- Graduate School of Medicine, Gunma University, Gunma, Japan
- Faculty of Health Care, Teikyo Heisei University, Tokyo, Japan
| | - Shinji Miura
- Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan
| | - Berge A Minassian
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Takashi Yamamoto
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Masanobu Wada
- Graduate School of Humanities and Social Sciences, Hiroshima University, Hiroshima, Japan
| | - Noriyuki Yanaka
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.
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4
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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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5
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Krishnan V, Wu J, Mazumder AG, Kamen JL, Schirmer C, Adhyapak N, Bass JS, Lee SC, Maheshwari A, Molinaro G, Gibson JR, Huber KM, Minassian BA. Clinicopathologic Dissociation: Robust Lafora Body Accumulation in Malin KO Mice Without Observable Changes in Home-cage Behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.11.557226. [PMID: 37745312 PMCID: PMC10515855 DOI: 10.1101/2023.09.11.557226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Lafora Disease (LD) is a syndrome of progressive myoclonic epilepsy and cumulative neurocognitive deterioration caused by recessively inherited genetic lesions of EPM2A (laforin) or NHLRC1 (malin). Neuropsychiatric symptomatology in LD is thought to be directly downstream of neuronal and astrocytic polyglucosan aggregates, termed Lafora bodies (LBs), which faithfully accumulate in an age-dependent manner in all mouse models of LD. In this study, we applied home-cage monitoring to examine the extent of neurobehavioral deterioration in a model of malin-deficient LD, as a means to identify robust preclinical endpoints that may guide the selection of novel genetic treatments. At 6 weeks, ~6-7 months and ~12 months of age, malin deficient mice ("KO") and wild type (WT) littermates underwent a standardized home-cage behavioral assessment designed to non-obtrusively appraise features of rest/arousal, consumptive behaviors, risk aversion and voluntary wheel-running. At all timepoints, and over a range of metrics that we report transparently, WT and KO mice were essentially indistinguishable. In contrast, within WT mice compared across timepoints, we identified age-related nocturnal hypoactivity, diminished sucrose preference and reduced wheel-running. Neuropathological examinations in subsets of the same mice revealed expected age dependent LB accumulation, gliosis and microglial activation in cortical and subcortical brain regions. At 12 months of age, despite the burden of neocortical LBs, we did not identify spontaneous seizures during an electroencephalographic (EEG) survey, and KO and WT mice exhibited similar spectral EEG features. Using an in vitro assay of neocortical function, paroxysmal increases in network activity (UP states) in KO slices were more prolonged at 3 and 6 months of age, but were similar to WT at 12 months. KO mice displayed a distinct response to pentylenetetrazole, with a greater incidence of clonic seizures and a more pronounced post-ictal suppression of movement, feeding and drinking behavior. Together, these results highlight a stark clinicopathologic dissociation in a mouse model of LD, where LBs accrue substantially without clinically meaningful changes in overall wellbeing. Our findings allude to a delay between LB accumulation and neurobehavioral decline: one that may provide a window for treatment, and whose precise duration may be difficult to ascertain within the typical lifespan of a laboratory mouse.
