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Skwarzynska D, Sun H, Kasprzak I, Sharma S, Williamson J, Kapur J. Glycolytic lactate production supports status epilepticus in experimental animals. Ann Clin Transl Neurol 2023; 10:1873-1884. [PMID: 37632130 PMCID: PMC10578888 DOI: 10.1002/acn3.51881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/27/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
OBJECTIVE Status epilepticus (SE) requires rapid intervention to prevent cerebral injury and mortality. The ketogenic diet, which bypasses glycolysis, is a promising remedy for patients with refractory SE. We tested the role of glycolytic lactate production in sustaining SE. METHODS Extracellular lactate and glucose concentration during a seizure and SE in vivo was measured using lactate and glucose biosensors. A lactate dehydrogenase inhibitor, oxamate, blocked pyruvate to lactate conversion during SE. Video-EEG recordings evaluated seizure duration, severity, and immunohistochemistry was used to determine neuronal loss. Genetically encoded calcium indicator GCaMP7 was used to study the effect of oxamate on CA1 pyramidal neurons in vitro. Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded from CA1 neurons to study oxamate's impact on neurotransmission. RESULTS The extracellular glucose concentration dropped rapidly during seizures, and lactate accumulated in the extracellular space. Inhibition of pyruvate to lactate conversion with oxamate terminated SE in mice. There was less neuronal loss in treated compared to control mice. Oxamate perfusion decreased tonic and phasic neuronal activity of GCaMP7-expressing CA1 pyramidal neurons in vitro. Oxamate application reduced the frequency, but not amplitude of sEPSCs recorded from CA1 neurons, suggesting an effect on the presynaptic glutamatergic neurotransmission. INTERPRETATION A single seizure and SE stimulate lactate production. Diminishing pyruvate to lactate conversion with oxamate terminated SE and reduced associated neuronal death. Oxamate reduced neuronal excitability and excitatory neurotransmission at the presynaptic terminal. Glycolytic lactate production sustains SE and is an attractive therapeutic target.
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Affiliation(s)
- Daria Skwarzynska
- Neuroscience Graduate ProgramUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - Huayu Sun
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - Izabela Kasprzak
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - Supriya Sharma
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - John Williamson
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
| | - Jaideep Kapur
- Department of NeurologyUniversity of VirginiaCharlottesvilleVirginia22908USA
- UVA Brain InstituteUniversity of VirginiaCharlottesvilleVirginia22908USA
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Sutula TP, Wilson ST, Franzoso S, Stafstrom CE. 2-Deoxy-D-glucose administration after seizures has disease-modifying effects on kindling progression. Epilepsy Res 2023; 193:107169. [PMID: 37263021 DOI: 10.1016/j.eplepsyres.2023.107169] [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: 02/06/2023] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 06/03/2023]
Abstract
2-deoxy-D-glucose (2DG) is a glucose analog and reversible inhibitor of glycolysis with anticonvulsant and antiepileptic effects in multiple seizure models. 2DG at a dose of 250 mg/kg intraperitoneally (IP) delays progression of repeated seizures evoked by kindling in rats when administered 30 min prior to twice daily kindling stimulation. As toxicological studies have demonstrated that repeated daily oral administration of 2DG at doses of 60-375 mg/kg/day in rats induces dose-dependent, reversible cardiac myocyte vacuolation, it was of interest to determine if 2DG also slowed kindling progression when administered at or below doses causing cardiac toxicity and at various time points after evoked seizures. We found that: (1) 2DG slowed kindling progression nearly 2-fold when administered at a dose of 37.5 mg/kg given IP 30 min prior to kindling stimulation, and (2) 2DG 37.5 mg/kg IP also slowed kindling progression when given immediately after, and for as long as 10 min after evoked (kindled) seizures. These observations suggest potential clinical usefulness of post-seizure administration of 2DG to reduce seizure clusters and long-term consequences of repeated seizures at human equivalent doses that are likely to be safe and well tolerated in patients.
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Affiliation(s)
- Thomas P Sutula
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA.
| | | | - Sheilah Franzoso
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Carl E Stafstrom
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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3
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Khatibi VA, Salimi M, Rahdar M, Rezaei M, Nazari M, Dehghan S, Davoudi S, Raoufy MR, Mirnajafi-Zadeh J, Javan M, Hosseinmardi N, Behzadi G, Janahmadi M. Glycolysis inhibition partially resets epilepsy-induced alterations in the dorsal hippocampus-basolateral amygdala circuit involved in anxiety-like behavior. Sci Rep 2023; 13:6520. [PMID: 37085688 PMCID: PMC10119516 DOI: 10.1038/s41598-023-33710-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 04/18/2023] [Indexed: 04/23/2023] Open
Abstract
Pharmacoresistant temporal lobe epilepsy affects millions of people around the world with uncontrolled seizures and comorbidities, like anxiety, being the most problematic aspects calling for novel therapies. The intrahippocampal kainic acid model of temporal lobe epilepsy is an appropriate rodent model to evaluate the effects of novel interventions, including glycolysis inhibition, on epilepsy-induced alterations. Here, we investigated kainic acid-induced changes in the dorsal hippocampus (dHPC) and basolateral amygdala (BLA) circuit and the efficiency of a glycolysis inhibitor, 2-deoxy D-glucose (2-DG), in resetting such alterations using simultaneous local field potentials (LFP) recording and elevated zero-maze test. dHPC theta and gamma powers were lower in epileptic groups, both in the baseline and anxiogenic conditions. BLA theta power was higher in baseline condition while it was lower in anxiogenic condition in epileptic animals and 2-DG could reverse it. dHPC-BLA coherence was altered only in anxiogenic condition and 2-DG could reverse it only in gamma frequency. This coherence was significantly correlated with the time in which the animals exposed themselves to the anxiogenic condition. Further, theta-gamma phase-locking was lower in epileptic groups in the dHPC-BLA circuit and 2-DG could considerably increase it.
