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Alves M, Gil B, Villegas-Salmerón J, Salari V, Martins-Ferreira R, Arribas Blázquez M, Menéndez Méndez A, Da Rosa Gerbatin R, Smith J, de Diego-Garcia L, Conte G, Sierra-Marquez J, Merino Serrais P, Mitra M, Fernandez Martin A, Wang Y, Kesavan J, Melia C, Parras A, Beamer E, Zimmer B, Heiland M, Cavanagh B, Parcianello Cipolat R, Morgan J, Teng X, Prehn JHM, Fabene PF, Bertini G, Artalejo AR, Ballestar E, Nicke A, Olivos-Oré LA, Connolly NMC, Henshall DC, Engel T. Opposing effects of the purinergic P2X7 receptor on seizures in neurons and microglia in male mice. Brain Behav Immun 2024; 120:121-140. [PMID: 38777288 DOI: 10.1016/j.bbi.2024.05.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 04/28/2024] [Accepted: 05/19/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND The purinergic ATP-gated P2X7 receptor (P2X7R) is increasingly recognized to contribute to pathological neuroinflammation and brain hyperexcitability. P2X7R expression has been shown to be increased in the brain, including both microglia and neurons, in experimental models of epilepsy and patients. To date, the cell type-specific downstream effects of P2X7Rs during seizures remain, however, incompletely understood. METHODS Effects of P2X7R signaling on seizures and epilepsy were analyzed in induced seizure models using male mice including the kainic acid model of status epilepticus and pentylenetetrazole model and in male and female mice in a genetic model of Dravet syndrome. RNA sequencing was used to analyze P2X7R downstream signaling during seizures. To investigate the cell type-specific role of the P2X7R during seizures and epilepsy, we generated mice lacking exon 2 of the P2rx7 gene in either microglia (P2rx7:Cx3cr1-Cre) or neurons (P2rx7:Thy-1-Cre). To investigate the protective potential of overexpressing P2X7R in GABAergic interneurons, P2X7Rs were overexpressed using adeno-associated virus transduction under the mDlx promoter. RESULTS RNA sequencing of hippocampal tissue from wild-type and P2X7R knock-out mice identified both glial and neuronal genes, in particular genes involved in GABAergic signaling, under the control of the P2X7R following seizures. Mice with deleted P2rx7 in microglia displayed less severe acute seizures and developed a milder form of epilepsy, and microglia displayed an anti-inflammatory molecular profile. In contrast, mice lacking P2rx7 in neurons showed a more severe seizure phenotype when compared to epileptic wild-type mice. Analysis of single-cell expression data revealed that human P2RX7 expression is elevated in the hippocampus of patients with temporal lobe epilepsy in excitatory and inhibitory neurons. Functional studies determined that GABAergic interneurons display increased responses to P2X7R activation in experimental epilepsy. Finally, we show that viral transduction of P2X7R in GABAergic interneurons protects against evoked and spontaneous seizures in experimental temporal lobe epilepsy and in mice lacking Scn1a, a model of Dravet syndrome. CONCLUSIONS Our results suggest a dual and opposing action of P2X7R in epilepsy and suggest P2X7R overexpression in GABAergic interneurons as a novel therapeutic strategy for acquired and, possibly, genetic forms of epilepsy.
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Affiliation(s)
- Mariana Alves
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland
| | - Beatriz Gil
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland
| | - Javier Villegas-Salmerón
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; The SFI Centre for Research Training in Genomics Data Science, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland
| | - Valentina Salari
- Department of Neurosciences, Biomedicine and Movement Sciences, School of Medicine, University of Verona, 37134 Verona, Italy
| | - Ricardo Martins-Ferreira
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916 Badalona, Barcelona, Spain; Immunogenetics Laboratory, Molecular Pathology and Immunology, Instituto de Ciências Biomédicas Abel Salazar - Universidade do Porto (ICBAS-UP), Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; Autoimmunity and Neuroscience Group, UMIB - Unit for Multidisciplinary Research in Biomedicine, ICBAS - School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal; ITR - Laboratory for Integrative and Translational Research in Population Health, Porto, Portugal
| | - Marina Arribas Blázquez
- Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - Aida Menéndez Méndez
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; Department of Medicine, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, 28670, Villaviciosa de Odon, Spain
| | - Rogerio Da Rosa Gerbatin
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Jonathon Smith
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Laura de Diego-Garcia
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; Ocupharm Research Group, Faculty of Optics and Optometry, Complutense University of Madrid, Avda. Arcos de Jalon, 118 (28037), Madrid, Spain
| | - Giorgia Conte
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland
| | - Juan Sierra-Marquez
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany; Laboratorio Cajal de Circuitos Corticales (CTB), Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Campus Montegancedo S/N, Pozuelo de Alarcon, 28223 Madrid, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid 28002, Spain; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Instituto de Salud Carlos III, Madrid 28031, Spain
| | - Paula Merino Serrais
- Laboratorio Cajal de Circuitos Corticales (CTB), Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Campus Montegancedo S/N, Pozuelo de Alarcon, 28223 Madrid, Spain
| | - Meghma Mitra
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland
| | - Ana Fernandez Martin
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland
| | - Yitao Wang
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Jaideep Kesavan
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Ciara Melia
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; VivoArchitect, Route de la Corniche 5, 1066 Epalinges, Vaud, Switzerland
| | - Alberto Parras
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland
| | - Edward Beamer
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Béla Zimmer
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mona Heiland
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Brenton Cavanagh
- Cellular and Molecular Imaging Core, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - Rafael Parcianello Cipolat
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - James Morgan
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PL, UK
| | - Xinchen Teng
- College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Jochen H M Prehn
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Paolo F Fabene
- Department of Neurosciences, Biomedicine and Movement Sciences, School of Medicine, University of Verona, 37134 Verona, Italy; Section of Anatomy and Histology, Department of Neurosciences, Biomedicine, and Movement Science, Faculty of Medicine, University of Verona, Verona, Italy; Section of Innovation Biomedicine, Department of Engineering for Innovation Medicine, Faculty of Medicine, University of Verona, Verona, Italy
| | - Giuseppe Bertini
- Department of Neurosciences, Biomedicine and Movement Sciences, School of Medicine, University of Verona, 37134 Verona, Italy
| | - Antonio R Artalejo
- Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - Esteban Ballestar
- Epigenetics and Immune Disease Group, Josep Carreras Research Institute (IJC), 08916 Badalona, Barcelona, Spain; Epigenetics in Inflammatory and Metabolic Diseases Laboratory, Health Science Center (HSC), East China Normal University (ECNU), Shanghai 200241, China
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Luis A Olivos-Oré
- Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - Niamh M C Connolly
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - David C Henshall
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland
| | - Tobias Engel
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin D02 YN77, Ireland.