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Affiliation(s)
- Vaishnav Krishnan
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Jun Wu
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Arindam Ghosh Mazumder
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Jessica L. Kamen
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Catharina Schirmer
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Nandani Adhyapak
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - John Samuel Bass
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Samuel C. Lee
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Atul Maheshwari
- Department of Neurology, Peter Kellaway Section of Neurophysiology and Epilepsy, Baylor College of Medicine, Houston, TX
| | - Gemma Molinaro
- Department of Neuroscience University of Texas Southwestern Medical Center, Dallas, TX
| | - Jay R. Gibson
- Department of Neuroscience University of Texas Southwestern Medical Center, Dallas, TX
| | - Kimberly M. Huber
- Department of Neuroscience University of Texas Southwestern Medical Center, Dallas, TX
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
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6
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Montgomery MK, De Nardo W, Watt MJ. Exercise training induces depot-specific remodeling of protein secretion in skeletal muscle and adipose tissue of obese male mice. Am J Physiol Endocrinol Metab 2023; 325:E227-E238. [PMID: 37493472 DOI: 10.1152/ajpendo.00178.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/21/2023] [Accepted: 07/21/2023] [Indexed: 07/27/2023]
Abstract
Acute exercise induces changes in circulating proteins, which are known to alter metabolism and systemic energy balance. Skeletal muscle is a primary contributor to changes in the plasma proteome with acute exercise. An important consideration when assessing the endocrine function of muscle is the presence of different fiber types, which show distinct functional and metabolic properties and likely secrete different proteins. Similarly, adipokines are important regulators of systemic metabolism and have been shown to differ between depots. Given the health-promoting effects of exercise, we proposed that understanding depot-specific remodeling of protein secretion in muscle and adipose tissue would provide new insights into intertissue communication and uncover novel regulators of energy homeostasis. Here, we examined the effect of endurance exercise training on protein secretion from fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscle and visceral and subcutaneous adipose tissue. High-fat diet-fed mice were exercise trained for 6 wk, whereas a Control group remained sedentary. Secreted proteins from excised EDL and soleus muscle, inguinal, and epididymal adipose tissues were detected using mass spectrometry. We detected 575 and 784 secreted proteins from EDL and soleus muscle and 738 and 920 proteins from inguinal and epididymal adipose tissue, respectively. Of these, 331 proteins were secreted from all tissues, whereas secretion of many other proteins was tissue and depot specific. Exercise training led to substantial remodeling of protein secretion from EDL, whereas soleus showed only minor changes. Myokines released exclusively from EDL or soleus were associated with glycogen metabolism and cellular stress response, respectively. Adipokine secretion was completely refractory to exercise regulation in both adipose depots. This study provides an in-depth resource of protein secretion from muscle and adipose tissue, and its regulation following exercise training, and identifies distinct depot-specific secretion patterns that are related to the metabolic properties of the tissue of origin.NEW & NOTEWORTHY The present study examines the effects of exercise training on protein secretion from fast-twitch and slow-twitch muscle as well as visceral and subcutaneous adipose tissue of obese mice. Although exercise training leads to substantial remodeling of protein secretion from fast-twitch muscle, adipose tissue is completely refractory to exercise regulation.
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Affiliation(s)
- Magdalene K Montgomery
- Faculty of Medicine, Dentistry & Health Sciences, Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - William De Nardo
- Faculty of Medicine, Dentistry & Health Sciences, Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Matthew J Watt
- Faculty of Medicine, Dentistry & Health Sciences, Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Melbourne, Victoria, Australia
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7
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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: 12] [Impact Index Per Article: 6.0] [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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8
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Yang Q, Chan P. Skeletal Muscle Metabolic Alternation Develops Sarcopenia. Aging Dis 2022; 13:801-814. [PMID: 35656108 PMCID: PMC9116905 DOI: 10.14336/ad.2021.1107] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/28/2021] [Indexed: 11/23/2022] Open
Abstract
Sarcopenia is a new type of senile syndrome with progressive skeletal muscle mass loss with age, accompanied by decreased muscle strength and/or muscle function. Sarcopenia poses a serious threat to the health of the elderly and increases the burden of family and society. The underlying pathophysiological mechanisms of sarcopenia are still unclear. Recent studies have shown that changes of skeletal muscle metabolism are the risk factors for sarcopenia. Furthermore, the importance of the skeletal muscle metabolic microenvironment in regulating satellite cells (SCs) is gaining significant attention. Skeletal muscle metabolism has intrinsic relationship with the regulation of skeletal muscle mass and regeneration. This review is to discuss recent findings regarding skeletal muscle metabolic alternation and the development of sarcopenia, hoping to contribute better understanding and treatment of sarcopenia.
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Affiliation(s)
- Qiumei Yang
- Department of Neurology, Geriatrics and Neurobiology, National Clinical Research Center of Geriatric Disorders, Xuanwu Hospital of Capital Medical University, Beijing, China.
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China.
| | - Piu Chan
- Department of Neurology, Geriatrics and Neurobiology, National Clinical Research Center of Geriatric Disorders, Xuanwu Hospital of Capital Medical University, Beijing, China.
- Clinical Center for Parkinson’s Disease, Capital Medical University, Beijing Institute of Geriatrics, Beijing, China.
- Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Beijing Key Laboratory for Parkinson’s Disease, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China.
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China.
- Correspondence should be addressed to: Dr. Piu Chan, Department of Neurobiology, Xuanwu Hospital of Capital Medical University, 45 Changchun Road, Beijing 100053, China. .
