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Zhou C, Satpute V, Yip KL, Anderson LL, Hawkins N, Kearney J, Arnold JC. A high seizure burden increases several prostaglandin species in the hippocampus of a Scn1a +/- mouse model of Dravet syndrome. Prostaglandins Other Lipid Mediat 2024; 172:106836. [PMID: 38599513 DOI: 10.1016/j.prostaglandins.2024.106836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/12/2024]
Abstract
Dravet syndrome is an intractable epilepsy with a high seizure burden that is resistant to current anti-seizure medications. There is evidence that neuroinflammation plays a role in epilepsy and seizures, however few studies have specifically examined neuroinflammation in Dravet syndrome under conditions of a higher seizure burden. Here we used an established genetic mouse model of Dravet syndrome (Scn1a+/- mice), to examine whether a higher seizure burden impacts the number and morphology of microglia in the hippocampus. Moreover, we examined whether a high seizure burden influences classical inflammatory mediators in this brain region. Scn1a+/- mice with a high seizure burden induced by thermal priming displayed a localised reduction in microglial cell density in the granule cell layer and subgranular zone of the dentate gyrus, regions important to postnatal neurogenesis. However, microglial cell number and morphology remained unchanged in other hippocampal subfields. The high seizure burden in Scn1a+/- mice did not affect hippocampal mRNA expression of classical inflammatory mediators such as interleukin 1β and tumour necrosis factor α, but increased cyclooxygenase 2 (COX-2) expression. We then quantified hippocampal levels of prostanoids that arise from COX-2 mediated metabolism of fatty acids and found that Scn1a+/- mice with a high seizure burden displayed increased hippocampal concentrations of numerous prostaglandins, notably PGF2α, PGE2, PGD2, and 6-K-PGF1A, compared to Scn1a+/- mice with a low seizure burden. In conclusion, a high seizure burden increased hippocampal concentrations of various prostaglandin mediators in a mouse model of Dravet syndrome. Future studies could interrogate the prostaglandin pathways to further better understand their role in the pathophysiology of Dravet syndrome.
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Affiliation(s)
- Cilla Zhou
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia; Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Vaishali Satpute
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Ka Lai Yip
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Lyndsey L Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Nicole Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jennifer Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jonathon C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.
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Zierath DK, Davidson S, Manoukian J, Knox KM, White HS, Meeker S, Ericsson A, Barker-Haliski M. Diet composition and sterilization modifies intestinal microbiome diversity and burden of Theiler's virus infection-induced acute seizures. Epilepsia 2024; 65:1777-1790. [PMID: 38491947 DOI: 10.1111/epi.17946] [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: 10/19/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/18/2024]
Abstract
OBJECTIVE Brain infection with Theiler's murine encephalomyelitis virus (TMEV) in C57BL/6J mice can induce acquired epileptogenesis. Diet alters acute seizure incidence in TMEV-infected mice; yet it is unclear whether intestinal dysbiosis may also impact acute or chronic behavioral comorbidities. This study thus assessed the impact of diet formulation and sterilization on acute seizure presentation, gut microbiome composition, and epilepsy-related chronic behavioral comorbidities. METHODS Baseline fecal samples were collected from male C57BL/6J mice (4- to 5-weeks-old; Jackson Labs) upon facility arrival. Mice were randomized to either autoclaved (AC) or irradiated diet (IR) (Prolab RMH 3000) or IR (Picolab 5053). Three days later, mice underwent intracerebral TMEV or phosphate-buffered saline (PBS) injection. Fecal samples were collected from a subset of mice at infection (Day 0) and Day 7 post-infection. Epilepsy-related working memory deficits and seizure threshold were assessed 6 weeks post-infection. Gut microbiome diversity was determined by 16S rRNA amplicon sequencing of fecal samples. RESULTS TMEV-infected mice displayed acute handling-induced seizures, regardless of diet: 28 of 57 IR Picolab 5053 (49.1%), 30 of 41 IR Prolab RMH 3000 (73.2%), and 47 of 77 AC Prolab RMH 3000 (61%) mice displayed seizures. The number of observed seizures differed significantly by diet: IR Picolab 5053 diet-fed mice had 2.2 ± 2.8 seizures (mean ± standard deviation), IR Prolab RMH 3000 diet-fed mice had 3.5 ± 2.9 seizures, and AC Prolab RMH 3000 diet-fed mice had 4.4 ± 3.8 seizures during the 7-day monitoring period. Gut microbiome composition differed significantly in TMEV-infected mice fed the AC Prolab RMH 3000 diet, with measured differences in gram-positive bacteria. These mice also displayed worsened long-term working memory deficits. SIGNIFICANCE Diet-induced differences in intestinal dysbiosis in the TMEV model are associated with marked changes in acute seizure presentation, symptomatic recovery, and onset of chronic behavioral comorbidities of epilepsy. Our study reveals a novel disease-modifying impact of dietary manipulation on intestinal bacterial species after TMEV-induced acute seizures.
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Affiliation(s)
- Dannielle K Zierath
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Stephanie Davidson
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Jonathan Manoukian
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Kevin M Knox
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Stacey Meeker
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Aaron Ericsson
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri, USA
| | - Melissa Barker-Haliski
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
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Patel DC, Swift N, Tewari BP, Browning JL, Prim C, Chaunsali L, Kimbrough IF, Olsen ML, Sontheimer H. Increased expression of chondroitin sulfate proteoglycans in dentate gyrus and amygdala causes postinfectious seizures. Brain 2024; 147:1856-1870. [PMID: 38146224 PMCID: PMC11068111 DOI: 10.1093/brain/awad430] [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: 06/27/2023] [Revised: 10/05/2023] [Accepted: 12/08/2023] [Indexed: 12/27/2023] Open
Abstract
Alterations in the extracellular matrix are common in patients with epilepsy and animal models of epilepsy, yet whether they are the cause or consequence of seizures and epilepsy development is unknown. Using Theiler's murine encephalomyelitis virus (TMEV) infection-induced model of acquired epilepsy, we found de novo expression of chondroitin sulfate proteoglycans (CSPGs), a major extracellular matrix component, in dentate gyrus (DG) and amygdala exclusively in mice with acute seizures. Preventing the synthesis of CSPGs specifically in DG and amygdala by deletion of the major CSPG aggrecan reduced seizure burden. Patch-clamp recordings from dentate granule cells revealed enhanced intrinsic and synaptic excitability in seizing mice that was significantly ameliorated by aggrecan deletion. In situ experiments suggested that dentate granule cell hyperexcitability results from negatively charged CSPGs increasing stationary cations on the membrane, thereby depolarizing neurons, increasing their intrinsic and synaptic excitability. These results show increased expression of CSPGs in the DG and amygdala as one of the causal factors for TMEV-induced acute seizures. We also show identical changes in CSPGs in pilocarpine-induced epilepsy, suggesting that enhanced CSPGs in the DG and amygdala may be a common ictogenic factor and potential therapeutic target.
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Affiliation(s)
- Dipan C Patel
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Nathaniel Swift
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Bhanu P Tewari
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Jack L Browning
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Courtney Prim
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Lata Chaunsali
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Ian F Kimbrough
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Michelle L Olsen
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Harald Sontheimer
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
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Zhang S, Xie S, Zheng Y, Chen Z, Xu C. Current advances in rodent drug-resistant temporal lobe epilepsy models: Hints from laboratory studies. Neurochem Int 2024; 174:105699. [PMID: 38382810 DOI: 10.1016/j.neuint.2024.105699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/23/2024] [Accepted: 02/18/2024] [Indexed: 02/23/2024]
Abstract
Anti-seizure drugs (ASDs) are the first choice for the treatment of epilepsy, but there is still one-third of patients with epilepsy (PWEs) who are resistant to two or more appropriately chosen ASDs, named drug-resistant epilepsy (DRE). Temporal lobe epilepsy (TLE), a common type of epilepsy usually associated with hippocampal sclerosis (HS), shares the highest proportion of drug resistance (approximately 70%). In view of the key role of the temporal lobe in memory, emotion, and other physiological functions, patients with drug-resistant temporal lobe epilepsy (DR-TLE) are often accompanied by serious complications, and surgical procedures also yield extra considerations. The exact mechanisms for the genesis of DR-TLE remain unillustrated, which makes it hard to manage patients with DR-TLE in clinical practice. Animal models of DR-TLE play an irreplaceable role in both understanding the mechanism and searching for new therapeutic strategies or drugs. In this review article, we systematically summarized different types of current DR-TLE models, and then recent advances in mechanism investigations obtained in these models were presented, especially with the development of advanced experimental techniques and tools. We are deeply encouraged that novel strategies show great therapeutic potential in those DR-TLE models. Based on the big steps reached from the bench, a new light has been shed on the precise management of DR-TLE.
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Affiliation(s)
- Shuo Zhang
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Shengyang Xie
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China
| | - Yang Zheng
- Department of Neurology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhong Chen
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Department of Neurology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Cenglin Xu
- Department of Pharmacy, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Department of Neurology, The First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine), Hangzhou, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
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Iglesias LP, Soares N, Asth L, Moreira FA, Aguiar DC. Minocycline as a potential anxiolytic drug: systematic review and meta-analysis of evidence in murine models. Behav Pharmacol 2024; 35:4-13. [PMID: 38375658 DOI: 10.1097/fbp.0000000000000754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Minocycline is a tetracycline antibiotic with off-label use as an anti-inflammatory drug. Because it can cross the blood-brain barrier, minocycline has been proposed as an alternative treatment for psychiatric disorders, in which inflammation plays an important role. However, its beneficial effects on anxiety disorders are unclear. Therefore, we performed a systematic review and meta-analysis to evaluate the efficacy of minocycline as an anxiolytic drug in preclinical models. We performed a PubMed search according to the PRISMA guidelines and PICOS strategy. The risk of bias was evaluated using the SYRCLE tool. We included studies that determined the efficacy of minocycline in animal models of anxiety that may involve exposures (e.g. stressors, immunomodulators, injury). Data extracted included treatment effect, dose range, route of administration, and potential mechanisms for the anxiolytic effect. Meta-analysis of twenty studies showed that minocycline reduced anxiety-like behavior in rodents previously exposed to stress or immunostimulants but not in exposure-naïve animals. This effect was not associated with the dose administered or treatment duration. The mechanism for the anxiolytic activity of minocycline may depend on its anti-inflammatory effects in the brain regions involving anxiety. These suggest that minocycline could be repurposed as a treatment for anxiety and related disorders and warrants further evaluation.
