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Xu W, Borges K. Case for supporting astrocyte energetics in glucose transporter 1 deficiency syndrome. Epilepsia 2024. [PMID: 38767952 DOI: 10.1111/epi.18013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 05/22/2024]
Abstract
In glucose transporter 1 deficiency syndrome (Glut1DS), glucose transport into brain is reduced due to impaired Glut1 function in endothelial cells at the blood-brain barrier. This can lead to shortages of glucose in brain and is thought to contribute to seizures. Ketogenic diets are the first-line treatment and, among many beneficial effects, provide auxiliary fuel in the form of ketone bodies that are largely metabolized by neurons. However, Glut1 is also the main glucose transporter in astrocytes. Here, we review data indicating that glucose shortage may also impact astrocytes in addition to neurons and discuss the expected negative biochemical consequences of compromised astrocytic glucose transport for neurons. Based on these effects, auxiliary fuels are needed for both cell types and adding medium chain triglycerides (MCTs) to ketogenic diets is a biochemically superior treatment for Glut1DS compared to classical ketogenic diets. MCTs provide medium chain fatty acids (MCFAs), which are largely metabolized by astrocytes and not neurons. MCFAs supply energy and contribute carbons for glutamine and γ-aminobutyric acid synthesis, and decanoic acid can also block α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptors. MCTs do not compete with metabolism of ketone bodies mostly occurring in neurons. Triheptanoin, an anaplerotic but also gluconeogenic uneven MCT, may be another potential addition to ketogenic diets, although maintenance of "ketosis" can be difficult. Gene therapy has also targeted both endothelial cells and astrocytes. Other approaches to increase fuel delivery to the brain currently investigated include exchange of Glut1DS erythrocytes with healthy cells, infusion of lactate, and pharmacological improvement of glucose transport. In conclusion, although it remains difficult to assess impaired astrocytic energy metabolism in vivo, astrocytic energy needs are most likely not met by ketogenic diets in Glut1DS. Thus, we propose prospective studies including monitoring of blood MCFA levels to find optimal doses for add-on MCT to ketogenic diets and assessing of short- and long-term outcomes.
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Affiliation(s)
- Weizhi Xu
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, Australia
| | - Karin Borges
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, Australia
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Zeng C, Lu Y, Wei X, Sun L, Wei L, Ou S, Huang Q, Wu Y. Parvalbumin Regulates GAD Expression through Calcium Ion Concentration to Affect the Balance of Glu-GABA and Improve KA-Induced Status Epilepticus in PV-Cre Transgenic Mice. ACS Chem Neurosci 2024; 15:1951-1966. [PMID: 38696478 DOI: 10.1021/acschemneuro.3c00600] [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] [Indexed: 05/04/2024] Open
Abstract
Aims: the study aimed to (i) use adeno-associated virus technology to modulate parvalbumin (PV) gene expression, both through overexpression and silencing, within the hippocampus of male mice and (ii) assess the impact of PV on the metabolic pathway of glutamate and γ-aminobutyric acid (GABA). Methods: a status epilepticus (SE) mouse model was established by injecting kainic acid into the hippocampus of transgenic mice. When the seizures of mice reached SE, the mice were killed at that time point and 30 min after the onset of SE. Hippocampal tissues were extracted and the mRNA and protein levels of PV and the 65 kDa (GAD65) and 67 kDa (GAD67) isoforms of glutamate decarboxylase were assessed using real-time quantitative polymerase chain reaction and Western blot, respectively. The concentrations of glutamate and GABA were detected with high-performance liquid chromatography (HPLC), and the intracellular calcium concentration was detected using flow cytometry. Results: we demonstrate that the expression of PV is associated with GAD65 and GAD67 and that PV regulates the levels of GAD65 and GAD67. PV was correlated with calcium concentration and GAD expression. Interestingly, PV overexpression resulted in a reduction in calcium ion concentration, upregulation of GAD65 and GAD67, elevation of GABA concentration, reduction in glutamate concentration, and an extension of seizure latency. Conversely, PV silencing induced the opposite effects. Conclusion: parvalbumin may affect the expression of GAD65 and GAD67 by regulating calcium ion concentration, thereby affecting the metabolic pathways associated with glutamate and GABA. In turn, this contributes to the regulation of seizure activity.
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Affiliation(s)
- Chunmei Zeng
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, #6 Shuangyong Road,Nanning, Guangxi 530021, China
| | - Yuling Lu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, #6 Shuangyong Road,Nanning, Guangxi 530021, China
| | - Xing Wei
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, #6 Shuangyong Road,Nanning, Guangxi 530021, China
| | - Lanfeng Sun
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, #6 Shuangyong Road,Nanning, Guangxi 530021, China
| | - Lei Wei
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, #6 Shuangyong Road,Nanning, Guangxi 530021, China
| | - Sijie Ou
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, #6 Shuangyong Road,Nanning, Guangxi 530021, China
| | - Qi Huang
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, #6 Shuangyong Road,Nanning, Guangxi 530021, China
| | - Yuan Wu
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, #6 Shuangyong Road,Nanning, Guangxi 530021, China
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DiNuzzo M, Dienel GA, Behar KL, Petroff OA, Benveniste H, Hyder F, Giove F, Michaeli S, Mangia S, Herculano-Houzel S, Rothman DL. Neurovascular coupling is optimized to compensate for the increase in proton production from nonoxidative glycolysis and glycogenolysis during brain activation and maintain homeostasis of pH, pCO 2, and pO 2. J Neurochem 2024; 168:632-662. [PMID: 37150946 PMCID: PMC10628336 DOI: 10.1111/jnc.15839] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 04/22/2023] [Accepted: 05/02/2023] [Indexed: 05/09/2023]
Abstract
During transient brain activation cerebral blood flow (CBF) increases substantially more than cerebral metabolic rate of oxygen consumption (CMRO2) resulting in blood hyperoxygenation, the basis of BOLD-fMRI contrast. Explanations for the high CBF versus CMRO2 slope, termed neurovascular coupling (NVC) constant, focused on maintenance of tissue oxygenation to support mitochondrial ATP production. However, paradoxically the brain has a 3-fold lower oxygen extraction fraction (OEF) than other organs with high energy requirements, like heart and muscle during exercise. Here, we hypothesize that the NVC constant and the capillary oxygen mass transfer coefficient (which in combination determine OEF) are co-regulated during activation to maintain simultaneous homeostasis of pH and partial pressure of CO2 and O2 (pCO2 and pO2). To test our hypothesis, we developed an arteriovenous flux balance model for calculating blood and brain pH, pCO2, and pO2 as a function of baseline OEF (OEF0), CBF, CMRO2, and proton production by nonoxidative metabolism coupled to ATP hydrolysis. Our model was validated against published brain arteriovenous difference studies and then used to calculate pH, pCO2, and pO2 in activated human cortex from published calibrated fMRI and PET measurements. In agreement with our hypothesis, calculated pH, pCO2, and pO2 remained close to constant independently of CMRO2 in correspondence to experimental measurements of NVC and OEF0. We also found that the optimum values of the NVC constant and OEF0 that ensure simultaneous homeostasis of pH, pCO2, and pO2 were remarkably similar to their experimental values. Thus, the high NVC constant is overall determined by proton removal by CBF due to increases in nonoxidative glycolysis and glycogenolysis. These findings resolve the paradox of the brain's high CBF yet low OEF during activation, and may contribute to explaining the vulnerability of brain function to reductions in blood flow and capillary density with aging and neurovascular disease.
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Affiliation(s)
| | - Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205 USA
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, NM, 87131 USA
| | - Kevin L Behar
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511 USA
| | - Ognen A Petroff
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511 USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale University, New Haven, CT, 06520 USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520 USA
| | - Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520 USA
- Department of Radiology, Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, 06520 USA
| | - Federico Giove
- Centro Ricerche Enrico Fermi, Rome, RM, 00184 Italy
- Fondazione Santa Lucia IRCCS, Rome, RM, 00179 Italy
| | - Shalom Michaeli
- Department of Radiology, Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, 55455 USA
| | - Silvia Mangia
- Department of Radiology, Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, 55455 USA
| | - Suzana Herculano-Houzel
- Department of Psychology, Vanderbilt University, Nashville, TN
- Department of Biological Sciences, Vanderbilt University, Nashville, TN
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN
| | - Douglas L Rothman
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520 USA
- Department of Radiology, Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, 06520 USA
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Tejero A, León-Navarro DA, Martín M. Effect of chronic maternal L-Glu intake during gestation and/or lactation on oxidative stress markers, AMPA Glu1 receptor and adenosine A 1 signalling pathway from foetal and neonatal cerebellum. Purinergic Signal 2024; 20:181-192. [PMID: 37458955 PMCID: PMC10997561 DOI: 10.1007/s11302-023-09959-6] [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: 03/29/2023] [Accepted: 07/07/2023] [Indexed: 04/06/2024] Open
Abstract
L-Glutamate (L-Glu) is an amino acid present in the diet that plays a fundamental role in the central nervous system, as the main excitatory neurotransmitter participating in learning and memory processes. In addition, the nucleoside adenosine has a crucial role in L-Glu metabolism, by regulating the liberation of this neurotransmitter through four different receptors: A1, A2A, A2B and A3, which activate (A2A and A2B) or inhibit (A1 and A3) adenylate cyclase pathway. L-Glu at high concentrations can act as a neurotoxin and induce oxidative stress. The study of the oxidative stress correlated with an excess of L-Glu consumption during maternity is key to understand its effects on foetuses and neonates. Previous studies have shown that there is a change in the receptor levels in the brain of pregnant rats and their foetuses when mothers are administered L-Glu during gestation; however, its effect on the cerebellum is unknown. Cerebellum is known to be responsible for motor, cognitive and emotional functions, so its possible involvement after L-Glu consumption is an important issue to study. Therefore, the aim of the present work was to study the effect of L-Glu exposure during gestation and lactation on oxidative stress biomarkers and neurotransmitter receptors from the cerebellum of foetuses and neonates. After maternal L-Glu intake during gestation, oxidative stress was increased, as the ionotropic L-Glu receptors, and GluR1 AMPA subunit levels were altered in foetuses. A1 adenosine receptor suffered changes after L-Glu treatment during gestation, lactation or both, in lactating neonate cerebellum, while adenylate cyclase activity remain unaltered. Further studies will be necessary to elucidate the importance of L-Glu intake and its possible excitotoxicity in the cerebellum of Wistar rats during the pregnancy period and their involvement in long-term neurodegeneration.
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Affiliation(s)
- Adrián Tejero
- Department of Inorganic and Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real. Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071, Ciudad Real, Spain
| | - David Agustín León-Navarro
- Department of Inorganic and Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real. Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071, Ciudad Real, Spain
| | - Mairena Martín
- Department of Inorganic and Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real. Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071, Ciudad Real, Spain.
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Ozdemir E. Adrenergic receptor system as a pharmacological target in the treatment of epilepsy (Review). MEDICINE INTERNATIONAL 2024; 4:20. [PMID: 38476984 PMCID: PMC10928664 DOI: 10.3892/mi.2024.144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/16/2024] [Indexed: 03/14/2024]
Abstract
Epilepsy is a complex and common neurological disorder characterized by spontaneous and recurrent seizures, affecting ~75 million individuals worldwide. Numerous studies have been conducted to develop new pharmacological drugs for the effective treatment of epilepsy. In recent years, numerous experimental and clinical studies have focused on the role of the adrenergic receptor (AR) system in the regulation of epileptogenesis, seizure susceptibility and convulsions. α1-ARs (α1A, α1B and α1D), α2-ARs (α2A, α2B and α2C) and β-ARs (β1, β2 and β3), known to have convulsant or anticonvulsant effects, have been isolated. Norepinephrine (NE), the key endogenous agonist of ARs, is considered to play a crucial role in the pathophysiology of epileptic seizures. However, the effects of NE on different ARs have not been fully elucidated. Although the activation of some AR subtypes produces conflicting results, the activation of α1, α2 and β receptor subtypes, in particular, produces anticonvulsant effects. The present review focuses on NE and ARs involved in epileptic seizure formation and discusses therapeutic approaches.
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Affiliation(s)
- Ercan Ozdemir
- Department of Physiology, Faculty of Medicine, Sivas Cumhuriyet University, 58140 Sivas, Turkey
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6
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Nogueira CO, Rocha T, Messor DF, Souza INO, Clarke JR. Fundamental neurochemistry review: Glutamatergic dysfunction as a central mechanism underlying flavivirus-induced neurological damage. J Neurochem 2023; 166:915-927. [PMID: 37603368 DOI: 10.1111/jnc.15935] [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: 05/15/2023] [Revised: 07/06/2023] [Accepted: 07/26/2023] [Indexed: 08/22/2023]
Abstract
The Flaviviridae family comprises positive-sense single-strand RNA viruses mainly transmitted by arthropods. Many of these pathogens are especially deleterious to the nervous system, and a myriad of neurological symptoms have been associated with infections by Zika virus (ZIKV), West Nile virus (WNV), and Japanese encephalitis virus (JEV) in humans. Studies suggest that viral replication in neural cells and the massive release of pro-inflammatory mediators lead to morphological alterations of synaptic spine structure and changes in the balance of excitatory/inhibitory neurotransmitters and receptors. Glutamate is the predominant excitatory neurotransmitter in the brain, and studies propose that either enhanced release or impaired uptake of this amino acid contributes to brain damage in several conditions. Here, we review existing evidence suggesting that glutamatergic dysfunction-induced by flaviviruses is a central mechanism for neurological damage and clinical outcomes of infection. We also discuss current data suggesting that pharmacological approaches that counteract glutamatergic dysfunction show benefits in animal models of such viral diseases.