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Affiliation(s)
- Vahid Ahli Khatibi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Morteza Salimi
- Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mona Rahdar
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahmoud Rezaei
- Department of Physiology, School of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Milad Nazari
- Department of Molecular Biology and Genetics, Aarhus University, Åarhus, Denmark
| | - Samaneh Dehghan
- Stem Cell and Regenerative Medicine Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Shima Davoudi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Raoufy
- Department of Physiology, School of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, School of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Javan
- Department of Physiology, School of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Narges Hosseinmardi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Gila Behzadi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadi
- Neuroscience Research Center and Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Sutula TP, Fountain NB. 2DG and glycolysis as therapeutic targets for status epilepticus. Epilepsy Behav 2023; 140:109108. [PMID: 36804714 PMCID: PMC10032166 DOI: 10.1016/j.yebeh.2023.109108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/21/2023] [Indexed: 02/18/2023]
Abstract
2-deoxy-D-glucose (2DG) is a glucose analog differing from glucose only by removal of an oxygen atom at the 2 position, which prevents the isomerization of glucose-6-phosphate to fructose-6-phosphate, and thereby reversibly inhibits glycolysis. PET studies of regional brain glucose utilization positron-emitting 18F-2DG demonstrate that brain regions generating seizures have diminished glucose utilization during interictal conditions, but rapidly transition to markedly increased glucose delivery and utilization during seizures, particularly in status epilepticus (SE). 2-deoxy-D-glucose has acute antiseizure actions in multiple in vivo and in vitro seizure models, including models of SE induced by the chemo convulsants pilocarpine and kainic acid, suggesting that focal enhanced delivery of 2DG to ictal brain circuits is a potential novel anticonvulsant intervention for the treatment of SE.
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Affiliation(s)
- Thomas P Sutula
- Department of Neurology, University of Wisconsin, Madison, WI, USA; Hexokine Therapeutics, Inc., Madison, WI, USA.
| | - Nathan B Fountain
- Department of Neurology, F.E. Dreifuss Comprehensive Epilepsy Program, University of Virginia, Charlottesville, VA, USA; Hexokine Therapeutics, Inc., Madison, WI, USA
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Khatibi VA, Rahdar M, Rezaei M, Davoudi S, Nazari M, Mohammadi M, Raoufy MR, Mirnajafi-Zadeh J, Hosseinmardi N, Behzadi G, Janahmadi M. The Glycolysis Inhibitor 2-Deoxy-D-Glucose Exerts Different Neuronal Effects at Circuit and Cellular Levels, Partially Reverses Behavioral Alterations and does not Prevent NADPH Diaphorase Activity Reduction in the Intrahippocampal Kainic Acid Model of Temporal Lobe Epilepsy. Neurochem Res 2023; 48:210-228. [PMID: 36064822 PMCID: PMC9444119 DOI: 10.1007/s11064-022-03740-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/31/2022] [Accepted: 08/27/2022] [Indexed: 01/11/2023]
Abstract
Temporal lobe epilepsy is the most drug-resistant type with the highest incidence among the other focal epilepsies. Metabolic manipulations are of great interest among others, glycolysis inhibitors like 2-deoxy D-glucose (2-DG) being the most promising intervention. Here, we sought to investigate the effects of 2-DG treatment on cellular and circuit level electrophysiological properties using patch-clamp and local field potentials recordings and behavioral alterations such as depression and anxiety behaviors, and changes in nitric oxide signaling in the intrahippocampal kainic acid model. We found that epileptic animals were less anxious, more depressed, with more locomotion activity. Interestingly, by masking the effect of increased locomotor activity on the parameters of the zero-maze test, no altered anxiety behavior was noted in epileptic animals. However, 2-DG could partially reverse the behavioral changes induced by kainic acid. The findings also showed that 2-DG treatment partially suppresses cellular level alterations while failing to reverse circuit-level changes resulting from kainic acid injection. Analysis of NADPH-diaphorase positive neurons in the CA1 area of the hippocampus revealed that the number of positive neurons was significantly reduced in dorsal CA1 of the epileptic animals and 2-DG treatment did not affect the diminishing effect of kainic acid on NADPH-d+ neurons in the CA1 area. In the control group receiving 2-DG, however, an augmented NADPH-d+ cell number was noted. These data suggest that 2-DG cannot suppress epileptiform activity at the circuit-level in this model of epilepsy and therefore, may fail to control the seizures in temporal lobe epilepsy cases.
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Affiliation(s)
- Vahid Ahli Khatibi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mona Rahdar
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahmoud Rezaei
- Department of Physiology, School of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Shima Davoudi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Milad Nazari
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Mohammad Mohammadi
- Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Mohammad Reza Raoufy
- Department of Physiology, School of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, School of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Narges Hosseinmardi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Gila Behzadi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Wijayasinghe YS, Bhansali MP, Borkar MR, Chaturbhuj GU, Muntean BS, Viola RE, Bhansali PR. A Comprehensive Biological and Synthetic Perspective on 2-Deoxy-d-Glucose (2-DG), A Sweet Molecule with Therapeutic and Diagnostic Potentials. J Med Chem 2022; 65:3706-3728. [PMID: 35192360 DOI: 10.1021/acs.jmedchem.1c01737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Glucose, the primary substrate for ATP synthesis, is catabolized during glycolysis to generate ATP and precursors for the synthesis of other vital biomolecules. Opportunistic viruses and cancer cells often hijack this metabolic machinery to obtain energy and components needed for their replication and proliferation. One way to halt such energy-dependent processes is by interfering with the glycolytic pathway. 2-Deoxy-d-glucose (2-DG) is a synthetic glucose analogue that can inhibit key enzymes in the glycolytic pathway. The efficacy of 2-DG has been reported across an array of diseases and disorders, thereby demonstrating its broad therapeutic potential. Recent approval of 2-DG in India as a therapeutic approach for the management of the COVID-19 pandemic has brought renewed attention to this molecule. The purpose of this perspective is to present updated therapeutic avenues as well as a variety of chemical synthetic strategies for this medically useful sugar derivative, 2-DG.