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Affiliation(s)
- Lia P Iglesias
- Graduate School in Neuroscience, Universidade Federal de Minas Gerais (UFMG)
| | - Nicia Soares
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Laila Asth
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Fabricio A Moreira
- Graduate School in Neuroscience, Universidade Federal de Minas Gerais (UFMG)
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Daniele C Aguiar
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
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DePaula-Silva AB. The Contribution of Microglia and Brain-Infiltrating Macrophages to the Pathogenesis of Neuroinflammatory and Neurodegenerative Diseases during TMEV Infection of the Central Nervous System. Viruses 2024; 16:119. [PMID: 38257819 PMCID: PMC10819099 DOI: 10.3390/v16010119] [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: 12/05/2023] [Revised: 01/06/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
The infection of the central nervous system (CNS) with neurotropic viruses induces neuroinflammation and is associated with the development of neuroinflammatory and neurodegenerative diseases, including multiple sclerosis and epilepsy. The activation of the innate and adaptive immune response, including microglial, macrophages, and T and B cells, while required for efficient viral control within the CNS, is also associated with neuropathology. Under healthy conditions, resident microglia play a pivotal role in maintaining CNS homeostasis. However, during pathological events, such as CNS viral infection, microglia become reactive, and immune cells from the periphery infiltrate into the brain, disrupting CNS homeostasis and contributing to disease development. Theiler's murine encephalomyelitis virus (TMEV), a neurotropic picornavirus, is used in two distinct mouse models: TMEV-induced demyelination disease (TMEV-IDD) and TMEV-induced seizures, representing mouse models of multiple sclerosis and epilepsy, respectively. These murine models have contributed substantially to our understanding of the pathophysiology of MS and seizures/epilepsy following viral infection, serving as critical tools for identifying pharmacological targetable pathways to modulate disease development. This review aims to discuss the host-pathogen interaction during a neurotropic picornavirus infection and to shed light on our current understanding of the multifaceted roles played by microglia and macrophages in the context of these two complexes viral-induced disease.
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Affiliation(s)
- Ana Beatriz DePaula-Silva
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT 84112, USA
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Zierath DK, Davidson S, Manoukian J, White HS, Meeker S, Ericsson A, Barker-Haliski M. Diet composition and sterilization modifies intestinal microbiome diversity and burden of Theiler's virus infection-induced acute seizures. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.17.562694. [PMID: 37905123 PMCID: PMC10614857 DOI: 10.1101/2023.10.17.562694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Objective Central nervous system infection with Theiler's murine encephalomyelitis virus (TMEV) in C57BL/6J mice can model acquired epileptogenesis. Diet alters the acute seizure incidence in TMEV-infected mice; yet it is unclear whether intestinal dysbiosis may also impact acute or chronic behavioral comorbidities. This study thus assessed the impact of diet sterilization in a specific pathogen-free vivarium on acute seizure presentation, the composition of the gut microbiome, and chronic behavioral comorbidities of epilepsy. Methods Baseline fecal samples were collected from male C57BL/6J mice (4-5 weeks-old; Jackson Labs) upon arrival. Mice were randomized to either autoclaved (AC) or irradiated (IR) diet (Prolab RMH 3000 - UU diets) or IR (Picolab 5053 - UW IR diet). Mice then underwent intracerebral TMEV or PBS injection three days later. Fecal samples were collected from a subset of mice at infection (Day 0) and Day 7 post-infection. Epilepsy-related working memory deficits and seizure threshold were assessed 6 weeks post-infection. Gut microbiome diversity was determined by 16S rRNA amplicon sequencing of fecal samples. Results TMEV-infected mice displayed acute handling-induced seizures, regardless of diet: 28/57 UW IR (49.1%), 30/41 UU IR (73.2%), and 47/77 UU AC (61%) mice displayed seizures. The number of observed seizures significantly differed: UW IR mice had 2.2±2.8 seizures (mean±standard deviation), UU IR mice had 3.5±2.9 seizures, and UU AC mice had 4.4±3.8 seizures during the 7-day monitoring period. The composition of the gut microbiome significantly differed in TMEV-infected mice fed the UU AC diet, with most measured differences occurring in Gram-positive bacteria. TMEV-infected mice fed the UU AC diet displayed worsened chronic working memory. Significance Intestinal dysbiosis evokes stark differences in acute seizure presentation in the TMEV model and vastly influences the trajectory of post-TMEV infection-induced behavioral comorbidities of epilepsy. Our study reveals a novel disease-modifying contribution of intestinal bacterial species after TMEV-induced acute seizures.
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Affiliation(s)
- Dannielle K. Zierath
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA
| | - Stephanie Davidson
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA
| | - Jonathan Manoukian
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA
| | - H. Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA
| | - Stacey Meeker
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH
| | - Aaron Ericsson
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO
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Patel DC, Swift N, Tewari BP, Browning JL, Prim C, Chaunsali L, Kimbrough I, Olsen ML, Sontheimer H. Infection-induced epilepsy is caused by increased expression of chondroitin sulfate proteoglycans in hippocampus and amygdala. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.16.541066. [PMID: 37292901 PMCID: PMC10245664 DOI: 10.1101/2023.05.16.541066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Alterations in the extracellular matrix (ECM) are common in epilepsy, yet whether they are cause or consequence of disease is unknow. Using Theiler's virus infection model of acquired epilepsy we find de novo expression of chondroitin sulfate proteoglycans (CSPGs), a major ECM component, in dentate gyrus (DG) and amygdala exclusively in mice with seizures. Preventing synthesis of CSPGs specifically in DG and amygdala by deletion of major CSPG aggrecan reduced seizure burden. Patch-clamp recordings from dentate granule cells (DGCs) revealed enhanced intrinsic and synaptic excitability in seizing mice that was normalized by aggrecan deletion. In situ experiments suggest that DGCs hyperexcitability results from negatively charged CSPGs increasing stationary cations (K+, Ca2+) on the membrane thereby depolarizing neurons, increasing their intrinsic and synaptic excitability. We show similar changes in CSPGs in pilocarpine-induced epilepsy suggesting enhanced CSPGs in the DG and amygdala may be a common ictogenic factor and novel therapeutic potential.
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Affiliation(s)
- Dipan C Patel
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Nathaniel Swift
- Department of Internal Medicine, Gerontology and Geriatric Medicine, School of Medicine, Wake Forest University, Winston-Salem, NC 27157, USA
| | - Bhanu P Tewari
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Jack L Browning
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Courtney Prim
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Lata Chaunsali
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Ian Kimbrough
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
| | - Michelle L Olsen
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Harald Sontheimer
- Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22903, USA
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Chronic seizures induce sex-specific cognitive deficits with loss of presenilin 2 function. Exp Neurol 2023; 361:114321. [PMID: 36634751 DOI: 10.1016/j.expneurol.2023.114321] [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: 06/06/2022] [Revised: 10/04/2022] [Accepted: 01/06/2023] [Indexed: 01/11/2023]
Abstract
Patients with early-onset Alzheimer's disease (EOAD) are at elevated risk for seizures, including patients with presenilin 2 (PSEN2) variants. Like people with epilepsy, uncontrolled seizures may worsen cognitive function in AD. While the relationship between seizures and amyloid beta accumulation has been more thoroughly investigated, the role of other drivers of seizure susceptibility in EOAD remain relatively understudied. We therefore sought to define the impact of loss of normal PSEN2 function and chronic seizures on cognitive function in the aged brain. Male and female PSEN2 KO and age- and sex-matched wild-type (WT) mice were sham or corneal kindled beginning at 6-months-old. Kindled and sham-kindled mice were then challenged up to 6 weeks later in a battery of cognitive tests: non-habituated open field (OF), T-maze spontaneous alternation (TM), and Barnes maze (BM), followed by immunohistochemistry for markers of neuroinflammation and neuroplasticity. PSEN2 KO mice required significantly more stimulations to kindle (males: p < 0.02; females: p < 0.02) versus WT. Across a range of behavioral tests, the cognitive performance of kindled female PSEN2 KO mice was most significantly impaired versus age-matched WT females. Male BM performance was generally worsened by seizures (p = 0.038), but loss of PSEN2 function did not itself worsen cognitive performance. Conversely, kindled PSEN2 KO females made the most BM errors (p = 0.007). Chronic seizures also significantly altered expression of hippocampal neuroinflammation and neuroplasticity markers in a sex-specific manner. Chronic seizures may thus significantly worsen hippocampus-dependent cognitive deficits in aged female, but not male, PSEN2 KO mice. Our work suggests that untreated focal seizures may worsen cognitive burden with loss of normal PSEN2 function in a sex-related manner.
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Del Pozo A, Barker-Haliski M. Cannabidiol reveals a disruptive strategy for 21st century epilepsy drug discovery. Exp Neurol 2023; 360:114288. [PMID: 36471511 PMCID: PMC9789191 DOI: 10.1016/j.expneurol.2022.114288] [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: 09/27/2022] [Revised: 11/11/2022] [Accepted: 11/25/2022] [Indexed: 11/27/2022]
Abstract
Over 30 antiseizure medicines (ASMs) have been uncovered in a diversity of preclinical seizure and epilepsy models, with several critical inflection points in the 20th century fundamentally transforming ASM discovery. This commentary aims to review the historical relevance of cannabidiol's (CBD; Epidiolex) approval for epilepsy in the context of other ASMs brought to market. Further, we highlight how CBD's approval may represent an inflection point for 21st century ASM discovery. CBD is one of the main phytocannabinoids of Cannabis sativa. Unlike its related phytocannabinoid, Δ9-tetrahydrocannabinol, CBD does not exert any euphorigenic, tolerance, or withdrawal effects at anticonvulsant doses. CBD also possess marked anti-inflammatory effects, offering the tantalizing potential of a new pharmacological approach in epilepsy. For decades, hints of the anticonvulsant profile of CBD had been suggested with a small handful of studies in rodent seizure models, yet difficulties in formulation, compounded by the social and regulatory pressures related to medical use of cannabis plant-derived agents constrained any clinical implementation. Nonetheless, CBD possesses a broad antiseizure profile in preclinical seizure and epilepsy models, but the transformative impact of CBD'-s approval came because of studies in a rodent model of the orphan disease Dravet syndrome (DS). DS is a pediatric developmental epileptic encephalopathy with high mortality, frequent spontaneous recurrent seizures, and marked resistance to conventional ASMs, such as phenytoin and carbamazepine. CBD was approved for DS by the US Food and Drug Administration in 2018 after convincing efficacy was established in randomized, placebo-controlled trials in children. Because of the clinical approval of CBD as a novel, cannabis plantderived ASM for DS, CBD has revealed a new strategy in ASM discovery to reignite 21st century therapeutic development for epilepsy. In this commentary, we review the major preclinical and clinical milestones of the late 20th century that made CBD, a compound historically subjected to regulatory restrictions, a key driver of a new discovery strategy for epilepsy in the 21st century.
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Affiliation(s)
- Aaron Del Pozo
- Department of Pharmacy, University of Washington, Seattle, WA 98195, United States of America
| | - Melissa Barker-Haliski
- Department of Pharmacy, University of Washington, Seattle, WA 98195, United States of America.