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Thakku Sivakumar D, Jain K, Alfehaid N, Wang Y, Teng X, Fischer W, Engel T. The Purinergic P2X7 Receptor as a Target for Adjunctive Treatment for Drug-Refractory Epilepsy. Int J Mol Sci 2024; 25:6894. [PMID: 39000004 PMCID: PMC11241490 DOI: 10.3390/ijms25136894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/06/2024] [Accepted: 06/17/2024] [Indexed: 07/14/2024] Open
Abstract
Epilepsy is one of the most common neurological diseases worldwide. Anti-seizure medications (ASMs) with anticonvulsants remain the mainstay of epilepsy treatment. Currently used ASMs are, however, ineffective to suppress seizures in about one third of all patients. Moreover, ASMs show no significant impact on the pathogenic mechanisms involved in epilepsy development or disease progression and may cause serious side-effects, highlighting the need for the identification of new drug targets for a more causal therapy. Compelling evidence has demonstrated a role for purinergic signalling, including the nucleotide adenosine 5'-triphosphate (ATP) during the generation of seizures and epilepsy. Consequently, drugs targeting specific ATP-gated purinergic receptors have been suggested as promising treatment options for epilepsy including the cationic P2X7 receptor (P27XR). P2X7R protein levels have been shown to be increased in the brain of experimental models of epilepsy and in the resected brain tissue of patients with epilepsy. Animal studies have provided evidence that P2X7R blocking can reduce the severity of acute seizures and the epileptic phenotype. The current review will provide a brief summary of recent key findings on P2X7R signalling during seizures and epilepsy focusing on the potential clinical use of treatments based on the P2X7R as an adjunctive therapeutic strategy for drug-refractory seizures and epilepsy.
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Affiliation(s)
- Divyeshz Thakku Sivakumar
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Krishi Jain
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Noura Alfehaid
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Yitao Wang
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
- International College of Pharmaceutical Innovation, Soochow University, Suzhou 215123, China
| | - Xinchen Teng
- International College of Pharmaceutical Innovation, Soochow University, Suzhou 215123, China
| | | | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
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Fukuyama K, Motomura E, Okada M. Age-Dependent Activation of Purinergic Transmission Contributes to the Development of Epileptogenesis in ADSHE Model Rats. Biomolecules 2024; 14:204. [PMID: 38397441 PMCID: PMC10886636 DOI: 10.3390/biom14020204] [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: 12/19/2023] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
To explore the developmental processes of epileptogenesis/ictogenesis, this study determined age-dependent functional abnormalities associated with purinergic transmission in a genetic rat model (S286L-TG) of autosomal-dominant sleep-related hypermotor epilepsy (ADSHE). The age-dependent fluctuations in the release of ATP and L-glutamate in the orbitofrontal cortex (OFC) were determined using microdialysis and ultra-high-performance liquid chromatography with mass spectrometry (UHPLC-MS). ATP release from cultured astrocytes was also determined using UHPLC-MS. The expressions of P2X7 receptor (P2X7R), connexin 43, phosphorylated-Akt and phosphorylated-Erk were determined using capillary immunoblotting. No functional abnormalities associated with purinergic transmission could be detected in the OFC of 4-week-old S286L-TG and cultured S286L-TG astrocytes. However, P2X7R expression, as well as basal and P2X7R agonist-induced ATP releases, was enhanced in S286L-TG OFC in the critical ADSHE seizure onset period (7-week-old). Long-term exposure to a modest level of P2X7R agonist, which could not increase astroglial ATP release, for 14 d increased the expressions of P2X7R and connexin 43 and the signaling of Akt and Erk in astrocytes, and it enhanced the sensitivity of P2X7R to its agonists. Akt but not Erk increased P2X7R expression, whereas both Akt and Erk increased connexin 43 expression. Functional abnormalities, enhanced ATP release and P2X7R expression were already seen before the onset of ADSHE seizure in S286L-TG. Additionally, long-term exposure to the P2X7R agonist mimicked the functional abnormalities associated with purinergic transmission in astrocytes, similar to those in S286L-TG OFC. Therefore, these results suggest that long-term modestly enhanced purinergic transmission and/or activated P2X7R are, at least partially, involved in the development of the epileptogenesis of ADSHE, rather than that of ictogenesis.
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Affiliation(s)
| | | | - Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (E.M.)
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Zheng H, Liu Q, Zhou S, Luo H, Zhang W. Role and therapeutic targets of P2X7 receptors in neurodegenerative diseases. Front Immunol 2024; 15:1345625. [PMID: 38370420 PMCID: PMC10869479 DOI: 10.3389/fimmu.2024.1345625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
The P2X7 receptor (P2X7R), a non-selective cation channel modulated by adenosine triphosphate (ATP), localizes to microglia, astrocytes, oligodendrocytes, and neurons in the central nervous system, with the most incredible abundance in microglia. P2X7R partake in various signaling pathways, engaging in the immune response, the release of neurotransmitters, oxidative stress, cell division, and programmed cell death. When neurodegenerative diseases result in neuronal apoptosis and necrosis, ATP activates the P2X7R. This activation induces the release of biologically active molecules such as pro-inflammatory cytokines, chemokines, proteases, reactive oxygen species, and excitotoxic glutamate/ATP. Subsequently, this leads to neuroinflammation, which exacerbates neuronal involvement. The P2X7R is essential in the development of neurodegenerative diseases. This implies that it has potential as a drug target and could be treated using P2X7R antagonists that are able to cross the blood-brain barrier. This review will comprehensively and objectively discuss recent research breakthroughs on P2X7R genes, their structural features, functional properties, signaling pathways, and their roles in neurodegenerative diseases and possible therapies.
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Affiliation(s)
- Huiyong Zheng
- Second Clinical Medical School, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Qiang Liu
- Second Clinical Medical School, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Siwei Zhou
- Second Clinical Medical School, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Hongliang Luo
- Gastrointestinal Surgery, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Wenjun Zhang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
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Wei C, Fu M, Zhang H, Yao B. How is the P2X7 receptor signaling pathway involved in epileptogenesis? Neurochem Int 2024; 173:105675. [PMID: 38211839 DOI: 10.1016/j.neuint.2024.105675] [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: 09/21/2023] [Revised: 12/22/2023] [Accepted: 01/03/2024] [Indexed: 01/13/2024]
Abstract
Epilepsy, a condition characterized by spontaneous recurrent epileptic seizures, is among the most prevalent neurological disorders. This disorder is estimated to affect approximately 70 million people worldwide. Although antiseizure medications are considered the first-line treatments for epilepsy, most of the available antiepileptic drugs are not effective in nearly one-third of patients. This calls for the development of more effective drugs. Evidence from animal models and epilepsy patients suggests that strategies that interfere with the P2X7 receptor by binding to adenosine triphosphate (ATP) are potential treatments for this patient population. This review describes the role of the P2X7 receptor signaling pathways in epileptogenesis. We highlight the genes, purinergic signaling, Pannexin1, glutamatergic signaling, adenosine kinase, calcium signaling, and inflammatory response factors involved in the process, and conclude with a synopsis of these key connections. By unraveling the intricate interplay between P2X7 receptors and epileptogenesis, this review provides ideas for designing potent clinical therapies that will revolutionize both prevention and treatment for epileptic patients.