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Affiliation(s)
- Yasanandana S Wijayasinghe
- Department of Biochemistry and Clinical Chemistry, Faculty of Medicine, University of Kelaniya, Ragama 11010, Sri Lanka
| | | | - Maheshkumar R Borkar
- Department of Pharmaceutical Chemistry, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai 400056, Maharashtra, India
| | - Ganesh U Chaturbhuj
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Matunga (E), Mumbai 400019, Maharashtra, India
| | - Brian S Muntean
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia 30912, United States
| | - Ronald E Viola
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Pravin R Bhansali
- Department of Science, Faculty of Science and Technology, Alliance University, Chikkahagade Cross, Chandapura-Anekal Main Road, Anekal, Bengaluru 562106, Karnataka, India
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Janicot R, Shao LR, Stafstrom CE. 2-deoxyglucose and β-hydroxybutyrate fail to attenuate seizures in the betamethasone-NMDA model of infantile spasms. Epilepsia Open 2021; 7:181-186. [PMID: 34784103 PMCID: PMC8886066 DOI: 10.1002/epi4.12561] [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: 08/17/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 02/05/2023] Open
Abstract
Infantile spasms (IS) is an epileptic encephalopathy with a poor neurodevelopmental prognosis, and limited, often ineffective treatment options. The effectiveness of metabolic approaches to seizure control is being increasingly shown in a wide variety of epilepsies. This study investigates the efficacy of the glycolysis inhibitor 2‐deoxyglucose (2‐DG) and the ketone body β‐hydroxybutyrate (BHB) in the betamethasone‐NMDA model of rat IS. Prenatal rats were exposed to betamethasone on gestational day 15 (G15) and NMDA on postnatal day 15 (P15). Video‐electroencephalography (v‐EEG) was used to monitor spasms. NMDA consistently induced hyperflexion spasms associated with interictal sharp‐slow wave EEG activity and ictal flattening of EEG signals, reminiscent of hypsarrhythmia and electrodecrement, respectively. 2‐DG (500 mg/kg, i.p), BHB (200 mg/kg, i.p.), or both were administered immediately after occurrence of the first spasm. No experimental treatment altered significantly the number, severity, or progression of spasms compared with saline treatment. These data suggest that metabolic inhibition of glycolysis or ketogenesis does not reduce infantile spasms in the NMDA model. The study further validates the betamethasone‐NMDA model in terms of its behavioral and electrographic resemblance to human IS and supports its use for preclinical drug screening.
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Affiliation(s)
- Remi Janicot
- Division of Pediatric Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Li-Rong Shao
- Division of Pediatric Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Carl E Stafstrom
- Division of Pediatric Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Janicot R, Stafstrom CE, Shao LR. The efficacy of fructose-1,6-bisphosphate in suppressing status epilepticus in developing rats. Epilepsy Res 2020; 168:106500. [DOI: 10.1016/j.eplepsyres.2020.106500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/12/2020] [Accepted: 10/30/2020] [Indexed: 12/18/2022]
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Shao LR, Janicot R, Stafstrom CE. Na +-K +-ATPase functions in the developing hippocampus: regional differences in CA1 and CA3 neuronal excitability and role in epileptiform network bursting. J Neurophysiol 2020; 125:1-11. [PMID: 33206576 DOI: 10.1152/jn.00453.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The Na+-K+-ATPase (Na+-K+ pump) is essential for setting resting membrane potential and restoring transmembrane Na+ and K+ gradients after neuronal firing, yet its roles in developing neurons are not well understood. This study examined the contribution of the Na+-K+ pump to resting membrane potential and membrane excitability of developing CA1 and CA3 neurons and its role in maintaining synchronous network bursting. Experiments were conducted in postnatal day (P)9 to P13 rat hippocampal slices using whole cell patch-clamp and extracellular field-potential recordings. Blockade of the Na+-K+ pump with strophanthidin caused marked depolarization (23.1 mV) in CA3 neurons but only a modest depolarization (3.3 mV) in CA1 neurons. Regarding other membrane properties, strophanthidin differentially altered the voltage-current responses, input resistance, action-potential threshold and amplitude, rheobase, and input-output relationship in CA3 vs. CA1 neurons. At the network level, strophanthidin stopped synchronous epileptiform bursting in CA3 induced by 0 Mg2+ and 4-aminopyridine. Furthermore, dual whole cell recordings revealed that strophanthidin disrupted the synchrony of CA3 neuronal firing. Finally, strophanthidin reduced spontaneous excitatory postsynaptic current (sEPSC) bursts (i.e., synchronous transmitter release) and transformed them into individual sEPSC events (i.e., nonsynchronous transmitter release). These data suggest that the Na+-K+ pump plays a more profound role in membrane excitability in developing CA3 neurons than in CA1 neurons and that the pump is essential for the maintenance of synchronous network bursting in CA3. Compromised Na+-K+ pump function leads to cessation of ongoing synchronous network activity, by desynchronizing neuronal firing and neurotransmitter release in the CA3 synaptic network. These findings have implications for the regulation of network excitability and seizure generation in the developing brain.NEW & NOTEWORTHY Despite the extensive literature showing the importance of the Na+-K+ pump in various neuronal functions, its roles in the developing brain are not well understood. This study reveals that the Na+-K+ pump differentially regulates the excitability of CA3 and CA1 neurons in the developing hippocampus, and the pump activity is crucial for maintaining network activity. Compromised Na+-K+ pump activity desynchronizes neuronal firing and transmitter release, leading to cessation of ongoing epileptiform network bursting.