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Löscher W, Stafstrom CE. Epilepsy and its neurobehavioral comorbidities: Insights gained from animal models. Epilepsia 2023; 64:54-91. [PMID: 36197310 DOI: 10.1111/epi.17433] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/04/2022] [Accepted: 10/04/2022] [Indexed: 01/21/2023]
Abstract
It is well established that epilepsy is associated with numerous neurobehavioral comorbidities, with a bidirectional relationship; people with epilepsy have an increased incidence of depression, anxiety, learning and memory difficulties, and numerous other psychosocial challenges, and the occurrence of epilepsy is higher in individuals with those comorbidities. Although the cause-and-effect relationship is uncertain, a fuller understanding of the mechanisms of comorbidities within the epilepsies could lead to improved therapeutics. Here, we review recent data on epilepsy and its neurobehavioral comorbidities, discussing mainly rodent models, which have been studied most extensively, and emphasize that clinically relevant information can be gained from preclinical models. Furthermore, we explore the numerous potential factors that may confound the interpretation of emerging data from animal models, such as the specific seizure induction method (e.g., chemical, electrical, traumatic, genetic), the role of species and strain, environmental factors (e.g., laboratory environment, handling, epigenetics), and the behavioral assays that are chosen to evaluate the various aspects of neural behavior and cognition. Overall, the interplay between epilepsy and its neurobehavioral comorbidities is undoubtedly multifactorial, involving brain structural changes, network-level differences, molecular signaling abnormalities, and other factors. Animal models are well poised to help dissect the shared pathophysiological mechanisms, neurological sequelae, and biomarkers of epilepsy and its comorbidities.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Barker-Haliski M, Nishi T, White HS. Soticlestat, a novel cholesterol 24-hydroxylase inhibitor, modifies acute seizure burden and chronic epilepsy-related behavioral deficits following Theiler's virus infection in mice. Neuropharmacology 2023; 222:109310. [PMID: 36341806 DOI: 10.1016/j.neuropharm.2022.109310] [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: 07/27/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
Temporal lobe epilepsy is the most common form of acquired epilepsy and can arise due to multiple inciting events, including central nervous system (CNS) infection. CNS infection with the Theiler's murine encephalomyelitis virus (TMEV) in male C57Bl/6J mice leads to acute, drug-resistant handling-induced seizures. Cholesterol 24-hydroxylase (CH24H) is a brain-specific enzyme that converts cholesterol into 24S-hydroxycholesterol; the primary mechanism of cholesterol catabolism in the brain. The novel CH24H inhibitor, soticlestat (SOT; or TAK-935), demonstrates the potential to restore excitatory/inhibitory balance in multiple preclinical models of hyperexcitability. This study thus sought to characterize the anticonvulsant potential of SOT in the TMEV model. Treatment with SOT (30 mg/kg, p.o.; n = 30) 0-7 days post-infection (DPI) reduced overall seizure burden and severity. SOT administration significantly delayed onset of infection-induced Racine stage 5 seizures, from 8.6 ± 0.6 (VEH-treated) to 10.8 ± 0.8 (SOT-treated) observation sessions. Infected mice were then allowed 36 days treatment-free recovery before assessing impact of earlier drug administration on epilepsy-related cognitive and behavioral comorbidities, including a non-habituated open field (OF) task. Total OF distance traveled was significantly less in SOT-treated mice compared to VEH-treated mice, suggesting attenuated TMEV-induced spatial memory deficits, or reduced chronic hyperexcitability. Mice with history of SOT treatment also spent significantly more time and traveled farther in the OF center, indicative of reduced epilepsy-induced anxiety-like behavior. These studies suggest that SOT is a mechanistically novel agent for symptomatic seizure control. Moreover, acute SOT administration during an epileptogenic insult may attenuate the resulting long-term behavioral comorbidities of epilepsy.
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Affiliation(s)
| | - Toshiya Nishi
- Research, Takeda Pharmaceutical Company Limited, Fujisawa, 251-8555, Japan; Takeda Pharmaceutical Company Limited, Cambridge, MA, 02139, USA.
| | - H Steve White
- University of Washington, Department of Pharmacy, Seattle, WA, USA
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Barker-Haliski M, Pitsch J, Galanopoulou AS, Köhling R. A companion to the preclinical common data elements for phenotyping seizures and epilepsy in rodent models. A report of the TASK3-WG1C: Phenotyping working group of the ILAE/AES joint translational task force. Epilepsia Open 2022. [PMID: 36461665 DOI: 10.1002/epi4.12676] [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: 11/18/2021] [Accepted: 05/23/2022] [Indexed: 12/04/2022] Open
Abstract
Epilepsy is a heterogeneous disorder characterized by spontaneous seizures and behavioral comorbidities. The underlying mechanisms of seizures and epilepsy across various syndromes lead to diverse clinical presentation and features. Similarly, animal models of epilepsy arise from numerous dissimilar inciting events. Preclinical seizure and epilepsy models can be evoked through many different protocols, leaving the phenotypic reporting subject to diverse interpretations. Serendipity can also play an outsized role in uncovering novel drivers of seizures or epilepsy, with some investigators even stumbling into epilepsy research because of a new genetic cross or unintentional drug effect. The heightened emphasis on rigor and reproducibility in preclinical research, including that which is conducted for epilepsy, underscores the need for standardized phenotyping strategies. To address this goal as part of the TASK3-WG1C Working Group of the International League Against Epilepsy (ILAE)/American Epilepsy Society (AES) Joint Translational Task Force, we developed a case report form (CRF) to describe the common data elements (CDEs) necessary for the phenotyping of seizure-like behaviors in rodents. This companion manuscript describes the use of the proposed CDEs and CRF for the visual, behavioral phenotyping of seizure-like behaviors. These phenotyping CDEs and accompanying CRF can be used in parallel with video-electroencephalography (EEG) studies or as a first visual screen to determine whether a model manifests seizure-like behaviors before utilizing more specialized diagnostic tests, like video-EEG. Systematic logging of seizure-like behaviors may help identify models that could benefit from more specialized diagnostic tests to determine whether these are epileptic seizures, such as video-EEG.
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Affiliation(s)
- Melissa Barker-Haliski
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Julika Pitsch
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Isabelle Rapin Division of Child Neurology, Laboratory of Developmental Epilepsy, Albert Einstein College of Medicine, Bronx, New York, USA
- Dominick P Purpura Department of Neuroscience, Isabelle Rapin Division of Child Neurology, Laboratory of Developmental Epilepsy, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rüdiger Köhling
- Oscar-Langendorff-Institut für Physiologie, Universitätsmedizin Rostock, Rostock, Germany
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Altered Extracellular Matrix as an Alternative Risk Factor for Epileptogenicity in Brain Tumors. Biomedicines 2022; 10:biomedicines10102475. [PMID: 36289737 PMCID: PMC9599244 DOI: 10.3390/biomedicines10102475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Seizures are one of the most common symptoms of brain tumors. The incidence of seizures differs among brain tumor type, grade, location and size, but paediatric-type diffuse low-grade gliomas/glioneuronal tumors are often highly epileptogenic. The extracellular matrix (ECM) is known to play a role in epileptogenesis and tumorigenesis because it is involved in the (re)modelling of neuronal connections and cell-cell signaling. In this review, we discuss the epileptogenicity of brain tumors with a focus on tumor type, location, genetics and the role of the extracellular matrix. In addition to functional problems, epileptogenic tumors can lead to increased morbidity and mortality, stigmatization and life-long care. The health advantages can be major if the epileptogenic properties of brain tumors are better understood. Surgical resection is the most common treatment of epilepsy-associated tumors, but post-surgery seizure-freedom is not always achieved. Therefore, we also discuss potential novel therapies aiming to restore ECM function.
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Löscher W, Howe CL. Molecular Mechanisms in the Genesis of Seizures and Epilepsy Associated With Viral Infection. Front Mol Neurosci 2022; 15:870868. [PMID: 35615063 PMCID: PMC9125338 DOI: 10.3389/fnmol.2022.870868] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/05/2022] [Indexed: 12/16/2022] Open
Abstract
Seizures are a common presenting symptom during viral infections of the central nervous system (CNS) and can occur during the initial phase of infection ("early" or acute symptomatic seizures), after recovery ("late" or spontaneous seizures, indicating the development of acquired epilepsy), or both. The development of acute and delayed seizures may have shared as well as unique pathogenic mechanisms and prognostic implications. Based on an extensive review of the literature, we present an overview of viruses that are associated with early and late seizures in humans. We then describe potential pathophysiologic mechanisms underlying ictogenesis and epileptogenesis, including routes of neuroinvasion, viral control and clearance, systemic inflammation, alterations of the blood-brain barrier, neuroinflammation, and inflammation-induced molecular reorganization of synapses and neural circuits. We provide clinical and animal model findings to highlight commonalities and differences in these processes across various neurotropic or neuropathogenic viruses, including herpesviruses, SARS-CoV-2, flaviviruses, and picornaviruses. In addition, we extensively review the literature regarding Theiler's murine encephalomyelitis virus (TMEV). This picornavirus, although not pathogenic for humans, is possibly the best-characterized model for understanding the molecular mechanisms that drive seizures, epilepsy, and hippocampal damage during viral infection. An enhanced understanding of these mechanisms derived from the TMEV model may lead to novel therapeutic interventions that interfere with ictogenesis and epileptogenesis, even within non-infectious contexts.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Center for Systems Neuroscience, Hannover, Germany
| | - Charles L. Howe
- Division of Experimental Neurology, Department of Neurology, Mayo Clinic, Rochester, MN, United States
- Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN, United States
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Reconnoitering the transformative journey of minocycline from an antibiotic to an antiepileptic drug. Life Sci 2022; 293:120346. [PMID: 35065989 DOI: 10.1016/j.lfs.2022.120346] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 01/04/2022] [Accepted: 01/16/2022] [Indexed: 12/20/2022]
Abstract
Minocycline, a second-generation tetracycline antibiotic is being widely tested in animals as well as clinical settings for the management of multiple neurological disorders. The drug has shown to exert protective action in a multitude of neurological disorders including spinal-cord injury, stroke, multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, and Parkinson's disease. Being highly lipophilic, minocycline easily penetrates the blood brain barrier and is claimed to have excellent oral absorption (~100% bioavailability). Minocycline possesses anti-inflammatory, immunomodulatory, and anti-apoptotic properties, thereby supporting its use in treating neurological disorders. The article henceforth reviews all the recent advances in the transformation of this antibiotic into a potential antiepileptic/antiepileptogenic agent. The article also gives an account of all the clinical trials undertaken till now validating the antiepileptic potential of minocycline. Based on the reported studies, minocycline seems to be an important molecule for treating epilepsy. However, the practical therapeutic implementations of this molecule require extensive mechanism-based in-vitro (cell culture) and in-vivo (animal models) studies followed by its testing in randomized, placebo controlled and double-blind clinical trials in large population as well as in different form of epilepsies.