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Affiliation(s)
- Caichuan Wei
- Department of Pediatrics, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuchang District, Wuhan, Hubei Province 430060, China
| | - Miaoying Fu
- Department of Pediatrics, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuchang District, Wuhan, Hubei Province 430060, China
| | - Haiju Zhang
- Department of Pediatrics, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuchang District, Wuhan, Hubei Province 430060, China
| | - Baozhen Yao
- Department of Pediatrics, Renmin Hospital of Wuhan University, 99 Zhang Zhidong Road, Wuchang District, Wuhan, Hubei Province 430060, China.
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Garcia-Durillo M, Frenguelli BG. Antagonism of P2X7 receptors enhances lorazepam action in delaying seizure onset in an in vitro model of status epilepticus. Neuropharmacology 2023; 239:109647. [PMID: 37459909 DOI: 10.1016/j.neuropharm.2023.109647] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/19/2023] [Accepted: 06/24/2023] [Indexed: 08/06/2023]
Abstract
Approximately 30% of patients with status epilepticus (SE) become refractory to two or more antiseizure medications (ASMs). There is thus a real need to identify novel targets against which to develop new ASMs for treating this clinical emergency. Among purinergic receptors, the ionotropic ATP-gated P2X7 receptor (P2X7R) has received attention as a potential ASM target. This study evaluated the effect of the selective P2X7R antagonist A740003 on acute seizures in the dentate gyrus (DG) of hippocampal brain slices, where P2X7Rs are highly expressed, with a view to establishing the potential of P2X7R antagonists as a therapy or adjunct with lorazepam (LZP) in refractory SE. Extracellular electrophysiological recordings were made from the DG of male mouse hippocampal slices. Spontaneous seizure-like events (SLEs) were induced by removing extracellular Mg2+ and sequentially adding the K+ channel blocker 4-aminopyridine and the adenosine A1 receptor antagonist 8-cyclopentyltheophylline, during which the early and late application of A740003 and/or lorazepam was evaluated. Our study revealed that, in the absence of changes in mRNA for P2X7Rs or inflammatory markers, P2X7R antagonism did not reduce the frequency of SLEs. However, A740003 in conjunction with LZP delayed the onset of seizures. Furthermore, our results support the need for employing LZP before seizures become refractory during SE as delayed application of LZP increased seizure frequency. These studies reveal possible sites of intervention that could have a positive impact in patients with high risk of suffering SE.
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Affiliation(s)
| | - Bruno G Frenguelli
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom.
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Gao X, You Z, Huang C, Liu Z, Tan Z, Li J, Liu Y, Liu X, Wei F, Fan Z, Qi S, Sun J. NCBP1 Improves Cognitive Function in Mice by Reducing Oxidative Stress, Neuronal Loss, and Glial Activation After Status Epilepticus. Mol Neurobiol 2023; 60:6676-6688. [PMID: 37474884 DOI: 10.1007/s12035-023-03497-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 07/10/2023] [Indexed: 07/22/2023]
Abstract
Status epilepticus (SE) is a severe manifestation of epilepsy which can cause neurologic injury and death. This study aimed to identify key proteins involved in the pathogenesis of epilepsy and find a potential drug target for SE treatment. Tandem mass tag (TMT)-based quantitative proteomic analysis was applied to screen differentially expressed proteins (DEPs) in epilepsy. The adeno-associated virus was employed to overexpress candidate DEP in mice, and kainic acid (KA) was used to generate a mouse model of epilepsy. Then histopathological examination of the hippocampal tissue was performed, and the inflammatory factors levels in serum and hippocampus were measured. The IP-MS analysis was carried out to identify the interacting protein of nuclear cap-binding protein 1 (NCBP1). The results were that NCBP1 was downregulated in the epileptic hippocampus. NCBP1 overexpression alleviated KA-induced cognitive impairment in mice and reduced the apoptosis and damage of hippocampal neurons. Additionally, overexpressed NCBP1 increased the expression of NeuN and reduced the expression of GFAP and IBA-1 in the hippocampus of the mice. Further study indicated that NCBP1 overexpression inhibited the expression of IL-6, IL-1β, and IFN-γ in serum and hippocampus as well as MDA and LDH in the hippocampus, whereas it increased the SOD levels, suggesting that overexpression of NCBP1 could diminish KA-induced inflammatory responses and oxidative stress. The IP-MS analysis identified that ELAVL4 was the NCBP1-interacting protein. In conclusion, this finding suggests that NCBP1 may potentially serve as a drug target for the treatment of epilepsy.
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Affiliation(s)
- Xiaoying Gao
- Department of Anesthesiology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Zhipeng You
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Cong Huang
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Zhixiong Liu
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Zixiao Tan
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Jiran Li
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Yang Liu
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Xingan Liu
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Fan Wei
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Zhijie Fan
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Sihua Qi
- Department of Anesthesiology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China.
| | - Jiahang Sun
- Department of Neurosurgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China.
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Ahn YH, Tang Y, Illes P. The neuroinflammatory astrocytic P2X7 receptor: Alzheimer's disease, ischemic brain injury, and epileptic state. Expert Opin Ther Targets 2023; 27:763-778. [PMID: 37712394 DOI: 10.1080/14728222.2023.2258281] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/04/2023] [Accepted: 09/08/2023] [Indexed: 09/16/2023]
Abstract
INTRODUCTION Astrocytes have previously been considered as cells supporting neuronal functions, but they are now recognized as active players in maintaining central nervous system (CNS) homeostasis. Astrocytes can communicate with other CNS cells, i.e. through the gliotransmitter ATP and P2X7 receptors (Rs). AREAS COVERED In this review, we will discuss how the P2X7R initiates the release of gliotransmitters and proinflammatory cytokines/chemokines, thereby establishing a dialog between astrocytes and neurons and, in addition, causing neuroinflammation. In astrocytes, dysregulation of P2X7Rs has been associated with neurodegenerative illnesses such as Alzheimer's disease (AD), as well as the consequences of cerebral ischemic injury and status epilepticus (SE). EXPERT OPINION Although all CNS cells are possible sources of ATP release, the targets of this ATP are primarily at microglial cells. However, astrocytes also contain ATP-sensitive P2X7Rs and have in addition the peculiar property over microglia to continuously interact with neurons via not only inflammatory mediators but also gliotransmitters, such as adenosine 5'-triphosphate (ATP), glutamate, γ-amino butyric acid (GABA), and D-serine. Cellular damage arising during AD, cerebral ischemia, and SE via P2X7R activation is superimposed upon the original disease, and their prevention by blood-brain barrier permeable pharmacological antagonists is a valid therapeutic option.
