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Sui AR, Piao H, Xiong ST, Zhang P, Guo SY, Kong Y, Gao CQ, Wang ZX, Yang J, Ge BY, Supratik K, Yang JY, Zhao J, Li S. Scorpion venom heat-resistant synthesized peptide ameliorates epileptic seizures and imparts neuroprotection in rats mediated by NMDA receptors. Eur J Pharmacol 2024:176704. [PMID: 38830458 DOI: 10.1016/j.ejphar.2024.176704] [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: 12/08/2023] [Revised: 03/13/2024] [Accepted: 05/31/2024] [Indexed: 06/05/2024]
Abstract
Finding new and effective natural products for designing antiepileptic drugs is highly important in the scientific community. The scorpion venom heat-resistant peptide (SVHRP) was purified from Buthus martensii Karsch scorpion venom, and subsequent analysis of the amino acid sequence facilitated the synthesis of a peptide known as scorpion venom heat-resistant synthesis peptide (SVHRSP) using a technique for peptide synthesis. Previous studies have demonstrated that the SVHRSP can inhibit neuroinflammation and provide neuroprotection. This study aimed to investigate the antiepileptic effect of SVHRSP on both acute and chronic kindling seizure models by inducing seizures in male rats through intraperitoneal administration of pentylenetetrazole (PTZ). Additionally, an N-methyl-D-aspartate (NMDA)-induced neuronal injury model was used to observe the anti-excitotoxic effect of SVHRSP in vitro. Our findings showed that treatment with SVHRSP effectively alleviated seizure severity, prolonged latency, and attenuated neuronal loss and glial cell activation. It also demonstrated the prevention of alterations in the expression levels of NMDA receptor subunits and phosphorylated p38 MAPK protein, as well as an improvement in spatial reference memory impairment during Morris water maze (MWM) testing in PTZ-kindled rats. In vitro experiments further revealed that SVHRSP was capable of attenuating neuronal action potential firing, inhibiting NMDA receptor currents and intracellular calcium overload, and reducing neuronal injury. These results suggest that the antiepileptic and neuroprotective effects of SVHRSP may be mediated through the regulation of NMDA receptor function and expression. This study provides new insight into therapeutic strategies for epilepsy.
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Affiliation(s)
- Ao-Ran Sui
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China
| | - Hua Piao
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China
| | - Si-Ting Xiong
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China
| | - Peng Zhang
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China
| | - Song-Yu Guo
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China; National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, 116044, China
| | - Yue Kong
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China
| | - Cheng-Qian Gao
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China
| | - Zhi-Xue Wang
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China
| | - Jun Yang
- Department of Child Health, Yantaishan Hospital, Yantai, 264008
| | - Bi-Ying Ge
- National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, 116044, China
| | - Kundu Supratik
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China
| | - Jin-Yi Yang
- Department of Urology, Affiliated Dalian Friendship Hospital of Dalian Medical University, Dalian, 116001, China.
| | - Jie Zhao
- National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, 116044, China.
| | - Shao Li
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, Dalian Medical University, Dalian, 116044, China; National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, 116044, China.
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Madireddy S, Madireddy S. Therapeutic Strategies to Ameliorate Neuronal Damage in Epilepsy by Regulating Oxidative Stress, Mitochondrial Dysfunction, and Neuroinflammation. Brain Sci 2023; 13:brainsci13050784. [PMID: 37239256 DOI: 10.3390/brainsci13050784] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/09/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Epilepsy is a central nervous system disorder involving spontaneous and recurring seizures that affects 50 million individuals globally. Because approximately one-third of patients with epilepsy do not respond to drug therapy, the development of new therapeutic strategies against epilepsy could be beneficial. Oxidative stress and mitochondrial dysfunction are frequently observed in epilepsy. Additionally, neuroinflammation is increasingly understood to contribute to the pathogenesis of epilepsy. Mitochondrial dysfunction is also recognized for its contributions to neuronal excitability and apoptosis, which can lead to neuronal loss in epilepsy. This review focuses on the roles of oxidative damage, mitochondrial dysfunction, NAPDH oxidase, the blood-brain barrier, excitotoxicity, and neuroinflammation in the development of epilepsy. We also review the therapies used to treat epilepsy and prevent seizures, including anti-seizure medications, anti-epileptic drugs, anti-inflammatory therapies, and antioxidant therapies. In addition, we review the use of neuromodulation and surgery in the treatment of epilepsy. Finally, we present the role of dietary and nutritional strategies in the management of epilepsy, including the ketogenic diet and the intake of vitamins, polyphenols, and flavonoids. By reviewing available interventions and research on the pathophysiology of epilepsy, this review points to areas of further development for therapies that can manage epilepsy.
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Affiliation(s)
- Sahithi Madireddy
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Naylor DE. In the fast lane: Receptor trafficking during status epilepticus. Epilepsia Open 2023; 8 Suppl 1:S35-S65. [PMID: 36861477 PMCID: PMC10173858 DOI: 10.1002/epi4.12718] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
Status epilepticus (SE) remains a significant cause of morbidity and mortality and often is refractory to standard first-line treatments. A rapid loss of synaptic inhibition and development of pharmacoresistance to benzodiazepines (BZDs) occurs early during SE, while NMDA and AMPA receptor antagonists remain effective treatments after BZDs have failed. Multimodal and subunit-selective receptor trafficking within minutes to an hour of SE involves GABA-A, NMDA, and AMPA receptors and contributes to shifts in the number and subunit composition of surface receptors with differential impacts on the physiology, pharmacology, and strength of GABAergic and glutamatergic currents at synaptic and extrasynaptic sites. During the first hour of SE, synaptic GABA-A receptors containing γ2 subunits move to the cell interior while extrasynaptic GABA-A receptors with δ subunits are preserved. Conversely, NMDA receptors containing N2B subunits are increased at synaptic and extrasynaptic sites, and homomeric GluA1 ("GluA2-lacking") calcium permeant AMPA receptor surface expression also is increased. Molecular mechanisms, largely driven by NMDA receptor or calcium permeant AMPA receptor activation early during circuit hyperactivity, regulate subunit-specific interactions with proteins involved with synaptic scaffolding, adaptin-AP2/clathrin-dependent endocytosis, endoplasmic reticulum (ER) retention, and endosomal recycling. Reviewed here is how SE-induced shifts in receptor subunit composition and surface representation increase the excitatory to inhibitory imbalance that sustains seizures and fuels excitotoxicity contributing to chronic sequela such as "spontaneous recurrent seizures" (SRS). A role for early multimodal therapy is suggested both for treatment of SE and for prevention of long-term comorbidities.
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Affiliation(s)
- David E Naylor
- VA Greater Los Angeles Healthcare System, Department of Neurology, David Geffen School of Medicine at UCLA, and The Lundquist Institute at Harbor-UCLA Medical Center, Los Angeles, California, USA
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4
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Magnesium and the Brain: A Focus on Neuroinflammation and Neurodegeneration. Int J Mol Sci 2022; 24:ijms24010223. [PMID: 36613667 PMCID: PMC9820677 DOI: 10.3390/ijms24010223] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
Magnesium (Mg) is involved in the regulation of metabolism and in the maintenance of the homeostasis of all the tissues, including the brain, where it harmonizes nerve signal transmission and preserves the integrity of the blood-brain barrier. Mg deficiency contributes to systemic low-grade inflammation, the common denominator of most diseases. In particular, neuroinflammation is the hallmark of neurodegenerative disorders. Starting from a rapid overview on the role of magnesium in the brain, this narrative review provides evidences linking the derangement of magnesium balance with multiple sclerosis, Alzheimer's, and Parkinson's diseases.
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Yang JS, Jeon S, Jang HJ, Yoon SH. Group 1 metabotropic glutamate receptor 5 is involved in synaptically-induced Ca 2+-spikes and cell death in cultured rat hippocampal neurons. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2022; 26:531-540. [PMID: 36302627 PMCID: PMC9614404 DOI: 10.4196/kjpp.2022.26.6.531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 10/14/2022] [Accepted: 10/14/2022] [Indexed: 11/07/2022]
Abstract
Group 1 metabotropic glutamate receptors (mGluRs) can positively affect postsynaptic neuronal excitability and epileptogenesis. The objective of the present study was to determine whether group 1 mGluRs might be involved in synaptically-induced intracellular free Ca2+ concentration ([Ca2+]i) spikes and neuronal cell death induced by 0.1 mM Mg2+ and 10 µM glycine in cultured rat hippocampal neurons from embryonic day 17 fetal Sprague–Dawley rats using imaging methods for Ca2+ and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays for cell survival. Reduction of extracellular Mg2+ concentration ([Mg2+]o) to 0.1 mM induced repetitive [Ca2+]i spikes within 30 sec at day 11.5. The mGluR5 antagonist 6-Methyl-2-(phenylethynyl) pyridine (MPEP) almost completely inhibited the [Ca2+]i spikes, but the mGluR1 antagonist LY367385 did not. The group 1 mGluRs agonist, 3,5-dihydroxyphenylglycine (DHPG), significantly increased the [Ca2+]i spikes. The phospholipase C inhibitor U73122 significantly inhibited the [Ca2+]i spikes in the absence or presence of DHPG. The IP3 receptor antagonist 2-aminoethoxydiphenyl borate or the ryanodine receptor antagonist 8-(diethylamino)octyl 3,4,5-trimethoxybenzoate also significantly inhibited the [Ca2+]i spikes in the absence or presence of DHPG. The TRPC channel inhibitors SKF96365 and flufenamic acid significantly inhibited the [Ca2+]i spikes in the absence or presence of DHPG. The mGluR5 antagonist MPEP significantly increased the neuronal cell survival, but mGluR1 antagonist LY367385 did not. These results suggest a possibility that mGluR5 is involved in synaptically-induced [Ca2+]i spikes and neuronal cell death in cultured rat hippocampal neurons by releasing Ca2+ from IP3 and ryanodine-sensitive intracellular stores and activating TRPC channels.