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Affiliation(s)
- Clara O Nogueira
- Programa de Pós-graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Tamires Rocha
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Daniel F Messor
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Isis N O Souza
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Julia R Clarke
- Programa de Pós-graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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7
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Zhai J, Traebert M, Zimmermann K, Delaunois A, Royer L, Salvagiotto G, Carlson C, Lagrutta A. Comparative study for the IMI2-NeuroDeRisk project on microelectrode arrays to derisk drug-induced seizure liability. J Pharmacol Toxicol Methods 2023; 123:107297. [PMID: 37499956 DOI: 10.1016/j.vascn.2023.107297] [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: 03/03/2023] [Revised: 06/01/2023] [Accepted: 07/19/2023] [Indexed: 07/29/2023]
Abstract
INTRODUCTION In the framework of the IMI2-NeuroDeRisk consortium, three in vitro electrophysiology assays were compared to improve preclinical prediction of seizure-inducing liabilities. METHODS Two cell models, primary rat cortical neurons and human induced pluripotent stem cell (hiPSC)-derived glutamatergic neurons co-cultured with hiPSC-derived astrocytes were tested on two different microelectrode array (MEA) platforms, Maestro Pro (Axion Biosystems) and Multiwell-MEA-System (Multi Channel Systems), in three separate laboratories. Pentylenetetrazole (PTZ) and/or picrotoxin (PTX) were included in each plate as positive (n = 3-6 wells) and ≤0.2% DMSO was used as negative controls (n = 3-12 wells). In general, concentrations in a range of 0.1-30 μM were tested, anchored, when possible, on clinically relevant exposures (unbound Cmax) were tested. Activity thresholds for drug-induced changes were set at 20%. To evaluate sensitivity, specificity and predictivity of the cell models, seizurogenic responses were defined as changes in 4 or more endpoints. Concentration dependence trends were also considered. RESULTS Neuronal activity of 33 compounds categorized as positive tool drugs, seizure-positive or seizure-negative compounds was evaluated. Acute drug effects (<60 min) were compared to baseline recordings. Time points < 15 min exhibited stronger, less variable responses to many of the test agents. For many compounds a reduction and cessation of neuronal activity was detected at higher test concentrations. There was not a single pattern of seizurogenic activity detected, even among tool compounds, likely due to different mechanisms of actions and/or off-target profiles. A post-hoc analysis focusing on changes indicative of neuronal excitation is presented. CONCLUSION All cell models showed good sensitivity, ranging from 70 to 86%. Specificity ranged from 40 to 70%. Compared to more conventional measurements of evoked activity in hippocampal slices, these plate-based models provide higher throughput and the potential to study subacute responses. Yet, they may be limited by the random, spontaneous nature of their network activity.
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Affiliation(s)
- Jin Zhai
- Merck & Co., Inc., Rahway, NJ, USA
| | | | | | | | | | | | - Coby Carlson
- Fujifilm Cellular Dynamics, Inc., Madison, WI, USA
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Zeng C, Lei D, Lu Y, Huang Q, Wu Y, Yang S, Wu Y. Parvalbumin in the metabolic pathway of glutamate and γ-aminobutyric acid: Influence on expression of GAD65 and GAD67. Arch Biochem Biophys 2023; 734:109499. [PMID: 36587827 DOI: 10.1016/j.abb.2022.109499] [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: 10/23/2022] [Revised: 12/19/2022] [Accepted: 12/28/2022] [Indexed: 12/31/2022]
Abstract
Parvalbumin-expressing neurons are a type of inhibitory intermediate neuron that play an important role in terminating seizures. The aim of the present study was to use lentiviral construction and packaging technology to overexpress and silence the parvalbumin gene in pheochromocytoma (PC12) cells, and to evaluate how parvalbumin influences the metabolic pathway involving glutamate and γ-aminobutyric acid (GABA). In this work, Immunofluorescence staining was used to verify the differentiation of PC12 cells into neurons after adding nerve growth factor (NGF). Western blotting and real-time quantitative polymerase chain reaction (qRT-PCR) were used to confirm lentivirus-mediated knockdown or overexpression of parvalbumin. Expression of parvalbumin, the 65-kDa GAD isoform (GAD65), and the 67-kDa GAD isoform (GAD67) in neuronal cells was examined at the mRNA and protein levels using qRT-PCR, western blotting and immunofluorescence staining, while intracellular glutamate and GABA levels were determined by high performance liquid chromatography (HPLC). We demonstrate that the expression of parvalbumin is associated with GAD65 and GAD67. Interestingly, overexpression of parvalbumin up-regulated GAD65 and GAD67, increased GABA concentration, and decreased glutamate concentration. Silencing of parvalbumin led to the opposite effects. Altogether, parvalbumin affected the expression of GAD65 and GAD67, thereby influencing the metabolic pathway involving glutamate and GABA.
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Affiliation(s)
- Chunmei Zeng
- Department of Neurology, The First Affiliated Hospital, Guangxi Medical University, #6 Shuangyong Road, Nanning, 530021, Guangxi, China
| | - Danqing Lei
- Experimental Center of Life Sciences Institutes, Guangxi Medical University, #22 Shuangyong Road, Nanning, 530021, Guangxi, China
| | - Yuling Lu
- Department of Neurology, The First Affiliated Hospital, Guangxi Medical University, #6 Shuangyong Road, Nanning, 530021, Guangxi, China
| | - Qi Huang
- Department of Neurology, The First Affiliated Hospital, Guangxi Medical University, #6 Shuangyong Road, Nanning, 530021, Guangxi, China
| | - Ying Wu
- Department of Neurology, The First Affiliated Hospital, Guangxi Medical University, #6 Shuangyong Road, Nanning, 530021, Guangxi, China
| | - Shengyu Yang
- Department of Neurology, The First Affiliated Hospital, Guangxi Medical University, #6 Shuangyong Road, Nanning, 530021, Guangxi, China
| | - Yuan Wu
- Department of Neurology, The First Affiliated Hospital, Guangxi Medical University, #6 Shuangyong Road, Nanning, 530021, Guangxi, China.
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Affiliation(s)
- Gerald A. Dienel
- Department of Neurology University of Arkansas for Medical Sciences Little Rock Arkansas USA
- Department of Cell Biology and Physiology University of New Mexico School of Medicine Albuquerque New Mexico USA
| | - Lisa Gillinder
- Mater Hospital South Brisbane Queensland Australia
- Faculty of Medicine Mater Research Institute, University of Queensland St Lucia Queensland Australia
| | - Aileen McGonigal
- Mater Hospital South Brisbane Queensland Australia
- Faculty of Medicine Mater Research Institute, University of Queensland St Lucia Queensland Australia
| | - Karin Borges
- Faculty of Medicine School of Biomedical Sciences, University of Queensland St Lucia Queensland Australia
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10
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Dienel GA, Gillinder L, McGonigal A, Borges K. Potential new roles for glycogen in epilepsy. Epilepsia 2023; 64:29-53. [PMID: 36117414 PMCID: PMC10952408 DOI: 10.1111/epi.17412] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/15/2022] [Accepted: 09/15/2022] [Indexed: 01/21/2023]
Abstract
Seizures often originate in epileptogenic foci. Between seizures (interictally), these foci and some of the surrounding tissue often show low signals with 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in many epileptic patients, even when there are no radiologically detectable structural abnormalities. Low FDG-PET signals are thought to reflect glucose hypometabolism. Here, we review knowledge about metabolism of glucose and glycogen and oxidative stress in people with epilepsy and in acute and chronic rodent seizure models. Interictal brain glucose levels are normal and do not cause apparent glucose hypometabolism, which remains unexplained. During seizures, high amounts of fuel are needed to satisfy increased energy demands. Astrocytes consume glycogen as an additional emergency fuel to supplement glucose during high metabolic demand, such as during brain stimulation, stress, and seizures. In rodents, brain glycogen levels drop during induced seizures and increase to higher levels thereafter. Interictally, in people with epilepsy and in chronic epilepsy models, normal glucose but high glycogen levels have been found in the presumed brain areas involved in seizure generation. We present our new hypothesis that as an adaptive response to repeated episodes of high metabolic demand, high interictal glycogen levels in epileptogenic brain areas are used to support energy metabolism and potentially interictal neuronal activity. Glycogenolysis, which can be triggered by stress or oxidative stress, leads to decreased utilization of plasma glucose in epileptogenic brain areas, resulting in low FDG signals that are related to functional changes underlying seizure onset and propagation. This is (partially) reversible after successful surgery. Last, we propose that potential interictal glycogen depletion in epileptogenic and surrounding areas may cause energy shortages in astrocytes, which may impair potassium buffering and contribute to seizure generation. Based on these hypotheses, auxiliary fuels or treatments that support glycogen metabolism may be useful to treat epilepsy.
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Affiliation(s)
- Gerald A. Dienel
- Department of NeurologyUniversity of Arkansas for Medical SciencesLittle RockArkansasUSA
- Department of Cell Biology and PhysiologyUniversity of New Mexico School of MedicineAlbuquerqueNew MexicoUSA
| | - Lisa Gillinder
- Mater HospitalSouth BrisbaneQueenslandAustralia
- Faculty of MedicineMater Research Institute, University of QueenslandSt LuciaQueenslandAustralia
| | - Aileen McGonigal
- Mater HospitalSouth BrisbaneQueenslandAustralia
- Faculty of MedicineMater Research Institute, University of QueenslandSt LuciaQueenslandAustralia
| | - Karin Borges
- Faculty of MedicineSchool of Biomedical Sciences, University of QueenslandSt LuciaQueenslandAustralia
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11
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Della Vecchia S, Marchese M, Santorelli FM. Glial Contributions to Lafora Disease: A Systematic Review. Biomedicines 2022; 10:biomedicines10123103. [PMID: 36551859 PMCID: PMC9776290 DOI: 10.3390/biomedicines10123103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Lafora disease (LD) is a neurodegenerative condition characterized by the accumulation of polyglucosan bodies (PBs) throughout the brain. Alongside metabolic and molecular alterations, neuroinflammation has emerged as another key histopathological feature of LD. METHODS To investigate the role of astrocytes and microglia in LD, we performed a systematic review according to the PRISMA statement. PubMed, Scopus, and Web-of-Science database searches were performed independently by two reviewers. RESULTS Thirty-five studies analyzing the relationship of astrocytes and microglia with LD and/or the effects of anti-inflammatory treatments in LD animal models were identified and included in the review. Although LD has long been dominated by a neuronocentric view, a growing body of evidence suggests a role of glial cells in the disease, starting with the finding that these cells accumulate PBs. We discuss the potential meaning of glial PB accumulations, the likely factors activating glial cells, and the possible contribution of glial cells to LD neurodegeneration and epilepsy. CONCLUSIONS Given the evidence for the role of neuroinflammation in LD, future studies should consider glial cells as a potential therapeutic target for modifying/delaying LD progression; however, it should be kept in mind that these cells can potentially assume multiple reactive phenotypes, which could influence the therapeutic response.
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Affiliation(s)
- Stefania Della Vecchia
- Molecular Medicine and Neurogenetics, IRCCS Stella Maris Foundation, Calambrone, 56128 Pisa, Italy
- Correspondence: (S.D.V.); (F.M.S.)
| | - Maria Marchese
- Neurobiology, IRCCS Stella Maris Foundation, Calambrone, 56128 Pisa, Italy
| | - Filippo Maria Santorelli
- Molecular Medicine and Neurogenetics, IRCCS Stella Maris Foundation, Calambrone, 56128 Pisa, Italy
- Neurobiology, IRCCS Stella Maris Foundation, Calambrone, 56128 Pisa, Italy
- Correspondence: (S.D.V.); (F.M.S.)
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12
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Kumar A, Kumari S, Singh D. Insights into the Cellular Interactions and Molecular Mechanisms of Ketogenic Diet for Comprehensive Management of Epilepsy. Curr Neuropharmacol 2022; 20:2034-2049. [PMID: 35450526 PMCID: PMC9886834 DOI: 10.2174/1570159x20666220420130109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 01/27/2022] [Accepted: 03/25/2022] [Indexed: 11/22/2022] Open
Abstract
A high-fat diet with appropriate protein and low carbohydrate content, widely known as the ketogenic diet (KD), is considered as an effective non-pharmacotherapeutic treatment option for certain types of epilepsies. Several preclinical and clinical studies have been carried out to elucidate its mechanism of antiepileptic action. Ketone bodies produced after KD's breakdown interact with cellular excito-inhibitory processes and inhibit abnormal neuronal firing. The generated ketone bodies decrease glutamate release by inhibiting the vesicular glutamate transporter 1 and alter the transmembrane potential by hyperpolarization. Apart from their effect on the well-known pathogenic mechanisms of epilepsy, some recent studies have shown the interaction of KD metabolites with novel neuronal targets, particularly adenosine receptors, adenosine triphosphate-sensitive potassium channel, mammalian target of rapamycin, histone deacetylase, hydroxycarboxylic acid receptors, and the NLR family pyrin domain containing 3 inflammasomes to suppress seizures. The role of KD in augmenting gut microbiota as a potential mechanism for epileptic seizure suppression has been established. Furthermore, some recent findings also support the beneficial effect of KD against epilepsy- associated comorbidities. Despite several advantages of the KD in epilepsy management, its use is also associated with a wide range of side effects. Hypoglycemia, excessive ketosis, acidosis, renal stones, cardiomyopathies, and other metabolic disturbances are the primary adverse effects observed with the use of KD. However, in some recent studies, modified KD has been tested with lesser side effects and better tolerability. The present review discusses the molecular mechanism of KD and its role in managing epilepsy and its associated comorbidities.