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Affiliation(s)
- Young Ha Ahn
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu, China
| | - Yong Tang
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu, China
- School of Acupuncture and Tuina, Chengdu University of TCM, Chengdu, China
| | - Peter Illes
- International Joint Research Center on Purinergic Signaling of Sichuan Province, Chengdu University of TCM, Chengdu, China
- Rudolf Boehm Institute of Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
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Escobar AP, Bonansco C, Cruz G, Dagnino-Subiabre A, Fuenzalida M, Negrón I, Sotomayor-Zárate R, Martínez-Pinto J, Jorquera G. Central and Peripheral Inflammation: A Common Factor Causing Addictive and Neurological Disorders and Aging-Related Pathologies. Int J Mol Sci 2023; 24:10083. [PMID: 37373230 DOI: 10.3390/ijms241210083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Many diseases and degenerative processes affecting the nervous system and peripheral organs trigger the activation of inflammatory cascades. Inflammation can be triggered by different environmental conditions or risk factors, including drug and food addiction, stress, and aging, among others. Several pieces of evidence show that the modern lifestyle and, more recently, the confinement associated with the COVID-19 pandemic have contributed to increasing the incidence of addictive and neuropsychiatric disorders, plus cardiometabolic diseases. Here, we gather evidence on how some of these risk factors are implicated in activating central and peripheral inflammation contributing to some neuropathologies and behaviors associated with poor health. We discuss the current understanding of the cellular and molecular mechanisms involved in the generation of inflammation and how these processes occur in different cells and tissues to promote ill health and diseases. Concomitantly, we discuss how some pathology-associated and addictive behaviors contribute to worsening these inflammation mechanisms, leading to a vicious cycle that promotes disease progression. Finally, we list some drugs targeting inflammation-related pathways that may have beneficial effects on the pathological processes associated with addictive, mental, and cardiometabolic illnesses.
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Affiliation(s)
- Angélica P Escobar
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Christian Bonansco
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Gonzalo Cruz
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Alexies Dagnino-Subiabre
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Marco Fuenzalida
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Ignacio Negrón
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Ramón Sotomayor-Zárate
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Jonathan Martínez-Pinto
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Gonzalo Jorquera
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago 7830490, Chile
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Sluyter R, Adriouch S, Fuller SJ, Nicke A, Sophocleous RA, Watson D. Animal Models for the Investigation of P2X7 Receptors. Int J Mol Sci 2023; 24:ijms24098225. [PMID: 37175933 PMCID: PMC10179175 DOI: 10.3390/ijms24098225] [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: 04/04/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
The P2X7 receptor is a trimeric ligand-gated cation channel activated by extracellular adenosine 5'-triphosphate. The study of animals has greatly advanced the investigation of P2X7 and helped to establish the numerous physiological and pathophysiological roles of this receptor in human health and disease. Following a short overview of the P2X7 distribution, roles and functional properties, this article discusses how animal models have contributed to the generation of P2X7-specific antibodies and nanobodies (including biologics), recombinant receptors and radioligands to study P2X7 as well as to the pharmacokinetic testing of P2X7 antagonists. This article then outlines how mouse and rat models have been used to study P2X7. These sections include discussions on preclinical disease models, polymorphic P2X7 variants, P2X7 knockout mice (including bone marrow chimeras and conditional knockouts), P2X7 reporter mice, humanized P2X7 mice and P2X7 knockout rats. Finally, this article reviews the limited number of studies involving guinea pigs, rabbits, monkeys (rhesus macaques), dogs, cats, zebrafish, and other fish species (seabream, ayu sweetfish, rainbow trout and Japanese flounder) to study P2X7.
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Affiliation(s)
- Ronald Sluyter
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Sahil Adriouch
- UniRouen, INSERM, U1234, Pathophysiology, Autoimmunity, and Immunotherapy, (PANTHER), Univ Rouen Normandie, University of Rouen, F-76000 Rouen, France
| | - Stephen J Fuller
- Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Nepean Hospital, Kingswood, NSW 2750, Australia
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336 Munich, Germany
| | - Reece A Sophocleous
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Debbie Watson
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
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11
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Cherninskyi A, Storozhuk M, Maximyuk O, Kulyk V, Krishtal O. Triggering of Major Brain Disorders by Protons and ATP: The Role of ASICs and P2X Receptors. Neurosci Bull 2023; 39:845-862. [PMID: 36445556 PMCID: PMC9707125 DOI: 10.1007/s12264-022-00986-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/14/2022] [Indexed: 11/30/2022] Open
Abstract
Adenosine triphosphate (ATP) is well-known as a universal source of energy in living cells. Less known is that this molecule has a variety of important signaling functions: it activates a variety of specific metabotropic (P2Y) and ionotropic (P2X) receptors in neuronal and non-neuronal cell membranes. So, a wide variety of signaling functions well fits the ubiquitous presence of ATP in the tissues. Even more ubiquitous are protons. Apart from the unspecific interaction of protons with any protein, many physiological processes are affected by protons acting on specific ionotropic receptors-acid-sensing ion channels (ASICs). Both protons (acidification) and ATP are locally elevated in various pathological states. Using these fundamentally important molecules as agonists, ASICs and P2X receptors signal a variety of major brain pathologies. Here we briefly outline the physiological roles of ASICs and P2X receptors, focusing on the brain pathologies involving these receptors.
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Affiliation(s)
- Andrii Cherninskyi
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine.
| | - Maksim Storozhuk
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Oleksandr Maximyuk
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Vyacheslav Kulyk
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Oleg Krishtal
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
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12
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Purnell BS, Alves M, Boison D. Astrocyte-neuron circuits in epilepsy. Neurobiol Dis 2023; 179:106058. [PMID: 36868484 DOI: 10.1016/j.nbd.2023.106058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/20/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
The epilepsies are a diverse spectrum of disease states characterized by spontaneous seizures and associated comorbidities. Neuron-focused perspectives have yielded an array of widely used anti-seizure medications and are able to explain some, but not all, of the imbalance of excitation and inhibition which manifests itself as spontaneous seizures. Furthermore, the rate of pharmacoresistant epilepsy remains high despite the regular approval of novel anti-seizure medications. Gaining a more complete understanding of the processes that turn a healthy brain into an epileptic brain (epileptogenesis) as well as the processes which generate individual seizures (ictogenesis) may necessitate broadening our focus to other cell types. As will be detailed in this review, astrocytes augment neuronal activity at the level of individual neurons in the form of gliotransmission and the tripartite synapse. Under normal conditions, astrocytes are essential to the maintenance of blood-brain barrier integrity and remediation of inflammation and oxidative stress, but in epilepsy these functions are impaired. Epilepsy results in disruptions in the way astrocytes relate to each other by gap junctions which has important implications for ion and water homeostasis. In their activated state, astrocytes contribute to imbalances in neuronal excitability due to their decreased capacity to take up and metabolize glutamate and an increased capacity to metabolize adenosine. Furthermore, due to their increased adenosine metabolism, activated astrocytes may contribute to DNA hypermethylation and other epigenetic changes that underly epileptogenesis. Lastly, we will explore the potential explanatory power of these changes in astrocyte function in detail in the specific context of the comorbid occurrence of epilepsy and Alzheimer's disease and the disruption in sleep-wake regulation associated with both conditions.
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Affiliation(s)
- Benton S Purnell
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America
| | - Mariana Alves
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America; Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin D02 YN77, Ireland
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, United States of America; Brain Health Institute, Rutgers University, Piscataway, NJ, United States of America.