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Affiliation(s)
- Ji Seon Yang
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
| | - Sujeong Jeon
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
| | - Hyun-Jong Jang
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
| | - Shin Hee Yoon
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.,Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
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Research progress on oxidative stress regulating different types of neuronal death caused by epileptic seizures. Neurol Sci 2022; 43:6279-6298. [DOI: 10.1007/s10072-022-06302-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 07/24/2022] [Indexed: 12/09/2022]
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7
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Moro L, Rech G, Linazzi AM, Dos Santos TG, de Oliveira DL. An optimized method for adult zebrafish brain-tissue dissociation that allows access mitochondrial function under healthy and epileptic conditions. Brain Res 2021; 1765:147498. [PMID: 33894225 DOI: 10.1016/j.brainres.2021.147498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 03/27/2021] [Accepted: 04/19/2021] [Indexed: 11/26/2022]
Abstract
Mitochondria play key roles in brain metabolism. Not surprisingly, mitochondria dysfunction is a ubiquitous cause of neurodegenerative diseases. In turn, acquired forms of epilepsy etiology is specifically intriguing since mitochondria function and dysfunction remain not completely enlightened. Investigation in the field includes models of epileptic disorder using mainly rodents followed by mitochondrial function evaluation, which in general evidenced controversial data. So, we considered the efforts and limitations in this research field and we took into account that sample preparation and quality are critical for bioenergetics investigation. For these reasons the aim of the present study was to develop a thorough protocol for adult zebrafish brain-tissue dissociation to evaluate oxygen consumption flux and reach the bioenergetics profile in health and models of epileptic disorder in both, in vitro using pentylenetetrazole (PTZ) and N-methyl-D-Aspartic acid (NMDA), and in vivo after kainic acid (KA)-induced status epilepticus. In conclusion, we verify that fire-polished glass Pasteur pipette is eligible to brain-tissue dissociation and to study mitochondrial function and dysfunction in adult zebrafish. The results give evidence for large effect size in increase of coupling efficiency respiration (p/O2) correlated to treatment with PTZ and spare respiratory capacity (SRC) in KA-induced model indicating oxidative phosphorylation (OXPHOS) variable alterations. Further investigation is needed in order to clarify the bioenergetics role as well as other mitochondrial functions in epilepsy.
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Affiliation(s)
- Luana Moro
- Laboratory of Cellular Neurochemistry - Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Porto Alegre, RS, Brazil.
| | - Giovana Rech
- Laboratory of Cellular Neurochemistry - Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Porto Alegre, RS, Brazil.
| | - Amanda Martins Linazzi
- Laboratory of Cellular Neurochemistry - Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Porto Alegre, RS, Brazil
| | - Thainá Garbino Dos Santos
- Laboratory of Cellular Neurochemistry - Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Porto Alegre, RS, Brazil
| | - Diogo Lösch de Oliveira
- Laboratory of Cellular Neurochemistry - Universidade Federal do Rio Grande do Sul, Programa de Pós-Graduação em Ciências Biológicas - Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Porto Alegre, RS, Brazil
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Yang CS, Chiu SC, Liu PY, Wu SN, Lai MC, Huang CW. Gastrodin alleviates seizure severity and neuronal excitotoxicities in the rat lithium-pilocarpine model of temporal lobe epilepsy via enhancing GABAergic transmission. JOURNAL OF ETHNOPHARMACOLOGY 2021; 269:113751. [PMID: 33359863 DOI: 10.1016/j.jep.2020.113751] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 09/03/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Temporal lobe epilepsy remains one of the most drug-resistant focal epilepsy, leading to enormous healthcare burden. Among traditional herb medicine, some ingredients have the potential to treat seizure and alleviate the neuronal excitoxicity. The dried rhizome of Gastrodia elata Blume has been used to treat convulsive disorder, dizziness, dementia and migraine in eastern Asia. AIM OF THE STUDY To determine whether gastrodin, an active ingredient of Gastrodia elata Blume, can reduce lithium-pilocarpine induced seizure severity and neuronal excitotoxicity and explore the underlying mechanism. MATERIALS AND METHODS We divided the Sprague-Dawley rats into an experimental group (gastrodin group) and a control group (Dimethyl sulfoxide, vehicle group) and performed the behavioral analysis and electroencephalography to determine the effect of gastrodin on the seizure severity induced by lithium-pilocarpine injection. Nissl-stained histopathology elucidated the degree of rat hippocampal neuronal damage as markers of acute and subacute neuronal excitotoxicity. Besides, the Western blotting of dissected hippocampus was carried out to demonstrate the protein expression involving GABAergic transmission and metabolic pathway. RESULTS Gastrodin reduced the acute seizure severity in lithium-pilocarpine-induced seizure model. In electroencephalography recording, gastrodin exerted inhibitory action on epileptiform discharge. Compared with control group, gastrodin exhibited neuroprotective effect against seizure related hippocampal neuronal damage at acute and subacute stages. The Western blotting showed that gastrodin reversed the degradation of GABAA receptor after pilocarpine-induced seizures. CONCLUSIONS In the experimental seizure model, gastrodin showed anti-seizure and neuroprotective abilities. Enhancing the expression of GABAA receptor plays an important role in its antiepileptic mechanism. The results offer a new insight of developing new antiepileptic drugs from traditional Chinese medicine.
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Affiliation(s)
- Chih-Sheng Yang
- Department of Neurology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung City, 42743, Taiwan.
| | - Sheng-Chun Chiu
- Department of Research, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung City, 42743, Taiwan.
| | - Ping-Yen Liu
- Department of Cardiology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan City, 70101, Taiwan.
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan City, 70101, Taiwan; Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City, 70101, Taiwan; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung City, 40402, Taiwan.
| | - Ming-Chi Lai
- Department of Pediatrics, Chi-Mei Medical Center, Tainan City, 70101, Taiwan.
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan City, 70101, Taiwan.
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Joshi S, Goodkin HP. The Need to Intervene Before Time Point 2: Evidence From Clinical and Animal Data That Status Epilepticus Damages the Brain. J Clin Neurophysiol 2020; 37:375-380. [PMID: 32890057 DOI: 10.1097/wnp.0000000000000711] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Status epilepticus, a condition characterized by abnormally prolonged seizures, has the potential to cause irreversible, structural or functional, injury to the brain. Unfavorable consequences of these seizures include mortality, the risk of developing epilepsy, and cognitive impairment. We highlight key findings of clinical and laboratory studies that have provided insights into aspects of cell death, and anatomical and functional alterations triggered by status epilepticus that support the need to intervene before time point 2, the time after which the risk of these long-term consequences increases.
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Affiliation(s)
- Suchitra Joshi
- Department of Neurology, UVA Health, Charlottesville, Virginia, U.S.A
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Voss LJ, van Kan C, Envall G, Lamber O. Impact of variation in tissue preparation methodology on the functional outcome of neocortical mouse brain slices. Brain Res 2020; 1747:147043. [DOI: 10.1016/j.brainres.2020.147043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/13/2020] [Accepted: 07/30/2020] [Indexed: 12/29/2022]
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Liu X, Geng J, Guo H, Zhao H, Ai Y. Propofol inhibited apoptosis of hippocampal neurons in status epilepticus through miR-15a-5p/NR2B/ERK1/2 pathway. Cell Cycle 2020; 19:1000-1011. [PMID: 32212891 DOI: 10.1080/15384101.2020.1743909] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Although a previous study reported that propofol had a therapeutic effect in status epilepticus (SE), the mechanisms underlying the effect of propofol in SE remain unclear. The aim of this study was to explore the regulatory mechanisms underlying propofol-induced inhibition of SE.A rat SE model was established using the lithium-pilocarpine injection method. A qRT-PCR and Western blot were utilized to detect the expression of relative molecules. Cell apoptosis was evaluated by a flow cytometry assay. The interaction between miR-15a-5p and NR2B was assessed using a luciferase reporter assay.Propofol inhibited cell apoptosis and increased miR-15a-5p expression both in hippocampal tissues of SE rats and low Mg2+-induced hippocampal neurons. Propofol-induced attenuation of apoptosis of low Mg2+-induced hippocampal neurons was mediated by miR-15a-5p. miR-15a-5p targeted NR2B and negatively regulated its expression. Propofol downregulated NR2B expression, mediated by miR-15a-5p. In terms of the mechanism of action, propofol suppressed the apoptosis of Mg2+-induced hippocampal neurons through the miR-15a-5p/NR2B/ERK1/2 pathway. In vivo experiment suggested that propofol inhibited the apoptosis of hippocampal neurons in SE rats by upregulating miR-15a-5p.In terms of the molecular mechanism of propofol, it appears to inhibit apoptosis of hippocampal neurons in SE through the miR-15a-5p/NR2B/ERK1/2 pathway. The findings provide theoretical support for propofol treatment of SE.
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Affiliation(s)
- Xing Liu
- Department of Anaesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jiefeng Geng
- Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Haiming Guo
- Department of Anaesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Huaping Zhao
- Department of Anaesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yanqiu Ai
- Department of Anaesthesiology, Pain and Perioperative Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Burman RJ, Raimondo JV, Jefferys JG, Sen A, Akerman CJ. The transition to status epilepticus: how the brain meets the demands of perpetual seizure activity. Seizure 2020; 75:137-144. [DOI: 10.1016/j.seizure.2019.09.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 09/23/2019] [Indexed: 02/08/2023] Open
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13
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Alteration of Extracellular Matrix Molecules and Perineuronal Nets in the Hippocampus of Pentylenetetrazol-Kindled Mice. Neural Plast 2019; 2019:8924634. [PMID: 31827499 PMCID: PMC6885262 DOI: 10.1155/2019/8924634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/25/2019] [Accepted: 10/08/2019] [Indexed: 01/01/2023] Open
Abstract
The pathophysiological processes leading to epilepsy are poorly understood. Understanding the molecular and cellular mechanisms involved in the onset of epilepsy is crucial for drug development. Epileptogenicity is thought to be associated with changes in synaptic plasticity; however, whether extracellular matrix molecules—known regulators of synaptic plasticity—are altered during epileptogenesis is unknown. To test this, we used a pentylenetetrazole- (PTZ-) kindling model mouse to investigate changes to hippocampal parvalbumin- (PV-) positive neurons, extracellular matrix molecules, and perineuronal nets (PNNs) after the last kindled seizure. We found an increase in Wisteria floribunda agglutinin- (WFA-) and Cat-315-positive PNNs and a decrease in PV-positive neurons not surrounded by PNNs, in the hippocampus of PTZ-kindled mice compared to control mice. Furthermore, the expression of WFA- and Cat-315-positive molecules increased in the extracellular space of PTZ-kindled mice. In addition, consistent with previous studies, astrocytes were activated in PTZ-kindled mice. We propose that the increase in PNNs after kindling decreases neuroplasticity in the hippocampus and helps maintain the neural circuit for recurrent seizures. This study shows that possibility of changes in extracellular matrix molecules due to astrocyte activation is associated with epilepticus in PTZ-kindled mice.