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Affiliation(s)
- Amit Kumar
- Pharmacology and Toxicology Laboratory, Dietetics and Nutrition Technology Division, CSIR- Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; ,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Savita Kumari
- Pharmacology and Toxicology Laboratory, Dietetics and Nutrition Technology Division, CSIR- Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; ,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Damanpreet Singh
- Pharmacology and Toxicology Laboratory, Dietetics and Nutrition Technology Division, CSIR- Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; ,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India,Address correspondence to this author at the Pharmacology and Toxicology Laboratory, Dietetics and Nutrition Technology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur-176061, Himachal Pradesh, India; Tel: +91-9417923132; E-mails: ;
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13
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Kananen J, Järvelä M, Korhonen V, Tuovinen T, Huotari N, Raitamaa L, Helakari H, Väyrynen T, Raatikainen V, Nedergaard M, Ansakorpi H, Jacobs J, LeVan P, Kiviniemi V. Increased interictal synchronicity of respiratory related brain pulsations in epilepsy. J Cereb Blood Flow Metab 2022; 42:1840-1853. [PMID: 35570730 PMCID: PMC9536129 DOI: 10.1177/0271678x221099703] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Respiratory brain pulsations have recently been shown to drive electrophysiological brain activity in patients with epilepsy. Furthermore, functional neuroimaging indicates that respiratory brain pulsations have increased variability and amplitude in patients with epilepsy compared to healthy individuals. To determine whether the respiratory drive is altered in epilepsy, we compared respiratory brain pulsation synchronicity between healthy controls and patients. Whole brain fast functional magnetic resonance imaging was performed on 40 medicated patients with focal epilepsy, 20 drug-naïve patients and 102 healthy controls. Cerebrospinal fluid associated respiratory pulsations were used to generate individual whole brain respiratory synchronization maps, which were compared between groups. Finally, we analyzed the seizure frequency effect and diagnostic accuracy of the respiratory synchronization defect in epilepsy. Respiratory brain pulsations related to the verified fourth ventricle pulsations were significantly more synchronous in patients in frontal, periventricular and mid-temporal regions, while the seizure frequency correlated positively with synchronicity. The respiratory brain synchronicity had a good diagnostic accuracy (ROCAUC = 0.75) in discriminating controls from medicated patients. The elevated respiratory brain synchronicity in focal epilepsy suggests altered physiological effect of cerebrospinal fluid pulsations possibly linked to regional brain water dynamics involved with interictal brain physiology.
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Affiliation(s)
- Janne Kananen
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Matti Järvelä
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Vesa Korhonen
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Timo Tuovinen
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Niko Huotari
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Lauri Raitamaa
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Heta Helakari
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Tommi Väyrynen
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Ville Raatikainen
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY, USA.,Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hanna Ansakorpi
- Medical Research Center (MRC), Oulu, Finland.,Research Unit of Neuroscience, Neurology, University of Oulu, Oulu, Finland.,Department of Neurology, Oulu University Hospital, Oulu, Finland
| | - Julia Jacobs
- Department of Pediatric Neurology and Muscular Disease, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Paediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, Canada.,Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| | - Pierre LeVan
- Department of Paediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, Canada.,Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada.,Department of Radiology, Medical Physics, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Vesa Kiviniemi
- Oulu Functional NeuroImaging (OFNI), Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Medical Imaging, Physics and Technology (MIPT), Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center (MRC), Oulu, Finland
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14
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Vicente-Silva W, Silva-Freitas FR, Beserra-Filho JIA, Cardoso GN, Silva-Martins S, Sarno TA, Silva SP, Soares-Silva B, Dos Santos JR, da Silva RH, Prado CM, Ueno AK, Lago JHG, Ribeiro AM. Sakuranetin exerts anticonvulsant effect in bicuculline-induced seizures. Fundam Clin Pharmacol 2022; 36:663-673. [PMID: 35156229 DOI: 10.1111/fcp.12768] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 01/07/2023]
Abstract
Epilepsy is a chronic neurological disorder characterized by an abnormal, spontaneous, and synchronized neuronal hyperactivity. Therapeutic approaches for controlling epileptic seizures are associated with pharmacoresistance and side effects burden. Previous studies reported that different natural products may have neuroprotector effects. Sakuranetin (SAK) is a flavanone with antiparasitic, anti-inflammatory, antimutagenic, antiallergic, and antioxidant activity. In the present work, the effect of SAK on seizures in a model of status epilepticus induced by bicuculline (BIC) in mice was evaluated. Male Swiss mice received an intracerebroventricular injection (i.c.v.) of SAK (1, 10, or 20 mg/kg-SAK1, SAK10, or SAK20). Firstly, animals were evaluated in the open field (OF; 20 min), afterwards in the elevated plus maze (EPM) test (5 min). Next, 30 min prior the administration of BIC (1 mg/kg), mice received an injection of SAK (1 or 10 mg/kg, i.c.v.) and were observed in the OF (20 min) for seizures assessment. After behavioral procedures, immunohistochemical analysis of c-Fos was performed. Our main results showed that the lowest doses of SAK (1 and 10 mg/kg) increased the total distance traveled in the OF, moreover protected against seizures and death on the BIC-induced seizures model. Furthermore, SAK treatment reduced neuronal activity on the dentate gyrus of the BIC-treated animals. Taken together, our results suggest an anticonvulsant effect of SAK, which could be used for the development of anticonvulsants based on natural products from herbal source.
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Affiliation(s)
- Wilson Vicente-Silva
- Department of Biosciences, Federal University of São Paulo, Santos, São Paulo, Brazil
| | | | | | | | - Suellen Silva-Martins
- Department of Biosciences, Federal University of São Paulo, Santos, São Paulo, Brazil
| | - Tamires Alves Sarno
- Department of Biosciences, Federal University of São Paulo, Santos, São Paulo, Brazil
| | - Sara Pereira Silva
- Department of Biosciences, Federal University of São Paulo, Santos, São Paulo, Brazil
| | - Beatriz Soares-Silva
- Department of Biosciences, Federal University of São Paulo, Santos, São Paulo, Brazil
| | | | - Regina Helena da Silva
- Department of Pharmacology, Federal University of São Paulo, São Paulo, São Paulo, Brazil
| | - Carla Máximo Prado
- Department of Biosciences, Federal University of São Paulo, Santos, São Paulo, Brazil
| | - Anderson Keity Ueno
- Department of Biosciences, Federal University of São Paulo, Diadema, São Paulo, Brazil
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15
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Zhai J, Zhou YY, Lagrutta A. Sensitivity, specificity and limitation of in vitro hippocampal slice and neuron-based assays for assessment of drug-induced seizure liability. Toxicol Appl Pharmacol 2021; 430:115725. [PMID: 34536444 DOI: 10.1016/j.taap.2021.115725] [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: 05/08/2021] [Revised: 09/01/2021] [Accepted: 09/13/2021] [Indexed: 10/20/2022]
Abstract
An effective in vitro screening assay to detect seizure liability in preclinical development can contribute to better lead molecule optimization prior to candidate selection, providing higher throughput and overcoming potential brain exposure limitations in animal studies. This study explored effects of 26 positive and 14 negative reference pharmacological agents acting through different mechanisms, including 18 reference agents acting on glutamate signaling pathways, in a brain slice assay (BSA) of adult rat to define the assay's sensitivity, specificity, and limitations. Evoked population spikes (PS) were recorded from CA1 pyramidal neurons of hippocampus (HPC) in the BSA. Endpoints for analysis were PS area and PS number. Most positive references (24/26) elicited a concentration-dependent increase in PS area and/or PS number. The negative references (14/14) had little effect on the PS. Moreover, we studied the effects of 15 reference agents testing positive in the BSA on spontaneous activity in E18 rat HPC neurons monitored with microelectrode arrays (MEA), and compared these effects to the BSA results. From these in vitro studies we conclude that the BSA provides 93% sensitivity and 100% specificity in prediction of drug-induced seizure liability, including detecting seizurogenicity by 3 groups of metabotropic glutamate receptor (mGluR) ligands. The MEA results seemed more variable, both quantitatively and directionally, particularly for endpoints capturing synchronized electrical activity. We discuss these results from the two models, comparing each with published results, and provide potential explanations for differences and future directions.
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Affiliation(s)
- Jin Zhai
- Department of Genetic Toxicology and In Vitro Cellular Toxicity, Safety Assessment & Laboratory Animal Resources (SALAR), Merck & Co., Inc., West Point, PA 19486, USA.
| | - Ying-Ying Zhou
- Program Discovery and Development, Safety Assessment & Laboratory Animal Resources (SALAR), Merck & Co., Inc., West Point, PA 19486, USA
| | - Armando Lagrutta
- Program Discovery and Development, Safety Assessment & Laboratory Animal Resources (SALAR), Merck & Co., Inc., West Point, PA 19486, USA
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16
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Jeong J, Lee J, Kim JH, Lim C. Metabolic flux from the Krebs cycle to glutamate transmission tunes a neural brake on seizure onset. PLoS Genet 2021; 17:e1009871. [PMID: 34714823 PMCID: PMC8555787 DOI: 10.1371/journal.pgen.1009871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 10/11/2021] [Indexed: 01/18/2023] Open
Abstract
Kohlschütter-Tönz syndrome (KTS) manifests as neurological dysfunctions, including early-onset seizures. Mutations in the citrate transporter SLC13A5 are associated with KTS, yet their underlying mechanisms remain elusive. Here, we report that a Drosophila SLC13A5 homolog, I'm not dead yet (Indy), constitutes a neurometabolic pathway that suppresses seizure. Loss of Indy function in glutamatergic neurons caused "bang-induced" seizure-like behaviors. In fact, glutamate biosynthesis from the citric acid cycle was limiting in Indy mutants for seizure-suppressing glutamate transmission. Oral administration of the rate-limiting α-ketoglutarate in the metabolic pathway rescued low glutamate levels in Indy mutants and ameliorated their seizure-like behaviors. This metabolic control of the seizure susceptibility was mapped to a pair of glutamatergic neurons, reversible by optogenetic controls of their activity, and further relayed onto fan-shaped body neurons via the ionotropic glutamate receptors. Accordingly, our findings reveal a micro-circuit that links neural metabolism to seizure, providing important clues to KTS-associated neurodevelopmental deficits.
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Affiliation(s)
- Jiwon Jeong
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Jongbin Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Ji-hyung Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Chunghun Lim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
- * E-mail:
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17
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O’Hare L, Asher JM, Hibbard PB. Migraine Visual Aura and Cortical Spreading Depression-Linking Mathematical Models to Empirical Evidence. Vision (Basel) 2021; 5:30. [PMID: 34200625 PMCID: PMC8293461 DOI: 10.3390/vision5020030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/15/2021] [Accepted: 05/24/2021] [Indexed: 01/10/2023] Open
Abstract
This review describes the subjective experience of visual aura in migraine, outlines theoretical models of this phenomenon, and explores how these may be linked to neurochemical, electrophysiological, and psychophysical differences in sensory processing that have been reported in migraine with aura. Reaction-diffusion models have been used to model the hallucinations thought to arise from cortical spreading depolarisation and depression in migraine aura. One aim of this review is to make the underlying principles of these models accessible to a general readership. Cortical spreading depolarisation and depression in these models depends on the balance of the diffusion rate between excitation and inhibition and the occurrence of a large spike in activity to initiate spontaneous pattern formation. We review experimental evidence, including recordings of brain activity made during the aura and attack phase, self-reported triggers of migraine, and psychophysical studies of visual processing in migraine with aura, and how these might relate to mechanisms of excitability that make some people susceptible to aura. Increased cortical excitability, increased neural noise, and fluctuations in oscillatory activity across the migraine cycle are all factors that are likely to contribute to the occurrence of migraine aura. There remain many outstanding questions relating to the current limitations of both models and experimental evidence. Nevertheless, reaction-diffusion models, by providing an integrative theoretical framework, support the generation of testable experimental hypotheses to guide future research.
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Affiliation(s)
- Louise O’Hare
- Division of Psychology, Nottingham Trent University, Nottingham NG1 4FQ, UK
| | - Jordi M. Asher
- Department of Psychology, University of Essex, Colchester CO4 3SQ, UK; (J.M.A.); (P.B.H.)
| | - Paul B. Hibbard
- Department of Psychology, University of Essex, Colchester CO4 3SQ, UK; (J.M.A.); (P.B.H.)
