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Richardson RJ, Petrou S, Bryson A. Established and emerging GABA A receptor pharmacotherapy for epilepsy. Front Pharmacol 2024; 15:1341472. [PMID: 38449810 PMCID: PMC10915249 DOI: 10.3389/fphar.2024.1341472] [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: 11/20/2023] [Accepted: 02/07/2024] [Indexed: 03/08/2024] Open
Abstract
Drugs that modulate the GABAA receptor are widely used in clinical practice for both the long-term management of epilepsy and emergency seizure control. In addition to older medications that have well-defined roles for the treatment of epilepsy, recent discoveries into the structure and function of the GABAA receptor have led to the development of newer compounds designed to maximise therapeutic benefit whilst minimising adverse effects, and whose position within the epilepsy pharmacologic armamentarium is still emerging. Drugs that modulate the GABAA receptor will remain a cornerstone of epilepsy management for the foreseeable future and, in this article, we provide an overview of the mechanisms and clinical efficacy of both established and emerging pharmacotherapies.
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Affiliation(s)
- Robert J. Richardson
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
- Department of Neurology, Austin Health, Heidelberg, VIC, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
- Praxis Precision Medicines, Boston, MA, United States
| | - Alexander Bryson
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, VIC, Australia
- Department of Neurology, Austin Health, Heidelberg, VIC, Australia
- Department of Neurology, Eastern Health, Melbourne, VIC, Australia
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Shen W, Flamm C, Delahanty AJ, Casteel E, Biven M, DeLeeuw MB, Poliquin S, Nwosu G, Randhave K, Kang JQ. 4-Phenylbutyrate promoted wild-type γ-aminobutyric acid type A receptor trafficking, reduced endoplasmic reticulum stress, and mitigated seizures in Gabrg2 +/Q390X mice associated with Dravet syndrome. Epilepsia 2024; 65:204-217. [PMID: 37746768 PMCID: PMC10842976 DOI: 10.1111/epi.17779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/26/2023]
Abstract
OBJECTIVE γ-Aminobutyric acid type A (GABAA ) receptor subunit gene mutations are major causes of various epilepsy syndromes, including severe kinds such as Dravet syndrome. Although the GABAA receptor is a major target for antiseizure medications, treating GABAA receptor mutations with receptor channel modulators is ineffective. Here, we determined the effect of a novel treatment with 4-phenylbutyrate (PBA) in Gabrg2+/Q390X knockin mice associated with Dravet syndrome. METHODS We used biochemistry in conjunction with differential tagging of the wild-type and the mutant alleles, live brain slice surface biotinylation, microsome isolation, patch-clamp whole-cell recordings, and video-monitoring synchronized electroencephalographic (EEG) recordings in Gabrg2+/Q390X mice to determine the effect of PBA in vitro with recombinant GABAA receptors and in vivo with knockin mice. RESULTS We found that PBA reduced the mutant γ2(Q390X) subunit protein aggregates, enhanced the wild-type GABAA receptor subunits' trafficking, and increased the membrane expression of the wild-type receptors. PBA increased the current amplitude of GABA-evoked current in human embryonic kidney 293T cells and the neurons bearing the γ2(Q390X) subunit protein. PBA also proved to reduce endoplasmic reticulum (ER) stress caused by the mutant γ2(Q390X) subunit protein, as well as mitigating seizures and EEG abnormalities in the Gabrg2+/Q390X mice. SIGNIFICANCE This research has unveiled a promising and innovative approach for treating epilepsy linked to GABAA receptor mutations through an unconventional antiseizure mechanism. Rather than directly modulating the affected mutant channel, PBA facilitates the folding and transportation of wild-type receptor subunits to the cell membrane and synapse. Combining these findings with our previous study, which demonstrated PBA's efficacy in restoring GABA transporter 1 (encoded by SLC6A1) function, we propose that PBA holds significant potential for a wide range of genetic epilepsies. Its ability to target shared molecular pathways involving mutant protein ER retention and impaired protein membrane trafficking suggests broad application in treating such conditions.