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Ríos C, Farfán-Briseño AC, Manjarrez-Marmolejo J, Franco-Pérez J, Méndez-Armenta M, Nava-Ruiz C, Caballero-Chacón S, Ruiz-Diaz A, Baron-Flores V, Díaz-Ruiz A. Efficacy of dapsone administered alone or in combination with diazepam to inhibit status epilepticus in rats. Brain Res 2019; 1708:181-187. [DOI: 10.1016/j.brainres.2018.12.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/13/2018] [Accepted: 12/12/2018] [Indexed: 12/15/2022]
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Promising Neuroprotective Function for M2 Microglia in Kainic Acid-Induced Neurotoxicity Via the Down-Regulation of NF-κB and Caspase 3 Signaling Pathways. Neuroscience 2019; 406:86-96. [PMID: 30858108 DOI: 10.1016/j.neuroscience.2019.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 12/24/2022]
Abstract
Activated microglia have two functional states (M1 and M2) which play dual roles in neurodegenerative diseases. In the present study, we explored a possible neuroprotective function of M2 microglia against kainic acid (KA)-induced neurodegeneration in primary neurons co-cultured with different microglial populations. Neurons were isolated from the hippocampi and cortices of C57BL/6 embryos (embryonic day 16) and microglia were extracted from neonatal pups (postnatal days 0-2). Microglia were either unstimulated (M0-phenotype) or stimulated with lipopolysaccharide and interferon-γ to form the M1-phenotype, or with interleukin (IL)-4, IL-10, and transforming growth factor -β for the M2-phenotype. Neurons were co-cultured with each of the three microglial phenotypes and treated with KA for 24 h. Next, we analyzed the cell survival rate, nitric oxide (NO) levels, and lactate dehydrogenase production, cytokines levels, and expression of nuclear factor κB (NF-κB) and caspase 3 among the three groups before and after KA insult. Our results indicated that M2 microglia played a neuroprotective role in KA-induced neurotoxicity, as demonstrated by high neuronal survival as well as decreased production of NO and pro-inflammatory cytokines. In contrast, neurons co-cultured with M1 microglia exhibited the lowest survival rate as well as increased levels of NO and pro-inflammatory cytokines. Further, the expression of NF-κB and caspase 3 were significantly decreased in M2 microglia co-cultures compared to M1 or M0 microglia co-cultures after KA insult. Therefore, M2 microglia may exert a neuroprotective function in KA-induced neurotoxicity via the down-regulation of NF-κB and caspase 3 signaling pathways.
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16
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Jackson C, Ardinger C, Winter KM, McDonough JH, McCarren HS. Validating a model of benzodiazepine refractory nerve agent-induced status epilepticus by evaluating the anticonvulsant and neuroprotective effects of scopolamine, memantine, and phenobarbital. J Pharmacol Toxicol Methods 2019; 97:1-12. [PMID: 30790623 PMCID: PMC6529248 DOI: 10.1016/j.vascn.2019.02.006] [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: 10/24/2018] [Revised: 02/05/2019] [Accepted: 02/14/2019] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Organophosphorus nerve agents (OPNAs) irreversibly block acetylcholinesterase activity, resulting in accumulation of excess acetylcholine at neural synapses, which can lead to a state of prolonged seizures known as status epilepticus (SE). Benzodiazepines, the current standard of care for SE, become less effective as latency to treatment increases. In a mass civilian OPNA exposure, concurrent trauma and limited resources would likely cause a delay in first response time. To address this issue, we have developed a rat model to test novel anticonvulsant/ neuroprotectant adjuncts at delayed time points. METHODS For model development, adult male rats with cortical electroencephalographic (EEG) electrodes were exposed to soman and administered saline along with atropine, 2-PAM, and midazolam 5, 20, or 40 min after SE onset. We validated our model using three drugs: scopolamine, memantine, and phenobarbital. Using the same procedure outlined above, rats were given atropine, 2-PAM, midazolam and test treatment 20 min after SE onset. RESULTS Using gamma power, delta power, and spike rate to quantify EEG activity, we found that scopolamine was effective, memantine was minimally effective, and phenobarbital had a delayed effect on terminating SE. Fluoro-Jade B staining was used to assess neuroprotection in five brain regions. Each treatment provided significant protection compared to saline + midazolam in at least two brain regions. DISCUSSION Because our data agree with previously published studies on the efficacy of these compounds, we conclude that this model is a valid way to test novel anticonvulsants/ neuroprotectants for controlling benzodiazepine-resistant OPNA-induced SE and subsequent neuropathology.
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Affiliation(s)
| | | | | | | | - Hilary S. McCarren
- Corresponding author at: U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD 21010, USA
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Zeng X, Hu K, Chen L, Zhou L, Luo W, Li C, Zong W, Chen S, Gao Q, Zeng G, Jiang D, Li X, Zhou H, Ouyang DS. The Effects of Ginsenoside Compound K Against Epilepsy by Enhancing the γ-Aminobutyric Acid Signaling Pathway. Front Pharmacol 2018; 9:1020. [PMID: 30254585 PMCID: PMC6142013 DOI: 10.3389/fphar.2018.01020] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 08/22/2018] [Indexed: 01/15/2023] Open
Abstract
The imbalance between the GABA-mediated inhibition and the glutamate-mediated excitation is the primary pathological mechanism of epilepsy. GABAergic and glutamatergic neurotransmission have become the most important targets for controlling epilepsy. Ginsenoside compound K (GCK) is a main metabolic production of the ginsenoside Rb1, Rb2, and Rc in the intestinal microbiota. Previous studies show that GCK promoted the release of GABA from the hippocampal neurons and enhanced the activity of GABAA receptors. GCK is shown to reduce the expression of NMDAR and to attenuate the function of the NMDA receptors in the brain. The anti-seizure effects of GCK have not been reported so far. Therefore, this study aimed to investigate the effects of GCK on epilepsy and its potential mechanism. The rat model of seizure or status epilepticus (SE) was established with either Pentylenetetrazole or Lithium chloride-pilocarpine. The Racine's scale was used to evaluate seizure activity. The levels of the amino acid neurotransmitters were detected in the pilocarpine-induced epileptic rats. The expression levels of GABAARα1, NMDAR1, KCC2, and NKCC1 protein in the hippocampus were determined via western blot or immunohistochemistry after SE. We found that GCK had deceased seizure intensity and prolonged the latency of seizures. GCK increased the contents of GABA, while the contents of glutamate remained unchanged. GCK enhanced the expression of GABAARα1 in the brain and exhibited a tendency to decrease the expression of NMDAR1 protein in the hippocampus. The expression of KCC2 protein was elevated by the treatment of GCK after SE, while the expression of NKCC1 protein was reversely down-regulated. These findings suggested that GCK exerted anti-epileptic effects by promoting the hippocampal GABA release and enhancing the GABAAR-mediated inhibitory synaptic transmission.
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Affiliation(s)
- Xiangchang Zeng
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Kai Hu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Lulu Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Luping Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Wei Luo
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Chaopeng Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Wenjing Zong
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Siyu Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Qing Gao
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Guirong Zeng
- Hunan Key Laboratory of Pharmacodynamics and Safety Evaluation of New Drugs & Hunan Provincial Research Center for Safety Evaluation of Drugs, Changsha, China
| | - Dejian Jiang
- Hunan Key Laboratory of Pharmacodynamics and Safety Evaluation of New Drugs & Hunan Provincial Research Center for Safety Evaluation of Drugs, Changsha, China
| | - Xiaohui Li
- Department of Pharmacology, School of Pharmaceutical Sciences, Central South University, Changsha, China.,Hunan Key Laboratory for Bioanalysis of Complex Matrix Samples, Changsha Duxact Biotech Co., Ltd., Changsha, China
| | - Honghao Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Dong-Sheng Ouyang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China.,Hunan Key Laboratory for Bioanalysis of Complex Matrix Samples, Changsha Duxact Biotech Co., Ltd., Changsha, China
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18
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Gastrodin Suppresses Pentylenetetrazole-Induced Seizures Progression by Modulating Oxidative Stress in Zebrafish. Neurochem Res 2018; 43:904-917. [DOI: 10.1007/s11064-018-2496-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 02/01/2018] [Accepted: 02/05/2018] [Indexed: 01/06/2023]
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19
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Wu G, Yu J, Wang L, Ren S, Zhang Y. PKC/CREB pathway mediates the expressions of GABA A receptor subunits in cultured hippocampal neurons after low-Mg 2+ solution treatment. Epilepsy Res 2018; 140:155-161. [PMID: 29414524 DOI: 10.1016/j.eplepsyres.2017.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 10/08/2017] [Accepted: 11/16/2017] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To investigate the potential effects of the PKC/CREB pathway on the expressions of GABAA receptor subunits α1, γ2, and δ in cultured hippocampal neurons using a model of epilepsy that employed conditions of low magnesium (Mg2+). METHODS A total of 108 embryonic rats at the age of 18 embryonic days (E18)prepared from adult female SD rats were used as experimental subjects. Primary rat hippocampal cultures were prepared from the embryonic 18 days rats. The cultured hippocampal neurons were then treated with artificial cerebrospinal fluid containing low Mg2+ solutions to generate a low Mg2+ model of epilepsy. The low Mg2+ stimulation lasted for 3 h and then returned to in maintenance medium for 20 h. The changes of the GABAA receptor subunit α1, γ2, δ were observed by blocking or activating the function of the CREB. The quantification of the GABAA receptor subunit α1, γ2, δ and the CREB were determined by a qRT-PCR and a Western blot method. RESULTS After the neurons were exposed to a low-Mg2+ solution for 3 h, GABAA receptor mRNA expression markedly increased compared to the control, and then gradually decreased. In contrast, CREB mRNA levels exhibited a dramatic down-regulation 3 h after terminating low-Mg2+ treatment, and then peaked at 9 h. Western blot analyses verified that staurosporine suppressed CREB phosphorylation (p-CREB). The mRNA expression of GABAA receptor subunit α1 increased only in the presence of staurosporine, whereas the expressions of subunits γ2 and δ significantly increased in the presence of either KG-501 or staurosporine. Furthermore, phorbol 12-myristate 13-acetate (PMA) decreased the expressions of GABAA subunits α1, γ2, and δ when administered alone. However, the administration of either KG-501 or staurosporine reversed the inhibitory effects of PMA. CONCLUSIONS The PKC/CREB pathway may negatively regulate the expressions of GABAA receptor subunits α1, γ2, and δ in cultured hippocampal neurons in low Mg2+ model of epilepsy.