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18
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Nicolo JP, Chen Z, Moffat B, Wright DK, Sinclair B, Glarin R, Neal A, Thijs V, Seneviratne U, Yan B, Cloud G, O'Brien TJ, Kwan P. Study protocol for a phase II randomised, double-blind, placebo-controlled trial of perampanel as an antiepileptogenic treatment following acute stroke. BMJ Open 2021; 11:e043488. [PMID: 33972334 PMCID: PMC8112439 DOI: 10.1136/bmjopen-2020-043488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION Stroke is a common cause of epilepsy that may be mediated via glutamate dysregulation. There is currently no evidence to support the use of antiseizure medications as primary prevention against poststroke epilepsy. Perampanel has a unique antiglutamatergic mechanism of action and may have antiepileptogenic properties. This study aims to evaluate the efficacy and safety of perampanel as an antiepileptogenic treatment in patients at high risk of poststroke epilepsy. METHODS AND ANALYSIS Up to 328 patients with cortical ischaemic stroke or lobar haemorrhage will be enrolled, and receive their first treatment within 7 days of stroke onset. Patients will be randomised (1:1) to receive perampanel (titrated to 6 mg daily over 4 weeks) or matching placebo, stratified by stroke subtype (ischaemic or haemorrhagic). Treatment will be continued for 12 weeks after titration. 7T MRI will be performed at baseline for quantification of cerebral glutamate by magnetic resonance spectroscopy and glutamate chemical exchange saturation transfer imaging. Blood will be collected for measurement of plasma glutamate levels. Participants will be followed up for 52 weeks after randomisation.The primary study outcome will be the proportion of participants in each group free of late (more than 7 days after stroke onset) poststroke seizures by the end of the 12-month study period, analysed by Fisher's exact test. Secondary outcomes will include time to first seizure, time to treatment withdrawal and 3-month modified Rankin Scale score. Quality of life, cognitive function, mood and adverse events will be assessed by standardised questionnaires. Exploratory outcomes will include correlation between cerebral and plasma glutamate concentration and stroke and seizure outcomes. ETHICS AND DISSEMINATION This study was approved by the Alfred Health Human Research Ethics Committee (HREC No 44366, Reference 287/18). TRIAL REGISTRATION NUMBER ACTRN12618001984280; Pre-results.
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Affiliation(s)
- John-Paul Nicolo
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
- Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Neuroscience, Monash University Central Clinical School, Melbourne, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Zhibin Chen
- Department of Neuroscience, Monash University Central Clinical School, Melbourne, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Bradford Moffat
- Melbourne Node of the National Imaging Facility, Department of Radiology, University of Melbourne, Parkville, Victoria, Australia
| | - David K Wright
- Department of Neuroscience, Monash University Central Clinical School, Melbourne, Victoria, Australia
| | - Benjamin Sinclair
- Department of Neuroscience, Monash University Central Clinical School, Melbourne, Victoria, Australia
| | - Rebecca Glarin
- Melbourne Node of the National Imaging Facility, Department of Radiology, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew Neal
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
- Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Neuroscience, Monash University Central Clinical School, Melbourne, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Vincent Thijs
- Stroke Division, Florey Institute of Neuroscience and Mental Health-Austin Campus, Heidelberg, Victoria, Australia
- Department of Neurology, Austin Health, Heidelberg, Victoria, Australia
| | - Udaya Seneviratne
- Department of Neuroscience, Monash University, Clayton, Victoria, Australia
- Department of Neurology, Monash Medical Centre, Clayton, Victoria, Australia
| | - Bernard Yan
- Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Geoffrey Cloud
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
- Department of Neuroscience, Monash University Central Clinical School, Melbourne, Victoria, Australia
| | - Terence J O'Brien
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
- Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Neuroscience, Monash University Central Clinical School, Melbourne, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Patrick Kwan
- Department of Neurology, Alfred Hospital, Melbourne, Victoria, Australia
- Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Department of Neuroscience, Monash University Central Clinical School, Melbourne, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
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19
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Bencurova P, Baloun J, Hynst J, Oppelt J, Kubova H, Pospisilova S, Brazdil M. Dynamic miRNA changes during the process of epileptogenesis in an infantile and adult-onset model. Sci Rep 2021; 11:9649. [PMID: 33958654 PMCID: PMC8102630 DOI: 10.1038/s41598-021-89084-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 04/12/2021] [Indexed: 02/03/2023] Open
Abstract
Temporal lobe epilepsy (TLE) is the most common epilepsy type. TLE onset in infancy aggravates features like severity, drug responsiveness, or development of comorbidities. These aggravations may arise from altered micro RNA (miRNA) expression specific to the early onset of the disease. Although the miRNA involvement in TLE is widely studied, the relationship between the onset-age and miRNA expression has not been addressed. Here, we investigated the miRNA profile of infantile and adult-onset TLE in rats combining sequencing and PCR. Since miRNA expression changes with the disease progression, we scrutinized miRNA dynamics across three stages: acute, latent, and chronic. We report that infantile-onset TLE leads to changes in the expression of fewer miRNAs across these stages. Interestingly, the miRNA profile in the acute stage of infantile-onset TLE overlaps in dysregulation of miR-132-5p, -205, and -211-3p with the chronic stage of the disease starting in adulthood. The analysis of putative targets linked the majority of dysregulated miRNAs with pathways involved in epilepsy. Our profiling uncovered miRNA expression characteristic for infantile and adulthood-onset epileptogenesis, suggesting the distinct biology underlying TLE in the onset age-dependent matter. Our results indicate the necessity of addressing the onset age as an important parameter in future epilepsy research.
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Affiliation(s)
- Petra Bencurova
- grid.10267.320000 0001 2194 0956CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic ,grid.412752.70000 0004 0608 7557Brno Epilepsy Center, Department of Neurology, St. Anne’s University Hospital and Medical Faculty of Masaryk University, Pekarska 53, 656 91 Brno, Czech Republic
| | - Jiri Baloun
- grid.10267.320000 0001 2194 0956CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jakub Hynst
- grid.10267.320000 0001 2194 0956CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jan Oppelt
- grid.10267.320000 0001 2194 0956CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic ,grid.25879.310000 0004 1936 8972Department of Pathology and Laboratory Medicine, Division of Neuropathology, Perelman School of Medicine, University of Pennsylvania, 19104-6100 Philadelphia, PA USA
| | - Hana Kubova
- grid.418095.10000 0001 1015 3316Department of Developmental Epileptology, Institute of Physiology, Academy of Sciences Czech Republic, Videnska 1083, 14220 Prague, Czech Republic
| | - Sarka Pospisilova
- grid.10267.320000 0001 2194 0956CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Milan Brazdil
- grid.10267.320000 0001 2194 0956CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic ,grid.412752.70000 0004 0608 7557Brno Epilepsy Center, Department of Neurology, St. Anne’s University Hospital and Medical Faculty of Masaryk University, Pekarska 53, 656 91 Brno, Czech Republic
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20
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Mastrangelo M. Epilepsy in inherited neurotransmitter disorders: Spotlights on pathophysiology and clinical management. Metab Brain Dis 2021; 36:29-43. [PMID: 33095372 DOI: 10.1007/s11011-020-00635-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 10/16/2020] [Indexed: 01/02/2023]
Abstract
Inborn errors of neurotransmitter metabolism are ultrarare disorders affecting neurotransmitter biosynthesis, breakdown or transport or their essential cofactors. Neurotransmitter dysfunctions could also result from the impairment of neuronal receptors, intracellular signaling, vesicle release or other synaptic abnormalities. Epilepsy is the main clinical hallmark in some of these diseases (e.g. disorders of GABA metabolism, glycine encephalopathy) while it is infrequent in others (e.g. all the disorders of monoamine metabolism in exception for dihydropteridine reductase deficiency). This review analyzes the epileptogenic mechanisms, the epilepsy phenotypes and the principle for the clinical management of epilepsy in primary and secondary inherited disorders of neurotransmitter metabolism (disorders of GABA, serine and glycine metabolism, disorders of neurotransmitter receptors and secondary neurotransmitter diseases).
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Affiliation(s)
- Mario Mastrangelo
- Child Neurology and Psychiatry Unit-Department of Human Neuroscience, Sapienza Università di Roma-Umberto I Policlinico di Roma, Via dei Sabelli, 108 - 00141, Roma, Italy.
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21
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The effects of salmon calcitonin on epileptic seizures, epileptogenesis, and postseizure hippocampal neuronal damage in pentylenetetrazole-induced epilepsy model in rats. Epilepsy Behav 2020; 113:107501. [PMID: 33220584 DOI: 10.1016/j.yebeh.2020.107501] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 01/04/2023]
Abstract
Epilepsy is one of the most common neurological disorders that severely affect the life quality of many people worldwide. Excitatory-inhibitory mechanisms, oxidative stress, and also inflammation systems have been implicated in the pathogenesis of epilepsy. Recent studies have shown that salmon calcitonin (sCT) has positive effects on the nervous system. However, its relation with epilepsy is still unclear. This study aimed to investigate the effect of sCT on epileptic seizures, epileptogenesis, and postseizure hippocampal neuronal damage in pentylenetetrazole (PTZ)-induced epilepsy model in rats. The study was performed in two steps. In the first step, the effect of sCT on epileptic seizures was evaluated by using electroencephalography (EEG) in fully kindled rats. In the second step, the effect of sCT on epileptogenesis was evaluated by using the kindling process. Glutamate and gamma-aminobutyric acid (GABA), thiobarbituric acid reactive substance (TBARS), superoxide dismutase (SOD), catalase (CAT), tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1 β), and interleukin 6 (IL-6) were measured in the second group in the brain and serum. Hippocampal regions were stained with hematoxylin-eosin and toluidine blue to evaluate hippocampal neuronal damage histopathologically. Salmon calcitonin showed an antiepileptic effect in fully kindled rats and also prevented the development of epileptogenesis in the kindling process. Besides, sCT decreased glutamate and increased GABA levels. Furthermore, it reduced TBARS levels and increased SOD and CAT levels. On the other hand, it decreased TNF-α levels, IL-1 β levels, and IL-6 levels. Histopathologically, sCT decreased neuronal damage in all hippocampal regions. Our findings are the first preclinical report to show the positive effect of sCT on epileptic seizures and epileptogenesis. Further investigation is required to answer the questions raised about the probable mechanisms involved.
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22
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Huang LG, Luo YH, Xu JW, Lu QC. Plasma Exosomal MiRNAs Expression Profile in Mesial Temporal Lobe Epilepsy With Hippocampal Sclerosis: Case-Control Study and Analysis of Potential Functions. Front Mol Neurosci 2020; 13:584828. [PMID: 33240042 PMCID: PMC7680973 DOI: 10.3389/fnmol.2020.584828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 10/16/2020] [Indexed: 11/13/2022] Open
Abstract
Background To explore an expression profile in plasma exosomal miRNAs of mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE + HS) patients and investigate the associated clinical significance and putative pathways involved. Methods Plasma exosomal miRNAs were measured in six mTLE + HS patients who were confirmed with pre-surgical stereo-electroencephalography and six without hippocampal sclerosis (mTLE−HS) using Illumina HiSeq 2500. Then six dysregulated miRNAs were chosen for validation in an independent sample of 18 mTLE + HS patients and 18 mTLE−HS controls using RT-qPCR. Receiver operating characteristic curve was conducted to evaluate the diagnostic value of miRNAs in HS. Bioinformatic analyses were conducted to reveal in which pathways these miRNAs were involved. Results We revealed that a total of 42 exosomal miRNAs were differentially expressed in mTLE + HS. Among them, 25 were increased and 17 decreased. After validation, hsa-miR-129-5p, -214-3p, -219a-5p, and -34c-5p were confirmed as being upregulated, while hsa-miR-421 and -184 were significantly downregulated in mTLE + HS. Moreover, hsa-miR-184 had the best diagnostic value for discriminating mTLE + HS with 88.9% sensitivity and 83.3% specificity. These six miRNAs regulated several genes from neurotrophin-, hippo-, p53-, TGF- beta-, HIF- 1-, mTOR-related pathways. Conclusion Six miRNAs were dysregulated in mTLE + HS patients and targeted several genes. This result might facilitate pathological mechanistic studies of miRNAs in HS and represent potential diagnostic biomarkers. These provided the rationale for further confirmation studies in larger cohorts of prospective patients.
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Affiliation(s)
- Li-Gang Huang
- Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.,Minhang Hospital, Fudan University, Shanghai, China
| | - Yun-He Luo
- Minhang Hospital, Fudan University, Shanghai, China
| | - Ji-Wen Xu
- School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Qin-Chi Lu
- School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai, China
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23
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Duran J, Brewer MK, Hervera A, Gruart A, Del Rio JA, Delgado-García JM, Guinovart JJ. Lack of Astrocytic Glycogen Alters Synaptic Plasticity but Not Seizure Susceptibility. Mol Neurobiol 2020; 57:4657-4666. [PMID: 32770452 PMCID: PMC7530046 DOI: 10.1007/s12035-020-02055-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/31/2020] [Indexed: 12/18/2022]
Abstract
Brain glycogen is mainly stored in astrocytes. However, recent studies both in vitro and in vivo indicate that glycogen also plays important roles in neurons. By conditional deletion of glycogen synthase (GYS1), we previously developed a mouse model entirely devoid of glycogen in the central nervous system (GYS1Nestin-KO). These mice displayed altered electrophysiological properties in the hippocampus and increased susceptibility to kainate-induced seizures. To understand which of these functions are related to astrocytic glycogen, in the present study, we generated a mouse model in which glycogen synthesis is eliminated specifically in astrocytes (GYS1Gfap-KO). Electrophysiological recordings of awake behaving mice revealed alterations in input/output curves and impaired long-term potentiation, similar, but to a lesser extent, to those obtained with GYS1Nestin-KO mice. Surprisingly, GYS1Gfap-KO mice displayed no change in susceptibility to kainate-induced seizures as determined by fEPSP recordings and video monitoring. These results confirm the importance of astrocytic glycogen in synaptic plasticity.