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13
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The P2X7 Receptor as a Mechanistic Biomarker for Epilepsy. Int J Mol Sci 2023; 24:ijms24065410. [PMID: 36982485 PMCID: PMC10049244 DOI: 10.3390/ijms24065410] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023] Open
Abstract
Epilepsy, characterized by recurrent spontaneous seizures, is a heterogeneous group of brain diseases affecting over 70 million people worldwide. Major challenges in the management of epilepsy include its diagnosis and treatment. To date, video electroencephalogram (EEG) monitoring is the gold-standard diagnostic method, with no molecular biomarker in routine clinical use. Moreover, treatment based on anti-seizure medications (ASMs) remains ineffective in 30% of patients, and, even if seizure-suppressive, lacks disease-modifying potential. Current epilepsy research is, therefore, mainly focussed on the identification of new drugs with a different mechanism of action effective in patients not responding to current ASMs. The vast heterogeneity of epilepsy syndromes, including differences in underlying pathology, comorbidities and disease progression, represents, however, a particular challenge in drug discovery. Optimal treatment most likely requires the identification of new drug targets combined with diagnostic methods to identify patients in need of a specific treatment. Purinergic signalling via extracellularly released ATP is increasingly recognized to contribute to brain hyperexcitability and, consequently, drugs targeting this signalling system have been proposed as a new therapeutic strategy for epilepsy. Among the purinergic ATP receptors, the P2X7 receptor (P2X7R) has attracted particular attention as a novel target for epilepsy treatment, with P2X7Rs contributing to unresponsiveness to ASMs and drugs targeting the P2X7R modulating acute seizure severity and suppressing seizures during epilepsy. In addition, P2X7R expression has been reported to be altered in the brain and circulation in experimental models of epilepsy and patients, making it both a potential therapeutic and diagnostic target. The present review provides an update on the newest findings regarding P2X7R-based treatments for epilepsy and discusses the potential of P2X7R as a mechanistic biomarker.
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14
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MicroRNA: Crucial modulator in purinergic signalling involved diseases. Purinergic Signal 2023; 19:329-341. [PMID: 35106737 PMCID: PMC9984628 DOI: 10.1007/s11302-022-09840-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/03/2022] [Indexed: 12/13/2022] Open
Abstract
Both microRNAs (miRNAs) and purinergic signalling are widely and respectively expressed in various tissues of different organisms and play vital roles in a variety of physiological and pathological processes. Here, we reviewed the current publications contributed to the relationship of miRNAs and purinergic signalling in cardiovascular diseases, gastrointestinal diseases, neurological diseases, and ophthalmic diseases. We tried to decode the miRNAs-purinergic signalling network of purinergic signalling involved diseases. The evidence indicated that more than 30 miRNAs (miR-22, miR-30, miR-146, miR-150, miR-155, miR-187, etc.) directly or indirectly modulate P1 receptors (A1, A2A, A2B, A3), P2 receptors (P2X1, P2X3, P2X4, P2X7, P2Y2, P2Y6, P2Y12), and ecto-enzymes (CD39, CD73, ADA2); P2X7 and CD73 could be modulated by multiple miRNAs (P2X7: miR-21, miR-22, miR-30, miR-135a, miR-150, miR-186, miR-187, miR-216b; CD73: miR-141, miR-101, miR-193b, miR-340, miR-187, miR-30, miR-422a); miR-187 would be the common miRNA to modulate P2X7 and CD73.
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Vezzani A, Di Sapia R, Kebede V, Balosso S, Ravizza T. Neuroimmunology of status epilepticus. Epilepsy Behav 2023; 140:109095. [PMID: 36753859 DOI: 10.1016/j.yebeh.2023.109095] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 01/14/2023] [Indexed: 02/09/2023]
Abstract
Status epilepticus (SE) is a very heterogeneous clinical condition often refractory to available treatment options. Evidence in animal models shows that neuroinflammation arises in the brain during SE due to the activation of innate immune mechanisms in brain parenchyma cells. Intervention studies in animal models support the involvement of neuroinflammation in SE onset, duration, and severity, refractoriness to treatments, and long-term neurological consequences. Clinical evidence shows that neuroinflammation occurs in patients with SE of diverse etiologies likely representing a common phenomenon, thus broadening the involvement of the immune system beyond the infective and autoimmune etiologies. There is urgent need for novel therapies for refractory SE that rely upon a better understanding of the basic mechanisms underlying this clinical condition. Preclinical and clinical evidence encourage consideration of specific anti-inflammatory treatments for controlling SE and its consequences in patients.
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Affiliation(s)
- Annamaria Vezzani
- Department of Acute Brain Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Italy.
| | - Rossella Di Sapia
- Department of Acute Brain Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Italy
| | - Valentina Kebede
- Department of Acute Brain Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Italy
| | - Silvia Balosso
- Department of Acute Brain Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Italy
| | - Teresa Ravizza
- Department of Acute Brain Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Italy
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Morgan J, Moreno O, Alves M, Baz Z, Menéndez Méndez A, Leister H, Melia C, Smith J, Visekruna A, Nicke A, Bhattacharya A, Ceusters M, Henshall DC, Gómez-Vallejo V, Llop J, Engel T. Increased uptake of the P2X7 receptor radiotracer 18 F-JNJ-64413739 in the brain and peripheral organs according to the severity of status epilepticus in male mice. Epilepsia 2023; 64:511-523. [PMID: 36507708 PMCID: PMC10108015 DOI: 10.1111/epi.17484] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 12/02/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The P2X7 receptor (P2X7R) is an important contributor to neuroinflammation, responding to extracellularly released adenosine triphosphate. Expression of the P2X7R is increased in the brain in experimental and human epilepsy, and genetic or pharmacologic targeting of the receptor can reduce seizure frequency and severity in preclinical models. Experimentally induced seizures also increase levels of the P2X7R in blood. Here, we tested 18 F-JNJ-64413739, a positron emission tomography (PET) P2X7R antagonist, as a potential noninvasive biomarker of seizure-damage and epileptogenesis. METHODS Status epilepticus was induced via an intra-amygdala microinjection of kainic acid. Static PET studies (30 min duration, initiated 30 min after tracer administration) were conducted 48 h after status epilepticus via an intravenous injection of 18 F-JNJ-64413739. PET images were coregistered with a brain magnetic resonance imaging atlas, tracer uptake was determined in the different brain regions and peripheral organs, and values were correlated to seizure severity during status epilepticus. 18 F-JNJ-64413739 was also applied to ex vivo human brain slices obtained following surgical resection for intractable temporal lobe epilepsy. RESULTS P2X7R radiotracer uptake correlated strongly with seizure severity during status epilepticus in brain structures including the cerebellum and ipsi- and contralateral cortex, hippocampus, striatum, and thalamus. In addition, a correlation between radiotracer uptake and seizure severity was also evident in peripheral organs such as the heart and the liver. Finally, P2X7R radiotracer uptake was found elevated in brain sections from patients with temporal lobe epilepsy when compared to control. SIGNIFICANCE Taken together, our data suggest that P2X7R-based PET imaging may help to identify seizure-induced neuropathology and temporal lobe epilepsy patients with increased P2X7R levels possibly benefitting from P2X7R-based treatments.