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Affiliation(s)
- Guofeng Wu
- Emergency Department of the Affiliated Hospital, Guizhou Medical University, Guiyang City, 550004, PR China.
| | - Jinpeng Yu
- Emergency Department of the Affiliated Hospital, Guizhou Medical University, Guiyang City, 550004, PR China
| | - Likun Wang
- Emergency Department of the Affiliated Hospital, Guizhou Medical University, Guiyang City, 550004, PR China
| | - Siying Ren
- Emergency Department of the Affiliated Hospital, Guizhou Medical University, Guiyang City, 550004, PR China
| | - Yixia Zhang
- Guizhou Centre for Disease Control and Prevention, Guiyang City, 550004, PR China
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20
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McCarren HS, Arbutus JA, Ardinger C, Dunn EN, Jackson CE, McDonough JH. Dexmedetomidine stops benzodiazepine-refractory nerve agent-induced status epilepticus. Epilepsy Res 2018; 141:1-12. [PMID: 29414381 DOI: 10.1016/j.eplepsyres.2018.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/21/2017] [Accepted: 01/07/2018] [Indexed: 12/15/2022]
Abstract
Nerve agents are highly toxic chemicals that pose an imminent threat to soldiers and civilians alike. Nerve agent exposure leads to an increase in acetylcholine within the central nervous system, resulting in development of protracted seizures known as status epilepticus (SE). Currently, benzodiazepines are the standard of care for nerve agent-induced SE, but their efficacy quickly wanes as the time to treatment increases. Here, we examine the role of the α2-adrenoceptor in termination of nerve agent-induced SE using the highly specific agonist dexmedetomidine (DEX). Adult male rats were exposed to soman and entered SE as confirmed by electroencephalograph (EEG). We observed that administration of DEX in combination with the benzodiazepine midazolam (MDZ) 20 or 40 min after the onset of SE stopped seizures and returned processed EEG measurements to baseline levels. The protective effect of DEX was blocked by the α2-adrenoceptor antagonist atipamezole (ATI), but ATI failed to restore seizure activity after it was already halted by DEX in most cases, suggesting that α2-adrenoceptors may be involved in initiating SE cessation rather than merely suppressing seizure activity. Histologically, treatment with DEX + MDZ significantly reduced the number of dying neurons as measured by FluoroJade B in the amygdala, thalamus, and piriform cortex, but did not protect the hippocampus or parietal cortex even when SE was successfully halted. We conclude that DEX serves not just as a valuable potential addition to the anticonvulsant regimen for nerve agent exposure, but also as a tool for dissecting the neural circuitry that drives SE.
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Affiliation(s)
- Hilary S McCarren
- USAMRICD, Medical Toxicology Research Division, Neuroscience Branch, 2900 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, United States.
| | - Julia A Arbutus
- USAMRICD, Medical Toxicology Research Division, Neuroscience Branch, 2900 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, United States
| | - Cherish Ardinger
- USAMRICD, Medical Toxicology Research Division, Neuroscience Branch, 2900 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, United States
| | - Emily N Dunn
- USAMRICD, Medical Toxicology Research Division, Neuroscience Branch, 2900 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, United States
| | - Cecelia E Jackson
- USAMRICD, Medical Toxicology Research Division, Neuroscience Branch, 2900 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, United States
| | - John H McDonough
- USAMRICD, Medical Toxicology Research Division, Neuroscience Branch, 2900 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, United States
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21
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Tang L, Yan M, Leng T, Yin W, Cai S, Duan S, Zhu W, Lin S, Huang J, Yan G, Zheng G, Chen Y. Cholestane-3β, 5α, 6β-triol suppresses neuronal hyperexcitability via binding to voltage-gated sodium channels. Biochem Biophys Res Commun 2018; 496:95-100. [DOI: 10.1016/j.bbrc.2018.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 01/01/2018] [Indexed: 12/24/2022]
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22
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Liu HJ, Lai X, Xu Y, Miao JK, Li C, Liu JY, Hua YY, Ma Q, Chen Q. α-Asarone Attenuates Cognitive Deficit in a Pilocarpine-Induced Status Epilepticus Rat Model via a Decrease in the Nuclear Factor-κB Activation and Reduction in Microglia Neuroinflammation. Front Neurol 2017; 8:661. [PMID: 29312110 PMCID: PMC5735142 DOI: 10.3389/fneur.2017.00661] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/22/2017] [Indexed: 12/02/2022] Open
Abstract
Background Temporal lobe epilepsy (TLE) is one of the most drug-resistant types of epilepsy with about 80% of TLE patients falling into this category. Increasing evidence suggests that neuroinflammation, which has a critical role in the epileptogenesis of TLE, is associated with microglial activation. Therefore, agents that act toward the alleviation in microglial activation and the attenuation of neuroinflammation are promising candidates to treat TLE. α-Asarone is a major active ingredient of the Acori Graminei Rhizoma used in Traditional Chinese Medicine, which has been used to improve various disease conditions including stroke and convulsions. In addition, an increasing number of studies suggested that α-asarone can attenuate microglia-mediated neuroinflammation. Thus, we hypothesized that α-asarone is a promising neuroprotective agent for the treatment of the TLE. Methods The present study evaluated the therapeutic effects of α-asarone on microglia-mediated neuroinflammation and neuroprotection in vitro and in vivo, using an untreated control group, a status epilepticus (SE)-induced group, and an SE-induced α-asarone pretreated group. A pilocarpine-induced rat model of TLE was established to investigate the neuroprotective effects of α-asarone in vivo. For the in vitro study, lipopolysaccharide (LPS)-stimulated primary cultured microglial cells were used. Results The results indicated that the brain microglial activation in the rats of the SE rat model led to important learning and memory deficit. Preventive treatment with α-asarone restrained microglial activation and reduced learning and memory deficit. In the in vitro studies, α-asarone significantly suppressed proinflammatory cytokine production in primary cultured microglial cells and attenuated the LPS-stimulated neuroinflammatory responses. Our mechanistic study revealed that α-asarone inhibited inflammatory processes by regulation the transcription levels of kappa-B, by blocking the degradation pathway of kappa B-alpha [inhibitor kappa B-alpha (IκB-α)] and kappa B-beta (IκB-β) kinase in both the SE rats and in primary cultured microglial cells. Conclusion Taken together, these data demonstrate that α-asarone is a promising neuroprotective agent for the prevention and treatment of microglia-mediated neuroinflammatory conditions including TLE, for which further assessment studies are pertinent.
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Affiliation(s)
- Hui-Juan Liu
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Xin Lai
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Yan Xu
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
| | - Jing-Kun Miao
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China.,Center for Clinical Molecular Medicine, Chongqing, China
| | - Chun Li
- Department of Neonatology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
| | - Jing-Ying Liu
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Yuan-Yuan Hua
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Qian Ma
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Qixiong Chen
- Department of Neonatology, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
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Tran HQ, Chung YH, Shin EJ, Tran TV, Jeong JH, Jang CG, Nah SY, Yamada K, Nabeshima T, Kim HC. MK-801, but not naloxone, attenuates high-dose dextromethorphan-induced convulsive behavior: Possible involvement of the GluN2B receptor. Toxicol Appl Pharmacol 2017; 334:158-166. [PMID: 28916251 DOI: 10.1016/j.taap.2017.09.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 09/06/2017] [Accepted: 09/11/2017] [Indexed: 10/18/2022]
Abstract
Dextromethorphan (DM) is a dextrorotatory isomer of levorphanol, a typical morphine-like opioid. When administered at supra-antitussive doses, DM produces psychotoxic and neurotoxic effects in humans. Although DM abuse has been well-documented, few studies have examined the effects of high-dose DM. The present study aimed to explore the effects of a single high dose of DM on mortality and seizure occurrence. After intraperitoneal administration with a high dose of DM (80mg/kg), Sprague-Dawley rats showed increased seizure occurrence and intensity. Hippocampal expression levels of N-methyl-d-aspartate (NMDA) receptor subunits (GluN1<GluN2A<GluN2B), c-Fos and pro-apoptotic factors (Bax and cleaved caspase-3) were upregulated by DM treatment; while levels of anti-apoptotic factors (Bcl-2 and Bcl-xL) were downregulated. Consistently, DM also induced ultrastructural degeneration in the hippocampus. A non-competitive NMDA receptor antagonist, MK-801, attenuated these effects of high-dose DM, whereas an opioid antagonist, naloxone, did not affect DM-induced neurotoxicity. Moreover, pretreatment with a highly specific GluN2B subunit inhibitor, traxoprodil, was selectively effective in preventing DM-induced c-Fos expression and apoptotic changes. These results suggest that high-dose DM produces convulsive behaviors by activating GluN2B/NMDA signaling that leads to pro-apoptotic changes.
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Affiliation(s)
- Hai-Quyen Tran
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea
| | - Yoon Hee Chung
- Department of Anatomy, College of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea.
| | - The-Vinh Tran
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea
| | - Ji Hoon Jeong
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Choon-Gon Jang
- Department of Pharmacology, School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Seung-Yeol Nah
- Ginsentology Research Laboratory, Department of Physiology, College of Veterinary Medicine, Konkuk University, Seoul 05029, Republic of Korea
| | - Kiyofumi Yamada
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan
| | - Toshitaka Nabeshima
- Advanced Diagnostic System Research Laboratory, Fujita Health University Graduate School of Health Science, Aichi 470-1192, Japan
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea.
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Kovac S, Dinkova Kostova AT, Herrmann AM, Melzer N, Meuth SG, Gorji A. Metabolic and Homeostatic Changes in Seizures and Acquired Epilepsy-Mitochondria, Calcium Dynamics and Reactive Oxygen Species. Int J Mol Sci 2017; 18:E1935. [PMID: 28885567 PMCID: PMC5618584 DOI: 10.3390/ijms18091935] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 09/02/2017] [Accepted: 09/05/2017] [Indexed: 12/17/2022] Open
Abstract
Acquired epilepsies can arise as a consequence of brain injury and result in unprovoked seizures that emerge after a latent period of epileptogenesis. These epilepsies pose a major challenge to clinicians as they are present in the majority of patients seen in a common outpatient epilepsy clinic and are prone to pharmacoresistance, highlighting an unmet need for new treatment strategies. Metabolic and homeostatic changes are closely linked to seizures and epilepsy, although, surprisingly, no potential treatment targets to date have been translated into clinical practice. We summarize here the current knowledge about metabolic and homeostatic changes in seizures and acquired epilepsy, maintaining a particular focus on mitochondria, calcium dynamics, reactive oxygen species and key regulators of cellular metabolism such as the Nrf2 pathway. Finally, we highlight research gaps that will need to be addressed in the future which may help to translate these findings into clinical practice.