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Affiliation(s)
- Wangzhen Shen
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Carson Flamm
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Aiden J Delahanty
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Emmett Casteel
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Marshall Biven
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Melissa B DeLeeuw
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Sarah Poliquin
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Gerald Nwosu
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Karishma Randhave
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
| | - Jing-Qiong Kang
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
- the Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
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Nwosu GI, Shen W, Zavalin K, Poliquin S, Randhave K, Flamm C, Biven M, Langer K, Kang JQ. GABA A Receptor β3 Subunit Mutation N328D Heterozygous Knock-in Mice Have Lennox-Gastaut Syndrome. Int J Mol Sci 2023; 24:8458. [PMID: 37176165 PMCID: PMC10179596 DOI: 10.3390/ijms24098458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/19/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
Lennox-Gastaut Syndrome (LGS) is a developmental and epileptic encephalopathy (DEE) characterized by multiple seizure types, electroencephalogram (EEG) patterns, and cognitive decline. Its etiology has a prominent genetic component, including variants in GABRB3 that encodes the GABAA receptor (GABAAR) β3 subunit. LGS has an unknown pathophysiology, and few animal models are available for studying LGS. The objective of this study was to evaluate Gabrb3+/N328D knock-in mice as a model for LGS. We generated a heterozygous knock-in mouse expressing Gabrb3 (c.A982G, p.N238D), a de novo mutation identified in a patient with LGS. We investigated Gabrb3+/N328D mice for features of LGS. In 2-4-month-old male and female C57BL/J6 wild-type and Gabrb3+/N328D mice, we investigated seizure severity using video-monitored EEG, cognitive impairment using a suite of behavioral tests, and profiled GABAAR subunit expression by Western blot. Gabrb3+/N328D mice showed spontaneous seizures and signs of cognitive impairment, including deficits in spatial learning, memory, and locomotion. Moreover, Gabrb3+/N328D mice showed reduced β3 subunit expression in the cerebellum, hippocampus, and thalamus. This phenotype of epilepsy and neurological impairment resembles the LGS patient phenotype. We conclude that Gabrb3+/N328D mice provide a good model for investigating the pathophysiology and therapeutic intervention of LGS and DEEs.
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Affiliation(s)
- Gerald Ikemefuna Nwosu
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
| | - Wangzhen Shen
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
| | - Kirill Zavalin
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
| | - Sarah Poliquin
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
| | - Karishma Randhave
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
| | - Carson Flamm
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
| | - Marshall Biven
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
| | - Katherine Langer
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
| | - Jing-Qiong Kang
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Brain Institute, Nashville, TN 37232, USA
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
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Qu S, Jackson LG, Zhou C, Shen D, Shen W, Nwosu G, Howe R, Caltron M, Flamm C, Biven M, Kang JQ, Macdonald RL. Heterozygous GABA A receptor β3 subunit N110D knock-in mice have epileptic spasms. Epilepsia 2023; 64:1061-1073. [PMID: 36495145 PMCID: PMC10101922 DOI: 10.1111/epi.17470] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 11/01/2022] [Accepted: 11/16/2022] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Infantile spasms is an epileptic encephalopathy of childhood, and its pathophysiology is largely unknown. We generated a heterozygous knock-in mouse with the human infantile spasms-associated de novo mutation GABRB3 (c.A328G, p.N110D) to investigate its molecular mechanisms and to establish the Gabrb3+/N110D knock-in mouse as a model of infantile spasms syndrome. METHODS We used electroencephalography (EEG) and video monitoring to characterize seizure types, and a suite of behavioral tests to identify neurological and behavioral impairment in Gabrb3+/N110D knock-in mice. Miniature inhibitory postsynaptic currents (mIPSCs) were recorded from layer V/VI pyramidal neurons in somatosensory cortex, and extracellular multi-unit recordings from the ventral basal nucleus of the thalamus in a horizontal thalamocortical slice were used to assess spontaneous thalamocortical oscillations. RESULTS The infantile spasms-associated human de novo mutation GABRB3 (c.A328G, p.N110D) caused epileptic spasms early in development and multiple seizure types in adult Gabrb3+/N110D knock-in mice. Signs of neurological impairment, anxiety, hyperactivity, social impairment, and deficits in spatial learning and memory were also observed. Gabrb3+/N110D mice had reduced cortical mIPSCs and increased duration of spontaneous oscillatory firing in the somatosensory thalamocortical circuit. SIGNIFICANCE The Gabrb3+/N110D knock-in mouse has epileptic spasms, seizures, and other neurological impairments that are consistent with infantile spasms syndrome in patients. Multiple seizure types and abnormal behaviors indicative of neurological impairment both early and late in development suggest that Gabrb3+/N110D mice can be used to study the pathophysiology of infantile spasms. Reduced cortical inhibition and increased duration of thalamocortical oscillatory firing suggest perturbations in thalamocortical circuits.
