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Young Seo G, Neal ES, Han F, Vidovic D, Nooru-Mohamed F, Dienel GA, Sullivan MA, Borges K. Brain glycogen content is increased in the acute and interictal chronic stages of the mouse pilocarpine model of epilepsy. Epilepsia Open 2022; 7:361-367. [PMID: 35377551 PMCID: PMC9159246 DOI: 10.1002/epi4.12599] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/01/2022] [Accepted: 04/01/2022] [Indexed: 11/30/2022] Open
Abstract
Glucose is the main brain fuel in fed conditions, while astrocytic glycogen is used as supplemental fuel when the brain is stimulated. Brain glycogen levels are decreased shortly after induced seizures in rodents, but little is known about how glycogen levels are affected interictally in chronic models of epilepsy. Reduced glutamine synthetase activity has been suggested to lead to increased brain glycogen levels in humans with chronic epilepsy. Here, we used the mouse pilocarpine model of epilepsy to investigate whether brain glycogen levels are altered, both acutely and in the chronic stage of the model. One day after pilocarpine‐induced convulsive status epilepticus (CSE), glycogen levels were higher in the hippocampal formation, cerebral cortex, and cerebellum. Opposite to expected, this was accompanied by elevated glutamine synthetase activity in the hippocampus but not the cortex. Increased interictal glycogen amounts were seen in the hippocampal formation and cerebral cortex in the chronic stage of the model (21 days post‐CSE), suggesting long‐lasting alterations in glycogen metabolism. Glycogen solubility in the cerebral cortex was unaltered in this epilepsy mouse model. Glycogen synthase kinase 3 beta (Gsk3b) mRNA levels were reduced in the hippocampal formations of mice in the chronic stage, which may underlie the elevated brain glycogen content in this model. This is the first report of elevated interictal glycogen levels in a chronic epilepsy model. Increased glycogen amounts in the brain may influence seizure susceptibility in this model, and this warrants further investigation.
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Affiliation(s)
- Gi Young Seo
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Elliott S Neal
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Felicity Han
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Diana Vidovic
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Fathima Nooru-Mohamed
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA, 72205.,Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, NM, USA, 87131
| | - Mitchell A Sullivan
- Glycation and Diabetes Group, Mater Research Institute, Translational Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Queensland, 4072, Australia
| | - Karin Borges
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, 4072, Australia
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Oses JP, Müller AP, Strogulski NR, Moreira JD, Böhmer AE, Hansel G, Carteri RB, Busnello JV, Kopczynski A, Rodolphi MS, Souza DO, Portela LV. Sustained elevation of cerebrospinal fluid glucose and lactate after a single seizure does not parallel with mitochondria energy production. Epilepsy Res 2019; 152:35-41. [PMID: 30875635 DOI: 10.1016/j.eplepsyres.2019.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 02/18/2019] [Accepted: 03/09/2019] [Indexed: 12/22/2022]
Abstract
Generalized seizures trigger excessive neuronal firing that imposes large demands on the brain glucose/lactate availability and utilization, which synchronization requires an integral mitochondrial oxidative capability. We investigated whether a single convulsive crisis affects brain glucose/lactate availability and mitochondrial energy production. Adult male Wistar rats received a single injection of pentylentetrazol (PTZ, 60 mg/kg, i.p.) or saline. The cerebrospinal fluid (CSF) levels of glucose and lactate, mitochondrial respirometry, [14C]-2-deoxy-D-glucose uptake, glycogen content and cell viability in hippocampus were measured. CSF levels of glucose and lactate (mean ± SD) in control animals were 68.08 ± 11.62 mg/dL and 1.17 ± 0.32 mmol/L, respectively. Tonic-clonic seizures increased glucose levels at 10 min (96.25 ± 13.19) peaking at 60 min (113.03 ± 16.34) returning to control levels at 24 h (50.12 ± 12.81), while lactate increased at 10 min (3.23 ± 1.57) but returned to control levels at 360 min after seizures (1.58 ± 0.21). The hippocampal [14C]-2-deoxy-D-glucose uptake, glycogen content, and cell viability decreased up to 60 min after the seizures onset. Also, an uncoupling between mitochondrial oxygen consumption and ATP synthesis via FoF1-ATP synthase was observed at 10 min, 60 min and 24 h after seizures. In summary, after a convulsive seizure glucose and lactate levels immediately rise within the brain, however, considering the acute impact of this metabolic crisis, mitochondria are not able to increase energy production thereby affecting cell viability.