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Affiliation(s)
- Stjepana Kovac
- Department of Neurology, University of Münster, 48149 Münster, Germany.
| | - Albena T Dinkova Kostova
- Division of Cancer Research, School of Medicine, Jacqui Wood Cancer Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK.
- Departments of Medicine and Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | | | - Nico Melzer
- Department of Neurology, University of Münster, 48149 Münster, Germany.
| | - Sven G Meuth
- Department of Neurology, University of Münster, 48149 Münster, Germany.
| | - Ali Gorji
- Department of Neurology, University of Münster, 48149 Münster, Germany.
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran 1996836111, Iran.
- Department of Neuroscience, Mashhad University of Medical Sciences, Mashhad 9177948564, Iran.
- Department of Neurosurgery, University of Münster, 48149 Münster, Germany.
- Epilepsy Research Center, University of Münster, 48149 Münster, Germany.
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25
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Cho YJ, Kim H, Kim WJ, Chung S, Kim YH, Cho I, Lee BI, Heo K. Trafficking patterns of NMDA and GABA A receptors in a Mg 2+-free cultured hippocampal neuron model of status epilepticus. Epilepsy Res 2017; 136:143-148. [PMID: 28858777 DOI: 10.1016/j.eplepsyres.2017.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 07/01/2017] [Accepted: 08/12/2017] [Indexed: 11/27/2022]
Abstract
An altered pattern of receptor trafficking is one of the pathophysiologic mechanisms of status epilepticus (SE). The gradual internalization of GABAA receptors (GABARs) occurs in both in vitro and in vivo models of SE and is thought to be a cause of decreased GABAergic inhibition. Unlike GABARs, little is known about alterations in NMDA receptor (NMDAR) trafficking during SE, even though increased activity of NMDARs is indispensable for the induction and maintenance of SE. Therefore, we aimed to simultaneously investigate the changes in the trafficking patterns of GABARs and NMDARs in an in vitro cultured hippocampal neuron model of SE. For induction of epileptiform discharges, hippocampal neurons were exposed to external medium without Mg2+. Biotinylation assay and immunofluorescence staining for GABAR β2,3 and NMDAR NR1 subunits were performed to quantify and visualize surface GABARs and NMDARs, respectively. The frequency of spontaneous action potentials increased more than 4-fold after Mg2+-free induction. The level of surface GABARs decreased over time after Mg2+-free induction, dropping to approximately 50% of control levels an hour after Mg2+-free induction. By contrast, the trafficking of NMDARs to the surface was enhanced after a slight time lag, increasing by 30% of control levels an hour after Mg2+-free induction. Our data showed the changes of both NMDAR and GABAR trafficking during prolonged SE induced by a Mg2+-free extracellular environment and confirmed that this in vitro SE model is suitable for examining alterations in the receptor trafficking pattern by prolonged seizure activity. These results suggest that targeting of surface NMDAR could be a promising method in controlling benzodiazepine-resistant SE.
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Affiliation(s)
- Yang-Je Cho
- Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Hyunjeong Kim
- Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Won-Joo Kim
- Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Seungsoo Chung
- Department of Physiology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Young-Hwan Kim
- Department of Physiology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Inja Cho
- Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Brain Korea 21 Plus Project for Medical Science, Yonsei University, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Byung In Lee
- Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea; Department of Neurology, Inje University Haeundae Paik Hospital, 875 Haeun-daero, Haeundae-gu, Busan 48108, Republic of Korea
| | - Kyoung Heo
- Department of Neurology, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
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Medaglia JD. Functional Neuroimaging in Traumatic Brain Injury: From Nodes to Networks. Front Neurol 2017; 8:407. [PMID: 28883806 PMCID: PMC5574370 DOI: 10.3389/fneur.2017.00407] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 07/28/2017] [Indexed: 12/16/2022] Open
Abstract
Since the invention of functional magnetic resonance imaging (fMRI), thousands of studies in healthy and clinical samples have enlightened our understanding of the organization of cognition in the human brain and neuroplastic changes following brain disease and injury. Increasingly, studies involve analyses rooted in complex systems theory and analysis applied to clinical samples. Given the complexity in available approaches, concise descriptions of the theoretical motivation of network techniques and their relationship to traditional approaches and theory are necessary. To this end, this review concerns the use of fMRI to understand basic cognitive function and dysfunction in the human brain scaling from emphasis on basic units (or "nodes") in the brain to interactions within and between brain networks. First, major themes and theoretical issues in the scientific study of the injured brain are introduced to contextualize these analyses, particularly concerning functional "brain reorganization." Then, analytic approaches ranging from the voxel level to the systems level using graph theory and related approaches are reviewed as complementary approaches to examine neurocognitive processes following TBI. Next, some major findings relevant to functional reorganization hypotheses are discussed. Finally, major open issues in functional network analyses in neurotrauma are discussed in theoretical, analytic, and translational terms.
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Affiliation(s)
- John D Medaglia
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, United States
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Fournier K, Baumont E, Glorennec P, Bonvallot N. Relative toxicity for indoor semi volatile organic compounds based on neuronal death. Toxicol Lett 2017; 279:33-42. [PMID: 28709981 DOI: 10.1016/j.toxlet.2017.07.875] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 07/03/2017] [Accepted: 07/09/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND Semi Volatile Organic Compounds (SVOCs) are contaminants commonly found in dwellings as a result of their use as plasticizers, flame retardants, or pesticides in building materials and consumer products. Many SVOCs are suspected of being neurotoxic, based on mammal experimentation (impairment of locomotor activity, spatial learning/memory or behavioral changes), raising the question of cumulative risk assessment. The aim of this work is to estimate the relative toxicity of such SVOCs, based on neuronal death. METHOD SVOCs fulfilling the following conditions were included: detection frequency >10% in dwellings, availability of data on effects or mechanism of action for neurotoxicity, and availability of dose-response relationships based on cell viability assays as a proxy of neuronal death. Benchmark concentration values (BMC) were estimated using a Hill model, and compared to assess relative toxicity. RESULTS Of the 58 SVOCs selected, 28 were suspected of being neurotoxic in mammals, and 21 have been documented as inducing a decrease in cell viability in vitro. 13 have at least one dose-response relationship that can be used to derive a BMC based on a 10% fall in neuronal viability. Based on this in vitro endpoint, PCB-153 appeared to be the most toxic compound, having the lowest BMC10 (0.072μM) and diazinon the least toxic compound, having the highest BMC10 (94.35μM). We showed that experimental designs (in particular choice of cell lines) had a significant influence on BMC calculation. CONCLUSION For the first time, the relative in vitro toxicity of 13 indoor contaminants belonging to different chemical families has been assessed on the basis of neuronal cell viability. Lack of comparable toxicity datasets limits the number of SVOCs that can be included. More standardized protocols in terms of cell lines, species and exposure duration should be developed with a view to cumulative risk assessment.
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Affiliation(s)
- Kevin Fournier
- EHESP School of Public Health, Sorbonne Paris Cité, Avenue du Professeur Léon Bernard, 35043 Rennes Cedex, France; INSERM UMR1085 IRSET (Research Institute in Environmental and Occupational Health), Rennes, France.
| | - Emmanuel Baumont
- EHESP School of Public Health, Sorbonne Paris Cité, Avenue du Professeur Léon Bernard, 35043 Rennes Cedex, France; INSERM UMR1085 IRSET (Research Institute in Environmental and Occupational Health), Rennes, France.
| | - Philippe Glorennec
- EHESP School of Public Health, Sorbonne Paris Cité, Avenue du Professeur Léon Bernard, 35043 Rennes Cedex, France; INSERM UMR1085 IRSET (Research Institute in Environmental and Occupational Health), Rennes, France.
| | - Nathalie Bonvallot
- EHESP School of Public Health, Sorbonne Paris Cité, Avenue du Professeur Léon Bernard, 35043 Rennes Cedex, France; INSERM UMR1085 IRSET (Research Institute in Environmental and Occupational Health), Rennes, France.
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Walker MC. Pathophysiology of status epilepticus. Neurosci Lett 2016; 667:84-91. [PMID: 28011391 DOI: 10.1016/j.neulet.2016.12.044] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/16/2016] [Accepted: 12/17/2016] [Indexed: 12/22/2022]
Abstract
Status epilepticus (SE) is the maximal expression of epilepsy with a high morbidity and mortality. It occurs due to the failure of mechanisms that terminate seizures. Both human and animal data indicate that the longer a seizure lasts, the less likely it is to stop. Recent evidence suggests that there is a critical transition from an ictal to a post-ictal state, associated with a transition from a spatio-temporally desynchronized state to a highly synchronized state, respectively. As SE continues, it becomes progressively resistant to drugs, in particular benzodiazepines due partly to NMDA receptor-dependent internalization of GABA(A) receptors. Moreover, excessive calcium entry into neurons through excessive NMDA receptor activation results in activation of nitric oxide synthase, calpains, and NADPH oxidase. The latter enzyme plays a critical part in the generation of seizure-dependent reactive oxygen species. Calcium also accumulates in mitochondria resulting in mitochondrial failure (decreased ATP production), and opening of the mitochondrial permeability transition pore. Together these changes result in status epilepticus-dependent neuronal death via several pathways. Multiple downstream mechanisms including inflammation, break down of the blood-brain barrier, and changes in gene expression can contribute to later pathological processes including chronic epilepsy and cognitive decline.
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Affiliation(s)
- Matthew C Walker
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London WC1N 3BG, United Kingdom.