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Affiliation(s)
- Shimian Qu
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
| | - Laurel G. Jackson
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
- Program in Neuroscience, Vanderbilt University, Nashville, TN 37232
| | - Chengwen Zhou
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
| | - DingDing Shen
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
- Program in Neuroscience, Vanderbilt University, Nashville, TN 37232
| | - Wangzhen Shen
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
| | - Gerald Nwosu
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
- Program in Neuroscience, Vanderbilt University, Nashville, TN 37232
- Department of Biochemistry, Cancer Biology, Neuroscience and Pharmacology, Meharry Medical College, Vanderbilt University, Nashville, TN 37232
| | - Rachel Howe
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
| | - Mackenzie Caltron
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
- Program in Neuroscience, Vanderbilt University, Nashville, TN 37232
| | - Carson Flamm
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
| | - Marshall Biven
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
| | - Jing-Qiong Kang
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
- Pharmacology, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Kennedy Center of Human Development, Vanderbilt University, Nashville, TN 37232
| | - Robert L. Macdonald
- Departments of Neurology, Vanderbilt University, Nashville, TN 37232
- Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
- Pharmacology, Vanderbilt University, Nashville, TN 37232
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Catron MA, Howe RK, Besing GLK, St. John EK, Potesta CV, Gallagher MJ, Macdonald RL, Zhou C. Sleep slow-wave oscillations trigger seizures in a genetic epilepsy model of Dravet syndrome. Brain Commun 2022; 5:fcac332. [PMID: 36632186 PMCID: PMC9830548 DOI: 10.1093/braincomms/fcac332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/09/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Sleep is the preferential period when epileptic spike-wave discharges appear in human epileptic patients, including genetic epileptic seizures such as Dravet syndrome with multiple mutations including SCN1A mutation and GABAA receptor γ2 subunit Gabrg2Q390X mutation in patients, which presents more severe epileptic symptoms in female patients than male patients. However, the seizure onset mechanism during sleep still remains unknown. Our previous work has shown that the sleep-like state-dependent homeostatic synaptic potentiation can trigger epileptic spike-wave discharges in one transgenic heterozygous Gabrg2+/Q390X knock-in mouse model.1 Here, using this heterozygous knock-in mouse model, we hypothesized that slow-wave oscillations themselves in vivo could trigger epileptic seizures. We found that epileptic spike-wave discharges in heterozygous Gabrg2+/Q390X knock-in mice exhibited preferential incidence during non-rapid eye movement sleep period, accompanied by motor immobility/facial myoclonus/vibrissal twitching and more frequent spike-wave discharge incidence appeared in female heterozygous knock-in mice than male heterozygous knock-in mice. Optogenetically induced slow-wave oscillations in vivo significantly increased epileptic spike-wave discharge incidence in heterozygous Gabrg2+/Q390X knock-in mice with longer duration of non-rapid eye movement sleep or quiet-wakeful states. Furthermore, suppression of slow-wave oscillation-related homeostatic synaptic potentiation by 4-(diethylamino)-benzaldehyde injection (i.p.) greatly attenuated spike-wave discharge incidence in heterozygous knock-in mice, suggesting that slow-wave oscillations in vivo did trigger seizure activity in heterozygous knock-in mice. Meanwhile, sleep spindle generation in wild-type littermates and heterozygous Gabrg2+/Q390X knock-in mice involved the slow-wave oscillation-related homeostatic synaptic potentiation that also contributed to epileptic spike-wave discharge generation in heterozygous Gabrg2+/Q390X knock-in mice. In addition, EEG spectral power of delta frequency (0.1-4 Hz) during non-rapid eye movement sleep was significantly larger in female heterozygous Gabrg2+/Q390X knock-in mice than that in male heterozygous Gabrg2+/Q390X knock-in mice, which likely contributes to the gender difference in seizure incidence during non-rapid eye movement sleep/quiet-wake states of human patients. Overall, all these results indicate that slow-wave oscillations in vivo trigger the seizure onset in heterozygous Gabrg2+/Q390X knock-in mice, preferentially during non-rapid eye movement sleep period and likely generate the sex difference in seizure incidence between male and female heterozygous Gabrg2+/Q390X knock-in mice.