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Affiliation(s)
- Li-Rong Shao
- Division of Pediatric Neurology, Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Remi Janicot
- Division of Pediatric Neurology, Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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Janicot R, Stafstrom CE, Shao LR. 2-Deoxyglucose terminates pilocarpine-induced status epilepticus in neonatal rats. Epilepsia 2020; 61:1528-1537. [PMID: 32558935 DOI: 10.1111/epi.16583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Neonatal status epilepticus (SE) is a life-threatening medical emergency. Unfortunately, up to 50% of neonates with SE are resistant to current antiseizure drugs, highlighting the need for better treatments. This study aims to explore a novel metabolic approach as a potential alternative treatment to control neonatal SE, using the glycolytic inhibitor 2-deoxyglucose (2-DG). METHODS SE was induced by pilocarpine (300 mg/kg, intraperitoneally [ip]) in neonatal Sprague Dawley rats (postnatal day 10 [P10]-P17) and was monitored by video-electroencephalography (V-EEG). After 30 minutes of SE, 2-DG or one of two conventional antiseizure drugs with different mechanisms of action, phenobarbital or levetiracetam, was administrated ip, and V-EEG recording was continued for ~60 additional minutes. The time to seizure cessation after drug injection, EEG scores, and power spectra before and after drug or saline treatment were used to assess drug effects. RESULTS Once SE became sustained, administration of 2-DG (50, 100, or 500 mg/kg, ip) consistently stopped behavioral and electrographic seizures within 10-15 minutes; lower doses took longer (25-30 minutes) to stop SE, demonstrating a dose-dependent effect. Administration of phenobarbital (30 mg/kg, ip) or levetiracetam (100 mg/kg, ip) also stopped SE within 10-15 minutes in neonatal rats. SIGNIFICANCE Our results suggest that the glycolysis inhibitor 2-DG acts quickly to reduce neuronal hyperexcitability and effectively suppress ongoing seizure activity, which may provide translational value in the treatment of neonatal SE.
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Affiliation(s)
- Remi Janicot
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Li-Rong Shao
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Zelleke T, Pasupuleti A, Depositario-Cabacar D, Kao A. Antiepileptic Drugs in Pediatrics. Handb Exp Pharmacol 2020; 261:1-24. [PMID: 31342278 DOI: 10.1007/164_2019_248] [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: 06/10/2023]
Abstract
Epilepsy affects approximately 1% of the population. First-line treatment for epilepsy is the administration of anti-seizure medication, also referred to as antiepileptic drugs (AEDs), although this nomenclature is erroneous as these medications typically do not impact underlying epileptogenic processes; the goal of these medications is to control symptoms. Over 30% of patients are classified as having "medically refractory" epilepsy, i.e., lack of adequate seizure control despite trials of two or three AEDs (Kwan and Brodie, N Engl J Med 342:314-9, 2000). Epilepsy is associated with worse quality of life in children, adolescents, and their families (Cianchetti et al., Seizure 24:93-101, 2015). Patients with epilepsy have a two to three times greater risk of death than the general population, by various causes including sudden unexplained death in epilepsy patients (SUDEP) (Abdel-Mannan et al., Epilepsy Behav 90:99-106, 2019). It is these factors, among others, that have motivated the continued development of AEDs. This chapter will review the history and evolution of AED development, features of specific AEDs with a focus on the newest generation, and examples of AEDs in development.
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Affiliation(s)
- Tesfaye Zelleke
- Division of Epilepsy and Neurophysiology, Children's National Health System, Washington, DC, USA
| | - Archana Pasupuleti
- Division of Epilepsy and Neurophysiology, Children's National Health System, Washington, DC, USA
| | - Dewi Depositario-Cabacar
- Division of Epilepsy and Neurophysiology, Children's National Health System, Washington, DC, USA
| | - Amy Kao
- Division of Epilepsy and Neurophysiology, Children's National Health System, Washington, DC, USA.
- Center for Behavioral Neurosciences, Children's National Health System, Washington, DC, USA.
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Tourigny DS, Karim MKA, Echeveste R, Kotter MRN, O’Neill JS. Energetic substrate availability regulates synchronous activity in an excitatory neural network. PLoS One 2019; 14:e0220937. [PMID: 31408504 PMCID: PMC6692003 DOI: 10.1371/journal.pone.0220937] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 07/26/2019] [Indexed: 12/16/2022] Open
Abstract
Neural networks are required to meet significant metabolic demands associated with performing sophisticated computational tasks in the brain. The necessity for efficient transmission of information imposes stringent constraints on the metabolic pathways that can be used for energy generation at the synapse, and thus low availability of energetic substrates can reduce the efficacy of synaptic function. Here we study the effects of energetic substrate availability on global neural network behavior and find that glucose alone can sustain excitatory neurotransmission required to generate high-frequency synchronous bursting that emerges in culture. In contrast, obligatory oxidative energetic substrates such as lactate and pyruvate are unable to substitute for glucose, indicating that processes involving glucose metabolism form the primary energy-generating pathways supporting coordinated network activity. Our experimental results are discussed in the context of the role that metabolism plays in supporting the performance of individual synapses, including the relative contributions from postsynaptic responses, astrocytes, and presynaptic vesicle cycling. We propose a simple computational model for our excitatory cultures that accurately captures the inability of metabolically compromised synapses to sustain synchronous bursting when extracellular glucose is depleted.