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Shao H, Yang Y, Mi Z, Zhu GX, Qi AP, Ji WG, Zhu ZR. Anticonvulsant effect of Rhynchophylline involved in the inhibition of persistent sodium current and NMDA receptor current in the pilocarpine rat model of temporal lobe epilepsy. Neuroscience 2016; 337:355-369. [DOI: 10.1016/j.neuroscience.2016.09.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/12/2016] [Accepted: 09/16/2016] [Indexed: 01/28/2023]
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Kim HJ, Yang JS, Yoon SH. Brief low [Mg(2+)]o-induced Ca(2+) spikes inhibit subsequent prolonged exposure-induced excitotoxicity in cultured rat hippocampal neurons. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2015; 20:101-9. [PMID: 26807029 PMCID: PMC4722183 DOI: 10.4196/kjpp.2016.20.1.101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/23/2015] [Accepted: 11/30/2015] [Indexed: 12/18/2022]
Abstract
Reducing [Mg2+]o to 0.1 mM can evoke repetitive [Ca2+]i spikes and seizure activity, which induces neuronal cell death in a process called excitotoxicity. We examined the issue of whether cultured rat hippocampal neurons preconditioned by a brief exposure to 0.1 mM [Mg2+]o are rendered resistant to excitotoxicity induced by a subsequent prolonged exposure and whether Ca2+ spikes are involved in this process. Preconditioning by an exposure to 0.1 mM [Mg2+]o for 5 min inhibited significantly subsequent 24 h exposure-induced cell death 24 h later (tolerance). Such tolerance was prevented by both the NMDA receptor antagonist D-AP5 and the L-type Ca2+ channel antagonist nimodipine, which blocked 0.1 mM [Mg2+]o-induced [Ca2+]i spikes. The AMPA receptor antagonist NBQX significantly inhibited both the tolerance and the [Ca2+]i spikes. The intracellular Ca2+ chelator BAPTA-AM significantly prevented the tolerance. The nonspecific PKC inhibitor staurosporin inhibited the tolerance without affecting the [Ca2+]i spikes. While Gö6976, a specific inhibitor of PKCα had no effect on the tolerance, both the PKCε translocation inhibitor and the PKCζ pseudosubstrate inhibitor significantly inhibited the tolerance without affecting the [Ca2+]i spikes. Furthermore, JAK-2 inhibitor AG490, MAPK kinase inhibitor PD98059, and CaMKII inhibitor KN-62 inhibited the tolerance, but PI-3 kinase inhibitor LY294,002 did not. The protein synthesis inhibitor cycloheximide significantly inhibited the tolerance. Collectively, these results suggest that low [Mg2+]o preconditioning induced excitotoxic tolerance was directly or indirectly mediated through the [Ca2+]i spike-induced activation of PKCε and PKCξ, JAK-2, MAPK kinase, CaMKII and the de novo synthesis of proteins.
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Affiliation(s)
- Hee Jung Kim
- Department of Physiology, College of Medicine, Dankook University, Cheonan 31116, Korea
| | - Ji Seon Yang
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Shin Hee Yoon
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.; Catholic Neuroscience Institute, The Catholic University of Korea, Seoul 06591, Korea
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A Potential Role for Felbamate in TSC- and NF1-Related Epilepsy: A Case Report and Review of the Literature. Case Rep Neurol Med 2015; 2015:960746. [PMID: 26579319 PMCID: PMC4633543 DOI: 10.1155/2015/960746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 09/23/2015] [Accepted: 10/05/2015] [Indexed: 12/31/2022] Open
Abstract
A 15-year-old girl with maternal inheritance of neurofibromatosis type 1 (NF1) and paternal inheritance of tuberous sclerosis complex (TSC) developed intractable epilepsy at age 5. Her seizures were refractory to adequate doses of four antiepileptic medications until felbamate was initiated at age 7. She has since remained seizure-free on felbamate monotherapy. Although felbamate has multiple mechanisms of action, it is thought to have its most potent antiepileptic effects through inhibition of the N-methyl-D-aspartate receptor (NMDAR). Previous studies have shown that the NMDAR is altered in varying epilepsy syndromes and notably in the cortical tubers found in TSC. The aim of this paper is to examine how felbamate monotherapy was able to achieve such robust antiepileptic effects in a unique patient and possibly offer a novel therapeutic approach to patients suffering from TSC- and NF-related epilepsy.
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Ruangkittisakul A, Sharopov S, Kantor C, Kuribayashi J, Mildenberger E, Luhmann H, Kilb W, Ballanyi K. Methylxanthine-evoked perturbation of spontaneous and evoked activities in isolated newborn rat hippocampal networks. Neuroscience 2015; 301:106-20. [DOI: 10.1016/j.neuroscience.2015.05.069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/11/2015] [Accepted: 05/27/2015] [Indexed: 11/29/2022]
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Zhu X, Dong J, Shen K, Bai Y, Zhang Y, Lv X, Chao J, Yao H. NMDA receptor NR2B subunits contribute to PTZ-kindling-induced hippocampal astrocytosis and oxidative stress. Brain Res Bull 2015; 114:70-8. [DOI: 10.1016/j.brainresbull.2015.04.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 03/30/2015] [Accepted: 04/06/2015] [Indexed: 12/29/2022]
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Guo F, Zhou PD, Gao QH, Gong J, Feng R, Xu XX, Liu SY, Hu HY, Zhao MM, Adam HC, Cai JQ, Hao LY. Low-Mg(2+) treatment increases sensitivity of voltage-gated Na(+) channels to Ca(2+)/calmodulin-mediated modulation in cultured hippocampal neurons. Am J Physiol Cell Physiol 2015; 308:C594-605. [PMID: 25652447 DOI: 10.1152/ajpcell.00174.2014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 01/30/2015] [Indexed: 02/06/2023]
Abstract
Culture of hippocampal neurons in low-Mg(2+) medium (low-Mg(2+) neurons) results in induction of continuous seizure activity. However, the underlying mechanism of the contribution of low Mg(2+) to hyperexcitability of neurons has not been clarified. Our data, obtained using the patch-clamp technique, show that voltage-gated Na(+) channel (VGSC) activity, which is associated with a persistent, noninactivating Na(+) current (INa,P), was modulated by calmodulin (CaM) in a concentration-dependent manner in normal and low-Mg(2+) neurons, but the channel activity was more sensitive to Ca(2+)/CaM regulation in low-Mg(2+) than normal neurons. The increased sensitivity of VGSCs in low-Mg(2+) neurons was partially retained when CaM12 and CaM34, CaM mutants with disabled binding sites in the N or C lobe, were used but was diminished when CaM1234, a CaM mutant in which all four Ca(2+) sites are disabled, was used, indicating that functional Ca(2+)-binding sites from either lobe of CaM are required for modulation of VGSCs in low-Mg(2+) neurons. Furthermore, the number of neurons exhibiting colocalization of CaM with the VGSC subtypes NaV1.1, NaV1.2, and NaV1.3 was significantly higher in low- Mg(2+) than normal neurons, as shown by immunofluorescence. Our main finding is that low-Mg(2+) treatment increases sensitivity of VGSCs to Ca(2+)/CaM-mediated regulation. Our data reveal that CaM, as a core regulating factor, connects the functional roles of the three main intracellular ions, Na(+), Ca(2+), and Mg(2+), by modulating VGSCs and provides a possible explanation for the seizure discharge observed in low-Mg(2+) neurons.
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Affiliation(s)
- Feng Guo
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Pei-Dong Zhou
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Qing-Hua Gao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Jian Gong
- Department of Clinical Pharmacy, School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, China
| | - Rui Feng
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Xiao-Xue Xu
- Department of Neurology, The First Hospital of China Medical University, Shenyang, China; and
| | - Shu-Yuan Liu
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Hui-Yuan Hu
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Mei-Mi Zhao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Hogan-Cann Adam
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ji-Qun Cai
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Li-Ying Hao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
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Chang P, Zuckermann AME, Williams S, Close AJ, Cano-Jaimez M, McEvoy JP, Spencer J, Walker MC, Williams RSB. Seizure control by derivatives of medium chain fatty acids associated with the ketogenic diet show novel branching-point structure for enhanced potency. J Pharmacol Exp Ther 2014; 352:43-52. [PMID: 25326131 DOI: 10.1124/jpet.114.218768] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The medium chain triglyceride (MCT) ketogenic diet is a major treatment of drug-resistant epilepsy but is problematic, particularly in adults, because of poor tolerability. Branched derivatives of octanoic acid (OA), a medium chain fat provided in the diet have been suggested as potential new treatments for drug-resistant epilepsy, but the structural basis of this functionality has not been determined. Here we investigate structural variants of branched medium chain fatty acids as new seizure-control treatments. We initially employ a series of methyl-branched OA derivatives, and using the GABAA receptor antagonist pentylenetetrazol to induce seizure-like activity in rat hippocampal slices, we show a strong, branch-point-specific activity that improves upon the related epilepsy treatment valproic acid. Using low magnesium conditions to induce glutamate excitotoxicity in rat primary hippocampal neuronal cultures for the assessment of neuroprotection, we also show a structural dependence identical to that for seizure control, suggesting a related mechanism of action for these compounds in both seizure control and neuroprotection. In contrast, the effect of these compounds on histone deacetylase (HDAC) inhibition, associated with teratogenicity, shows no correlation with therapeutic efficacy. Furthermore, small structural modifications of the starting compounds provide active compounds without HDAC inhibitory effects. Finally, using multiple in vivo seizure models, we identify potent lead candidates for the treatment of epilepsy. This study therefore identifies a novel family of fatty acids, related to the MCT ketogenic diet, that show promise as new treatments for epilepsy control and possibly other MCT ketogenic diet-responding conditions, such as Alzheimer disease.
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Affiliation(s)
- Pishan Chang
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
| | - Alexandra M E Zuckermann
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
| | - Sophie Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
| | - Adam J Close
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
| | - Marife Cano-Jaimez
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
| | - James P McEvoy
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
| | - John Spencer
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
| | - Matthew C Walker
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
| | - Robin S B Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, United Kingdom (P.C., A.M.E.Z., J.P.M., R.S.B.W.); Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, United Kingdom (A.J.C., J.S.); and Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom (S.W., M.C.-J., M.C.W.)
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Li Q, Dong C, Li W, Bu W, Wu J, Zhao W. Neuropeptide Y protects cerebral cortical neurons by regulating microglial immune function. Neural Regen Res 2014; 9:959-67. [PMID: 25206918 PMCID: PMC4146213 DOI: 10.4103/1673-5374.133140] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2014] [Indexed: 11/29/2022] Open
Abstract
Neuropeptide Y has been shown to inhibit the immunological activity of reactive microglia in the rat cerebral cortex, to reduce N-methyl-D-aspartate current (INMDA) in cortical neurons, and protect neurons. In this study, after primary cultured microglia from the cerebral cortex of rats were treated with lipopolysaccharide, interleukin-1β and tumor necrosis factor-α levels in the cell culture medium increased, and mRNA expression of these cytokines also increased. After primary cultured cortical neurons were incubated with the lipopolysaccharide-treated microglial conditioned medium, peak INMDA in neurons increased. These effects of lipopolysaccharide were suppressed by neuropeptide Y. After addition of the neuropeptide Y Y1 receptor antagonist BIBP3226, the effects of neuropeptide Y completely disappeared. These results suggest that neuropeptide Y prevents excessive production of interleukin-1β and tumor necrosis factor-α by inhibiting microglial reactivity. This reduces INMDA in rat cortical neurons, preventing excitotoxicity, thereby protecting neurons.