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Affiliation(s)
- James Morgan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, UK
| | - Oscar Moreno
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), San Sebastian, Spain
| | - Mariana Alves
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Zuriñe Baz
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), San Sebastian, Spain
| | - Aida Menéndez Méndez
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Hanna Leister
- Institute for Medical Microbiology and Hygiene, Philipps University, Marburg, Germany
| | - Ciara Melia
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Jonathon Smith
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Alexander Visekruna
- Institute for Medical Microbiology and Hygiene, Philipps University, Marburg, Germany
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Anindya Bhattacharya
- Neuroimmunology Discover, Neuroscience, Janssen Research and Development, San Diego, California, USA
| | - Marc Ceusters
- Neuroscience Therapeutic Area, Janssen Research and Development, Janssen Pharmaceutica, Beerse, Belgium
- Marc Ceusters Company, Beerse, Belgium
| | - David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | | | - Jordi Llop
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), San Sebastian, Spain
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
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Zhuang XF, Liu YX, Yang ZH, Gao Q, Wang L, Ju C, Wang K. Attenuation of Epileptogenesis and Cognitive Deficits by a Selective and Potent Kv7 Channel Opener in Rodent Models of Seizures. J Pharmacol Exp Ther 2023; 384:315-325. [PMID: 36396352 DOI: 10.1124/jpet.122.001328] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/12/2022] [Accepted: 10/20/2022] [Indexed: 11/18/2022] Open
Abstract
Targeting neuronal Kv7 channels by pharmacological activation has been proven to be an attractive therapeutic strategy for epilepsy. Here, we show that activation of Kv7 channels by an opener SCR2682 dose-dependently reduces seizure activity and severity in rodent models of epilepsy induced by a GABAa receptor antagonist pentylenetetrazole (PTZ), maximal electroshock, and a glutamate receptor agonist kainic acid (KA). Electroencephalographic recordings of rat cerebral cortex confirm that SCR2682 also decreases epileptiform discharges in KA-induced seizures. Nissl and neuronal nuclei staining further demonstrates that SCR2682 also protects neurons from injury induced by KA. In Morris water maze navigation and Y-maze tests, SCR2682 improves PTZ- and KA-induced cognitive impairment. Taken together, our findings demonstrate that pharmacological activation of Kv7 by novel opener SCR2682 may hold promise for therapy of epilepsy with cognitive impairment. SIGNIFICANCE STATEMENT: A neuronal Kv7 channel opener SCR2682 attenuates epileptogenesis and seizure-induced cognitive impairment in rodent models of seizures, thus possessing a developmental potential for effective therapy of epilepsy with cognitive impairment.
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Affiliation(s)
- Xiao-Fei Zhuang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Yu-Xue Liu
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Zhi-Hong Yang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Qin Gao
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Lei Wang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - Chuanxia Ju
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
| | - KeWei Wang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College (X.-F.Z., Y.-X.L., Z.-H.Y., Q.G., L.W., C.J., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (K.W.)
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18
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Wong ZW, Engel T. More than a drug target: Purinergic signalling as a source for diagnostic tools in epilepsy. Neuropharmacology 2023; 222:109303. [PMID: 36309046 DOI: 10.1016/j.neuropharm.2022.109303] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/15/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
Epilepsy is one of the most common and disabling chronic neurological diseases affecting people of all ages. Major challenges of epilepsy management include the persistently high percentage of drug-refractoriness among patients, the absence of disease-modifying treatments, and its diagnosis and prognosis. To date, long-term video-electroencephalogram (EEG) recordings remain the gold standard for an epilepsy diagnosis. However, this is very costly, has low throughput, and in some instances has very limited availability. Therefore, much effort is put into the search for non-invasive diagnostic tests. Purinergic signalling, via extracellularly released adenosine triphosphate (ATP), is gaining increasing traction as a therapeutic strategy for epilepsy treatment which is supported by evidence from both experimental models and patients. This includes in particular the ionotropic P2X7 receptor. Besides that, other components from the ATPergic signalling cascade such as the metabotropic P2Y receptors (e.g., P2Y1 receptor) and ATP-release channels (e.g., pannexin-1), have also been shown to contribute to seizures and epilepsy. In addition to the therapeutic potential of purinergic signalling, emerging evidence has also shown its potential as a diagnostic tool. Following seizures and epilepsy, the concentration of purines in the blood and the expression of different compounds of the purinergic signalling cascade are significantly altered. Herein, this review will provide a detailed discussion of recent findings on the diagnostic potential of purinergic signalling for epilepsy management and the prospect of translating it for clinical application. This article is part of the Special Issue on 'Purinergic Signaling: 50 years'.
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Affiliation(s)
- Zheng Wei Wong
- School of Pharmacy, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland; FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland.
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19
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Mikkelsen JD, Aripaka SS, Kaad S, Pazarlar BA, Pinborg L, Finsen B, Varrone A, Bang-Andersen B, Bastlund JF. Characterization of the Novel P2X7 Receptor Radioligand [ 3H]JNJ-64413739 in Human Brain Tissue. ACS Chem Neurosci 2022; 14:111-118. [PMID: 36535632 PMCID: PMC9817075 DOI: 10.1021/acschemneuro.2c00561] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Radioligands targeting microglia cells have been developed to identify and determine neuroinflammation in the living brain. One recently discovered ligand is JNJ-64413739 that binds selectively to the purinergic receptor P2X7R. The expression of P2X7R is increased under inflammation; hence, the ligand is considered useful in the detection of neuroinflammation in the brain. [18F]JNJ-64413739 has been evaluated in healthy subjects with positron emission tomography; however, the in vitro binding properties of the ligand in human brain tissue have not been investigated. Therefore, the purpose of this study was to measure Bmax and Kd of [3H]JNJ-64413739 using autoradiography on human cortical tissue sections resected from a total of 48 patients with treatment-resistant epilepsy. Correlations between the specific binding of [3H]JNJ-64413739 with age, sex, and duration of disease were explored. Finally, to examine the relationship between P2X7R and TSPO availability, specific binding of [3H]JNJ-64413739 and [123I]CLINDE was examined in the same tissue. The binding was measured in both cortical gray and subcortical white matter. Saturation revealed a Kd (5 nM) value similar between gray and white matter but a larger Bmax in the white than in the gray matter. The binding was completely displaced by the cold ligand and structurally different P2X7R ligands. The variability in saturable binding among the samples was found to be 38% in gray and white matter but was not correlated to either age, sex, or the duration of the disease. Interestingly, there was no significant correlation between [3H]JNJ-64413739 and [123I]CLINDE binding. These data demonstrate that [3H]JNJ-64413739 is a suitable radioligand for evaluating the distribution and expression of the P2X7R in the human brain.