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Affiliation(s)
- David S. Tourigny
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Columbia University Irving Medical Center, New York, New York, United States of America
- * E-mail: (DST); (MRNK); (JSO)
| | - Muhammad Kaiser Abdul Karim
- Department of Clinical Neurosciences and Wellcome Trust- MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Rodrigo Echeveste
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Mark R. N. Kotter
- Department of Clinical Neurosciences and Wellcome Trust- MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- * E-mail: (DST); (MRNK); (JSO)
| | - John S. O’Neill
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
- * E-mail: (DST); (MRNK); (JSO)
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Koenig JB, Cantu D, Low C, Sommer M, Noubary F, Croker D, Whalen M, Kong D, Dulla CG. Glycolytic inhibitor 2-deoxyglucose prevents cortical hyperexcitability after traumatic brain injury. JCI Insight 2019; 5:126506. [PMID: 31038473 DOI: 10.1172/jci.insight.126506] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Traumatic brain injury (TBI) causes cortical dysfunction and can lead to post-traumatic epilepsy. Multiple studies demonstrate that GABAergic inhibitory network function is compromised following TBI, which may contribute to hyperexcitability and motor, behavioral, and cognitive deficits. Preserving the function of GABAergic interneurons, therefore, is a rational therapeutic strategy to preserve cortical function after TBI and prevent long-term clinical complications. Here, we explored an approach based on the ketogenic diet, a neuroprotective and anticonvulsant dietary therapy which results in reduced glycolysis and increased ketosis. Utilizing a pharmacologic inhibitor of glycolysis (2-deoxyglucose, or 2-DG), we found that acute in vitro application of 2-DG decreased the excitability of excitatory neurons, but not inhibitory interneurons, in cortical slices from naïve mice. Employing the controlled cortical impact (CCI) model of TBI in mice, we found that in vitro 2-DG treatment rapidly attenuated epileptiform activity seen in acute cortical slices 3 to 5 weeks after TBI. One week of in vivo 2-DG treatment immediately after TBI prevented the development of epileptiform activity, restored excitatory and inhibitory synaptic activity, and attenuated the loss of parvalbumin-expressing inhibitory interneurons. In summary, 2-DG may have therapeutic potential to restore network function following TBI.
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Affiliation(s)
- Jenny B Koenig
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA.,Neuroscience Program, Tufts University Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts, USA
| | - David Cantu
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Cho Low
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA.,Cellular, Molecular, and Developmental Biology Program, Tufts University Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts, USA
| | - Mary Sommer
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Farzad Noubary
- Department of Health Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts, USA
| | - Danielle Croker
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Michael Whalen
- Neuroscience Center, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Dong Kong
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
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Rho JM, Shao LR, Stafstrom CE. 2-Deoxyglucose and Beta-Hydroxybutyrate: Metabolic Agents for Seizure Control. Front Cell Neurosci 2019; 13:172. [PMID: 31114484 PMCID: PMC6503754 DOI: 10.3389/fncel.2019.00172] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 04/11/2019] [Indexed: 01/12/2023] Open
Abstract
Current anti-seizure drugs (ASDs) are believed to reduce neuronal excitability through modulation of ion channels and transporters that regulate excitability at the synaptic level. While most patients with epilepsy respond to ASDs, many remain refractory to medical treatment but respond favorably to a high-fat, low-carbohydrate metabolism-based therapy known as the ketogenic diet (KD). The clinical effectiveness of the KD has increasingly underscored the thesis that metabolic factors also play a crucial role in the dampening neuronal hyperexcitability that is a hallmark feature of epilepsy. This notion is further amplified by the clinical utility of other related metabolism-based diets such as the modified Atkins diet and the low-glycemic index treatment (LGIT). Traditional high-fat diets are characterized by enhanced fatty acid oxidation (which produces ketone bodies such as beta-hydroxybutyrate) and a reduction in glycolytic flux, whereas the LGIT is predicated mainly on the latter observation of reduced blood glucose levels. As dietary implementation is not without challenges regarding clinical administration and patient compliance, there is an inherent desire and need to determine whether specific metabolic substrates and/or enzymes might afford similar clinical benefits, hence validating the concept of a “diet in a pill.” Here, we discuss the evidence for one glycolytic inhibitor, 2-deoxyglucose (2DG) and one metabolic substrate, β-hydroxybutyrate (BHB) exerting direct effects on neuronal excitability, highlight their mechanistic differences, and provide the strengthening scientific rationale for their individual or possibly combined use in the clinical arena of seizure management.