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Metcalf CS, Vanegas F, Underwood T, Johnson K, West PJ, Smith MD, Wilcox KS. Screening of prototype antiseizure and anti-inflammatory compounds in the Theiler's murine encephalomyelitis virus model of epilepsy. Epilepsia Open 2021; 7:46-58. [PMID: 34668659 PMCID: PMC8886069 DOI: 10.1002/epi4.12550] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 10/10/2021] [Accepted: 10/12/2021] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE Infection with Theiler's murine encephalomyelitis virus (TMEV) in C57Bl/6J mice results in handling-induced seizures and is useful for evaluating compounds effective against infection-induced seizures. However, to date only a few compounds have been evaluated in this model, and a comprehensive study of antiseizure medications (ASMs) has not yet been performed. Furthermore, as the TMEV infection produces marked neuroinflammation, an evaluation of prototype anti-inflammatory compounds is needed as well. METHODS Male C57Bl/6J mice were inoculated with TMEV (day 0) followed by daily administrations of test compounds (day 3-7) and subsequent handling sessions (day 3-7). Doses of ASMs, comprising several mechanistic classes, were selected based on previously published data demonstrating the effect of these compounds in reducing seizures in the 6 Hz model of pharmacoresistant seizures. Doses of anti-inflammatory compounds, comprising several mechanistic classes, were selected based on published evidence of reduction of inflammation or inflammation-related endpoints. RESULTS Several prototype ASMs reduced acute seizures following TMEV infection: lacosamide, phenytoin, ezogabine, phenobarbital, tiagabine, gabapentin, levetiracetam, topiramate, and sodium valproate. Of these, phenobarbital and sodium valproate had the greatest effect (>95% seizure burden reduction). Prototype anti-inflammatory drugs celecoxib, dexamethasone, and prednisone also moderately reduced seizure burden. SIGNIFICANCE The TMEV model is utilized by the Epilepsy Therapy Screening Program (ETSP) as a tool for evaluation of novel compounds. Compounds reducing seizures in the TMEV comprise distinct mechanistic classes, some with mechanisms of action that extend beyond traditional ASMs.
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Affiliation(s)
- Cameron S Metcalf
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Fabiola Vanegas
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Tristan Underwood
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Kristina Johnson
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Peter J West
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Misty D Smith
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA.,School of Dentistry, University of Utah, Salt Lake City, Utah, USA
| | - Karen S Wilcox
- Epilepsy Therapy Screening Program Contract Site, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
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Knox KM, Zierath DK, White HS, Barker-Haliski M. Continuous seizure emergency evoked in mice with pharmacological, electrographic, and pathological features distinct from status epilepticus. Epilepsia 2021; 62:3076-3090. [PMID: 34625953 DOI: 10.1111/epi.17089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 09/22/2021] [Accepted: 09/22/2021] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Benzodiazepines are the standard of care for the management of sustained seizure emergencies, including status epilepticus (SE) and seizure clusters. Seizure clusters are a variably defined seizure emergency wherein a patient has multiple seizures above a baseline rate, with intervening periods of recovery, distinguishing clusters from SE. Although these seizure emergencies are phenotypically distinct, the precise pathophysiological and mechanistic differences between SE and seizure clusters are understudied. Emergency-specific preclinical models may differentiate the behavioral and pathological mechanisms that are acutely associated with seizure emergencies and seizure termination to better manage these events. METHODS Herein we characterize a novel model of sustained seizure emergency induced in CF-1 mice through the combined administration of high-dose phenytoin (PHT; 50 mg/kg, i.p.) and pentylenetetrazol (PTZ; 100 mg/kg, s.c.). RESULTS We presently describe a mouse model of sustained seizure emergency that is pathologically, pharmacologically, and behaviorally distinct from SE. Acute administration of PHT 1 h prior to PTZ led to significantly more mice with unremitting continuous seizure activity (CSA; 73.4%) vs vehicle-pretreated mice (13.8%; p < .0001). CSA was sensitive to lorazepam and valproic acid when administered at seizure onset and 30 minutes later. Carbamazepine worsened seizure control and post-CSA survival. Mice in CSA exhibited electroencephalography (EEG) patterns distinct from kainic acid-induced SE and PTZ alone, clearly differentiating CSA from SE and PTZ-induced myoclonic seizures. Neuropathological assessment by Fluoro-Jade C staining of brains collected 24 h post-CSA revealed no neurodegeneration in any mouse that underwent CSA, whereas there was widespread neuronal death in brains from KA-SE mice. Finally, immunohistochemistry revealed acute seizure-induced astrogliosis (glial fibrillary acid protein; GFAP) in hippocampal structures, whereas hippocampal neuronal nuclei (NeuN) protein expression was only reduced in KA-SE mice. SIGNIFICANCE We present a novel mouse model on which to further elucidate the mechanistic differences between sustained seizure emergencies (ie, SE and seizure clusters) to improve clinical interventions and define mechanisms of seizure termination.
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Affiliation(s)
- Kevin M Knox
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Dannielle K Zierath
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Melissa Barker-Haliski
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
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Lehmann L, Lo A, Knox KM, Barker-Haliski M. Alzheimer's Disease and Epilepsy: A Perspective on the Opportunities for Overlapping Therapeutic Innovation. Neurochem Res 2021; 46:1895-1912. [PMID: 33929683 PMCID: PMC8254705 DOI: 10.1007/s11064-021-03332-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/16/2021] [Accepted: 04/20/2021] [Indexed: 01/01/2023]
Abstract
Early-onset Alzheimer's disease (AD) is associated with variants in amyloid precursor protein (APP) and presenilin (PSEN) 1 and 2. It is increasingly recognized that patients with AD experience undiagnosed focal seizures. These AD patients with reported seizures may have worsened disease trajectory. Seizures in epilepsy can also lead to cognitive deficits, neuroinflammation, and neurodegeneration. Epilepsy is roughly three times more common in individuals aged 65 and older. Due to the numerous available antiseizure drugs (ASDs), treatment of seizures has been proposed to reduce the burden of AD. More work is needed to establish the functional impact of seizures in AD to determine whether ASDs could be a rational therapeutic strategy. The efficacy of ASDs in aged animals is not routinely studied, despite the fact that the elderly represents the fastest growing demographic with epilepsy. This leaves a particular gap in understanding the discrete pathophysiological overlap between hyperexcitability and aging, and AD more specifically. Most of our preclinical knowledge of hyperexcitability in AD has come from mouse models that overexpress APP. While these studies have been invaluable, other drivers underlie AD, e.g. PSEN2. A diversity of animal models should be more frequently integrated into the study of hyperexcitability in AD, which could be particularly beneficial to identify novel therapies. Specifically, AD-associated risk genes, in particular PSENs, altogether represent underexplored contributors to hyperexcitability. This review assesses the available studies of ASDs administration in clinical AD populations and preclinical studies with AD-associated models and offers a perspective on the opportunities for further therapeutic innovation.
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Affiliation(s)
- Leanne Lehmann
- Undergraduate Neuroscience Program, University of Washington, Seattle, WA, 98195, USA
| | - Alexandria Lo
- Department of Public Health-Global Health, School of Public Health, University of Washington, Seattle, WA, 98195, USA
| | - Kevin M Knox
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, 98195, USA
| | - Melissa Barker-Haliski
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, 98195, USA.
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Zhang R, Mu J, Chi J, Jiang W, Chi X. The role of picornavirus infection in epileptogenesis. ACTA EPILEPTOLOGICA 2021. [DOI: 10.1186/s42494-021-00040-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractPicornaviridae are a family of small positive-strand RNA viruses, and transmitted via the respiratory or fecal-oral route. The neurotropic picornaviruses can induce acute or late recurrent seizures following central nervous system infection, by infecting the peripheral nerve, crossing the blood-brain barrier and migrating in the Trojan-horse method. Theiler’s murine encephalomyelitis virus (TMEV), as a member of Picornaviridae family, can cause encephalitis, leading to chronic spontaneous seizures. TMEV-infected C57BL/6 mice have been used as an animal model for exploring the mechanism of epileptogenesis and assessing new antiepileptic drugs. Astrogliosis, neuronal death and microglial recruitment have been detected in the hippocampus following the picornaviruse-induced encephalitis. The macrophages, monocytes, neutrophils, as well as IL-6 and TNF-α released by them, play an important role in the epileptogenesis. In this review, we summarize the clinical characteristics of picornavirus infection, and the immunopathology involved in the TMEV-induced epilepsy.
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Castanospermine reduces Zika virus infection-associated seizure by inhibiting both the viral load and inflammation in mouse models. Antiviral Res 2020; 183:104935. [PMID: 32949636 PMCID: PMC7492813 DOI: 10.1016/j.antiviral.2020.104935] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 09/02/2020] [Accepted: 09/11/2020] [Indexed: 11/30/2022]
Abstract
Zika virus (ZIKV) outbreaks have been reported worldwide, including a recent occurrence in Brazil where it spread rapidly, and an association with increased cases of microcephaly was observed in addition to neurological issues such as GBS that were reported during previous outbreaks. Following infection of neuronal tissues, ZIKV can cause inflammation, which may lead to neuronal abnormalities, including seizures and paralysis. Therefore, a drug containing both anti-viral and immunosuppressive properties would be of great importance in combating ZIKV related neurological abnormalities. Castanospermine (CST) is potentially a right candidate drug as it reduced viral load and brain inflammation with the resulting appearance of delayed neuronal disorders, including seizures and paralysis in an Ifnar1−/− mouse. Anti-ZIKV activity of castanospermine (CST) In vivo and in vitro. CST reduces ZIKV induced inflammation of brain. CST delays the ZIKV induced seizure and improves neuronal disorders such as motor function. CST gives marginal improvement in survivability in Ifnar1−/− mice.
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Zhang P, Yang Y, Zou J, Yang X, Liu Q, Chen Y. Seizures and epilepsy secondary to viral infection in the central nervous system. ACTA EPILEPTOLOGICA 2020. [DOI: 10.1186/s42494-020-00022-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
AbstractViral infection in the central nervous system (CNS) is a common cause of seizures and epilepsy. Acute symptomatic seizures can occur in the context of almost all types of acute CNS viral infection. However, late unprovoked seizures and epilepsy may not be frequent after viral infection of the CNS. The incidence of seizures and epilepsy after CNS viral infection is mainly dependent on the brain region of infection. It remains to be determined whether treatment of CNS viral infection using antiepileptic drugs (AEDs) can prevent seizures and subsequent epilepsy in patients, particularly with regard to the timing, drug choice and dosage, and duration of AEDs. The postoperative outcome of seizures in patients with intractable epilepsy caused by viral encephalitis primarily depends on the epileptogenic zone. In addition, neuroinflammation is known to be widely involved in the generation of seizures during CNS viral infection, and the effects of anti-inflammatory therapies in preventing seizures and epilepsy secondary to CNS viral infection require further studies. In this review, we discuss the incidence, mechanisms, clinical management and prognosis of seizures and epilepsy secondary to CNS viral infection, and summarize common CNS viral infections that cause seizures and epilepsy.
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Yi Z, Keung KL, Li L, Hu M, Lu B, Nicholson L, Jimenez-Vera E, Menon MC, Wei C, Alexander S, Murphy B, O’Connell PJ, Zhang W. Key driver genes as potential therapeutic targets in renal allograft rejection. JCI Insight 2020; 5:136220. [PMID: 32634125 PMCID: PMC7455082 DOI: 10.1172/jci.insight.136220] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 06/24/2020] [Indexed: 01/09/2023] Open
Abstract
Acute rejection (AR) in renal transplantation is an established risk factor for reduced allograft survival. Molecules with regulatory control among immune pathways of AR that are inadequately suppressed, despite standard-of-care immunosuppression, could serve as important targets for therapeutic manipulation to prevent rejection. Here, an integrative, network-based computational strategy incorporating gene expression and genotype data of human renal allograft biopsy tissue was applied, to identify the master regulators - the key driver genes (KDGs) - within dysregulated AR pathways. A 982-meta-gene signature with differential expression in AR versus non-AR was identified from a meta-analysis of microarray data from 735 human kidney allograft biopsy samples across 7 data sets. Fourteen KDGs were derived from this signature. Interrogation of 2 publicly available databases identified compounds with predicted efficacy against individual KDGs or a key driver-based gene set, respectively, which could be repurposed for AR prevention. Minocycline, a tetracycline antibiotic, was chosen for experimental validation in a murine cardiac allograft model of AR. Minocycline attenuated the inflammatory profile of AR compared with controls and when coadministered with immunosuppression prolonged graft survival. This study demonstrates that a network-based strategy, using expression and genotype data to predict KDGs, assists target prioritization for therapeutics in renal allograft rejection.