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Affiliation(s)
- Jordi Duran
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029, Madrid, Spain.
| | - M Kathryn Brewer
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain
| | - Arnau Hervera
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, 08028, Barcelona, Spain
| | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, Seville, Spain
| | - Jose Antonio Del Rio
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain
- Institute of Neurosciences, University of Barcelona, 08028, Barcelona, Spain
| | | | - Joan J Guinovart
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, 08028, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029, Madrid, Spain
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028, Barcelona, Spain
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24
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Popov A, Denisov P, Bychkov M, Brazhe A, Lyukmanova E, Shenkarev Z, Lazareva N, Verkhratsky A, Semyanov A. Caloric restriction triggers morphofunctional remodeling of astrocytes and enhances synaptic plasticity in the mouse hippocampus. Cell Death Dis 2020; 11:208. [PMID: 32231202 PMCID: PMC7105492 DOI: 10.1038/s41419-020-2406-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 11/22/2022]
Abstract
Calorie-restricted (CR) diet has multiple beneficial effects on brain function. Here we report morphological and functional changes in hippocampal astrocytes in 3-months-old mice subjected to 1 month of the diet. Whole-cell patch-clamp recordings were performed in the CA1 stratum (str.) radiatum astrocytes of hippocampal slices. The cells were also loaded with fluorescent dye through the patch pipette. CR did not affect the number of astrocytic branches but increased the volume fraction (VF) of distal perisynaptic astrocytic leaflets. The astrocyte growth did not lead to a decrease in the cell input resistance, which may be attributed to a decrease in astrocyte coupling through the gap junctions. Western blotting revealed a decrease in the expression of Cx43 but not Cx30. Immunocytochemical analysis demonstrated a decrease in the density and size of Cx43 clusters. Cx30 cluster density did not change, while their size increased in the vicinity of astrocytic soma. CR shortened K+ and glutamate transporter currents in astrocytes in response to 5 × 50 Hz Schaffer collateral stimulation. However, no change in the expression of astrocytic glutamate transporter 1 (GLT-1) was observed, while the level of glutamine synthetase (GS) decreased. These findings suggest that enhanced enwrapping of synapses by the astrocytic leaflets reduces glutamate and K+ spillover. Reduced spillover led to a decreased contribution of extrasynaptic N2B containing N-methyl-D-aspartate receptors (NMDARs) to the tail of burst-induced EPSCs. The magnitude of long-term potentiation (LTP) in the glutamatergic CA3–CA1 synapses was significantly enhanced after CR. This enhancement was abolished by N2B-NMDARs antagonist. Our findings suggest that astrocytic morphofunctional remodeling is responsible for enhanced synaptic plasticity, which provides a basis for improved learning and memory reported after CR.
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Affiliation(s)
- Alexander Popov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Pavel Denisov
- University of Nizhny Novgorod, Gagarin Ave. 23, Nizhny Novgorod, 603950, Russia
| | - Maxim Bychkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Alexey Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia.,Faculty of Biology, Moscow State University, Leninskie Gory 1/12, Moscow, 119234, Russia
| | - Ekaterina Lyukmanova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Zakhar Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Natalia Lazareva
- Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya, 19с1, Moscow, 119146, Russia
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK. .,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia. .,Faculty of Biology, Moscow State University, Leninskie Gory 1/12, Moscow, 119234, Russia. .,Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya, 19с1, Moscow, 119146, Russia.
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25
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Nicolo JP, O'Brien TJ, Kwan P. Role of cerebral glutamate in post-stroke epileptogenesis. NEUROIMAGE-CLINICAL 2019; 24:102069. [PMID: 31795040 PMCID: PMC6883323 DOI: 10.1016/j.nicl.2019.102069] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/13/2019] [Accepted: 11/03/2019] [Indexed: 01/17/2023]
Abstract
Stroke is one of the most important causes of acquired epilepsy in the adult population. While factors such as cortical involvement and haemorrhage have been associated with increased seizure risk, the mechanisms underlying the development of epilepsy after stroke remain unclear. One hypothesised mechanism is an excitotoxic effect of abnormal glutamate release following a stroke. Cerebral extracellular glutamate levels are known to rise in the setting of acute stroke, and numerous studies have implicated glutamate in the pathogenesis of seizures and epilepsy, both through direct measurement of glutamate from the epileptic brain and by analysis of receptors and transporters central to glutamate homeostasis. While experimental evidence suggests the cellular injury induced by glutamate exposure may lead to development of an epileptic phenotype, there is little direct data linking the rise in glutamate during stroke with the later development of epilepsy. Clinical research in this field has been hampered by the lack of non-invasive methods to measure cerebral glutamate. However, with the increasing availability of 7T MRI technology, Magnetic Resonance Spectroscopy is able to better resolve glutamate from other chemical species at this field strength, and Glutamate Chemical Exchange Saturation Transfer (GluCEST) imaging has been applied to localise epileptic foci in non-lesional focal epilepsy. This review outlines the evidence implicating a pivotal role for cerebral glutamate in the development of post-stroke epilepsy, and exploring the role of MRI in studying glutamate as a biomarker and therefore its suitability as a molecular target for anti-epileptogenic therapies. We hypothesise that the rise in glutamate levels in the setting of acute stroke is a clinically relevant biomarker for the development of post-stroke epilepsy.
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Affiliation(s)
- John-Paul Nicolo
- Department of Neurology, Royal Melbourne Hospital, 300 Grattan Street Parkville Victoria Australia; Department of Neurology, Alfred Hospital, 55 Commercial Road, Melbourne Victoria Australia.
| | - Terence J O'Brien
- Department of Neuroscience, Monash University, Alfred Hospital, 55 Commercial Road, Melbourne Victoria Australia; Department of Medicine (The Royal Melbourne Hospital), The University of Melbourne, Royal Parade, Parkville Victoria Australia.
| | - Patrick Kwan
- Department of Neurology, Royal Melbourne Hospital, 300 Grattan Street Parkville Victoria Australia; Department of Neuroscience, Monash University, Alfred Hospital, 55 Commercial Road, Melbourne Victoria Australia.
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26
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De Caro C, Iannone LF, Citraro R, Striano P, De Sarro G, Constanti A, Cryan JF, Russo E. Can we 'seize' the gut microbiota to treat epilepsy? Neurosci Biobehav Rev 2019; 107:750-764. [PMID: 31626816 DOI: 10.1016/j.neubiorev.2019.10.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 02/08/2023]
Abstract
The gut-microbiota, the complex intestinal microbial ecosystem essential to health, is an emerging concept in medicine. Several studies demonstrate a microbiota-gut-brain bidirectional connection via neural, endocrine, metabolic and immune pathways. Accordingly, the gut microbiota has a crucial role in modulating intestinal permeability, to alter local/peripheral immune responses and in production of essential metabolites and neurotransmitters. Its alterations may consequently influence all these pathways that contribute to neuronal hyper-excitability and mirrored neuroinflammation in epilepsy and similarly other neurological conditions. Indeed, pre- and clinical studies support the role of the microbiome in pathogenesis, seizure modulation and responses to treatment in epilepsy. Up to now, researchers have focussed attention above all on the brain to develop antiepileptic treatments, but considering the microbiome, could extend our possibilities for developing novel therapies in the future. We provide here a comprehensive overview of the available data on the potential role of gut microbiota in the physiopathology and therapy of epilepsy and the supposed underlying mechanisms.
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Affiliation(s)
- Carmen De Caro
- Science of Health Department, School of Medicine, University Magna Graecia, Catanzaro, Italy
| | - Luigi Francesco Iannone
- Science of Health Department, School of Medicine, University Magna Graecia, Catanzaro, Italy
| | - Rita Citraro
- Science of Health Department, School of Medicine, University Magna Graecia, Catanzaro, Italy
| | - Pasquale Striano
- Paediatric Neurology and Muscular Diseases Unit, DINOGMI-Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, IRCCS "G. Gaslini" Institute, Genova, Italy
| | - Giovambattista De Sarro
- Science of Health Department, School of Medicine, University Magna Graecia, Catanzaro, Italy
| | - Andrew Constanti
- Department of Pharmacology, UCL School of Pharmacy, 29/39 Brunswick Square, London, United Kingdom
| | - John F Cryan
- UK.APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Emilio Russo
- Science of Health Department, School of Medicine, University Magna Graecia, Catanzaro, Italy.
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27
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Aygun H, Ayyildiz M, Agar E. Effects of vitamin D and paricalcitol on epileptogenesis and behavioral properties of WAG/Rij rats with absence epilepsy. Epilepsy Res 2019; 157:106208. [PMID: 31581040 DOI: 10.1016/j.eplepsyres.2019.106208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/10/2019] [Accepted: 09/14/2019] [Indexed: 10/26/2022]
Abstract
AIM Vitamin D (Vit D) has been considered as a neurosteroid and has a pivotal role in neuroprotection including epilepsy. Vit D regulator acts via a Vit D receptor (VDR). WAG/Rij rats have a genetically epileptic model of absence epilepsy with comorbidity of depression. The aim of the present study was to investigate the effect of Vit D and paricalcitol (PRC) on WAG/Rij rats. MATERIAL AND METHODS Sixty-three male WAG/Rij rats and seven male Wistar rats were used. The effects of acute and chronic treatment with Vit D (5.000 and 60.000 IU/kg, i.p) and PRC (0.5, 5 and 10 μg/kg, i.p) on absence seizures, and related psychiatric comorbidity were investigated in WAG/Rij rats. Depression-like behavior was assayed by using the forced swimming test (FST) and; anxiety-like behavior by using the open field test (OFT). RESULTS Acute Vit D treatments (5.000 and 60.000 IU/kg) similarly reduced the number and duration of spike-wave discharges (SWDs) and showed anxiolytic-antidepressive effect whereas there were no significant changes in other measured parameters between the daily and the bolus dose of Vit D. Acute administration of PRC (0.5, 5 and 10 μg/kg) showed anti-convulsive and anxiolytic-antidepressive effect. The dose (0.5 μg/kg) of PRC was the most effective dose. Chronic treatment was more effective than acute therapy in all parameters. CONCLUSION The results of the present study demonstrate that Vit D and PRC have antiepileptic and anxiolytic-antidepressive effects on the absence epilepsy in WAG/Rij rats.
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Affiliation(s)
- Hatice Aygun
- Department of Physiology, Faculty of Medicine, University of Tokat Gaziosmanpasa, Tokat, Turkey.
| | - Mustafa Ayyildiz
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
| | - Erdal Agar
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
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28
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Kuhlmann L, Lehnertz K, Richardson MP, Schelter B, Zaveri HP. Seizure prediction - ready for a new era. Nat Rev Neurol 2019; 14:618-630. [PMID: 30131521 DOI: 10.1038/s41582-018-0055-2] [Citation(s) in RCA: 191] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Epilepsy is a common disorder characterized by recurrent seizures. An overwhelming majority of people with epilepsy regard the unpredictability of seizures as a major issue. More than 30 years of international effort have been devoted to the prediction of seizures, aiming to remove the burden of unpredictability and to couple novel, time-specific treatment to seizure prediction technology. A highly influential review published in 2007 concluded that insufficient evidence indicated that seizures could be predicted. Since then, several advances have been made, including successful prospective seizure prediction using intracranial EEG in a small number of people in a trial of a real-time seizure prediction device. In this Review, we examine advances in the field, including EEG databases, seizure prediction competitions, the prospective trial mentioned and advances in our understanding of the mechanisms of seizures. We argue that these advances, together with statistical evaluations, set the stage for a resurgence in efforts towards the development of seizure prediction methodologies. We propose new avenues of investigation involving a synergy between mechanisms, models, data, devices and algorithms and refine the existing guidelines for the development of seizure prediction technology to instigate development of a solution that removes the burden of the unpredictability of seizures.
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Affiliation(s)
- Levin Kuhlmann
- Centre for Human Psychopharmacology, Swinburne University of Technology, Melbourne, Victoria, Australia.,Department of Medicine - St. Vincent's, The University of Melbourne, Parkville, Victoria, Australia.,Department of Biomedical Engineering, The University of Melbourne, Parkville, Victoria, Australia
| | - Klaus Lehnertz
- Department of Epileptology, University of Bonn, Bonn, Germany. .,Interdisciplinary Center for Complex Systems, University of Bonn, Bonn, Germany.
| | - Mark P Richardson
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Björn Schelter
- Institute for Complex Systems and Mathematical Biology, University of Aberdeen, Aberdeen, UK
| | - Hitten P Zaveri
- Department of Neurology, Yale University, New Haven, CT, USA
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29
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Héja L, Simon Á, Szabó Z, Kardos J. Feedback adaptation of synaptic excitability via Glu:Na + symport driven astrocytic GABA and Gln release. Neuropharmacology 2019; 161:107629. [PMID: 31103619 DOI: 10.1016/j.neuropharm.2019.05.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/30/2019] [Accepted: 05/07/2019] [Indexed: 02/08/2023]
Abstract
Glutamatergic transmission composed of the arriving of action potential at the axon terminal, fast vesicular Glu release, postsynaptic Glu receptor activation, astrocytic Glu clearance and Glu→Gln shuttle is an abundantly investigated phenomenon. Despite its essential role, however, much less is known about the consequences of the mechanistic connotations of Glu:Na+ symport. Due to the coupled Na+ transport, Glu uptake results in significantly elevated intracellular astrocytic [Na+] that markedly alters the driving force of other Na+-coupled astrocytic transporters. The resulting GABA and Gln release by reverse transport through the respective GAT-3 and SNAT3 transporters help to re-establish the physiological Na+ homeostasis without ATP dissipation and consequently leads to enhanced tonic inhibition and replenishment of axonal glutamate pool. Here, we place this emerging astrocytic adjustment of synaptic excitability into the centre of future perspectives. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.