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Affiliation(s)
- Jens D. Mikkelsen
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark,Institute
of Neuroscience, University of Copenhagen, Copenhagen 2200, Denmark,Department
of Molecular Medicine, University of Southern
Denmark, Odense 5000, Denmark,. Tel.: +45 3545 6701
| | - Sanjay S. Aripaka
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark
| | - Sif Kaad
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark
| | - Burcu A. Pazarlar
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark,Physiology
Department, Faculty of Medicine, Izmir Katip
Celebi University, Izmir 35330, Turkey
| | - Lars Pinborg
- Neurobiology
Research Unit, University Hospital Rigshospitalet, Copenhagen 2100, Denmark,Epilepsy
Clinic, Department of Neurology, Copenhagen
University Hospital, Rigshospitalet, Copenhagen 2100, Denmark
| | - Bente Finsen
- Department
of Molecular Medicine, University of Southern
Denmark, Odense 5000, Denmark
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20
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Fu Z, Lin Q, Xu Z, Fu W, Shi D, Cheng Y, Yang T, Liu G, Shi H, Cheng D. Longitudinal Positron Emission Tomography Imaging with P2X7 Receptor-Specific Radioligand 18F-FTTM in a Kainic Acid Rat Model of Temporal Lobe Epilepsy. ACS Chem Neurosci 2022; 13:3512-3522. [PMID: 36383137 DOI: 10.1021/acschemneuro.2c00557] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
P2X7 receptors (P2X7R), as a brain inflammation biomarker, play important roles in the epileptogenic progress. Mounting evidence supports their activation in the brain during epilepsy, and inhibition of the P2X7 receptor reduces the seizure frequency and severity. In this study, we investigate P2X7R-targeted (18F-FTTM) position emission tomography (PET) imaging in a rat model of temporal lobe epilepsy to obtain further insights into the role of P2X7R during epileptogenesis. 18F-FTTM (5-10% radiochemical yield, over 99% radiochemical purity, and a specific activity of 270-300 MBq/nmol, n = 6, EOS) was first synthesized. Then, the rat models induced by intrahippocampal injection of saline (1.2 μL, n = 15) or kainic acid (1.2 μL, 0.5 μg/μL, n = 35) were examined using 18F-FTTM Micro-PET/CT longitudinal imaging, respectively. The imaging results showed that increases in the 18F-FTTM uptake was evident after status epilepticus (SE) in the epileptogenesis-associated brain regions, such as the hippocampus, amygdala, or temporal cortex, and this peaked during the latent period. The histopathological analysis revealed that the P2X7R PET uptake reached a peak at 7 days after SE and was mostly related to microglial activation. Thus, P2X7R-targeted PET imaging agent 18F-FTTM may act as a useful tool for identifying brain inflammation during epilepsy. P2X7R PET is a highly potent longitudinal biomarker of epilepsy and could be of interest to determine the therapeutic windows in epilepsy and to monitor treatment response, and it warrants further clinical studies.
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Affiliation(s)
- Zhequan Fu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Qingyu Lin
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Zhan Xu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Wenhui Fu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Dai Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Yuan Cheng
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Tingting Yang
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Guobing Liu
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Hongcheng Shi
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
| | - Dengfeng Cheng
- Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China.,Institute of Nuclear Medicine, Fudan University, Shanghai 200032, China.,Shanghai Institute of Medical Imaging, Shanghai 200032, China
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21
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Vezzani A, Ravizza T, Bedner P, Aronica E, Steinhäuser C, Boison D. Astrocytes in the initiation and progression of epilepsy. Nat Rev Neurol 2022; 18:707-722. [PMID: 36280704 PMCID: PMC10368155 DOI: 10.1038/s41582-022-00727-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2022] [Indexed: 11/09/2022]
Abstract
Epilepsy affects ~65 million people worldwide. First-line treatment options include >20 antiseizure medications, but seizure control is not achieved in approximately one-third of patients. Antiseizure medications act primarily on neurons and can provide symptomatic control of seizures, but do not alter the onset and progression of epilepsy and can cause serious adverse effects. Therefore, medications with new cellular and molecular targets and mechanisms of action are needed. Accumulating evidence indicates that astrocytes are crucial to the pathophysiological mechanisms of epilepsy, raising the possibility that these cells could be novel therapeutic targets. In this Review, we discuss how dysregulation of key astrocyte functions - gliotransmission, cell metabolism and immune function - contribute to the development and progression of hyperexcitability in epilepsy. We consider strategies to mitigate astrocyte dysfunction in each of these areas, and provide an overview of how astrocyte activation states can be monitored in vivo not only to assess their contribution to disease but also to identify markers of disease processes and treatment effects. Improved understanding of the roles of astrocytes in epilepsy has the potential to lead to novel therapies to prevent the initiation and progression of epilepsy.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy.
| | - Teresa Ravizza
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano, Italy
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ, USA
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22
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Zhang Y, Yin HY, Rubini P, Illes P, Tang Y. ATP indirectly stimulates hippocampal CA1 and CA3 pyramidal neurons via the activation of neighboring P2X7 receptor-bearing astrocytes and NG2 glial cells, respectively. Front Pharmacol 2022; 13:944541. [PMID: 35935830 PMCID: PMC9355480 DOI: 10.3389/fphar.2022.944541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 06/29/2022] [Indexed: 11/24/2022] Open
Abstract
There is ongoing dispute on the question whether CNS neurons possess ATP-sensitive P2X7 receptors (Rs) or whether only non-neuronal cells bear this receptor-type and indirectly signal to the neighboring neurons. We genetically deleted P2X7Rs specifically in astrocytes, oligodendrocytes and microglia, and then recorded current responses in neurons to the prototypic agonist of this receptor, dibenzoyl-ATP (Bz-ATP). These experiments were made in brain slice preparations taken from the indicated variants of the P2X7R KO animals. In hippocampal CA3, but not CA1 pyramidal neurons, the deletion of oligodendrocytic (NG2 glial) P2X7Rs abolished the Bz-ATP-induced current responses. In contrast to the Bz-ATP-induced currents in CA3 pyramidal neurons, current amplitudes evoked by the ionotropic glutamate/GABAAR agonists AMPA/muscimol were not inhibited at all. Whereas in the CA3 area NG2 glia appeared to mediate the P2X7R-mediated stimulation of pyramidal neurons, in the CA1 area, astrocytic P2X7Rs had a somewhat similar effect. This was shown by recording the frequencies and amplitudes of spontaneous excitatory currents (sPSCs) in brain slice preparations. Bz-ATP increased the sPSC frequency in CA1, but not CA3 pyramidal neurons without altering the amplitude, indicating a P2X7R-mediated increase of the neuronal input. Micro-injection of the selective astrocytic toxin L-α-aminoadipate into both hippocampi, or the in vitro application of the GABAAR antagonistic gabazine, completely blocked the frequency increases of sPSCs. Hence, CA1 and CA3 pyramidal neurons of the mouse did not possess P2X7Rs, but were indirectly modulated by astrocytic and oligodendrocytic P2X7Rs, respectively.