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Affiliation(s)
- Zhengzi Yi
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Karen L. Keung
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
- Department of Nephrology, Prince of Wales Hospital, Sydney, Australia
| | - Li Li
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Sema4, Stamford, Connecticut, Connecticut, USA
| | - Min Hu
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Bo Lu
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Leigh Nicholson
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Elvira Jimenez-Vera
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Madhav C. Menon
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Chengguo Wei
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Stephen Alexander
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
- Nephrology Department, The Children’s Hospital at Westmead, Sydney, Australia
| | - Barbara Murphy
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Philip J. O’Connell
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
- Department of Nephrology, Westmead Hospital, Sydney, Australia
| | - Weijia Zhang
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Victor TR, Tsirka SE. Microglial contributions to aberrant neurogenesis and pathophysiology of epilepsy. NEUROIMMUNOLOGY AND NEUROINFLAMMATION 2020; 7:234-247. [PMID: 33154976 PMCID: PMC7641338 DOI: 10.20517/2347-8659.2020.02] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Microglia are dynamic cells that constitute the brain's innate immune system. Recently, research has demonstrated microglial roles beyond immunity, which include homeostatic roles in the central nervous system. The function of microglia is an active area of study, with insights into changes in neurogenesis and synaptic pruning being discovered in both health and disease. In epilepsy, activated microglia contribute to several changes that occur during epileptogenesis. In this review, we focus on the effects of microglia on neurogenesis and synaptic pruning, and discuss the current state of anti-seizure drugs and how they affect microglia during these processes. Our understanding of the role of microglia post-seizure is still limited and may be pivotal in recognizing new therapeutic targets for seizure intervention.
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Affiliation(s)
- Tanya R Victor
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Stella E Tsirka
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
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25
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Park D, Kim S, Kim H, Shin J, Jung H, Um JW. Seizure progression triggered by
IQSEC3
loss is mitigated by reducing activated microglia in mice. Glia 2020; 68:2661-2673. [DOI: 10.1002/glia.23876] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/29/2020] [Accepted: 06/04/2020] [Indexed: 01/02/2023]
Affiliation(s)
- Dongseok Park
- Department of Brain and Cognitive Sciences Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu South Korea
| | - Seungjoon Kim
- Department of Brain and Cognitive Sciences Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu South Korea
| | - Hyeonho Kim
- Department of Brain and Cognitive Sciences Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu South Korea
| | - Jungsu Shin
- Department of Brain and Cognitive Sciences Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu South Korea
| | - Hyeji Jung
- Department of Brain and Cognitive Sciences Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu South Korea
| | - Ji Won Um
- Department of Brain and Cognitive Sciences Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu South Korea
- Core Protein Resources Center, DGIST Daegu South Korea
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26
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Barker-Haliski M, Steve White H. Validated animal models for antiseizure drug (ASD) discovery: Advantages and potential pitfalls in ASD screening. Neuropharmacology 2019; 167:107750. [PMID: 31469995 DOI: 10.1016/j.neuropharm.2019.107750] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 08/14/2019] [Accepted: 08/23/2019] [Indexed: 12/18/2022]
Abstract
Since 1993, over 20 new anti-seizure drugs (ASDs) have been identified in well-established animal seizure and epilepsy models and subsequently demonstrated to be clinically effective in double-blinded, placebo-controlled clinical trials in patients with focal onset seizures. All clinically-available ASDs on the market today are effective in at least one of only three preclinical seizure and epilepsy models: the acute maximal electroshock (MES), the acute subcutaneous pentylenetetrazol (scPTZ) test, or the kindled rodent with chronic evoked seizures. Thus, it reasons that preclinical ASD discovery does not need significant revision to successfully identify ASDs for the symptomatic treatment of epilepsy. Unfortunately, a significant need still persists for more efficacious and better tolerated ASDs. This is particularly true for those patients whose seizures remain drug resistant. This review will focus on the continued utility of the acute MES and scPTZ tests, as well as the kindled rodent for current and future ASD discovery. These are the only "clinically validated" rodent models to date and been heavily used in the search for novel and more efficacious ASDs. This is to say that promising ASDs have been brought to the clinic on the basis of efficacy in these particular seizure and epilepsy models alone. This review also discusses some of the inherent advantages and limitations of these models relative to existing and emerging preclinical models. It then offers insight into future efforts to develop a preclinical model that will advance a truly transformative therapy for the symptomatic treatment of difficult to treat focal onset epilepsy. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, USA
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27
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Löscher W. The holy grail of epilepsy prevention: Preclinical approaches to antiepileptogenic treatments. Neuropharmacology 2019; 167:107605. [PMID: 30980836 DOI: 10.1016/j.neuropharm.2019.04.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/03/2019] [Accepted: 04/09/2019] [Indexed: 02/06/2023]
Abstract
A variety of acute brain insults can induce epileptogenesis, a complex process that results in acquired epilepsy. Despite advances in understanding mechanisms of epileptogenesis, there is currently no approved treatment that prevents the development or progression of epilepsy in patients at risk. The current concept of epileptogenesis assumes a window of opportunity following acute brain insults that allows intervention with preventive treatment. Recent results suggest that injury-induced epileptogenesis can be a much more rapid process than previously thought, suggesting that the 'therapeutic window' may only be open for a brief period, as in stroke therapy. However, experimental data also suggest a second, possibly delayed process ("secondary epileptogenesis") that influences the progression and refractoriness of the epileptic state over time, allowing interfering with this process even after onset of epilepsy. In this review, both methodological issues in preclinical drug development and novel targets for antiepileptogenesis will be discussed. Several promising drugs that either prevent epilepsy (antiepileptogenesis) or slow epilepsy progression and alleviate cognitive or behavioral comorbidities of epilepsy (disease modification) have been described in recent years, using diverse animal models of acquired epilepsy. Promising agents include TrkB inhibitors, losartan, statins, isoflurane, anti-inflammatory and anti-oxidative drugs, the SV2A modulator levetiracetam, and epigenetic interventions. Research on translational target validity and on prognostic biomarkers that can be used to stratify patients (or experimental animals) at high risk of developing epilepsy will hopefully soon lead to proof-of-concept clinical trials with the most promising drugs, which will be essential to make prevention of epilepsy a reality. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
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28
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Juda MB, Brooks AK, Towers AE, Freund GG, McCusker RH, Steelman AJ. Indoleamine 2,3-dioxygenase 1 deletion promotes Theiler's virus-induced seizures in C57BL/6J mice. Epilepsia 2019; 60:626-635. [PMID: 30770561 DOI: 10.1111/epi.14675] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Viral encephalitis increases the risk for developing seizures and epilepsy. Indoleamine 2,3-dioxygenase 1 (Ido1) is induced by inflammatory cytokines and functions to metabolize tryptophan to kynurenine. Kynurenine can be further metabolized to produce kynurenic acid and the N-methyl-d-aspartate receptor agonist quinolinic acid (QuinA). In the present study, we sought to determine the role of Ido1 in promoting seizures in an animal model of viral encephalitis. METHODS C57BL/6J and Ido1 knockout mice (Ido1-KO) were infected with Theiler's murine encephalomyelitis virus (TMEV). Quantitative real-time polymerase chain reaction was used to evaluate hippocampal expression of proinflammatory cytokines, Ido1, and viral RNA. Body weights and seizure scores were recorded daily. Elevated zero maze was used to assess differences in behavior, and hippocampal pathology was determined by immunohistochemistry. RESULTS Infected C57BL/6J mice up-regulated proinflammatory cytokines, Ido1, and genes encoding the enzymatic cascade responsible for QuinA production in the kynurenine pathway prior to the onset of seizures. Seizure incidence was elevated in Ido1-KO compared to C57BL/6J mice. Infection increased locomotor activity in Ido1-KO compared to C57BL/6J mice. Furthermore, the occurrence of seizures was associated with hyperexcitability. Neither expression of proinflammatory cytokines nor viral RNA was altered as a result of genotype. Immunohistochemical analysis revealed increased hippocampal pathology in Ido1-KO mice. SIGNIFICANCE Our findings suggest that Ido1 deletion promotes seizures and neuropathogenesis during acute TMEV encephalitis.
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Affiliation(s)
- Michal B Juda
- Department of Animal Sciences, College of Agricultural, Consumer, and Environmental Sciences, Urbana, Illinois
| | - Alexandra K Brooks
- Neuroscience Program, College of Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Albert E Towers
- Division of Nutritional Sciences, College of Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Gregory G Freund
- Department of Animal Sciences, College of Agricultural, Consumer, and Environmental Sciences, Urbana, Illinois.,Division of Nutritional Sciences, College of Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois.,Department of Pathology, College of Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Robert H McCusker
- Department of Animal Sciences, College of Agricultural, Consumer, and Environmental Sciences, Urbana, Illinois.,Neuroscience Program, College of Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois.,Department of Pathology, College of Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Andrew J Steelman
- Department of Animal Sciences, College of Agricultural, Consumer, and Environmental Sciences, Urbana, Illinois.,Neuroscience Program, College of Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois.,Division of Nutritional Sciences, College of Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois
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29
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Gerhauser I, Hansmann F, Ciurkiewicz M, Löscher W, Beineke A. Facets of Theiler's Murine Encephalomyelitis Virus-Induced Diseases: An Update. Int J Mol Sci 2019; 20:ijms20020448. [PMID: 30669615 PMCID: PMC6358740 DOI: 10.3390/ijms20020448] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 12/31/2022] Open
Abstract
Theiler’s murine encephalomyelitis virus (TMEV), a naturally occurring, enteric pathogen of mice is a Cardiovirus of the Picornaviridae family. Low neurovirulent TMEV strains such as BeAn cause a severe demyelinating disease in susceptible SJL mice following intracerebral infection. Furthermore, TMEV infections of C57BL/6 mice cause acute polioencephalitis initiating a process of epileptogenesis that results in spontaneous recurrent epileptic seizures in approximately 50% of affected mice. Moreover, C3H mice develop cardiac lesions after an intraperitoneal high-dose application of TMEV. Consequently, TMEV-induced diseases are widely used as animal models for multiple sclerosis, epilepsy, and myocarditis. The present review summarizes morphological lesions and pathogenic mechanisms triggered by TMEV with a special focus on the development of hippocampal degeneration and seizures in C57BL/6 mice as well as demyelination in the spinal cord in SJL mice. Furthermore, a detailed description of innate and adaptive immune responses is given. TMEV studies provide novel insights into the complexity of organ- and mouse strain-specific immunopathology and help to identify factors critical for virus persistence.