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9
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Mice with Whole-Body Disruption of AMPK-Glycogen Binding Have Increased Adiposity, Reduced Fat Oxidation and Altered Tissue Glycogen Dynamics. Int J Mol Sci 2021; 22:ijms22179616. [PMID: 34502525 PMCID: PMC8431764 DOI: 10.3390/ijms22179616] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/02/2021] [Accepted: 09/03/2021] [Indexed: 01/15/2023] Open
Abstract
The AMP-activated protein kinase (AMPK), a central regulator of cellular energy balance and metabolism, binds glycogen via its β subunit. However, the physiological effects of disrupting AMPK-glycogen interactions remain incompletely understood. To chronically disrupt AMPK-glycogen binding, AMPK β double knock-in (DKI) mice were generated with mutations in residues critical for glycogen binding in both the β1 (W100A) and β2 (W98A) subunit isoforms. We examined the effects of this DKI mutation on whole-body substrate utilization, glucose homeostasis, and tissue glycogen dynamics. Body composition, metabolic caging, glucose and insulin tolerance, serum hormone and lipid profiles, and tissue glycogen and protein content were analyzed in chow-fed male DKI and age-matched wild-type (WT) mice. DKI mice displayed increased whole-body fat mass and glucose intolerance associated with reduced fat oxidation relative to WT. DKI mice had reduced liver glycogen content in the fed state concomitant with increased utilization and no repletion of skeletal muscle glycogen in response to fasting and refeeding, respectively, despite similar glycogen-associated protein content relative to WT. DKI liver and skeletal muscle displayed reductions in AMPK protein content versus WT. These findings identify phenotypic effects of the AMPK DKI mutation on whole-body metabolism and tissue AMPK content and glycogen dynamics.
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Brain glycogen serves as a critical glucosamine cache required for protein glycosylation. Cell Metab 2021; 33:1404-1417.e9. [PMID: 34043942 PMCID: PMC8266748 DOI: 10.1016/j.cmet.2021.05.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/02/2021] [Accepted: 05/03/2021] [Indexed: 02/08/2023]
Abstract
Glycosylation defects are a hallmark of many nervous system diseases. However, the molecular and metabolic basis for this pathology is not fully understood. In this study, we found that N-linked protein glycosylation in the brain is metabolically channeled to glucosamine metabolism through glycogenolysis. We discovered that glucosamine is an abundant constituent of brain glycogen, which functions as a glucosamine reservoir for multiple glycoconjugates. We demonstrated the enzymatic incorporation of glucosamine into glycogen by glycogen synthase, and the release by glycogen phosphorylase by biochemical and structural methodologies, in primary astrocytes, and in vivo by isotopic tracing and mass spectrometry. Using two mouse models of glycogen storage diseases, we showed that disruption of brain glycogen metabolism causes global decreases in free pools of UDP-N-acetylglucosamine and N-linked protein glycosylation. These findings revealed fundamental biological roles of brain glycogen in protein glycosylation with direct relevance to multiple human diseases of the central nervous system.
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Nitschke S, Petković S, Ahonen S, Minassian BA, Nitschke F. Sensitive quantification of α-glucans in mouse tissues, cell cultures, and human cerebrospinal fluid. J Biol Chem 2020; 295:14698-14709. [PMID: 32817315 DOI: 10.1074/jbc.ra120.015061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/04/2020] [Indexed: 12/30/2022] Open
Abstract
The soluble α-polyglucan glycogen is a central metabolite enabling transient glucose storage to suit cellular energy needs. Glycogen storage diseases (GSDs) comprise over 15 entities caused by generalized or tissue-specific defects in enzymes of glycogen metabolism. In several, e.g. in Lafora disease caused by the absence of the glycogen phosphatase laforin or its interacting partner malin, degradation-resistant abnormally structured insoluble glycogen accumulates. Sensitive quantification methods for soluble and insoluble glycogen are critical to research, including therapeutic studies, in such diseases. This paper establishes methodological advancements relevant to glycogen metabolism investigations generally, and GSDs. Introducing a pre-extraction incubation method, we measure degradation-resistant glycogen in as little as 30 mg of skeletal muscle or a single hippocampus from Lafora disease mouse models. The digestion-resistant glycogen correlates with the disease-pathogenic insoluble glycogen and can readily be detected in very young mice where glycogen accumulation has just begun. Second, we establish a high-sensitivity glucose assay with detection of ATP depletion, enabling 1) quantification of α-glucans in cell culture using a medium-throughput assay suitable for assessment of candidate glycogen synthesis inhibitors, and 2) discovery of α-glucan material in healthy human cerebrospinal fluid, establishing a novel methodological platform for biomarker analyses in Lafora disease and other GSDs.