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Affiliation(s)
- László Héja
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| | - Ágnes Simon
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| | - Zsolt Szabó
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
| | - Julianna Kardos
- Functional Pharmacology Research Group, Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary.
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30
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Reuschlein AK, Jakobsen E, Mertz C, Bak LK. Aspects of astrocytic cAMP signaling with an emphasis on the putative power of compartmentalized signals in health and disease. Glia 2019; 67:1625-1636. [PMID: 31033018 DOI: 10.1002/glia.23622] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/29/2019] [Accepted: 03/29/2019] [Indexed: 12/17/2022]
Abstract
This review discusses aspects of known and putative compartmentalized 3',5'-cyclic adenosine monophosphate (cAMP) signaling in astrocytes, a cell type that has turned out to be a key player in brain physiology and pathology. cAMP has attracted less attention than Ca2+ in recent years, but could turn out to rival Ca2+ in its potential to drive cellular functions and responses to intra- and extracellular cues. Further, Ca2+ and cAMP are known to engage in extensive crosstalk and cAMP signals often take place within subcellular compartments revolving around multi-protein signaling complexes; however, we know surprisingly little about this in astrocytes. Here, we review aspects of astrocytic cAMP signaling, provide arguments for an increased interest in this subject, suggest possible future research directions within the field, and discuss putative drug targets.
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Affiliation(s)
- Ann-Kathrin Reuschlein
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil Jakobsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christoffer Mertz
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lasse K Bak
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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31
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Colombo MA, Napolitani M, Boly M, Gosseries O, Casarotto S, Rosanova M, Brichant JF, Boveroux P, Rex S, Laureys S, Massimini M, Chieregato A, Sarasso S. The spectral exponent of the resting EEG indexes the presence of consciousness during unresponsiveness induced by propofol, xenon, and ketamine. Neuroimage 2019; 189:631-644. [DOI: 10.1016/j.neuroimage.2019.01.024] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/20/2018] [Accepted: 01/09/2019] [Indexed: 11/17/2022] Open
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32
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Rubio-Villena C, Viana R, Bonet J, Garcia-Gimeno MA, Casado M, Heredia M, Sanz P. Astrocytes: new players in progressive myoclonus epilepsy of Lafora type. Hum Mol Genet 2019; 27:1290-1300. [PMID: 29408991 DOI: 10.1093/hmg/ddy044] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 01/30/2018] [Indexed: 12/16/2022] Open
Abstract
Lafora disease (LD) is a fatal form of progressive myoclonus epilepsy characterized by the accumulation of insoluble poorly branched glycogen-like inclusions named Lafora bodies (LBs) in the brain and peripheral tissues. In the brain, since its first discovery in 1911, it was assumed that these glycogen inclusions were only present in affected neurons. Mouse models of LD have been obtained recently, and we and others have been able to report the accumulation of glycogen inclusions in the brain of LD animals, what recapitulates the hallmark of the disease. In this work we present evidence indicating that, although in mouse models of LD glycogen inclusions co-localize with neurons, as originally established, most of them co-localize with astrocytic markers such as glial fibrillary acidic protein (GFAP) and glutamine synthase. In addition, we have observed that primary cultures of astrocytes from LD mouse models accumulate higher levels of glycogen than controls. These results suggest that astrocytes may play a crucial role in the pathophysiology of Lafora disease, as the accumulation of glycogen inclusions in these cells may affect their regular functionality leading them to a possible neuronal dysfunction.
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Affiliation(s)
- Carla Rubio-Villena
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (IBV-CSIC), Valencia, Spain
| | - Rosa Viana
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (IBV-CSIC), Valencia, Spain
| | - Jose Bonet
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (IBV-CSIC), Valencia, Spain
| | | | - Marta Casado
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (IBV-CSIC), Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), (Group CB06/04/1069) Madrid, Spain
| | - Miguel Heredia
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), (Group U742) Valencia, Spain
| | - Pascual Sanz
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (IBV-CSIC), Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), (Group U742) Valencia, Spain
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33
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DiNuzzo M, Walls AB, Öz G, Seaquist ER, Waagepetersen HS, Bak LK, Nedergaard M, Schousboe A. State-Dependent Changes in Brain Glycogen Metabolism. ADVANCES IN NEUROBIOLOGY 2019; 23:269-309. [PMID: 31667812 DOI: 10.1007/978-3-030-27480-1_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A fundamental understanding of glycogen structure, concentration, polydispersity and turnover is critical to qualify the role of glycogen in the brain. These molecular and metabolic features are under the control of neuronal activity through the interdependent action of neuromodulatory tone, ionic homeostasis and availability of metabolic substrates, all variables that concur to define the state of the system. In this chapter, we briefly describe how glycogen responds to selected behavioral, nutritional, environmental, hormonal, developmental and pathological conditions. We argue that interpreting glycogen metabolism through the lens of brain state is an effective approach to establish the relevance of energetics in connecting molecular and cellular neurophysiology to behavior.
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Affiliation(s)
- Mauro DiNuzzo
- Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Anne B Walls
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gülin Öz
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA
| | | | - Helle S Waagepetersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lasse K Bak
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maiken Nedergaard
- Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Center for Translational Neuromedicine, University of Rochester Medical School, Rochester, NY, USA
| | - Arne Schousboe
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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34
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Rothman DL, Dienel GA. Development of a Model to Test Whether Glycogenolysis Can Support Astrocytic Energy Demands of Na +, K +-ATPase and Glutamate-Glutamine Cycling, Sparing an Equivalent Amount of Glucose for Neurons. ADVANCES IN NEUROBIOLOGY 2019; 23:385-433. [PMID: 31667817 DOI: 10.1007/978-3-030-27480-1_14] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent studies of glycogen in brain have suggested a much more important role in brain energy metabolism and function than previously recognized, including findings of much higher than previously recognized concentrations, consumption at substantial rates compared with utilization of blood-borne glucose, and involvement in ion pumping and in neurotransmission and memory. However, it remains unclear how glycogenolysis is coupled to neuronal activity and provides support for neuronal as well as astroglial function. At present, quantitative aspects of glycogenolysis in brain functions are very difficult to assess due to its metabolic lability, heterogeneous distributions within and among cells, and extreme sensitivity to physiological stimuli. To begin to address this problem, the present study develops a model based on pathway fluxes, mass balance, and literature relevant to functions and turnover of pathways that intersect with glycogen mobilization. A series of equations is developed to describe the stoichiometric relationships between net glycogen consumption that is predominantly in astrocytes with the rate of the glutamate-glutamine cycle, rates of astrocytic and neuronal glycolytic and oxidative metabolism, and the energetics of sodium/potassium pumping in astrocytes and neurons during brain activation. Literature supporting the assumptions of the model is discussed in detail. The overall conclusion is that astrocyte glycogen metabolism is primarily coupled to neuronal function via fueling glycolytically pumping of Na+ and K+ and sparing glucose for neuronal oxidation, as opposed to previous proposals of coupling neurotransmission via glutamate transport, lactate shuttling, and neuronal oxidation of lactate.
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Affiliation(s)
- Douglas L Rothman
- Magnetic Resonance Research Center and Department of Radiology, Yale University, New Haven, CT, USA.
| | - Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.,Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, USA
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35
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Balakrishnan S, Mironov SL. Regenerative glutamate release in the hippocampus of Rett syndrome model mice. PLoS One 2018; 13:e0202802. [PMID: 30256804 PMCID: PMC6157837 DOI: 10.1371/journal.pone.0202802] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 08/09/2018] [Indexed: 11/18/2022] Open
Abstract
Excess glutamate during intense neuronal activity is not instantly cleared and may accumulate in the extracellular space. This has various long-term consequences such as ectopic signaling, modulation of synaptic efficacy and excitotoxicity; the latter implicated in various neurodevelopmental and neurodegenerative diseases. In this study, the quantitative imaging of glutamate homeostasis of hippocampal slices from methyl-CpG binding protein 2 knock-out (Mecp2-/y) mice, a model of Rett syndrome (RTT), revealed unusual repetitive glutamate transients. They appeared in phase with bursts of action potentials in the CA1 neurons. Both glutamate transients and bursting activity were suppressed by the blockade of sodium, AMPA and voltage-gated calcium channels (T- and R-type), and enhanced after the inhibition of HCN channels. HCN and calcium channels in RTT and wild-type (WT) CA1 neurons displayed different voltage-dependencies and kinetics. Both channels modulated postsynaptic integration and modified the pattern of glutamate spikes in the RTT hippocampus. Spontaneous glutamate transients were much less abundant in the WT preparations, and, when observed, had smaller amplitude and frequency. The basal ambient glutamate levels in RTT were higher and transient glutamate increases (spontaneous and evoked by stimulation of Schaffer collaterals) decayed slower. Both features indicate less efficient glutamate uptake in RTT. To explain the generation of repetitive glutamate spikes, we designed a novel model of glutamate-induced glutamate release. The simulations correctly predicted the patterns of spontaneous glutamate spikes observed under different experimental conditions. We propose that pervasive spontaneous glutamate release is a hallmark of Mecp2-/y hippocampus, stemming from and modulating the hyperexcitability of neurons.
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Affiliation(s)
- Saju Balakrishnan
- CNMPB (Centre for Nanoscale Microscopy and Molecular Physiology of the Brain, DFG Research Center 103), Institute of Neuro and Sensory Physiology, Georg-August-University, Göttingen, Germany
| | - Sergej L. Mironov
- CNMPB (Centre for Nanoscale Microscopy and Molecular Physiology of the Brain, DFG Research Center 103), Institute of Neuro and Sensory Physiology, Georg-August-University, Göttingen, Germany
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36
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Plata A, Lebedeva A, Denisov P, Nosova O, Postnikova TY, Pimashkin A, Brazhe A, Zaitsev AV, Rusakov DA, Semyanov A. Astrocytic Atrophy Following Status Epilepticus Parallels Reduced Ca 2+ Activity and Impaired Synaptic Plasticity in the Rat Hippocampus. Front Mol Neurosci 2018; 11:215. [PMID: 29997475 PMCID: PMC6028739 DOI: 10.3389/fnmol.2018.00215] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/30/2018] [Indexed: 11/13/2022] Open
Abstract
Epilepsy is a group of neurological disorders commonly associated with the neuronal malfunction leading to generation of seizures. Recent reports point to a possible contribution of astrocytes into this pathology. We used the lithium-pilocarpine model of status epilepticus (SE) in rats to monitor changes in astrocytes. Experiments were performed in acute hippocampal slices 2-4 weeks after SE induction. Nissl staining revealed significant neurodegeneration in the pyramidal cell layers of hippocampal CA1, CA3 areas, and the hilus, but not in the granular cell layer of the dentate gyrus. A significant increase in the density of astrocytes stained with an astrocyte-specific marker, sulforhodamine 101, was observed in CA1 stratum (str.) radiatum. Astrocytes in this area were also whole-cell loaded with a morphological tracer, Alexa Fluor 594, for two-photon excitation imaging. Sholl analyses showed no changes in the size of the astrocytic domain or in the number of primary astrocytic branches, but a significant reduction in the number of distal branches that are resolved with diffraction-limited light microscopy (and are thought to contain Ca2+ stores, such as mitochondria and endoplasmic reticulum). The atrophy of astrocytic branches correlated with the reduced size, but not overall frequency of Ca2+ events. The volume tissue fraction of nanoscopic (beyond the diffraction limit) astrocytic leaflets showed no difference between control and SE animals. The results of spatial entropy-complexity spectrum analysis were also consistent with changes in ratio of astrocytic branches vs. leaflets. In addition, we observed uncoupling of astrocytes through the gap-junctions, which was suggested as a mechanism for reduced K+ buffering. However, no significant difference in time-course of synaptically induced K+ currents in patch-clamped astrocytes argued against possible alterations in K+ clearance by astrocytes. The magnitude of long-term-potentiation (LTP) was reduced after SE. Exogenous D-serine, a co-agonist of NMDA receptors, has rescued the initial phase of LTP. This suggests that the reduced Ca2+-dependent release of D-serine by astrocytes impairs initiation of synaptic plasticity. However, it does not explain the failure of LTP maintenance which may be responsible for cognitive decline associated with epilepsy.