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Affiliation(s)
- Qijun Li
- Graduate School, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Changzheng Dong
- Department of Functional Neurosurgery, Hebei General Hospital, Shijiazhuang, Hebei Province, China
| | - Wenling Li
- Department of Functional Neurosurgery, Hebei General Hospital, Shijiazhuang, Hebei Province, China
| | - Wei Bu
- Department of Neurosurgery, Third Hospital, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Jiang Wu
- Department of Functional Neurosurgery, Hebei General Hospital, Shijiazhuang, Hebei Province, China
| | - Wenqing Zhao
- Graduate School, Hebei Medical University, Shijiazhuang, Hebei Province, China ; Department of Functional Neurosurgery, Hebei General Hospital, Shijiazhuang, Hebei Province, China
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Ginseng extract attenuates early MRI changes after status epilepticus and decreases subsequent reduction of hippocampal volume in the rat brain. Epilepsy Res 2014; 108:223-31. [DOI: 10.1016/j.eplepsyres.2013.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 09/15/2013] [Accepted: 11/21/2013] [Indexed: 11/21/2022]
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Clerc P, Young CA, Bordt EA, Grigore AM, Fiskum G, Polster BM. Magnesium sulfate protects against the bioenergetic consequences of chronic glutamate receptor stimulation. PLoS One 2013; 8:e79982. [PMID: 24236167 PMCID: PMC3827425 DOI: 10.1371/journal.pone.0079982] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 09/28/2013] [Indexed: 11/26/2022] Open
Abstract
Extracellular glutamate is elevated following brain ischemia or trauma and contributes to neuronal injury. We tested the hypothesis that magnesium sulfate (MgSO4, 3 mM) protects against metabolic failure caused by excitotoxic glutamate exposure. Rat cortical neuron preparations treated in medium already containing a physiological concentration of Mg2+ (1 mM) could be segregated based on their response to glutamate (100 µM). Type I preparations responded with a decrease or small transient increase in oxygen consumption rate (OCR). Type II neurons responded with >50% stimulation in OCR, indicating a robust response to increased energy demand without immediate toxicity. Pre-treatment with MgSO4 improved the initial bioenergetic response to glutamate and ameliorated subsequent loss of spare respiratory capacity, measured following addition of the uncoupler FCCP, in Type I but not Type II neurons. Spare respiratory capacity in Type I neurons was also improved by incubation with MgSO4 or NMDA receptor antagonist MK801 in the absence of glutamate treatment. This finding indicates that the major difference between Type I and Type II preparations is the amount of endogenous glutamate receptor activity. Incubation of Type II neurons with 5 µM glutamate prior to excitotoxic (100 µM) glutamate exposure recapitulated a Type I phenotype. MgSO4 protected against an excitotoxic glutamate-induced drop in neuronal ATP both with and without prior 5 µM glutamate exposure. Results indicate that MgSO4 protects against chronic moderate glutamate receptor stimulation and preserves cellular ATP following treatment with excitotoxic glutamate.
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Affiliation(s)
- Pascaline Clerc
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Christina A. Young
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Evan A. Bordt
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Alina M. Grigore
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Gary Fiskum
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Brian M. Polster
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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Voss LJ, van Kan C, Sleigh JW. Quantitative investigation into methods for evaluating neocortical slice viability. BMC Neurosci 2013; 14:137. [PMID: 24195598 PMCID: PMC4228277 DOI: 10.1186/1471-2202-14-137] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 10/31/2013] [Indexed: 11/10/2022] Open
Abstract
Background In cortical and hippocampal brain slice experiments, the viability of processed tissue is usually judged by the amplitude of extracellularly-recorded seizure-like event (SLE) activity. Surprisingly, the suitability of this approach for evaluating slice quality has not been objectively studied. Furthermore, a method for gauging the viability of quiescent tissue, in which SLE activity is intentionally suppressed, has not been documented. In this study we undertook to address both of these matters using the zero-magnesium SLE model in neocortical slices. Methods Using zero-magnesium SLE activity as the output parameter, we investigated: 1) changes in the pattern (amplitude, frequency and length) of SLE activity as slice health either deteriorated; or was compromised by altering the preparation methodology and; 2) in quiescent tissue, whether the triggering of high frequency field activity following electrode insertion predicted subsequent development of SLE activity — and hence slice viability. Results SLE amplitude was the single most important variable correlating with slice viability, with a value less than 50 μV indicative of tissue unlikely to be able to sustain population activity for more than 30–60 minutes. In quiescent slices, an increase in high frequency field activity immediately after electrode insertion predicted the development of SLE activity in 100% of cases. Furthermore, the magnitude of the increase in spectral power correlated with the amplitude of succeeding SLE activity (R2 40.9%, p < 0.0001). Conclusion In conclusion, the findings confirm that the amplitude of population activity is a suitable field potential parameter for judging brain slice viability — and can be applied independent of the mechanism of tissue activation.
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Affiliation(s)
- Logan J Voss
- Anaesthesia Department, Waikato District Health Board, Hamilton 3240, New Zealand.
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Guo F, Xu X, Cai J, Hu H, Sun W, He G, Shao D, Wang L, Chen T, Shaw C, Zhu T, Hao L. The up-regulation of voltage-gated sodium channels subtypes coincides with an increased sodium current in hippocampal neuronal culture model. Neurochem Int 2013; 62:287-95. [DOI: 10.1016/j.neuint.2013.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 12/06/2012] [Accepted: 01/06/2013] [Indexed: 01/24/2023]
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Naylor DE, Liu H, Niquet J, Wasterlain CG. Rapid surface accumulation of NMDA receptors increases glutamatergic excitation during status epilepticus. Neurobiol Dis 2013; 54:225-38. [PMID: 23313318 DOI: 10.1016/j.nbd.2012.12.015] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 12/20/2012] [Accepted: 12/28/2012] [Indexed: 02/06/2023] Open
Abstract
After 1h of lithium-pilocarpine status epilepticus (SE), immunocytochemical labeling of NMDA receptor NR1 subunits reveals relocation of subunits from the interior to the cell surface of dentate gyrus granule cells and CA3 pyramidal cells. Simultaneously, an increase in NMDA-miniature excitatory postsynaptic currents (mEPSC) as well as an increase in NMDA receptor-mediated tonic currents is observed in hippocampal slices after SE. Mean-variance analysis of NMDA-mEPSCs estimates that the number of functional postsynaptic NMDA receptors per synapse increases 38% during SE, and antagonism by ifenprodil suggests that an increase in the surface representation of NR2B-containing NMDA receptors is responsible for the augmentation of both the phasic and tonic excitatory currents with SE. These results provide a potential mechanism for an enhancement of glutamatergic excitation that maintains SE and may contribute to excitotoxic injury during SE. Therapies that directly antagonize NMDA receptors may be a useful therapeutic strategy during refractory SE.
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Affiliation(s)
- David E Naylor
- Department of Neurology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, USA; Department of Neurology, Veterans Administration Greater Los Angeles Healthcare System, USA.
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Yu YH, Xie W, Bao Y, Li HM, Hu SJ, Xing JL. Saikosaponin a mediates the anticonvulsant properties in the HNC models of AE and SE by inhibiting NMDA receptor current and persistent sodium current. PLoS One 2012; 7:e50694. [PMID: 23209812 PMCID: PMC3510157 DOI: 10.1371/journal.pone.0050694] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 10/23/2012] [Indexed: 11/18/2022] Open
Abstract
Epilepsy is one of the most common neurological disorders, yet its treatment remains unsatisfactory. Saikosaponin a (SSa), a triterpene saponin derived from Bupleurum chinensis DC., has been demonstrated to have significant antiepileptic activity in a variety of epilepsy models in vivo. However, the electrophysiological activities and mechanisms of the antiepileptic properties of SSa remain unclear. In this study, whole-cell current-clamp recordings were used to evaluate the anticonvulsant activities of SSa in the hippocampal neuronal culture (HNC) models of acquired epilepsy (AE) and status epilepticus (SE). Whole-cell voltage-clamp recordings were used to evaluate the modulation effects of SSa on NMDA-evoked current and sodium currents in cultured hippocampal neurons. We found that SSa effectively terminated spontaneous recurrent epileptiform discharges (SREDs) in the HNC model of AE and continuous epileptiform high-frequency bursts (SE) in the HNC model of SE, in a concentration-dependent manner with an IC(50) of 0.42 µM and 0.62 µM, respectively. Furthermore, SSa significantly reduced the peak amplitude of NMDA-evoked current and the peak current amplitude of I(NaP). These results suggest for the first time that the inhibitions of NMDA receptor current and I(NaP) may be the underlying mechanisms of SSa's anticonvulsant properties, including the suppression of SREDs and SE in the HNC models of AE and SE. In addition, effectively abolishing the refractory SE implies that SSa may be a potential anticonvulsant candidate for the clinical treatment of epilepsy.
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Affiliation(s)
- Yun-Hong Yu
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guang Zhou, People’s Republic of China
- School of Traditional Chinese Medicine, Southern Medical University, Guang Zhou, People’s Republic of China
- Institute of Neuroscience, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Wei Xie
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guang Zhou, People’s Republic of China
- School of Traditional Chinese Medicine, Southern Medical University, Guang Zhou, People’s Republic of China
- * E-mail: (WX); (JLX)
| | - Yong Bao
- Department of Neurology, Traditional Chinese Hospital of Lu’an, Lu’an, People’s Republic of China
| | - Hui-Ming Li
- Institute of Neuroscience, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - San-Jue Hu
- Institute of Neuroscience, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Jun-Ling Xing
- Institute of Neuroscience, Fourth Military Medical University, Xi’an, People’s Republic of China
- * E-mail: (WX); (JLX)
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Kim HJ, Kim TH, Choi SJ, Hong YJ, Yang JS, Sung KW, Rhie DJ, Hahn SJ, Yoon SH. Fluoxetine suppresses synaptically induced [Ca²⁺]i spikes and excitotoxicity in cultured rat hippocampal neurons. Brain Res 2012; 1490:23-34. [PMID: 23131584 DOI: 10.1016/j.brainres.2012.10.062] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 10/21/2012] [Accepted: 10/30/2012] [Indexed: 10/27/2022]
Abstract
Fluoxetine is a widely used antidepressant with an action that is primarily attributed to the inhibition of serotonin re-uptake into the synaptic terminals of the central nervous system. Fluoxetine also has blocking effects on various ion channels, including Ca(2+) channels. It remains unclear, however, how fluoxetine may affect synaptically induced [Ca(2+)](i) spikes. We investigated the effects of fluoxetine on [Ca(2+)](i) spikes, along with the subsequent neurotoxicity that is synaptically evoked by lowering extracellular Mg(2+) in cultured rat hippocampal neurons. Fluoxetine inhibited the synaptically induced [Ca(2+)](i) spikes in p-chloroamphetamine-treated and non-treated neurons, in a concentration-dependent manner. However, other selective serotonin reuptake inhibitors, such as paroxetine and citalopram, did not significantly affect the spikes. Pretreatment with fluoxetine for 5 min inhibited [Ca(2+)](i) increases induced by glutamate, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, and N-methyl-d-aspartate. Fluoxetine also inhibited α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-induced currents. In addition, fluoxetine decreased the [Ca(2+)](i) responses induced by the metabotrophic glutamate receptor agonist (S)-3,5-dihydroxyphenylglycine or the ryanodine receptor agonist caffeine. Fluoxetine inhibited [Ca(2+)](i) responses induced by 20mM KCl. Fluoxetine decreased the release of FM1-43 induced by electric field stimulation. Furthermore, fluoxetine inhibited 0.1mM [Mg(2+)](o)-induced cell death. Collectively, our results suggest that fluoxetine suppresses the spikes and protects neurons against excitotoxicity, particularly in cultured rat hippocampal neurons, presumably due to both direct inhibition of presynaptic glutamate release and postsynaptic glutamate receptor-mediated [Ca(2+)](i) signaling. In addition to an indirect inhibitory effect via 5-HT levels, these data suggest a new, possibly direct inhibitory action of fluoxetine on synaptically induced [Ca(2+)](i) spikes and neuronal cell death.