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Affiliation(s)
- Jean Pierre Oses
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Alexandre Pastoris Müller
- Unidade de Ciências da Saúde, Laboratório de Bioquímica e Fisiologia do Exercício Universidade do Extremo Sul Catarinense-UNESC, Av. Universitária, 1105 - Bairro Universitário, CEP 88806-000, Criciúma, Santa Catarina, Brazil
| | - Nathan Ryzewski Strogulski
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Julia D Moreira
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Departamento de Nutrição, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Ana Elisa Böhmer
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Gisele Hansel
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Randhall Bruce Carteri
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - João Vicente Busnello
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
| | - Afonso Kopczynski
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Marcelo Salimen Rodolphi
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Diogo Onofre Souza
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Luis Valmor Portela
- Programa de Pós-graduação em Ciências Biológicas, Bioquímica, Laboratório de Neurotrauma e Biomarcadores, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
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Gotoh H, Nomura T, Ono K. Glycogen serves as an energy source that maintains astrocyte cell proliferation in the neonatal telencephalon. J Cereb Blood Flow Metab 2017; 37:2294-2307. [PMID: 27601444 PMCID: PMC5464718 DOI: 10.1177/0271678x16665380] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Large amounts of energy are required when cells undergo cell proliferation and differentiation for mammalian neuronal development. Early neonatal mice face transient starvation and use stored energy for survival or to support development. Glycogen is a branched polysaccharide that is formed by glucose, and serves as an astrocytic energy store for rapid energy requirements. Although it is present in radial glial cells and astrocytes, the role of glycogen during development remains unclear. In the present study, we demonstrated that glycogen accumulated in glutamate aspartate transporter (GLAST)+ astrocytes in the subventricular zone and rostral migratory stream. Glycogen levels markedly decreased after birth due to the increase of glycogen phosphorylase, an essential enzyme for glycogen metabolism. In primary cultures and in vivo, the inhibition of glycogen phosphorylase decreased the proliferation of astrocytic cells. The number of cells in the G1 phase increased in combination with the up-regulation of cyclin-dependent kinase inhibitors or down-regulation of the phosphorylation of retinoblastoma protein (pRB), a determinant for cell cycle progression. These results suggest that glycogen accumulates in astrocytes located in specific areas during the prenatal stage and is used as an energy source to maintain normal development in the early postnatal stage.
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Affiliation(s)
- Hitoshi Gotoh
- 1 Department of Biology, Kyoto Prefectural University of Medicine, Sakyo-ku, Kyoto, Japan
| | - Tadashi Nomura
- 1 Department of Biology, Kyoto Prefectural University of Medicine, Sakyo-ku, Kyoto, Japan.,2 Japan Science and Technology Agency (JST), PRESTO, Saitama, Japan
| | - Katsuhiko Ono
- 1 Department of Biology, Kyoto Prefectural University of Medicine, Sakyo-ku, Kyoto, Japan
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Lucchi C, Vinet J, Meletti S, Biagini G. Ischemic-hypoxic mechanisms leading to hippocampal dysfunction as a consequence of status epilepticus. Epilepsy Behav 2015; 49:47-54. [PMID: 25934585 DOI: 10.1016/j.yebeh.2015.04.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 04/01/2015] [Accepted: 04/02/2015] [Indexed: 10/23/2022]
Abstract
Status epilepticus (SE) is one of the recognized primary precipitating events that can lead to temporal lobe epilepsy (TLE) associated with hippocampal sclerosis. This type of epilepsy is characterized by poor response to drug treatment, often requiring surgical intervention to remove the mesial temporal regions involved in the seizure onset. However, even neurosurgery may not be completely successful. Thus, the prevention of hippocampal damage and epileptogenesis is currently evaluated as a possible alternative therapeutic approach to prevent the development of pharmacoresistant TLE. Lines of evidence suggest that ischemic-hypoxic lesions might occur in different brain regions, including the hippocampus, during SE. Especially in the hippocampal CA3 region, an ischemic-like lesion develops in the stratum lacunosum-moleculare and is mainly characterized by a loss of astrocytes and neuronal processes and increased immunostaining of pimonidazole which probes areas exposed to hypoxia. Interestingly, these mechanisms can contribute to neuronal cell loss and may be counteracted by drugs that can afford vascular protection, as in the case of ligands of the ghrelin receptor. Notably, some of the ghrelin receptor ligands possess a double edge effect, since they are anticonvulsant and vascular-protective, thus, potentially representing new tools to counteract the consequences of SE. This article is part of a Special Issue entitled "Status Epilepticus".