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Affiliation(s)
- Silvia Nitschke
- Departments of Pediatrics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sara Petković
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Saija Ahonen
- Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Berge A Minassian
- Departments of Pediatrics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Felix Nitschke
- Departments of Pediatrics and Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
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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: 39] [Impact Index Per Article: 9.8] [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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Brewer MK, Putaux JL, Rondon A, Uittenbogaard A, Sullivan MA, Gentry MS. Polyglucosan body structure in Lafora disease. Carbohydr Polym 2020; 240:116260. [PMID: 32475552 DOI: 10.1016/j.carbpol.2020.116260] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/16/2020] [Accepted: 04/03/2020] [Indexed: 12/18/2022]
Abstract
Abnormal carbohydrate structures known as polyglucosan bodies (PGBs) are associated with neurological disorders, glycogen storage diseases (GSDs), and aging. A hallmark of the GSD Lafora disease (LD), a fatal childhood epilepsy caused by recessive mutations in the EPM2A or EPM2B genes, are cytoplasmic PGBs known as Lafora bodies (LBs). LBs result from aberrant glycogen metabolism and drive disease progression. They are abundant in brain, muscle and heart of LD patients and Epm2a-/- and Epm2b-/- mice. LBs and PGBs are histologically reminiscent of starch, semicrystalline carbohydrates synthesized for glucose storage in plants. In this study, we define LB architecture, tissue-specific differences, and dynamics. We propose a model for how small polyglucosans aggregate to form LBs. LBs are very similar to PGBs of aging and other neurological disorders, and so these studies have direct relevance to the general understanding of PGB structure and formation.
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Affiliation(s)
- M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40536, USA; Lafora Epilepsy Cure Initiative, Epilepsy and Brain Metabolism Center, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, 40536, USA; Institute for Research in Biomedicine (IRB Barcelona), 08028, Barcelona, Spain
| | - Jean-Luc Putaux
- Univ. Grenoble Alpes, CNRS, CERMAV, F-38000, Grenoble, France
| | - Alberto Rondon
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Annette Uittenbogaard
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
| | - Mitchell A Sullivan
- Glycation and Diabetes Group, Mater Research Institute-The University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40536, USA; Lafora Epilepsy Cure Initiative, Epilepsy and Brain Metabolism Center, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.
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Takahashi Y, Matsunaga Y, Banjo M, Takahashi K, Sato Y, Seike K, Nakano S, Hatta H. Effects of Nutrient Intake Timing on Post-Exercise Glycogen Accumulation and its Related Signaling Pathways in Mouse Skeletal Muscle. Nutrients 2019; 11:nu11112555. [PMID: 31652791 PMCID: PMC6893707 DOI: 10.3390/nu11112555] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 01/19/2023] Open
Abstract
We investigated the effects of nutrient intake timing on glycogen accumulation and its related signals in skeletal muscle after an exercise that did not induce large glycogen depletion. Male ICR mice ran on a treadmill at 25 m/min for 60 min under a fed condition. Mice were orally administered a solution containing 1.2 mg/g carbohydrate and 0.4 mg/g protein or water either immediately (early nutrient, EN) or 180 min (late nutrient, LN) after the exercise. Tissues were harvested at 30 min after the oral administration. No significant difference in blood glucose or plasma insulin concentrations was found between the EN and LN groups. The plantaris muscle glycogen concentration was significantly (p < 0.05) higher in the EN group—but not in the LN group—compared to the respective time-matched control group. Akt Ser473 phosphorylation was significantly higher in the EN group than in the time-matched control group (p < 0.01), while LN had no effect. Positive main effects of time were found for the phosphorylations in Akt substrate of 160 kDa (AS160) Thr642 (p < 0.05), 5′-AMP-activated protein kinase (AMPK) Thr172 (p < 0.01), and acetyl-CoA carboxylase Ser79 (p < 0.01); however, no effect of nutrient intake was found for these. We showed that delayed nutrient intake could not increase muscle glycogen after endurance exercise which did not induce large glycogen depletion. The results also suggest that post-exercise muscle glycogen accumulation after nutrient intake might be partly influenced by Akt activation. Meanwhile, increased AS160 and AMPK activation by post-exercise fasting might not lead to glycogen accumulation.