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Affiliation(s)
- Ingo Gerhauser
- Department of Pathology, University of Veterinary Medicine, Bünteweg 17, 30559 Hannover, Germany.
| | - Florian Hansmann
- Department of Pathology, University of Veterinary Medicine, Bünteweg 17, 30559 Hannover, Germany.
- Center for System Neuroscience, 30559 Hannover, Germany.
| | - Malgorzata Ciurkiewicz
- Department of Pathology, University of Veterinary Medicine, Bünteweg 17, 30559 Hannover, Germany.
- Center for System Neuroscience, 30559 Hannover, Germany.
| | - Wolfgang Löscher
- Center for System Neuroscience, 30559 Hannover, Germany.
- Department of Pharmacology, University of Veterinary Medicine, Bünteweg 17, 30559 Hannover, Germany.
| | - Andreas Beineke
- Department of Pathology, University of Veterinary Medicine, Bünteweg 17, 30559 Hannover, Germany.
- Center for System Neuroscience, 30559 Hannover, Germany.
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30
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Anjum SMM, Käufer C, Hopfengärtner R, Waltl I, Bröer S, Löscher W. Automated quantification of EEG spikes and spike clusters as a new read out in Theiler's virus mouse model of encephalitis-induced epilepsy. Epilepsy Behav 2018; 88:189-204. [PMID: 30292054 DOI: 10.1016/j.yebeh.2018.09.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/13/2018] [Accepted: 09/16/2018] [Indexed: 12/17/2022]
Abstract
Intracerebral infection of C57BL/6 mice with Theiler's murine encephalomyelitis virus (TMEV) replicates many features of viral encephalitis-induced epilepsy in humans, including neuroinflammation, early (insult-associated) and late (spontaneous) seizures, neurodegeneration in the hippocampus, and cognitive and behavioral alterations. Thus, this model may be ideally suited to study mechanisms involved in encephalitis-induced epilepsy as potential targets for epilepsy prevention. However, spontaneous recurrent seizures (SRS) occur too infrequently to be useful as a biomarker of epilepsy, e.g., for drug studies. This prompted us to evaluate whether epileptiform spikes or spike clusters in the cortical electroencephalogram (EEG) may be a useful surrogate of epilepsy in this model. For this purpose, we developed an algorithm that allows efficient and large-scale EEG analysis of early and late seizures, spikes, and spike clusters in the EEG. While 77% of the infected mice exhibited early seizures, late seizures were only observed in 33% of the animals. The clinical characteristics of early and late seizures did not differ except that late generalized convulsive (stage 5) seizures were significantly longer than early stage 5 seizures. Furthermore, the frequency of SRS was much lower than the frequency of early seizures. Continuous (24/7) video-EEG monitoring over several months following infection indicated that the latent period to onset of SRS was 61 (range 16-91) days. Spike and spike clusters were significantly more frequent in infected mice with late seizures than in infected mice without seizures or in mock-infected sham controls. Based on the results of this study, increases in EEG spikes and spike clusters in groups of infected mice may be used as a new readout for studies on antiepileptogenic or disease-modifying drug effects in this model, because the significant increase in average spike counts in mice with late seizures obviously indicates a proepileptogenic alteration.
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Affiliation(s)
- Syed Muhammad Muneeb Anjum
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Christopher Käufer
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | | | - Inken Waltl
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Sonja Bröer
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
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31
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Hanak TJ, Libbey JE, Doty DJ, Sim JT, DePaula-Silva AB, Fujinami RS. Positive modulation of mGluR5 attenuates seizures and reduces TNF-α + macrophages and microglia in the brain in a murine model of virus-induced temporal lobe epilepsy. Exp Neurol 2018; 311:194-204. [PMID: 30316834 DOI: 10.1016/j.expneurol.2018.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 09/12/2018] [Accepted: 10/10/2018] [Indexed: 12/29/2022]
Abstract
Viral encephalitis markedly increases the risk for the development of epilepsy. The Theiler's murine encephalomyelitis virus (TMEV)-induced model of seizures/epilepsy is a murine model of both viral-induced seizures/epilepsy and human Temporal Lobe Epilepsy. The inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α have been shown to play a role in seizure development in the TMEV-induced model of seizures/epilepsy, and infiltrating macrophages along with microglia have been shown to be major producers of these cytokines. The metabotropic glutamate receptor 5 (mGluR5) is a G-protein coupled receptor that has been shown to reduce IL-6 and TNF-α and to provide neuroprotection in other disease models. Therefore, we hypothesized that stimulation of mGluR5 would not only reduce seizures but attenuate IL-6 and TNF-α production in microglia and macrophages in the TMEV model. We found that pharmacological stimulation of mGluR5 with the selective positive allosteric modulator VU0360172 not only reduced acute seizure outcomes, but also reduced the percent of microglia and macrophages producing TNF-α 3 days post infection. Furthermore, treatment with VU0360172 did not alter the level of viral antigen, compared to controls, showing that this treatment does not compromise viral clearance. These results establish that mGluR5 may represent a therapeutic target in the TMEV-induced model of seizures/epilepsy.
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Affiliation(s)
- Tyler J Hanak
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT 84112, USA; Interdepartmental Program in Neuroscience, University of Utah, 20 South 2030 East, Salt Lake City, UT 84112, USA
| | - Jane E Libbey
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT 84112, USA
| | - Daniel J Doty
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT 84112, USA
| | - Jordan T Sim
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT 84112, USA
| | - Ana Beatriz DePaula-Silva
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT 84112, USA
| | - Robert S Fujinami
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT 84112, USA.
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Ketogenic diet regulates the antioxidant catalase via the transcription factor PPARγ2. Epilepsy Res 2018; 147:71-74. [PMID: 30261354 DOI: 10.1016/j.eplepsyres.2018.09.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/29/2018] [Accepted: 09/18/2018] [Indexed: 12/20/2022]
Abstract
We have previously found that the transcription factor PPARγ2 contributes to the mechanism of action of the ketogenic diet (KD), an established treatment for pediatric refractory epilepsy. Among the wide-array of genes regulated by PPARγ, previous studies have suggested that antioxidants such as catalase may have prominent roles in KD neuroprotective and antiseizure effects. Here, we tested the hypothesis that the KD increases catalase through activation of PPARγ2, and that this action is part of the mechanism of antiseizure efficacy of the KD. We determined catalase mRNA and protein expression in hippocampal tissue from epileptic Kcna1-/- mice, Pparγ2+/+ mice and Pparγ2-/- mice. We found that a KD increases hippocampal catalase expression in Kcna1-/- and Pparγ2+/+ mice, but not Pparγ2-/- mice. Next, we determined whether catalase contributes to KD seizure protection. We found that the KD reduces pentylenetetrazole (PTZ)-induced seizures; however, pretreatment with a catalase inhibitor occluded KD effects on PTZ seizures. These results suggest that the KD regulates catalase expression through PPARγ2 activation, and that catalase may contribute to the KD antiseizure efficacy.
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Chemokine receptors CCR2 and CX3CR1 regulate viral encephalitis-induced hippocampal damage but not seizures. Proc Natl Acad Sci U S A 2018; 115:E8929-E8938. [PMID: 30181265 PMCID: PMC6156634 DOI: 10.1073/pnas.1806754115] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Viral encephalitis is a major risk factor for the development of seizures, epilepsy, and hippocampal damage with associated cognitive impairment, markedly reducing quality of life in survivors. The mechanisms underlying seizures and hippocampal neurodegeneration developing during and after viral encephalitis are only incompletely understood, hampering the development of preventive treatments. Recent findings suggest that brain invasion of blood-born monocytes may be critically involved in both seizures and brain damage in response to encephalitis, whereas the relative role of microglia, the brain's resident immune cells, in these processes is not clear. CCR2 and CX3CR1 are two chemokine receptors that regulate the responses of myeloid cells, such as monocytes and microglia, during inflammation. We used Ccr2-KO and Cx3cr1-KO mice to understand the role of these receptors in viral encephalitis-associated seizures and neurodegeneration, using the Theiler's virus model of encephalitis in C57BL/6 mice. Our results show that CCR2 as well as CX3CR1 plays a key role in the accumulation of myeloid cells in the CNS and activation of hippocampal myeloid cells upon infection. Furthermore, by using Cx3cr1-creER+/-tdTomatoSt/Wt reporter mice, we show that, with regard to CD45 and CD11b expression, some microglia become indistinguishable from monocytes during CNS infection. Interestingly, the lack of CCR2 or CX3CR1 receptors was associated with almost complete prevention of hippocampal damage but did not prevent seizure development after viral CNS infection. These data are compatible with the hypothesis that CNS inflammatory mechanism(s) other than the infiltrating myeloid cells trigger the development of seizures during viral encephalitis.
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Amini-Khoei H, Kordjazy N, Haj-Mirzaian A, Amiri S, Haj-Mirzaian A, Shirzadian A, Hasanvand A, Balali-Dehkordi S, Hassanipour M, Dehpour AR. Anticonvulsant effect of minocycline on pentylenetetrazole-induced seizure in mice: involvement of nitric oxide and N-methyl-d-aspartate receptor. Can J Physiol Pharmacol 2018; 96:742-750. [DOI: 10.1139/cjpp-2017-0673] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Anticonvulsant effects of minocycline have been explored recently. This study was designed to examine the anticonvulsant effect of acute administration of minocycline on pentylenetetrazole-induced seizures in mouse considering the possible role of the nitric oxide/N-methyl-d-aspartate (NMDA) pathway. We induced seizure using intravenous administration of pentylenetetrazole. Our results showed that acute administration of minocycline increased the seizure threshold. Furthermore, co-administration of subeffective doses of the nonselective nitric oxide synthase (NOS) inhibitor NG-l-arginine methyl ester (10 mg/kg) and the neuronal NOS inhibitor 7-nitroindazole (40 mg/kg) enhanced the anticonvulsant effect of subeffective doses of minocycline (40 mg/kg). We found that inducible NOS inhibitor aminoguanidine (100 mg/kg) had no effect on the antiseizure effect of minocycline. Moreover, l-arginine (60 mg/kg), as a NOS substrate, reduced the anticonvulsant effect of minocycline. We also demonstrated that pretreatment with the NMDA receptor antagonists ketamine (0.5 mg/kg) and MK-801 (0.05 mg/kg) increased the anticonvulsant effect of subeffective doses of minocycline. Results showed that minocycline significantly decreased the hippocampal nitrite level. Furthermore, co-administration of a neuronal NOS inhibitor like NMDA receptor antagonists augmented the effect of minocycline on the hippocampal nitrite level. In conclusion, we revealed that anticonvulsant effect of minocycline might be, at least in part, due to a decline in constitutive hippocampal nitric oxide activity as well as inhibition of NMDA receptors.