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Affiliation(s)
- Alex Plata
- UNN Institute of Neuroscience, N. I. Lobachevsky State University of Nizhny Novgorod, University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Albina Lebedeva
- UNN Institute of Neuroscience, N. I. Lobachevsky State University of Nizhny Novgorod, University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Pavel Denisov
- UNN Institute of Neuroscience, N. I. Lobachevsky State University of Nizhny Novgorod, University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Olga Nosova
- UNN Institute of Neuroscience, N. I. Lobachevsky State University of Nizhny Novgorod, University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Tatiana Y. Postnikova
- Laboratory of Molecular Mechanisms of Neural Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
- Department of Medical Physics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Alexey Pimashkin
- UNN Institute of Neuroscience, N. I. Lobachevsky State University of Nizhny Novgorod, University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Alexey Brazhe
- Department of Biophysics, Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Aleksey V. Zaitsev
- Laboratory of Molecular Mechanisms of Neural Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, St. Petersburg, Russia
| | - Dmitri A. Rusakov
- UNN Institute of Neuroscience, N. I. Lobachevsky State University of Nizhny Novgorod, University of Nizhny Novgorod, Nizhny Novgorod, Russia
- UCL Institute of Neurology, University College London, London, United Kingdom
| | - Alexey Semyanov
- UNN Institute of Neuroscience, N. I. Lobachevsky State University of Nizhny Novgorod, University of Nizhny Novgorod, Nizhny Novgorod, Russia
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- All-Russian Research Institute of Medicinal and Aromatic Plants, Moscow, Russia
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37
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Fonseca BM, Cristóvão AC, Alves G. An easy-to-use liquid chromatography method with fluorescence detection for the simultaneous determination of five neuroactive amino acids in different regions of rat brain. J Pharmacol Toxicol Methods 2018; 91:72-79. [DOI: 10.1016/j.vascn.2018.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/27/2018] [Accepted: 02/02/2018] [Indexed: 11/17/2022]
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38
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Glucagon-like Peptide-1 (GLP-1) and neurotransmitters signaling in epilepsy: An insight review. Neuropharmacology 2017; 136:271-279. [PMID: 29129776 DOI: 10.1016/j.neuropharm.2017.11.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 11/07/2017] [Accepted: 11/08/2017] [Indexed: 12/16/2022]
Abstract
Epilepsy is one of the most prevalent neurological disorder affecting more than 50 million people worldwide. Numerous studies have suggested that an imbalance in glutamatergic (excitatory) and GABAergic (inhibitory) neurotransmitter system is one of the dominating pathophysiological mechanisms underlying the occurrence and progression of seizures. Further, this alteration in GABAergic and glutamatergic system disrupts the delicate balance of other neurotransmitters system in the brain. Emerging strides have documented the protective role of GLP-1 signaling on altered neurotransmitters signaling in Epilepsy and associated co-morbidities. GLP-1 is neuropeptide and synthesized by preproglucagon (PPG) neurons in the brain. GLP-1 receptors are widely distributed throughout the brain including hippocampus (CA3 and CA1 region) and implicated in various neurological disorders like Epilepsy. A complete understanding of alteration in neurotransmitters signaling will provide essential insight into the basic pathogenic mechanisms of epilepsy and may uncover novel targets for future drug therapies. Presently, treatment of epilepsy is palliative in nature, providing only symptomatic relief to patients. The apparent or traditional approach of treating epileptic subjects with anti-epileptic drugs is associated with variety of adverse effects. Therefore, alternative approaches that can restore altered neurotransmitter signaling are being tried and adopted. Present review is an attempt to highlight the emerging protective role of GLP-1 signaling on altered neurotransmitters signaling in epilepsy. Authors have made significant efforts to discuss effect of various GLP-1 analogs on various neurotransmitters system and associated molecular and cellular pathways as a potential drug target for the management of epilepsy and associated co-morbidities. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'
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39
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Bazzigaluppi P, Ebrahim Amini A, Weisspapir I, Stefanovic B, Carlen PL. Hungry Neurons: Metabolic Insights on Seizure Dynamics. Int J Mol Sci 2017; 18:ijms18112269. [PMID: 29143800 PMCID: PMC5713239 DOI: 10.3390/ijms18112269] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 10/24/2017] [Accepted: 10/26/2017] [Indexed: 12/18/2022] Open
Abstract
Epilepsy afflicts up to 1.6% of the population and the mechanisms underlying the appearance of seizures are still not understood. In past years, many efforts have been spent trying to understand the mechanisms underlying the excessive and synchronous firing of neurons. Traditionally, attention was pointed towards synaptic (dys)function and extracellular ionic species (dys)regulation. Recently, novel clinical and preclinical studies explored the role of brain metabolism (i.e., glucose utilization) of seizures pathophysiology revealing (in most cases) reduced metabolism in the inter-ictal period and increased metabolism in the seconds preceding and during the appearance of seizures. In the present review, we summarize the clinical and preclinical observations showing metabolic dysregulation during epileptogenesis, seizure initiation, and termination, and in the inter-ictal period. Recent preclinical studies have shown that 2-Deoxyglucose (2-DG, a glycolysis blocker) is a novel therapeutic approach to reduce seizures. Furthermore, we present initial evidence for the effectiveness of 2-DG in arresting 4-Aminopyridine induced neocortical seizures in vivo in the mouse.
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Affiliation(s)
- Paolo Bazzigaluppi
- Krembil Research Institute, Fundamental Neurobiology, Toronto, ON M5T 2S8, Canada.
- Sunnybrook Research Institute, Medical Biophysics, Toronto, ON M4N 3M5, Canada.
| | - Azin Ebrahim Amini
- Krembil Research Institute, Fundamental Neurobiology, Toronto, ON M5T 2S8, Canada.
- Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, ON M5S 3G9, Canada.
| | - Iliya Weisspapir
- Krembil Research Institute, Fundamental Neurobiology, Toronto, ON M5T 2S8, Canada.
| | - Bojana Stefanovic
- Sunnybrook Research Institute, Medical Biophysics, Toronto, ON M4N 3M5, Canada.
| | - Peter L Carlen
- Krembil Research Institute, Fundamental Neurobiology, Toronto, ON M5T 2S8, Canada.
- Department of Medicine & Physiology, and Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, ON M5S 1A8, Canada.
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40
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Pannexin-1 channels in epilepsy. Neurosci Lett 2017; 695:71-75. [PMID: 28886985 DOI: 10.1016/j.neulet.2017.09.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 07/20/2017] [Accepted: 09/01/2017] [Indexed: 02/07/2023]
Abstract
Pannexin-1 (Panx1) expression is raised in several animal seizure models and in resected human epileptic brain tissue, suggesting relevance to epilepsy. Multiple factors that are characteristic of seizures are thought to regulate Panx1 channel opening, including elevated levels of extracellular K+. Panx1, when open, 1) releases ATP, glutamate, and other metabolites into the extracellular medium, and 2) may depolarize the membrane due to a channel reversal potential around 0mV. Resultant ATP release from stimulated Panx1 can activate purinergic receptors, including P2X7 receptors. Glutamate and other signaling molecules released by Panx1 opening may have both excitatory and inhibitory actions on seizure generation. This review examines the critical and complex roles of Panx1 channels in epilepsy, which could provide a basis for future therapeutics.
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41
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Bencurova P, Baloun J, Musilova K, Radova L, Tichy B, Pail M, Zeman M, Brichtova E, Hermanova M, Pospisilova S, Mraz M, Brazdil M. MicroRNA and mesial temporal lobe epilepsy with hippocampal sclerosis: Whole miRNome profiling of human hippocampus. Epilepsia 2017; 58:1782-1793. [PMID: 28815576 DOI: 10.1111/epi.13870] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2017] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Mesial temporal lobe epilepsy (mTLE) is a severe neurological disorder characterized by recurrent seizures. mTLE is frequently accompanied by neurodegeneration in the hippocampus resulting in hippocampal sclerosis (HS), the most common morphological correlate of drug resistance in mTLE patients. Incomplete knowledge of pathological changes in mTLE+HS complicates its therapy. The pathological mechanism underlying mTLE+HS may involve abnormal gene expression regulation, including posttranscriptional networks involving microRNAs (miRNAs). miRNA expression deregulation has been reported in various disorders, including epilepsy. However, the miRNA profile of mTLE+HS is not completely known and needs to be addressed. METHODS Here, we have focused on hippocampal miRNA profiling in 33 mTLE+HS patients and nine postmortem controls to reveal abnormally expressed miRNAs. In this study, we significantly reduced technology-related bias (the most common source of false positivity in miRNA profiling data) by combining two different miRNA profiling methods, namely next generation sequencing and miRNA-specific quantitative real-time polymerase chain reaction. RESULTS These methods combined have identified and validated 20 miRNAs with altered expression in the human epileptic hippocampus; 19 miRNAs were up-regulated and one down-regulated in mTLE+HS patients. Nine of these miRNAs have not been previously associated with epilepsy, and 19 aberrantly expressed miRNAs potentially regulate the targets and pathways linked with epilepsy (such as potassium channels, γ-aminobutyric acid, neurotrophin signaling, and axon guidance). SIGNIFICANCE This study extends current knowledge of miRNA-mediated gene expression regulation in mTLE+HS by identifying miRNAs with altered expression in mTLE+HS, including nine novel abnormally expressed miRNAs and their putative targets. These observations further encourage the potential of microRNA-based biomarkers or therapies.
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Affiliation(s)
- Petra Bencurova
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic.,Department of Neurology, Brno Epilepsy Center, St. Anne's University Hospital, Brno, Czech Republic.,Medical Faculty of Masaryk University, Brno, Czech Republic
| | - Jiri Baloun
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic.,Department of Neurology, Brno Epilepsy Center, St. Anne's University Hospital, Brno, Czech Republic.,Medical Faculty of Masaryk University, Brno, Czech Republic
| | - Katerina Musilova
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic.,Medical Faculty of Masaryk University, Brno, Czech Republic
| | - Lenka Radova
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Boris Tichy
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Martin Pail
- Department of Neurology, Brno Epilepsy Center, St. Anne's University Hospital, Brno, Czech Republic.,Medical Faculty of Masaryk University, Brno, Czech Republic
| | - Martin Zeman
- Medical Faculty of Masaryk University, Brno, Czech Republic.,Department of Forensic Medicine, St. Anne's University Hospital, Brno, Czech Republic
| | - Eva Brichtova
- Medical Faculty of Masaryk University, Brno, Czech Republic.,Department of Neurosurgery, St. Anne's University Hospital, Brno, Czech Republic
| | - Marketa Hermanova
- Medical Faculty of Masaryk University, Brno, Czech Republic.,First Department of Pathological Anatomy, St. Anne's University Hospital, Brno, Czech Republic
| | - Sarka Pospisilova
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Marek Mraz
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Milan Brazdil
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic.,Department of Neurology, Brno Epilepsy Center, St. Anne's University Hospital, Brno, Czech Republic.,Medical Faculty of Masaryk University, Brno, Czech Republic
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42
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Li X, Zhang HJ, Wang Q, Zhang DW, Wu D, Li W, Quan ZS. Current Study of the Mechanism of Action of the Potential Anti-Epileptic Agent Q808. Molecules 2017; 22:molecules22071134. [PMID: 28686214 PMCID: PMC6152255 DOI: 10.3390/molecules22071134] [Citation(s) in RCA: 4] [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: 05/23/2017] [Accepted: 07/01/2017] [Indexed: 11/23/2022] Open
Abstract
Our previous study showed that the anticonvulsant Q808 might be effective against seizures induced by maximal electroshock, pentylenetetrazole (PTZ), isoniazid (ISO), thiosemicarbazide (THIO), and 3-mercaptopropionic acid (3-MP). In the present study, we explored the possible mechanism of action of Q808. Results obtained with high-performance liquid chromatography (HPLC) suggest that Q808 may affect neurotransmitter content in the brain, by specifically increasing GABA content in the rat hippocampus at doses of 40 mg/kg and 80 mg/kg, and by reducing the content of glutamate and glutamine in the rat thalamus at a dose of 80 mg/kg. Intriguingly, there were no changes in the neurotransmitter content in the cortex in response to Q808. In vitro brain slice electrophysiological studies showed that 10−5 M Q808 enhanced the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) in corn cells of the CA1 area of the hippocampus, and had no effect on the amplitude of sIPSCs, the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs), or γ-aminobutyric acid (GABA) receptor-mediated currents in primary cultured hippocampal neurons. These findings suggest that the antiepileptic activity of Q808 may be due to its ability to increase the amount of GABA between synapses, without affecting the function of GABA receptors.
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Affiliation(s)
- Xiang Li
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Sciences, Jilin University, No. 2699 Qianjin Street, Changchun 130012, China.
| | - Hong-Jian Zhang
- Key Laboratory of Natural Resources and Functional Molecules of the Changbai Mountain, Affiliated Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, China.
| | - Qing Wang
- Academy of Chinese Medical Sciences of Jilin Province, Changchun 130012, China.
| | - Dian-Wen Zhang
- Academy of Chinese Medical Sciences of Jilin Province, Changchun 130012, China.
| | - Di Wu
- Academy of Chinese Medical Sciences of Jilin Province, Changchun 130012, China.
| | - Wei Li
- Academy of Chinese Medical Sciences of Jilin Province, Changchun 130012, China.
| | - Zhe-Shan Quan
- Key Laboratory of Natural Resources and Functional Molecules of the Changbai Mountain, Affiliated Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, China.