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Affiliation(s)
- Hee Jung Kim
- Department of Physiology, College of Medicine, Dankook University, San #29, Anseo-dong, Dongnam-gu, Cheonan, Chungnam 330-714, South Korea
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Rajasekaran K, Todorovic M, Kapur J. Calcium-permeable AMPA receptors are expressed in a rodent model of status epilepticus. Ann Neurol 2012; 72:91-102. [PMID: 22829271 DOI: 10.1002/ana.23570] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE A study was undertaken to characterize the plasticity of AMPA receptor (AMPAR)-mediated neurotransmission in the hippocampus during status epilepticus (SE). METHODS SE was induced by pilocarpine, and animals were studied 10 minutes (refractory SE) or 60 minutes (late SE) after the onset of the first grade 5 seizures. AMPAR-mediated currents were recorded from CA1 pyramidal neurons and dentate granule cells (DGCs) by voltage clamp technique. The surface expression of GluA2 subunit on hippocampal membranes was determined using a biotinylation assay. GluA2 internalization and changes in intracellular calcium ([Ca](i)) levels were studied in hippocampal cultures using immunocytochemical and live-imaging techniques. AMPAR antagonist treatment of SE was evaluated by video and electroencephalography. RESULTS AMPAR-mediated currents recorded from CA1 neurons from refractory and late SE animals were inwardly rectifying, and philanthotoxin-sensitive; similar changes were observed in recordings obtained from DGCs from refractory SE animals. GluA2 subunit surface expression was reduced in the hippocampus during refractory and late SE. In cultured hippocampal pyramidal neurons, recurrent bursting diminished surface expression of the GluA2 subunit and enhanced its internalization rate. Recurrent bursting-induced increase in [Ca](i) levels was reduced by selective inhibition of GluA2-lacking AMPARs. GYKI-52466 terminated diazepam-refractory SE. INTERPRETATION During SE, there is rapid, ongoing plasticity of AMPARs with the expression of GluA2-lacking AMPARs. These receptors provide another source of Ca(2+) entry into the principal neurons. Benzodiazepam-refractory SE can be terminated by AMPAR antagonism. The data identify AMPARs as a potential therapeutic target for the treatment of SE.
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Hypothermia reduces calcium entry via the N-methyl-D-aspartate and ryanodine receptors in cultured hippocampal neurons. Eur J Pharmacol 2012; 698:186-92. [PMID: 23085028 DOI: 10.1016/j.ejphar.2012.10.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 09/28/2012] [Accepted: 10/06/2012] [Indexed: 11/21/2022]
Abstract
Hypothermia is a powerful neuroprotective method when induced following cardiac arrest, stroke, and traumatic brain injury. The physiological effects of hypothermia are multifaceted and therefore a better knowledge of its therapeutic targets will be central to developing innovative combination therapies to augment the protective benefits of hypothermia. Altered neuronal calcium dynamics have been implicated following stroke, status epilepticus and traumatic brain injury. This study was therefore initiated to evaluate the effect of hypothermia on various modes of calcium entry into a neuron. Here, we utilized various pharmacological agents to stimulate major routes of calcium entry in primary cultured hippocampal neurons. Fluorescent calcium indicator Fura-2AM was used to compare calcium ratio under normothermic (37 °C) and hypothermic (31 °C) conditions. The results of this study indicate that hypothermia preferentially reduces calcium entry through N-methyl-D-aspartate receptors and ryanodine receptors. Hypothermia, on the other hand, did not have a significant effect on calcium entry through the voltage-dependent calcium channels or the inositol tri-phosphate receptors. The ability of hypothermia to selectively affect both N-methyl-D-aspartate receptors and ryanodine receptors-mediated calcium systems makes it an attractive intervention for alleviating calcium elevations that are present following many neurological injuries.
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Emerging genetic influences in benign epilepsy with centro-temporal spikes - BECTS. Epilepsy Res 2012; 101:197-201. [PMID: 22818593 DOI: 10.1016/j.eplepsyres.2012.06.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Revised: 06/06/2012] [Accepted: 06/30/2012] [Indexed: 02/06/2023]
Abstract
BECTS is considered to be the most common childhood epileptic syndrome. Multifactorial inheritance is the most important model accounting for the genetic behavior of the common epilepsies. In recent years, different mutations in genes that control the excitability of neurons have been described. Recent reports on the involvement of the BDNF and ELP4 genes with possible roles in cell motility, migration, and adhesion have provided first insights into the complex molecular bases of childhood focal epilepsies. However, in the most common idiopathic benign childhood epilepsies (BECTS and occipital epilepsies), major breakthroughs are still awaited.
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Mastrangelo M, Celato A. Diagnostic work-up and therapeutic options in management of pediatric status epilepticus. World J Pediatr 2012; 8:109-15. [PMID: 22573420 DOI: 10.1007/s12519-012-0348-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 02/06/2012] [Indexed: 02/06/2023]
Abstract
BACKGROUND Status epilepticus (SE) is a life-threatening neurologic disorder comprising prolonged and unremitting crisis, and two or more series of seizures without complete intercritical recovery. DATA SOURCES We reviewed the literature through a Pubmed/Medline research using key words including status epilepticus, antiepileptic drugs and children, in order to revise and compare international/national protocols and to examine pediatric guidelines in SE management. RESULTS Neurologic impairment and SE etiology seem to be the most independent risks for mortality. A deep semiologic evaluation is essential to addressing diagnostic work-up. Ematochemical parameters, plasma levels of antiepileptic drugs and clinically oriented toxic/metabolic screening should be mandatory for investigating both causes and effects of SE. Electroencephalography is clearly helpful to characterize focal from generalized SE and to distinguish epileptic events from pseudoseizures, and it is deal to find nonconvulsive SE. Neuroimaging techniques could detect epileptogenic lesions (such as cortical malformations, tumors, demyelinating disorders or strokes) but are common in practice to find negative or controversial results. Pharmacologic management can be essentially arranged in three stages: benzodiazepines for early SE (lasting less than 30 minutes), phenytoin/fosphenytoin, phenobarbital, valproate, levetiracetam or lacosamide for established SE (30-90 minutes), and anesthetics for refractory SE (more than 90 minutes). CONCLUSIONS Status epilepticus is the most common neurologic emergency in childhood. A systematic diagnostic work-up and a three steps based therapeutic approach is required at this age.
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Affiliation(s)
- Mario Mastrangelo
- Department of Pediatrics, Child Neurology and Psychiatry, La Sapienza-University of Rome, Rome, Italy.
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Hansen SL, Sterjev Z, Werngreen M, Simonsen BJ, Knudsen KE, Nielsen AH, Pedersen ME, Badolo L, Kristiansen U, Vestergaard HT. Does brain slices from pentylenetetrazole-kindled mice provide a more predictive screening model for antiepileptic drugs? Eur J Pharmacol 2012; 682:43-9. [DOI: 10.1016/j.ejphar.2012.01.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 01/17/2012] [Accepted: 01/28/2012] [Indexed: 12/01/2022]
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Kovac S, Domijan AM, Walker MC, Abramov AY. Prolonged seizure activity impairs mitochondrial bioenergetics and induces cell death. J Cell Sci 2012; 125:1796-806. [PMID: 22328526 DOI: 10.1242/jcs.099176] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
The mechanisms underlying neuronal death following excessive activity such as occurs during prolonged seizures are unclear, but mitochondrial dysfunction has been hypothesised to play a role. Here, we tested this with fluorescence imaging techniques in rat glio-neuronal neocortical co-cultures using low Mg(2+) levels to induce seizure-like activity. Glutamate activation of NMDA receptors resulted in Ca(2+) oscillations in neurons and a sustained depolarisation of the mitochondrial membrane potential, which was cyclosporine A sensitive, indicating mitochondrial permeability and transition pore opening. It was also dependent on glutamate release and NMDA receptor activation, because depolarisation was not observed after depleting vesicular glutamate with vacuolar-type H(+)-ATPase concanamycin A or blocking NMDA receptors with APV. Neuronal ATP levels in soma and dendrites decreased significantly during prolonged seizures and correlated with the frequency of the oscillatory Ca(2+) signal, indicative of activity-dependent ATP consumption. Blocking mitochondrial complex I, complex V or uncoupling mitochondrial oxidative phosphorylation under low-Mg(2+) conditions accelerated activity-dependent neuronal ATP consumption. Neuronal death increased after two and 24 hours of low Mg(2+) levels compared with control treatment, and was reduced by supplementation with the mitochondrial complex I substrate pyruvate. These findings demonstrate a crucial role for mitochondrial dysfunction in seizure-activity-induced neuronal death, and that strategies aimed at redressing this are neuroprotective.
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Affiliation(s)
- Stjepana Kovac
- UCL Institute of Neurology, University College London, London, UK
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Domijan AM, Kovac S, Abramov A. Impact of fumonisin B1 on glutamate toxicity and low magnesium-induced seizure activity in neuronal primary culture. Neuroscience 2012; 202:10-6. [DOI: 10.1016/j.neuroscience.2011.12.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 11/07/2011] [Accepted: 12/02/2011] [Indexed: 11/26/2022]
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