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Affiliation(s)
- Hossein Amini-Khoei
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
- Department of Physiology and Pharmacology, School of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Nastaran Kordjazy
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Arvin Haj-Mirzaian
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Shayan Amiri
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Regenerative Medicine Program, Department of Biochemistry and Medical Genetics, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Arya Haj-Mirzaian
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Armin Shirzadian
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Amin Hasanvand
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Shima Balali-Dehkordi
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mahsa Hassanipour
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
- Department of Physiology and Pharmacology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, 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
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35
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Campos G, Fortuna A, Falcão A, Alves G. In vitro and in vivo experimental models employed in the discovery and development of antiepileptic drugs for pharmacoresistant epilepsy. Epilepsy Res 2018; 146:63-86. [PMID: 30086482 DOI: 10.1016/j.eplepsyres.2018.07.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 06/16/2018] [Accepted: 07/20/2018] [Indexed: 12/23/2022]
Abstract
Epilepsy is one of the most common chronic, recurrent and progressive neurological diseases. In spite of the large number of antiepileptic drugs currently available for the suppression of seizures, about one-third of patients develop drug-resistant epilepsy, even when they are administered the most appropriate treatment available. Thus, nonclinical models can be valuable tools for the elucidation of the mechanisms underlying the development of pharmacoresistance and also for the development of new therapeutic agents that may be promising therapeutic approaches for this unmet medical need. Up today, several epilepsy and seizure models have been developed, exhibiting similar physiopathological features of human drug-resistant epilepsy; moreover, pharmacological response to antiepileptic drugs clinically available tends to be similar in animal models and humans. Therefore, they should be more intensively used in the preclinical discovery and development of new candidates to antiepileptic drugs. Although useful, in vitro models cannot completely replicate the complexity of a living being and their potential for a systematic use in antiepileptic drug screening is limited. The whole-animal models are the most commonly employed and they can be classified as per se drug-resistant due to an inherent poor drug response or be based on the selection of subgroups of epileptic animals that respond or not to a specific antiepileptic drug. Although more expensive and time-consuming, the latter are chronic models of epilepsy that better exhibit the disease-associated alterations found in human epilepsy. Several antiepileptic drugs in development or already marketed have been already tested and shown to be effective in these models of drug-resistant epilepsy, constituting a new hope for the treatment of drug-resistant epilepsy. This review will provide epilepsy researchers with detailed information on the in vitro and in vivo nonclinical models of interest in drug-resistant epilepsy, which may enable a refined selection of most relevant models for understanding the mechanisms of the disease and developing novel antiepileptic drugs.
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Affiliation(s)
- Gonçalo Campos
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506, Covilhã, Portugal
| | - Ana Fortuna
- CIBIT - Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Portugal; Laboratory of Pharmacology, Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
| | - Amílcar Falcão
- CIBIT - Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Portugal; Laboratory of Pharmacology, Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal
| | - Gilberto Alves
- CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506, Covilhã, Portugal.
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Bartolini L, Libbey JE, Ravizza T, Fujinami RS, Jacobson S, Gaillard WD. Viral Triggers and Inflammatory Mechanisms in Pediatric Epilepsy. Mol Neurobiol 2018; 56:1897-1907. [PMID: 29978423 DOI: 10.1007/s12035-018-1215-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/27/2018] [Indexed: 12/21/2022]
Abstract
Experimental and clinical findings suggest a crucial role for inflammation in the onset of pediatric seizures; this mechanism is not targeted by conventional antiepileptic drugs and may contribute to refractory epilepsy. Several triggers, including infection with neurotropic viruses such as human herpesvirus 6 (HHV-6), other herpesviruses, and picornaviruses, appear to induce activation of the innate and adaptive immune systems, which results in several neuroinflammatory responses, leading to enhanced neuronal excitability, and ultimately contributing to epileptogenesis. This review discusses the proposed mechanisms by which infection with herpesviruses, and particularly with HHV-6, and ensuing inflammation may lead to seizure generation, and later development of epilepsy. We also examine the evidence that links herpesvirus and picornavirus infections with acute seizures and chronic forms of epilepsy. Understanding the mechanisms by which specific viruses may trigger a cascade of alterations in the CNS ultimately leading to epilepsy appears critical for the development of therapeutic agents that may target the virus or inflammatory mechanisms early and prevent progression of epileptogenesis.
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Affiliation(s)
- Luca Bartolini
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, NIH, Building 10, room 7-5680, 10 Center Drive, Bethesda, MD, 20814, USA. .,Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, NIH, 10 Center Drive, Bethesda, MD, 20892, USA. .,Center for Neuroscience, Children's National Medical Center, George Washington University, 111 Michigan Ave NW, Washington, DC, 20010, USA.
| | - Jane E Libbey
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT, 84112, USA
| | - Teresa Ravizza
- Neuroscience Department, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Via La Masa 19, 20156, Milan, Italy
| | - Robert S Fujinami
- Department of Pathology, University of Utah School of Medicine, 15 North Medical Drive East, 2600 EEJMRB, Salt Lake City, UT, 84112, USA
| | - Steven Jacobson
- Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, NIH, 10 Center Drive, Bethesda, MD, 20892, USA
| | - William D Gaillard
- Center for Neuroscience, Children's National Medical Center, George Washington University, 111 Michigan Ave NW, Washington, DC, 20010, USA
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Koneval Z, Knox KM, White HS, Barker-Haliski M. Lamotrigine-resistant corneal-kindled mice: A model of pharmacoresistant partial epilepsy for moderate-throughput drug discovery. Epilepsia 2018; 59:1245-1256. [PMID: 29750337 DOI: 10.1111/epi.14190] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2018] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Despite numerous treatments for epilepsy, over 30% of patients remain resistant to available antiseizure drugs (ASDs). Thus, there is a strong need for more effective ASDs for these individuals. Early ASD discovery has historically relied on acute in vivo seizure models (maximal electroshock, subcutaneous pentylenetetrazol, 6 Hz), which lack the pathophysiology that defines chronic epilepsy. Etiologically relevant rodent models of pharmacoresistant epilepsy exist (eg, phenytoin (PHT)- and lamotrigine (LTG)-resistant amygdala-kindled rat and focal kainic acid mouse), but these models are resource- and labor-intensive and thus unsuitable for frontline ASD discovery. METHODS We adapted the LTG-resistant amygdala-kindled rat protocol to the 60 Hz corneal-kindled mouse (CKM) to develop a medium-throughput model of pharmacoresistant chronic seizures. Male CF-1 mice were administered either vehicle (VEH; 0.5% methylcellulose) or LTG (8.5 mg/kg, ip) 30 minutes prior to each twice-daily corneal stimulation until mice achieved kindling criterion. Prototype ASDs were then evaluated in fully kindled mice. Compounds with specific mechanisms of action of interest to epilepsy (fluoxetine, minocycline, and celecoxib) were also evaluated. RESULTS LTG did not modify kindling acquisition. A challenge dose of 17 mg/kg (ip) LTG did not block the secondarily generalized kindled seizure in LTG-kindled mice (mean seizure score [MSS] ± standard error of the mean: 5.67 ± 0.14), whereas VEH-treated mice were sensitive (MSS: 2.25 ± 0.30); confirming LTG-resistance. LTG-resistant CKM were also resistant to carbamazepine, retigabine, and valproic acid at doses that significantly reduced MSS in VEH-treated kindled mice. Fluoxetine, minocycline, and celecoxib were ineffective at the doses tested in either kindled cohort. Finally, the behavioral phenotype of LTG-resistant CKM was also characterized. CKM demonstrated exacerbated hyperexcitability and increased anxiety-like behavior in an open field relative to sham-kindled mice regardless of LTG sensitivity. SIGNIFICANCE The pharmacoresistant LTG-resistant CKM provides an etiologically relevant moderate-throughput platform that is suitable for early compound discovery before advancing to more resource-intensive models of epilepsy.
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Affiliation(s)
- Zachery Koneval
- Department of Pharmacy, University of Washington, Seattle, WA, USA
| | - Kevin M Knox
- Department of Pharmacy, University of Washington, Seattle, WA, USA
| | - H Steve White
- Department of Pharmacy, University of Washington, Seattle, WA, USA
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Klein P, Dingledine R, Aronica E, Bernard C, Blümcke I, Boison D, Brodie MJ, Brooks-Kayal AR, Engel J, Forcelli PA, Hirsch LJ, Kaminski RM, Klitgaard H, Kobow K, Lowenstein DH, Pearl PL, Pitkänen A, Puhakka N, Rogawski MA, Schmidt D, Sillanpää M, Sloviter RS, Steinhäuser C, Vezzani A, Walker MC, Löscher W. Commonalities in epileptogenic processes from different acute brain insults: Do they translate? Epilepsia 2018; 59:37-66. [PMID: 29247482 PMCID: PMC5993212 DOI: 10.1111/epi.13965] [Citation(s) in RCA: 189] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2017] [Indexed: 12/12/2022]
Abstract
The most common forms of acquired epilepsies arise following acute brain insults such as traumatic brain injury, stroke, or central nervous system infections. Treatment is effective for only 60%-70% of patients and remains symptomatic despite decades of effort to develop epilepsy prevention therapies. Recent preclinical efforts are focused on likely primary drivers of epileptogenesis, namely inflammation, neuron loss, plasticity, and circuit reorganization. This review suggests a path to identify neuronal and molecular targets for clinical testing of specific hypotheses about epileptogenesis and its prevention or modification. Acquired human epilepsies with different etiologies share some features with animal models. We identify these commonalities and discuss their relevance to the development of successful epilepsy prevention or disease modification strategies. Risk factors for developing epilepsy that appear common to multiple acute injury etiologies include intracranial bleeding, disruption of the blood-brain barrier, more severe injury, and early seizures within 1 week of injury. In diverse human epilepsies and animal models, seizures appear to propagate within a limbic or thalamocortical/corticocortical network. Common histopathologic features of epilepsy of diverse and mostly focal origin are microglial activation and astrogliosis, heterotopic neurons in the white matter, loss of neurons, and the presence of inflammatory cellular infiltrates. Astrocytes exhibit smaller K+ conductances and lose gap junction coupling in many animal models as well as in sclerotic hippocampi from temporal lobe epilepsy patients. There is increasing evidence that epilepsy can be prevented or aborted in preclinical animal models of acquired epilepsy by interfering with processes that appear common to multiple acute injury etiologies, for example, in post-status epilepticus models of focal epilepsy by transient treatment with a trkB/PLCγ1 inhibitor, isoflurane, or HMGB1 antibodies and by topical administration of adenosine, in the cortical fluid percussion injury model by focal cooling, and in the albumin posttraumatic epilepsy model by losartan. Preclinical studies further highlight the roles of mTOR1 pathways, JAK-STAT3, IL-1R/TLR4 signaling, and other inflammatory pathways in the genesis or modulation of epilepsy after brain injury. The wealth of commonalities, diversity of molecular targets identified preclinically, and likely multidimensional nature of epileptogenesis argue for a combinatorial strategy in prevention therapy. Going forward, the identification of impending epilepsy biomarkers to allow better patient selection, together with better alignment with multisite preclinical trials in animal models, should guide the clinical testing of new hypotheses for epileptogenesis and its prevention.