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Affiliation(s)
- Mackenzie A Catron
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Rachel K Howe
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Gai-Linn K Besing
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Emily K St. John
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | - Martin J Gallagher
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Robert L Macdonald
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Balestrini S, Doccini V, Boncristiano A, Lenge M, De Masi S, Guerrini R. Efficacy and Safety of Long-Term Treatment with Stiripentol in Children and Adults with Drug-Resistant Epilepsies: A Retrospective Cohort Study of 196 Patients. Drugs Real World Outcomes 2022; 9:451-461. [PMID: 35680739 PMCID: PMC9392664 DOI: 10.1007/s40801-022-00305-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Stiripentol is an antiseizure medication with multiple potential mechanisms of action, indicated as adjunctive therapy in people with Dravet syndrome, whose seizures are not adequately controlled with clobazam and valproate. However, there are scattered data on its efficacy in other epilepsy aetiologies and types. We previously reported our single-centre experience on the efficacy of adjunctive stiripentol treatment in a cohort of 132 patients with different types of refractory epilepsies. OBJECTIVE We aimed to expand our analysis to a larger cohort of 196 patients with a long-term follow-up. METHODS We retrospectively evaluated long-term efficacy, tolerability and predictors of treatment response in 196 patients with a long-term follow-up (range 0.5-232.8 months). RESULTS After an initial median follow-up of 3 months after stiripentol introduction, we observed a responder rate of 53% including seizure freedom in 9%. At subsequent follow-ups at 12 and 24 months, responder rates were 29% and 22%, respectively. Aetiology was associated with sustained response over time, with Dravet syndrome being the aetiology with the highest responder rate (64%) at 48 months compared with syndromes with other genetic causes (13%) or unknown aetiology (38%). A higher responder rate over time was also observed in patients with generalised (44%) and combined focal and generalised epilepsies (28%) than in patients with focal epilepsies (20%). The highest relapse free-survival was observed when stiripentol was initiated at the youngest age (0-4 years) or in adulthood. The retention rate (i.e. proportion of patients who continued stiripentol with no change in either pharmacological or non-pharmacological therapy) was 53% at 12 months and 33% at 24 months. CONCLUSIONS Based on our findings, we suggest that stiripentol is an effective and well-tolerated therapeutic option not only in Dravet syndrome but also in other epilepsy syndromes with or without an established genetic aetiology. Response duration was influenced by age at stiripentol initiation across different aetiologies.
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Affiliation(s)
- Simona Balestrini
- Neuroscience Department, Meyer Children's Hospital-University of Florence, Viale Pieraccini 24, 50139, Florence, Italy
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
- Chalfont Centre for Epilepsy, Buckinghamshire, UK
| | - Viola Doccini
- Neuroscience Department, Meyer Children's Hospital-University of Florence, Viale Pieraccini 24, 50139, Florence, Italy
| | - Alessandra Boncristiano
- Neuroscience Department, Meyer Children's Hospital-University of Florence, Viale Pieraccini 24, 50139, Florence, Italy
| | - Matteo Lenge
- Neuroscience Department, Meyer Children's Hospital-University of Florence, Viale Pieraccini 24, 50139, Florence, Italy
| | - Salvatore De Masi
- Clinical Trial Office, Meyer Children's University Hospital, Florence, Italy
| | - Renzo Guerrini
- Neuroscience Department, Meyer Children's Hospital-University of Florence, Viale Pieraccini 24, 50139, Florence, Italy.
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Zimmern V, Minassian B, Korff C. A Review of Targeted Therapies for Monogenic Epilepsy Syndromes. Front Neurol 2022; 13:829116. [PMID: 35250833 PMCID: PMC8891748 DOI: 10.3389/fneur.2022.829116] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 01/13/2022] [Indexed: 11/15/2022] Open
Abstract
Genetic sequencing technologies have led to an increase in the identification and characterization of monogenic epilepsy syndromes. This increase has, in turn, generated strong interest in developing “precision therapies” based on the unique molecular genetics of a given monogenic epilepsy syndrome. These therapies include diets, vitamins, cell-signaling regulators, ion channel modulators, repurposed medications, molecular chaperones, and gene therapies. In this review, we evaluate these therapies from the perspective of their clinical validity and discuss the future of these therapies for individual syndromes.