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43
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Kumar M, Kumar P. Protective effect of spermine against pentylenetetrazole kindling epilepsy induced comorbidities in mice. Neurosci Res 2017; 120:8-17. [DOI: 10.1016/j.neures.2017.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 02/03/2017] [Accepted: 02/08/2017] [Indexed: 01/18/2023]
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The Influence of Solid Microneedles on the Transdermal Delivery of Selected Antiepileptic Drugs. Pharmaceutics 2016; 8:pharmaceutics8040033. [PMID: 27854292 PMCID: PMC5198017 DOI: 10.3390/pharmaceutics8040033] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 10/22/2016] [Accepted: 11/04/2016] [Indexed: 12/13/2022] Open
Abstract
The aim of this project was to examine the effect of microneedle rollers on the percutaneous penetration of tiagabine hydrochloride and carbamazepine across porcine skin in vitro. Liquid chromatography-mass spectrometric analysis was carried out using an Agilent 1200 Series HPLC system coupled to an Agilent G1969A TOF-MS system. Transdermal flux values of the drugs were determined from the steady-state portion of the cumulative amount versus time curves. Following twelve hours of microneedle roller application, there was a 6.74-fold increase in the percutaneous penetration of tiagabine hydrochloride (86.42 ± 25.66 µg/cm2/h) compared to passive delivery (12.83 ± 6.30 µg/cm2/h). For carbamazepine in 20% ethanol, passive transdermal flux of 7.85 ± 0.60 µg/cm2/h was observed compared to 10.85 ± 0.11 µg/cm2/h after microneedle treatment. Carbamazepine reconstituted in 30% ethanol resulted in only a 1.19-fold increase in drug permeation across porcine skin (36.73 ± 1.83 µg/cm2/h versus 30.74 ± 1.32 µg/cm2/h). Differences in flux values of untreated and microneedle-treated porcine skin using solid microneedles for the transdermal delivery of tiagabine were statistically significant. Although there were 1.38- and 1.19-fold increases in transdermal flux values of carbamazepine when applied as 20% and 30% ethanol solutions across microneedle-treated porcine skin, respectively, the increases were not statistically significant.
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Moen MN, Fjær R, Hamdani EH, Laerdahl JK, Menchini RJ, Vigeland MD, Sheng Y, Undlien DE, Hassel B, Salih MA, El Khashab HY, Selmer KK, Chaudhry FA. Pathogenic variants in KCTD7 perturb neuronal K+ fluxes and glutamine transport. Brain 2016; 139:3109-3120. [PMID: 27742667 DOI: 10.1093/brain/aww244] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 06/11/2016] [Accepted: 08/17/2016] [Indexed: 12/11/2022] Open
Abstract
Progressive myoclonus epilepsy is a heterogeneous group of disorders characterized by myoclonic and tonic-clonic seizures, ataxia and cognitive decline. We here present two affected brothers. At 9 months of age the elder brother developed ataxia and myoclonic jerks. In his second year he lost the ability to walk and talk, and he developed drug-resistant progressive myoclonus epilepsy. The cerebrospinal fluid level of glutamate was decreased while glutamine was increased. His younger brother manifested similar symptoms from 6 months of age. By exome sequencing of the proband we identified a novel homozygous frameshift variant in the potassium channel tetramerization domain 7 (KCTD7) gene (NM_153033.1:c.696delT: p.F232fs), which results in a truncated protein. The identified F232fs variant is inherited in an autosomal recessive manner, and the healthy consanguineous parents carry the variant in a heterozygous state. Bioinformatic analyses and structure modelling showed that KCTD7 is a highly conserved protein, structurally similar to KCTD5 and several voltage-gated potassium channels, and that it may form homo- or heteromultimers. By heterologous expression in Xenopus laevis oocytes, we demonstrate that wild-type KCTD7 hyperpolarizes cells in a K+ dependent manner and regulates activity of the neuronal glutamine transporter SAT2 (Slc38a2), while the F232fs variant impairs K+ fluxes and obliterates SAT2-dependent glutamine transport. Characterization of four additional disease-causing variants (R94W, R184C, N273I, Y276C) bolster these results and reveal the molecular mechanisms involved in the pathophysiology of KCTD7-related progressive myoclonus epilepsy. Thus, our data demonstrate that KCTD7 has an impact on K+ fluxes, neurotransmitter synthesis and neuronal function, and that malfunction of the encoded protein may lead to progressive myoclonus epilepsy.
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Affiliation(s)
- Marivi Nabong Moen
- 1 The Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, Oslo, Norway
| | - Roar Fjær
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway
| | - El Hassan Hamdani
- 1 The Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, Oslo, Norway.,3 Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
| | - Jon K Laerdahl
- 4 Department of Microbiology, Oslo University Hospital, Oslo, Norway.,5 Bioinformatics Core Facility, Department of Informatics, University of Oslo, Oslo, Norway
| | - Robin Johansen Menchini
- 1 The Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, Oslo, Norway
| | - Magnus Dehli Vigeland
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway
| | - Ying Sheng
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway
| | - Dag Erik Undlien
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway
| | - Bjørnar Hassel
- 6 Department of Complex Neurology and Neurohabilitation, Oslo University Hospital, Oslo, Norway
| | - Mustafa A Salih
- 7 Division of Paediatric Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Heba Y El Khashab
- 7 Division of Paediatric Neurology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.,8 Department of Paediatrics, Ain Shams University, Cairo, Egypt
| | - Kaja Kristine Selmer
- 2 Department of Medical Genetics, Oslo University Hospital and University of Oslo, Norway.,9 National Centre for Rare Epilepsy-related Disorders, Oslo University Hospital, Oslo, Norway
| | - Farrukh Abbas Chaudhry
- 1 The Institute of Basic Medical Sciences, Department of Molecular Medicine, University of Oslo, Oslo, Norway .,3 Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
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46
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DiNuzzo M, Giove F, Maraviglia B, Mangia S. Computational Flux Balance Analysis Predicts that Stimulation of Energy Metabolism in Astrocytes and their Metabolic Interactions with Neurons Depend on Uptake of K + Rather than Glutamate. Neurochem Res 2016; 42:202-216. [PMID: 27628293 PMCID: PMC5283516 DOI: 10.1007/s11064-016-2048-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 08/22/2016] [Accepted: 08/24/2016] [Indexed: 12/04/2022]
Abstract
Brain activity involves essential functional and metabolic interactions between neurons and astrocytes. The importance of astrocytic functions to neuronal signaling is supported by many experiments reporting high rates of energy consumption and oxidative metabolism in these glial cells. In the brain, almost all energy is consumed by the Na+/K+ ATPase, which hydrolyzes 1 ATP to move 3 Na+ outside and 2 K+ inside the cells. Astrocytes are commonly thought to be primarily involved in transmitter glutamate cycling, a mechanism that however only accounts for few % of brain energy utilization. In order to examine the participation of astrocytic energy metabolism in brain ion homeostasis, here we attempted to devise a simple stoichiometric relation linking glutamatergic neurotransmission to Na+ and K+ ionic currents. To this end, we took into account ion pumps and voltage/ligand-gated channels using the stoichiometry derived from available energy budget for neocortical signaling and incorporated this stoichiometric relation into a computational metabolic model of neuron-astrocyte interactions. We aimed at reproducing the experimental observations about rates of metabolic pathways obtained by 13C-NMR spectroscopy in rodent brain. When simulated data matched experiments as well as biophysical calculations, the stoichiometry for voltage/ligand-gated Na+ and K+ fluxes generated by neuronal activity was close to a 1:1 relationship, and specifically 63/58 Na+/K+ ions per glutamate released. We found that astrocytes are stimulated by the extracellular K+ exiting neurons in excess of the 3/2 Na+/K+ ratio underlying Na+/K+ ATPase-catalyzed reaction. Analysis of correlations between neuronal and astrocytic processes indicated that astrocytic K+ uptake, but not astrocytic Na+-coupled glutamate uptake, is instrumental for the establishment of neuron-astrocytic metabolic partnership. Our results emphasize the importance of K+ in stimulating the activation of astrocytes, which is relevant to the understanding of brain activity and energy metabolism at the cellular level.
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Affiliation(s)
- Mauro DiNuzzo
- Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 24.2.40, 2200, Copenhagen N, Denmark.
| | - Federico Giove
- Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi", Rome, Italy.,Fondazione Santa Lucia IRCCS, Rome, Italy
| | - Bruno Maraviglia
- Museo Storico della Fisica e Centro Studi e Ricerche "Enrico Fermi", Rome, Italy.,Fondazione Santa Lucia IRCCS, Rome, Italy
| | - Silvia Mangia
- Center for Magnetic Resonance Research, Department of Radiology, Univeristy of Minnesota, Minneapolis, MN, USA
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47
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Koshal P, Kumar P. Neurochemical modulation involved in the beneficial effect of liraglutide, GLP-1 agonist on PTZ kindling epilepsy-induced comorbidities in mice. Mol Cell Biochem 2016; 415:77-87. [PMID: 26965494 DOI: 10.1007/s11010-016-2678-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 03/04/2016] [Indexed: 12/15/2022]
Abstract
Epilepsy is a neurological disorder which occurs due to excessive firing of excitatory neurons in specific region of brain and associated with cognitive impairment and depression. GLP-1 has been reported to maintain hyperexcitability of neurons. Therefore, this study was designed to investigate the neuroprotective effect of liraglutide, GLP-1 analogue in PTZ kindling epilepsy-induced comorbidities and neurochemical alteration in mice. Male albino mice were administered PTZ (35 mg/kg) on every alternate day up to 29th days and challenge test was performed on 33rd day. From 1st day liraglutide (75 and 150 µg/kg) and diazepam (3 mg/kg) were administered up to 33rd day, 30 min prior to PTZ treatment. On 30th day animals were trained on elevated plus maze and passive shock avoidance paradigm and retention was recorded on 31st and 33rd day. On 32nd day tail suspension test was performed. Animals were sacrificed on 34th day for biochemical (LPO, GSH, and nitrite) and neurotransmitters (GABA, glutamate, DA, NE, 5-HT and their metabolites) estimation. Chronic treatment with PTZ developed generalized tonic-clonic seizures, reduced cognitive skills, increased oxidative stress and alteration in the level of neurotransmitters. Pre-treatment with liraglutide (75 and 150 μg/kg) significantly prevented the seizure severity, restored behavioural activity, oxidative defence enzymes, and altered level of neurochemicals in mice brain. The protective effect of liraglutide is attributed to restoration of altered level of GABA, glutamate, DA, NE, and 5-HT by the up-regulation of GLP-1Rs in mice brain.
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Affiliation(s)
- Prashant Koshal
- Department of Pharmacology, ISF College of Pharmacy, Ferozepur Road, Ghal Kalan, Moga, Punjab, 142001, India
| | - Puneet Kumar
- Department of Pharmacology, ISF College of Pharmacy, Ferozepur Road, Ghal Kalan, Moga, Punjab, 142001, India.
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48
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Role of GABA(B) receptors in learning and memory and neurological disorders. Neurosci Biobehav Rev 2016; 63:1-28. [PMID: 26814961 DOI: 10.1016/j.neubiorev.2016.01.007] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 12/31/2015] [Accepted: 01/21/2016] [Indexed: 01/13/2023]
Abstract
Although it is evident from the literature that altered GABAB receptor function does affect behavior, these results often do not correspond well. These differences could be due to the task protocol, animal strain, ligand concentration, or timing of administration utilized. Because several clinical populations exhibit learning and memory deficits in addition to altered markers of GABA and the GABAB receptor, it is important to determine whether altered GABAB receptor function is capable of contributing to the deficits. The aim of this review is to examine the effect of altered GABAB receptor function on synaptic plasticity as demonstrated by in vitro data, as well as the effects on performance in learning and memory tasks. Finally, data regarding altered GABA and GABAB receptor markers within clinical populations will be reviewed. Together, the data agree that proper functioning of GABAB receptors is crucial for numerous learning and memory tasks and that targeting this system via pharmaceuticals may benefit several clinical populations.
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49
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Jiang P, Zhu WY, He X, Tang MM, Dang RL, Li HD, Xue Y, Zhang LH, Wu YQ, Cao LJ. Association between Vitamin D Receptor Gene Polymorphisms with Childhood Temporal Lobe Epilepsy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:13913-22. [PMID: 26528998 PMCID: PMC4661623 DOI: 10.3390/ijerph121113913] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 12/29/2022]
Abstract
Vitamin D (VD) is implicated in multiple aspects of human physiology and vitamin D receptor (VDR) polymorphisms are associated with a variety of neuropsychiatric disorders. Although VD deficiency is highly prevalent in epilepsy patients and converging evidence indicates a role for VD in the development of epilepsy, no data is available on the possible relationship between epilepsy and genetic variations of VDR. In this study, 150 controls and 82 patients with temporal lobe epilepsy (TLE) were genotyped for five common VDR polymorphisms (Cdx-2, FokI, BsmI, ApaI and TaqI) by the polymerase chain reaction-ligase detection reaction method. Our results revealed that the frequency of FokI AC genotype was significantly higher in the control group than in the patients (p = 0.003, OR = 0.39, 95% CI = 0.21–0.73), whereas the AA genotype of ApaI SNP was more frequent in patients than in controls (p = 0.018, OR = 2.92, 95% CI = 1.2–7.1). However, no statistically significant association was found between Cdx-2, BsmI and TaqI polymorphisms and epilepsy. Additionally, in haplotype analysis, we found the haplotype GAT (BsmI/ApaI/TaqI) conferred significantly increased risk for developing TLE (p = 0.039, OR = 1.62, 95% CI = 1.02–2.56). As far as we know, these results firstly underline the importance of VDR polymorphisms for the genetic susceptibility to epilepsy.
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Affiliation(s)
- Pei Jiang
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
- Department of Pharmacy, Jining First People's Hospital, Jining 272011, China.
| | - Wen-Ye Zhu
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Xin He
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Mi-Mi Tang
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Rui-Li Dang
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Huan-De Li
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Ying Xue
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Li-Hong Zhang
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Yan-Qin Wu
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
| | - Ling-Juan Cao
- Institute of Clinical Pharmacy and Pharmacology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
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50
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Disrupted glutamate-glutamine cycle in acute encephalopathy with biphasic seizures and late reduced diffusion. Neuroradiology 2015; 57:1163-8. [DOI: 10.1007/s00234-015-1573-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 08/05/2015] [Indexed: 10/23/2022]
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