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Affiliation(s)
- Jong M Rho
- Section of Pediatric Neurology, Department of Pediatrics, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Li-Rong Shao
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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15
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Pan YZ, Sutula TP, Rutecki PA. 2-Deoxy-d-glucose reduces epileptiform activity by presynaptic mechanisms. J Neurophysiol 2019; 121:1092-1101. [PMID: 30673364 DOI: 10.1152/jn.00723.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
2-Deoxy-d-glucose (2DG), a glucose analog that inhibits glycolysis, has acute and chronic antiepileptic effects. We evaluated 2DG's acute effects on synaptic and membrane properties of CA3 pyramidal neurons in vitro. 2DG (10 mM) had no effects on spontaneously occurring postsynaptic currents (PSCs) in 3.5 mM extracellular potassium concentration ([K+]o). In 7.5 mM [K+]o, 2DG significantly reduced the frequency of epileptiform bursting and the charge carried by postsynaptic currents (PSCs) with a greater effect on inward excitatory compared with outward inhibitory charge (71% vs. 40%). In 7.5 mM [K+]o and bicuculline, 2DG reduced significantly the excitatory charge by 67% and decreased the frequency but not amplitude of excitatory PSCs between bursts. In 7.5 mM [K+]o, 2DG reduced pharmacologically isolated inhibitory PSC frequency without a change in amplitude. The frequency but not amplitude of inward miniature PSCs was reduced when 2DG was applied in 7.5 mM [K+]o before bath application of TTX, but there was no effect when 2DG was applied after TTX, indicating a use-dependent uptake of 2DG was required for its actions at a presynaptic locus. 2DG did not alter membrane properties of CA3 neurons except for reducing the slow afterhyperpolarization in 3.5 but not 7.5 mM [K+]o. The reduction in frequency of spontaneous and inward miniature PSCs in elevated [K+]o indicates a presynaptic mechanism of action. 2DG effects required use-dependent uptake and suggest an important role for glycolysis in neuronal metabolism and energetics in states of high neural activity as occur during abnormal network synchronization and seizures. NEW & NOTEWORTHY 2-Deoxy-d-glucose (2DG) is a glycolytic inhibitor and suppresses epileptiform activity acutely and has chronic antiepileptic effects. The mechanisms of the acute effects are not well delineated. In this study, we show 2DG suppressed abnormal network epileptiform activity without effecting normal synaptic network activity or membrane properties. The effects appear to be use dependent and have a presynaptic locus of action. Inhibition of glycolysis is a novel presynaptic mechanism to limit abnormal neuronal network activity and seizures.
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Affiliation(s)
- Yu-Zhen Pan
- Department of Neurology, University of Wisconsin , Madison, Wisconsin
| | - Thomas P Sutula
- Department of Neurology, University of Wisconsin , Madison, Wisconsin
| | - Paul A Rutecki
- Department of Neurology, University of Wisconsin , Madison, Wisconsin.,William S. Middleton Memorial Veterans Hospital , Madison, Wisconsin
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16
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Koenig JB, Dulla CG. Dysregulated Glucose Metabolism as a Therapeutic Target to Reduce Post-traumatic Epilepsy. Front Cell Neurosci 2018; 12:350. [PMID: 30459556 PMCID: PMC6232824 DOI: 10.3389/fncel.2018.00350] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 09/19/2018] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) is a significant cause of disability worldwide and can lead to post-traumatic epilepsy. Multiple molecular, cellular, and network pathologies occur following injury which may contribute to epileptogenesis. Efforts to identify mechanisms of disease progression and biomarkers which predict clinical outcomes have focused heavily on metabolic changes. Advances in imaging approaches, combined with well-established biochemical methodologies, have revealed a complex landscape of metabolic changes that occur acutely after TBI and then evolve in the days to weeks after. Based on this rich clinical and preclinical data, combined with the success of metabolic therapies like the ketogenic diet in treating epilepsy, interest has grown in determining whether manipulating metabolic activity following TBI may have therapeutic value to prevent post-traumatic epileptogenesis. Here, we focus on changes in glucose utilization and glycolytic activity in the brain following TBI and during seizures. We review relevant literature and outline potential paths forward to utilize glycolytic inhibitors as a disease-modifying therapy for post-traumatic epilepsy.
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Affiliation(s)
- Jenny B Koenig
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
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17
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Kovács R, Gerevich Z, Friedman A, Otáhal J, Prager O, Gabriel S, Berndt N. Bioenergetic Mechanisms of Seizure Control. Front Cell Neurosci 2018; 12:335. [PMID: 30349461 PMCID: PMC6187982 DOI: 10.3389/fncel.2018.00335] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/12/2018] [Indexed: 12/14/2022] Open
Abstract
Epilepsy is characterized by the regular occurrence of seizures, which follow a stereotypical sequence of alterations in the electroencephalogram. Seizures are typically a self limiting phenomenon, concluding finally in the cessation of hypersynchronous activity and followed by a state of decreased neuronal excitability which might underlie the cognitive and psychological symptoms the patients experience in the wake of seizures. Many efforts have been devoted to understand how seizures spontaneously stop in hope to exploit this knowledge in anticonvulsant or neuroprotective therapies. Besides the alterations in ion-channels, transmitters and neuromodulators, the successive build up of disturbances in energy metabolism have been suggested as a mechanism for seizure termination. Energy metabolism and substrate supply of the brain are tightly regulated by different mechanisms called neurometabolic and neurovascular coupling. Here we summarize the current knowledge whether these mechanisms are sufficient to cover the energy demand of hypersynchronous activity and whether a mismatch between energy need and supply could contribute to seizure control.