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Affiliation(s)
- Vincent Zimmern
- Division of Child Neurology, University of Texas Southwestern, Dallas, TX, United States
- *Correspondence: Vincent Zimmern
| | - Berge Minassian
- Division of Child Neurology, University of Texas Southwestern, Dallas, TX, United States
| | - Christian Korff
- Pediatric Neurology Unit, University Hospitals, Geneva, Switzerland
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Jahanbani R, Bahramnejad E, Rahimi N, Shafaroodi H, Sheibani N, Moosavi-Movahedi AA, Dehpour AR, Vahdati K. Anti-seizure effects of walnut peptides in mouse models of induced seizure: The involvement of GABA and nitric oxide pathways. Epilepsy Res 2021; 176:106727. [PMID: 34333374 DOI: 10.1016/j.eplepsyres.2021.106727] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 11/17/2022]
Abstract
Epilepsy is one of the foremost medical disorders. Oxidative stress is a well-known mechanism in epileptogenesis, and many studies suggest that oxidative stress affects the onset and evolution of epilepsy. Here we evaluated the walnut peptide extracts' anti-seizure property in three different mouse seizure models including pentylenetetrazole-induced clonic seizure, chemical kindling, and maximal electroshock. Walnut peptides (20 mg/Kg) were administered by intraperitoneal (IP) injection of mice 60 min before seizure induction in the three models. To delineate the mechanisms of walnut peptides anti-seizure activity, we evaluated the impact of diazepam, flumazenil, and a NOS inhibitor on this activity. Intraperitoneal administration of walnut peptides significantly increased the seizure threshold. Our results also demonstrated that walnut peptides exert their anti-seizure properties through the modulation of benzodiazepine receptors. Thus, walnut peptides may be considered as a new anti-convulsion agent, which can reduce seizure occurrence and slow down seizure progression.
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Affiliation(s)
- Raheleh Jahanbani
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Erfan Bahramnejad
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Nastaran Rahimi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamed Shafaroodi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Sciences, Cell and Regenerative Biology, and Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Ali Akbar Moosavi-Movahedi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; UNESCO Chair on Interdisciplinary Research in Diabetes, University of Tehran, Tehran, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Kourosh Vahdati
- Department of Horticulture, College of Aburaihan, University of Tehran, Tehran, Iran.
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9
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Zhang CQ, Catron MA, Ding L, Hanna CM, Gallagher MJ, Macdonald RL, Zhou C. Impaired State-Dependent Potentiation of GABAergic Synaptic Currents Triggers Seizures in a Genetic Generalized Epilepsy Model. Cereb Cortex 2020; 31:768-784. [PMID: 32930324 DOI: 10.1093/cercor/bhaa256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/13/2020] [Accepted: 08/13/2020] [Indexed: 11/14/2022] Open
Abstract
Epileptic activity in genetic generalized epilepsy (GGE) patients preferentially appears during sleep and its mechanism remains unknown. Here, we found that sleep-like slow-wave oscillations (0.5 Hz SWOs) potentiated excitatory and inhibitory synaptic currents in layer V cortical pyramidal neurons from wild-type (wt) mouse brain slices. In contrast, SWOs potentiated excitatory, but not inhibitory, currents in cortical neurons from a heterozygous (het) knock-in (KI) Gabrg2+Q/390X model of Dravet epilepsy syndrome. This created an imbalance between evoked excitatory and inhibitory currents to effectively prompt neuronal action potential firings. Similarly, physiologically similar up-/down-state induction (present during slow-wave sleep) in cortical neurons also potentiated excitatory synaptic currents within brain slices from wt and het KI mice. Moreover, this state-dependent potentiation of excitatory synaptic currents entailed some signaling pathways of homeostatic synaptic plasticity. Consequently, in het KI mice, in vivo SWO induction (using optogenetic methods) triggered generalized epileptic spike-wave discharges (SWDs), being accompanied by sudden immobility, facial myoclonus, and vibrissa twitching. In contrast, in wt littermates, SWO induction did not cause epileptic SWDs and motor behaviors. To our knowledge, this is the first mechanism to explain why epileptic SWDs preferentially happen during non rapid eye-movement sleep and quiet-wakefulness in human GGE patients.
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Affiliation(s)
- Chun-Qing Zhang
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Mackenzie A Catron
- Department of Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Li Ding
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Caitlyn M Hanna
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Martin J Gallagher
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Robert L Macdonald
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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