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Affiliation(s)
- Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, MD, USA
| | | | - Eleonora Aronica
- Department of (Neuro) Pathology, Academic Medical Center and Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
| | - Christophe Bernard
- Aix Marseille Univ, Inserm, INS, Instit Neurosci Syst, Marseille, 13005, France
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute, Portland, OR, USA
| | - Martin J Brodie
- Epilepsy Unit, West Glasgow Ambulatory Care Hospital-Yorkhill, Glasgow, UK
| | - Amy R Brooks-Kayal
- Division of Neurology, Departments of Pediatrics and Neurology, University of Colorado School of Medicine, Aurora, CO, USA
- Children's Hospital Colorado, Aurora, CO, USA
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Jerome Engel
- Departments of Neurology, Neurobiology, and Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, Brain Research Institute, University of California, Los Angeles, CA, USA
| | | | | | | | | | - Katja Kobow
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | | | - Phillip L Pearl
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Asla Pitkänen
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Noora Puhakka
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Michael A Rogawski
- Department of Neurology, University of California, Davis, Sacramento, CA, USA
| | | | - Matti Sillanpää
- Departments of Child Neurology and General Practice, University of Turku and Turku University Hospital, Turku, Finland
| | - Robert S Sloviter
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Annamaria Vezzani
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Institute for Pharmacological Research, Milan,, Italy
| | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Center for Systems Neuroscience, Hannover, Germany
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Anticonvulsant Effect of Swertiamarin Against Pilocarpine-Induced Seizures in Adult Male Mice. Neurochem Res 2017; 42:3103-3113. [PMID: 28681096 DOI: 10.1007/s11064-017-2347-0] [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: 04/24/2017] [Revised: 06/13/2017] [Accepted: 06/29/2017] [Indexed: 12/28/2022]
Abstract
Epilepsy is one of the common and major neurological disorders, approximately a third of the individuals with epilepsy suffer from seizures and not able to successfully respond to available medications. Current study was designed to investigate whether Swertiamarin (Swe) had anticonvulsant activity in the pilocarpine (PILO)-treated mice. Thirty minutes prior to the PILO (280 mg/kg) injection, the mice were administrated with Swe (50, 150, and 450 mg/kg) and valproate sodium (VPA, 200 mg/kg) once. Seizures and electroencephalography (EEG) were observed, and then the mice were killed for Nissl, Fluoro-jade B (FJB) staining. Astrocytic activation was examined in the hippocampus. Western blot analysis was used to examine the expressions of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10). The results indicated that pretreatment with Swe (150, 450 mg/kg) and VPA (200 mg/kg) significantly delayed the onset of the first convulsion and reduced the incidence of status epilepticus and mortality. Analysis of EEG recordings demonstrated that Swe (150, 450 mg/kg) and VPA (200 mg/kg) sharply decreased epileptiform discharges. Furthermore, Nissl and FJB staining revealed that Swe (150, 450 mg/kg) and VPA (200 mg/kg) relieved the neuronal damage. Additionally, Swe (450 mg/kg) dramatically inhibited astrocytic activation. Western blot analysis showed that Swe (450 mg/kg) significantly decreased the expressions of IL-1β, IL-6, TNF-α and elevated the expression of IL-10. Taken together, these findings revealed that Swe exerted anticonvulsant effects on PILO-treated mice. Further studies are encouraged to investigate these beneficial effects of Swe as an adjuvant in epilepsy.
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Kehne JH, Klein BD, Raeissi S, Sharma S. The National Institute of Neurological Disorders and Stroke (NINDS) Epilepsy Therapy Screening Program (ETSP). Neurochem Res 2017; 42:1894-1903. [PMID: 28462454 PMCID: PMC5504134 DOI: 10.1007/s11064-017-2275-z] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 03/10/2017] [Accepted: 04/13/2017] [Indexed: 01/01/2023]
Abstract
For over 40 years, the National Institute of Neurological Disorders and Stroke/National Institutes of Health-funded Anticonvulsant Screening Program has provided a preclinical screening service for participants world-wide that helped identify/characterize new antiseizure compounds, a number of which advanced to the market for the treatment of epilepsy. The newly-renamed Epilepsy Therapy Screening Program (ETSP) has a refocused mission to identify novel agents which will help address the considerable remaining unmet medical needs in epilepsy. These include identifying antiseizure agents for treatment-resistant epilepsy, as well as anti-epileptogenic agents that will prevent the development of epilepsy or disease-modifying agents that will ameliorate or even cure established epilepsy and its comorbidities. This manuscript provides an overview of the ETSP's efforts aimed at identifying the next generation of therapeutic agents to further reduce the suffering from and burden of epilepsy.
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Affiliation(s)
- John H Kehne
- National Institutes of Health/National Institute of Neurological Disorders and Stroke, Rockville, MD, 20852, USA.
| | - Brian D Klein
- National Institutes of Health/National Institute of Neurological Disorders and Stroke, Rockville, MD, 20852, USA
| | - Shamsi Raeissi
- National Institutes of Health/National Institute of Neurological Disorders and Stroke, Rockville, MD, 20852, USA
| | - Shalini Sharma
- National Institutes of Health/National Institute of Neurological Disorders and Stroke, Rockville, MD, 20852, USA
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41
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Barker-Haliski ML, Löscher W, White HS, Galanopoulou AS. Neuroinflammation in epileptogenesis: Insights and translational perspectives from new models of epilepsy. Epilepsia 2017; 58 Suppl 3:39-47. [PMID: 28675559 PMCID: PMC5604891 DOI: 10.1111/epi.13785] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2017] [Indexed: 12/25/2022]
Abstract
Animal models have provided a wealth of information on mechanisms of epileptogenesis and comorbidogenesis, and have significantly advanced our ability to investigate the potential of new therapies. Processes implicating brain inflammation have been increasingly observed in epilepsy research. Herein we discuss the progress on animal models of epilepsy and comorbidities that inform us on the potential role of inflammation in epileptogenesis and comorbidity pathogenesis in rodent models of West syndrome and the Theiler's murine encephalomyelitis virus (TMEV) mouse model of viral encephalitis-induced epilepsy. Rat models of infantile spasms were generated in rat pups after right intracerebral injections of proinflammatory compounds (lipopolysaccharides with or without doxorubicin, or cytokines) and were longitudinally monitored for epileptic spasms and neurodevelopmental and cognitive deficits. Anti-inflammatory treatments were tested after the onset of spasms. The TMEV mouse model was induced with intracerebral administration of TMEV and prospective monitoring for handling-induced seizures or seizure susceptibility, as well as long-term evaluations of behavioral comorbidities of epilepsy. Inflammatory processes are evident in both models and are implicated in the pathogenesis of the observed seizures and comorbidities. A common feature of these models, based on the data so far available, is their pharmacoresistant profile. The presented data support the role of inflammatory pathways in epileptogenesis and comorbidities in two distinct epilepsy models. Pharmacoresistance is a common feature of both inflammation-based models. Utilization of these models may facilitate the identification of age-specific, syndrome- or etiology-specific therapies for the epilepsies and attendant comorbidities, including the drug-resistant forms.
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Affiliation(s)
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - H. Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, USA
| | - Aristea S. Galanopoulou
- Saul R. Korey Department of Neurology, Dominick P. Purpura Department of Neuroscience, Laboratory of Developmental Epilepsy, Bronx NY USA
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42
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Barker-Haliski ML, Johnson K, Billingsley P, Huff J, Handy LJ, Khaleel R, Lu Z, Mau MJ, Pruess TH, Rueda C, Saunders G, Underwood TK, Vanegas F, Smith MD, West PJ, Wilcox KS. Validation of a Preclinical Drug Screening Platform for Pharmacoresistant Epilepsy. Neurochem Res 2017; 42:1904-1918. [PMID: 28303498 DOI: 10.1007/s11064-017-2227-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/07/2017] [Accepted: 03/09/2017] [Indexed: 12/11/2022]
Abstract
The successful identification of promising investigational therapies for the treatment of epilepsy can be credited to the use of numerous animal models of seizure and epilepsy for over 80 years. In this time, the maximal electroshock test in mice and rats, the subcutaneous pentylenetetrazol test in mice and rats, and more recently the 6 Hz assay in mice, have been utilized as primary models of electrically or chemically-evoked seizures in neurologically intact rodents. In addition, rodent kindling models, in which chronic network hyperexcitability has developed, have been used to identify new agents. It is clear that this traditional screening approach has greatly expanded the number of marketed drugs available to manage the symptomatic seizures associated with epilepsy. In spite of the numerous antiseizure drugs (ASDs) on the market today, the fact remains that nearly 30% of patients are resistant to these currently available medications. To address this unmet medical need, the National Institute of Neurological Disorders and Stroke (NINDS) Epilepsy Therapy Screening Program (ETSP) revised its approach to the early evaluation of investigational agents for the treatment of epilepsy in 2015 to include a focus on preclinical approaches to model pharmacoresistant seizures. This present report highlights the in vivo and in vitro findings associated with the initial pharmacological validation of this testing approach using a number of mechanistically diverse, commercially available antiseizure drugs, as well as several probe compounds that are of potential mechanistic interest to the clinical management of epilepsy.
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Affiliation(s)
| | - Kristina Johnson
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Peggy Billingsley
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Jennifer Huff
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Laura J Handy
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Rizvana Khaleel
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Zhenmei Lu
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Matthew J Mau
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Timothy H Pruess
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Carlos Rueda
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Gerald Saunders
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Tristan K Underwood
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Fabiola Vanegas
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA
| | - Misty D Smith
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA.,Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT, 84112, USA
| | - Peter J West
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA.,Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT, 84112, USA
| | - Karen S Wilcox
- Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, 84112, USA.,Department of Pharmacology & Toxicology, University of Utah, Salt Lake City, UT, 84112, USA
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43
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Animal Models of Seizures and Epilepsy: Past, Present, and Future Role for the Discovery of Antiseizure Drugs. Neurochem Res 2017; 42:1873-1888. [PMID: 28290134 DOI: 10.1007/s11064-017-2222-z] [Citation(s) in RCA: 207] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/01/2017] [Accepted: 03/02/2017] [Indexed: 12/14/2022]
Abstract
The identification of potential therapeutic agents for the treatment of epilepsy requires the use of seizure models. Except for some early treatments, including bromides and phenobarbital, the antiseizure activity of all clinically used drugs was, for the most part, defined by acute seizure models in rodents using the maximal electroshock and subcutaneous pentylenetetrazole seizure tests and the electrically kindled rat. Unfortunately, the clinical evidence to date would suggest that none of these models, albeit useful, are likely to identify those therapeutics that will effectively manage patients with drug resistant seizures. Over the last 30 years, a number of animal models have been developed that display varying degrees of pharmacoresistance, such as the phenytoin- or lamotrigine-resistant kindled rat, the 6-Hz mouse model of partial seizures, the intrahippocampal kainate model in mice, or rats in which spontaneous recurrent seizures develops after inducing status epilepticus by chemical or electrical stimulation. As such, these models can be used to study mechanisms of drug resistance and may provide a unique opportunity for identifying a truly novel antiseizure drug (ASD), but thus far clinical evidence for this hope is lacking. Although animal models of drug resistant seizures are now included in ASD discovery approaches such as the ETSP (epilepsy therapy screening program), it is important to note that no single model has been validated for use to identify potential compounds for as yet drug resistant seizures, but rather a battery of such models should be employed, thus enhancing the sensitivity to discover novel, highly effective ASDs. The present review describes the previous and current approaches used in the search for new ASDs and offers some insight into future directions incorporating new and emerging animal models of therapy resistance.
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