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Affiliation(s)
- Richard Kovács
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Zoltan Gerevich
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Alon Friedman
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beersheba, Israel.,Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Jakub Otáhal
- Institute of Physiology, Czech Academy of Sciences, Prague, Czechia
| | - Ofer Prager
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Siegrun Gabriel
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Neurophysiologie, Berlin, Germany
| | - Nikolaus Berndt
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institut für Biochemie, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute for Computational and Imaging Science in Cardiovascular Medicine, Berlin, Germany
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18
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Shao LR, Rho JM, Stafstrom CE. Glycolytic inhibition: A novel approach toward controlling neuronal excitability and seizures. Epilepsia Open 2018; 3:191-197. [PMID: 30564778 PMCID: PMC6293058 DOI: 10.1002/epi4.12251] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2018] [Indexed: 12/31/2022] Open
Abstract
Conventional antiseizure medications reduce neuronal excitability through effects on ion channels or synaptic function. In recent years, it has become clear that metabolic factors also play a crucial role in the modulation of neuronal excitability. Indeed, metabolic regulation of neuronal excitability is pivotal in seizure pathogenesis and control. The clinical effectiveness of a variety of metabolism‐based diets, especially for children with medication‐refractory epilepsy, underscores the applicability of metabolic approaches to the control of seizures and epilepsy. Such diets include the ketogenic diet, the modified Atkins diet, and the low‐glycemic index treatment (among others). A promising avenue to alter cellular metabolism, and hence excitability, is by partial inhibition of glycolysis, which has been shown to reduce seizure susceptibility in a variety of animal models as well as in cellular systems in vitro. One such glycolytic inhibitor, 2‐deoxy‐d‐glucose (2DG), increases seizure threshold in vivo and reduces interictal and ictal epileptiform discharges in hippocampal slices. Here, we review the role of glucose metabolism and glycolysis on neuronal excitability, with specific reference to 2DG, and discuss the potential use of 2DG and similar agents in the clinical arena for seizure management.
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Affiliation(s)
- Li-Rong Shao
- Division of Pediatric Neurology Department of Neurology Johns Hopkins University School of Medicine Baltimore Maryland U.S.A
| | - Jong M Rho
- Departments of Pediatrics, Clinical Neurosciences, Physiology and Pharmacology Alberta Children's Hospital Research Institute Hotchkiss Brain Institute Cumming School of Medicine University of Calgary Calgary Alberta Canada
| | - Carl E Stafstrom
- Division of Pediatric Neurology Department of Neurology Johns Hopkins University School of Medicine Baltimore Maryland U.S.A
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19
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Amengual-Gual M, Sánchez Fernández I, Wainwright MS. Novel drugs and early polypharmacotherapy in status epilepticus. Seizure 2018; 68:79-88. [PMID: 30473267 DOI: 10.1016/j.seizure.2018.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 08/05/2018] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Rescue medications for status epilepticus (SE) have a relatively high rate of failure. The purpose of this review is to summarize the evidence for the efficacy of novel drugs and early polypharmacotherapy for SE. METHOD Literature review. RESULTS New drugs and treatment strategies aim to target the pathophysiology of SE in order to improve seizure control and outcomes. Changes at the synapse level during SE include a progressive decrease in synaptic GABAA receptors and increase in synaptic NMDA receptors. These changes tend to promote self-sustaining seizures. Current SE guidelines recommend a rapid stepwise treatment using benzodiazepines in monotherapy as the first-line treatment, targeting GABAA synaptic receptors. Novel treatment approaches target GABAA synaptic and extrasynaptic receptors with allopregnanolone, and NMDA receptors with ketamine. Novel rescue treatments used for SE include topiramate, brivaracetam, and perampanel, which are already marketed in epilepsy. Some available drugs not marketed for use in epilepsy have been used in the treatment of SE, and other agents are being studied for this purpose. Early polytherapy, most frequently combining a benzodiazepine with a second-line drug or an NMDA receptor antagonist, might potentially increase seizure control with relatively minor increase in side effects. Although many preclinical studies support novel drugs and early polytherapy in SE, human studies are scarce and inconclusive. Currently, evidence is lacking to recommend specific combinations of these new agents. CONCLUSIONS Novel drugs and strategies target the underlying pathophysiology of SE with the intent to improve seizure control and outcomes.
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Affiliation(s)
- Marta Amengual-Gual
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Pediatric Neurology Unit, Department of Pediatrics, Hospital Universitari Son Espases, Universitat de les Illes Balears, Palma, Spain.
| | - Iván Sánchez Fernández
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA; Department of Child Neurology, Hospital Sant Joan de Déu, Universidad de Barcelona, Spain
| | - Mark S Wainwright
- Department of Neurology, Division of Pediatric Neurology. University of Washington School of Medicine, Seattle, WA, USA
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20
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Shao LR, Wang G, Stafstrom CE. The Glycolytic Metabolite, Fructose-1,6-bisphosphate, Blocks Epileptiform Bursts by Attenuating Voltage-Activated Calcium Currents in Hippocampal Slices. Front Cell Neurosci 2018; 12:168. [PMID: 29962940 PMCID: PMC6013557 DOI: 10.3389/fncel.2018.00168] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 05/30/2018] [Indexed: 01/24/2023] Open
Abstract
Manipulation of metabolic pathways (e.g., ketogenic diet (KD), glycolytic inhibition) alters neural excitability and represents a novel strategy for treatment of drug-refractory seizures. We have previously shown that inhibition of glycolysis suppresses epileptiform activity in hippocampal slices. In the present study, we aimed to examine the role of a “branching” metabolic pathway stemming off glycolysis (i.e., the pentose-phosphate pathway, PPP) in regulating seizure activity, by using a potent PPP stimulator and glycolytic intermediate, fructose-1,6-bisphosphate (F1,6BP). Employing electrophysiological approaches, we investigated the action of F1,6BP on epileptiform population bursts, intrinsic neuronal firing, glutamatergic and GABAergic synaptic transmission and voltage-activated calcium currents (ICa) in the CA3 area of hippocampal slices. Bath application of F1,6BP (2.5–5 mM) blocked epileptiform population bursts induced in Mg2+-free medium containing 4-aminopyridine, in ~2/3 of the slices. The blockade occurred relatively rapidly (~4 min), suggesting an extracellular mechanism. However, F1,6BP did not block spontaneous intrinsic firing of the CA3 neurons (when synaptic transmission was eliminated with DNQX, AP-5 and SR95531), nor did it significantly reduce AMPA or NMDA receptor-mediated excitatory postsynaptic currents (EPSCAMPA and EPSCNMDA). In contrast, F1,6BP caused moderate reduction (~50%) in GABAA receptor-mediated current, suggesting it affects excitatory and inhibitory synapses differently. Finally and unexpectedly, F1,6BP consistently attenuated ICa by ~40% without altering channel activation or inactivation kinetics, which may explain its anticonvulsant action, at least in this in vitro seizure model. Consistent with these results, epileptiform population bursts in CA3 were readily blocked by the nonspecific Ca2+ channel blocker, CdCl2 (20 μM), suggesting that these bursts are calcium dependent. Altogether, these data demonstrate that the glycolytic metabolite, F1,6BP, blocks epileptiform activity via a previously unrecognized extracellular effect on ICa, which provides new insight into the metabolic control of neural excitability.