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Affiliation(s)
- Yumiko Takahashi
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Yutaka Matsunaga
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Mai Banjo
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Kenya Takahashi
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Yosuke Sato
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Kohei Seike
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Suguru Nakano
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Hideo Hatta
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
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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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Brewer MK, Gentry MS. Brain Glycogen Structure and Its Associated Proteins: Past, Present and Future. ADVANCES IN NEUROBIOLOGY 2019; 23:17-81. [PMID: 31667805 PMCID: PMC7239500 DOI: 10.1007/978-3-030-27480-1_2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This chapter reviews the history of glycogen-related research and discusses in detail the structure, regulation, chemical properties and subcellular distribution of glycogen and its associated proteins, with particular focus on these aspects in brain tissue.
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Affiliation(s)
- M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry, Epilepsy and Brain Metabolism Center, Lafora Epilepsy Cure Initiative, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, Epilepsy and Brain Metabolism Center, Lafora Epilepsy Cure Initiative, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, USA.
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18
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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: 56] [Impact Index Per Article: 9.3] [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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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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Abstract
Lafora disease (LD) is an autosomal recessive progressive myoclonus epilepsy due to mutations in the EPM2A (laforin) and EPM2B (malin) genes, with no substantial genotype-phenotype differences between the two. Founder effects and recurrent mutations are common, and mostly isolated to specific ethnic groups and/or geographical locations. Pathologically, LD is characterized by distinctive polyglucosans, which are formations of abnormal glycogen. Polyglucosans, or Lafora bodies (LB) are typically found in the brain, periportal hepatocytes of the liver, skeletal and cardiac myocytes, and in the eccrine duct and apocrine myoepithelial cells of sweat glands. Mouse models of the disease and other naturally occurring animal models have similar pathology and phenotype. Hypotheses of LB formation remain controversial, with compelling evidence and caveats for each hypothesis. However, it is clear that the laforin and malin functions regulating glycogen structure are key. With the exception of a few missense mutations LD is clinically homogeneous, with onset in adolescence. Symptoms begin with seizures, and neurological decline follows soon after. The disease course is progressive and fatal, with death occurring within 10 years of onset. Antiepileptic drugs are mostly non-effective, with none having a major influence on the progression of cognitive and behavioral symptoms. Diagnosis and genetic counseling are important aspects of LD, and social support is essential in disease management. Future therapeutics for LD will revolve around the pathogenesics of the disease. Currently, efforts at identifying compounds or approaches to reduce brain glycogen synthesis appear to be highly promising.
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Cartee GD. Mechanisms for greater insulin-stimulated glucose uptake in normal and insulin-resistant skeletal muscle after acute exercise. Am J Physiol Endocrinol Metab 2015; 309:E949-59. [PMID: 26487009 PMCID: PMC4816200 DOI: 10.1152/ajpendo.00416.2015] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/14/2015] [Indexed: 02/08/2023]
Abstract
Enhanced skeletal muscle and whole body insulin sensitivity can persist for up to 24-48 h after one exercise session. This review focuses on potential mechanisms for greater postexercise and insulin-stimulated glucose uptake (ISGU) by muscle in individuals with normal or reduced insulin sensitivity. A model is proposed for the processes underlying this improvement; i.e., triggers initiate events that activate subsequent memory elements, which store information that is relayed to mediators, which translate memory into action by controlling an end effector that directly executes increased insulin-stimulated glucose transport. Several candidates are potential triggers or memory elements, but none have been conclusively verified. Regarding potential mediators in both normal and insulin-resistant individuals, elevated postexercise ISGU with a physiological insulin dose coincides with greater Akt substrate of 160 kDa (AS160) phosphorylation without improved proximal insulin signaling at steps from insulin receptor binding to Akt activity. Causality remains to be established between greater AS160 phosphorylation and improved ISGU. The end effector for normal individuals is increased GLUT4 translocation, but this remains untested for insulin-resistant individuals postexercise. Following exercise, insulin-resistant individuals can attain ISGU values similar to nonexercising healthy controls, but after a comparable exercise protocol performed by both groups, ISGU for the insulin-resistant group has been consistently reported to be below postexercise values for the healthy group. Further research is required to fully understand the mechanisms underlying the improved postexercise ISGU in individuals with normal or subnormal insulin sensitivity and to explain the disparity between these groups after similar exercise.
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Affiliation(s)
- Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, Department of Molecular and Integrative Physiology, and Institute of Gerontology, University of Michigan, Ann Arbor, Michigan
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