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Affiliation(s)
- Chiara Lucchi
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Jonathan Vinet
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy
| | - Stefano Meletti
- Department of Biomedical, Metabolic and Neural Sciences, Neurology Unit, University of Modena and Reggio Emilia, Modena, Italy
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences, Laboratory of Experimental Epileptology, University of Modena and Reggio Emilia, Modena, Italy; Department of Neurosciences, NOCSAE Hospital, AUSL Modena, Modena, Italy.
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DiNuzzo M, Mangia S, Maraviglia B, Giove F. Does abnormal glycogen structure contribute to increased susceptibility to seizures in epilepsy? Metab Brain Dis 2015; 30:307-16. [PMID: 24643875 PMCID: PMC4169361 DOI: 10.1007/s11011-014-9524-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 03/05/2014] [Indexed: 12/22/2022]
Abstract
Epilepsy is a family of brain disorders with a largely unknown etiology and high percentage of pharmacoresistance. The clinical manifestations of epilepsy are seizures, which originate from aberrant neuronal synchronization and hyperexcitability. Reactive astrocytosis, a hallmark of the epileptic tissue, develops into loss-of-function of glutamine synthetase, impairment of glutamate-glutamine cycle and increase in extracellular and astrocytic glutamate concentration. Here, we argue that chronically elevated intracellular glutamate level in astrocytes is instrumental to alterations in the metabolism of glycogen and leads to the synthesis of polyglucosans. Unaccessibility of glycogen-degrading enzymes to these insoluble molecules compromises the glycogenolysis-dependent reuptake of extracellular K(+) by astrocytes, thereby leading to increased extracellular K(+) and associated membrane depolarization. Based on current knowledge, we propose that the deterioration in structural homogeneity of glycogen particles is relevant to disruption of brain K(+) homeostasis and increased susceptibility to seizures in epilepsy.
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Affiliation(s)
- Mauro DiNuzzo
- MARBILab, Museo storico della fisica e Centro di studi e ricerche "Enrico Fermi", Rome, Italy,
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Lethbridge RL, Walling SG, Harley CW. Modulation of the perforant path-evoked potential in dentate gyrus as a function of intrahippocampal β-adrenoceptor agonist concentration in urethane-anesthetized rat. Brain Behav 2014; 4:95-103. [PMID: 24653959 PMCID: PMC3937711 DOI: 10.1002/brb3.199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 10/04/2013] [Accepted: 11/24/2013] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND β-adrenoceptor activation in the hippocampus is sufficient to induce heterosynaptic long-term potentiation of perforant path input to the dentate gyrus. However, in vitro and in vivo studies suggest the plasticity effects of β-adrenoceptor activation may vary depending on the level of receptor activation. METHODS The present experiments use an in vivo model concurrently infusing differing concentrations of the β-adrenoceptor agonist, isoproterenol (ISO; 0, 0.1, 1, 10, and 100 μmol/L in aCSF; 1 μL over 12.5 min) in the dentate gyrus, while monitoring changes in the perforant path-evoked potential at the same site. RESULTS Long-term depression (LTD) of fEPSP slope was elicited by 0.1 μmol/L ISO. Higher doses did not alter fEPSP slope. Maximal long-term potentiation of the perforant path-evoked population spike (183% >3 h) occurred at 10 μmol/L ISO. Transient depression of spike amplitude occurred at 0.1 μmol/L ISO. CONCLUSIONS These data demonstrate concentration-dependent effects of β-adrenoceptor activation on the perforant path-evoked potential. Long-term depression and long-term potentiation of perforant path-evoked responses are variably elicited as a function of the degree of receptor activation.
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Affiliation(s)
- Rebecca L Lethbridge
- Behavioral Neuroscience, Psychology Department, Memorial University of Newfoundland St. John's, NL, A1B 3X9, Canada
| | - Susan G Walling
- Behavioral Neuroscience, Psychology Department, Memorial University of Newfoundland St. John's, NL, A1B 3X9, Canada
| | - Carolyn W Harley
- Behavioral Neuroscience, Psychology Department, Memorial University of Newfoundland St. John's, NL, A1B 3X9, Canada
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Increased perivascular laminin predicts damage to astrocytes in CA3 and piriform cortex following chemoconvulsive treatments. Neuroscience 2012; 218:278-94. [DOI: 10.1016/j.neuroscience.2012.05.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 04/24/2012] [Accepted: 05/06/2012] [Indexed: 11/18/2022]
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