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Affiliation(s)
- Li-Rong Shao
- Division of Pediatric Neurology, Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Guangxin Wang
- Department of Medicine, Qilu Children's Hospital, Shandong University, Jinan, China
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
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21
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Nedergaard S, Andreasen M. Opposing effects of 2-deoxy-d-glucose on interictal- and ictal-like activity when K+ currents and GABAA receptors are blocked in rat hippocampus in vitro. J Neurophysiol 2018; 119:1912-1923. [DOI: 10.1152/jn.00732.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The ketogenic diet (KD), a high-fat, carbohydrate-restricted diet, is used as an alternative treatment for drug-resistant epileptic patients. Evidence suggests that compromised glucose metabolism has a significant role in the anticonvulsant action of the KD; however, it is unclear what part of the glucose metabolism that is important. The present study investigates how selective alterations in glycolysis and oxidative phosphorylation influence epileptiform activity induced by blocking K+ currents and GABAA and NMDA receptors in the hippocampal slice preparation. Blocking glycolysis with the glucose derivative 2-deoxy-d-glucose (2-DG; 10 mM) gave a fast reduction of the frequency of interictal discharge (IED) consistent with findings in other in vitro models. However, this was followed by the induction of seizure-like discharges in area CA1 and CA3. Substituting glucose with sucrose (glucopenia) had effects similar to those of 2-DG, whereas substitution with l-lactate or pyruvate reduced the IED but had a less proconvulsant effect. Blockade of ATP-sensitive K+ channels, glycine or adenosine 1 receptors, or depletion of the endogenous anticonvulsant compound glutathione did not prevent the actions of 2-DG. Baclofen (2 μM) reproduced the effect of 2-DG on IED activity. The proconvulsant effect of 2-DG could be reproduced by blocking the oxidative phosphorylation with the complex I toxin rotenone (4 μM). The data suggest that inhibition of IED, induced by 2-DG and glucopenia, is a direct consequence of impairment of glycolysis, likely exerted via a decreased recurrent excitatory synaptic transmission in area CA3. The accompanying proconvulsant effect is caused by an excitatory mechanism, depending on impairment of oxidative phosphorylation. NEW & NOTEWORTHY This study reveals two opposing effects of 2-deoxy-d-glucose (2-DG) and glucopenia on in vitro epileptiform discharge observed during combined blockade of K+ currents and GABAA receptors. Interictal-like activity is inhibited by a mechanism that selectively depends on impairment of glycolysis and that results from a decrease in the strength of excitatory recurrent synaptic transmission in area CA3. In contrast, 2-DG and glucopenia facilitate ictal-like activity by an excitatory mechanism, depending on impairment of mitochondrial oxidative phosphorylation.
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22
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Contribution of Intrinsic Lactate to Maintenance of Seizure Activity in Neocortical Slices from Patients with Temporal Lobe Epilepsy and in Rat Entorhinal Cortex. Int J Mol Sci 2017; 18:ijms18091835. [PMID: 28832554 PMCID: PMC5618484 DOI: 10.3390/ijms18091835] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 08/11/2017] [Accepted: 08/14/2017] [Indexed: 12/20/2022] Open
Abstract
Neuronal lactate uptake supports energy metabolism associated with synaptic signaling and recovery of extracellular ion gradients following neuronal activation. Altered expression of the monocarboxylate transporters (MCT) in temporal lobe epilepsy (TLE) hampers lactate removal into the bloodstream. The resulting increase in parenchymal lactate levels might exert both, anti- and pro-ictogen effects, by causing acidosis and by supplementing energy metabolism, respectively. Hence, we assessed the contribution of lactate to the maintenance of transmembrane potassium gradients, synaptic signaling and pathological network activity in chronic epileptic human tissue. Stimulus induced and spontaneous field potentials and extracellular potassium concentration changes (∆[K⁺]O) were recorded in parallel with tissue pO₂ and pH in slices from TLE patients while blocking MCTs by α-cyano-4-hydroxycinnamic acid (4-CIN) or d-lactate. Intrinsic lactate contributed to the oxidative energy metabolism in chronic epileptic tissue as revealed by the changes in pO₂ following blockade of lactate uptake. However, unlike the results in rat hippocampus, ∆[K⁺]O recovery kinetics and field potential amplitude did not depend on the presence of lactate. Remarkably, inhibition of lactate uptake exerted pH-independent anti-seizure effects both in healthy rat and chronic epileptic tissue and this effect was partly mediated via adenosine 1 receptor activation following decreased oxidative metabolism.
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