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Affiliation(s)
- Ying Zhang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Hai-Yan Yin
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Patrizia Rubini
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- International Collaborative Center on Big Science Plan for Purinergic Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Peter Illes
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- International Collaborative Center on Big Science Plan for Purinergic Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
- *Correspondence: Peter Illes, ; Yong Tang,
| | - Yong Tang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- International Collaborative Center on Big Science Plan for Purinergic Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Key Laboratory of Sichuan Province for Acupuncture and Chronobiology, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- *Correspondence: Peter Illes, ; Yong Tang,
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23
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Guerra Leal B, Barros-Barbosa A, Ferreirinha F, Chaves J, Rangel R, Santos A, Carvalho C, Martins-Ferreira R, Samões R, Freitas J, Lopes J, Ramalheira J, Lobo MG, Martins da Silva A, Costa PP, Correia-de-Sá P. Mesial Temporal Lobe Epilepsy (MTLE) Drug-Refractoriness Is Associated With P2X7 Receptors Overexpression in the Human Hippocampus and Temporal Neocortex and May Be Predicted by Low Circulating Levels of miR-22. Front Cell Neurosci 2022; 16:910662. [PMID: 35875355 PMCID: PMC9300956 DOI: 10.3389/fncel.2022.910662] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Objective: ATP-gated ionotropic P2X7 receptors (P2X7R) actively participate in epilepsy and other neurological disorders. Neocortical nerve terminals of patients with Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis (MTLE-HS) express higher P2X7R amounts. Overexpression of P2X7R bolsters ATP signals during seizures resulting in glial cell activation, cytokines production, and GABAergic rundown with unrestrained glutamatergic excitation. In a mouse model of status epilepticus, increased expression of P2X7R has been associated with the down-modulation of the non-coding micro RNA, miR-22. MiR levels are stable in biological fluids and normally reflect remote tissue production making them ideal disease biomarkers. Here, we compared P2X7R and miR-22 expression in epileptic brains and in the serum of patients with MTLE-HS, respectively.Methods: Quantitative RT-PCR was used to evaluate the expression of P2X7R in the hippocampus and anterior temporal lobe of 23 patients with MTLE-HS and 10 cadaveric controls. Confocal microscopy and Western blot analysis were performed to assess P2X7R protein amounts. MiR-22 expression was evaluated in cell-free sera of 40 MTLE-HS patients and 48 healthy controls.Results: Nerve terminals of the hippocampus and neocortical temporal lobe of MTLE-HS patients overexpress (p < 0.05) an 85 kDa P2X7R protein whereas the normally occurring 67 kDa receptor protein dominates in the brain of the cadaveric controls. Contrariwise, miR-22 serum levels are diminished (p < 0.001) in MTLE-HS patients compared to age-matched control blood donors, a situation that is more evident in patients requiring multiple (>3) anti-epileptic drug (AED) regimens.Conclusion: Data show that there is an inverse relationship between miR-22 serum levels and P2X7R expression in the hippocampus and neocortex of MTLE-HS patients, which implies that measuring serum miR-22 may be a clinical surrogate of P2X7R brain expression in the MTLE-HS. Moreover, the high area under the ROC curve (0.777; 95% CI 0.629–0.925; p = 0.001) suggests that low miR-22 serum levels may be a sensitive predictor of poor response to AEDs among MTLE-HS patients. Results also anticipate that targeting the miR-22/P2X7R axis may be a good strategy to develop newer AEDs.
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Affiliation(s)
- Bárbara Guerra Leal
- Unit for Multidisciplinary Research in Biomedicine (UMIB), Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), Porto, Portugal
- Immunogenetics Laboratory, Molecular Pathology and Immunology Department, ICBAS-UP, Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
| | - Aurora Barros-Barbosa
- Laboratório de Farmacologia e Neurobiologia—Center for Drug Discovery and Innovative Medicines (MedInUP), ICBAS-UP, Porto, Portugal
| | - Fátima Ferreirinha
- Laboratório de Farmacologia e Neurobiologia—Center for Drug Discovery and Innovative Medicines (MedInUP), ICBAS-UP, Porto, Portugal
| | - João Chaves
- Unit for Multidisciplinary Research in Biomedicine (UMIB), Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), Porto, Portugal
- Serviço de Neurologia, Hospital de Santo António—Centro Hospitalar e Universitário do Porto (HSA-CHUP), Porto, Portugal
| | - Rui Rangel
- Serviço de Neurocirurgia, HSA-CHUP, Porto, Portugal
| | - Agostinho Santos
- Serviço de Patologia Forense, Instituto Nacional de Medicina Legal e Ciências Forenses—Delegação do Norte (INMLCF-DN), Porto, Portugal
| | - Cláudia Carvalho
- Immunogenetics Laboratory, Molecular Pathology and Immunology Department, ICBAS-UP, Porto, Portugal
| | - Ricardo Martins-Ferreira
- Unit for Multidisciplinary Research in Biomedicine (UMIB), Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), Porto, Portugal
- Immunogenetics Laboratory, Molecular Pathology and Immunology Department, ICBAS-UP, Porto, Portugal
| | - Raquel Samões
- Serviço de Neurologia, Hospital de Santo António—Centro Hospitalar e Universitário do Porto (HSA-CHUP), Porto, Portugal
| | - Joel Freitas
- Serviço de Neurofisiologia, HSA-CHUP, Porto, Portugal
| | - João Lopes
- Serviço de Neurofisiologia, HSA-CHUP, Porto, Portugal
| | | | - Maria Graça Lobo
- Laboratório de Farmacologia e Neurobiologia—Center for Drug Discovery and Innovative Medicines (MedInUP), ICBAS-UP, Porto, Portugal
| | - António Martins da Silva
- Unit for Multidisciplinary Research in Biomedicine (UMIB), Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
- Serviço de Neurofisiologia, HSA-CHUP, Porto, Portugal
| | - Paulo P. Costa
- Unit for Multidisciplinary Research in Biomedicine (UMIB), Instituto de Ciências Biomédicas Abel Salazar—Universidade do Porto (ICBAS-UP), Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
- Departamento de Genética, Instituto Nacional de Saúde Dr. Ricardo Jorge, Porto, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia—Center for Drug Discovery and Innovative Medicines (MedInUP), ICBAS-UP, Porto, Portugal
- *Correspondence: Paulo Correia-de-Sá orcid.org/0000-0002-6114-9189
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24
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Sun J, Zheng Y, Chen Z, Wang Y. The role of Na + -K + -ATPase in the epileptic brain. CNS Neurosci Ther 2022; 28:1294-1302. [PMID: 35751846 PMCID: PMC9344081 DOI: 10.1111/cns.13893] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 11/26/2022] Open
Abstract
Na+-K+-ATPase, a P-type ATP-powered ion transporter on cell membrane, plays a vital role in cellular excitability. Cellular hyperexcitability, accompanied by hypersynchronous firing, is an important basis for seizures/epilepsy. An increasing number of studies point to a significant contribution of Na+-K+-ATPase to epilepsy, although discordant results exist. In this review, we comprehensively summarize the structure and physiological function of Na+-K+-ATPase in the central nervous system and critically evaluate the role of Na+-K+-ATPase in the epileptic brain. Importantly, we further provide perspectives on some possible research directions and discuss its potential as a therapeutic target for the treatment of epilepsy.
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Affiliation(s)
- Jinyi Sun
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yang Zheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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25
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Whyte-Fagundes P, Taskina D, Safarian N, Zoidl C, Carlen PL, Donaldson LW, Zoidl GR. Panx1 channels promote both anti- and pro-seizure-like activities in the zebrafish via p2rx7 receptors and ATP signaling. Commun Biol 2022; 5:472. [PMID: 35585187 PMCID: PMC9117279 DOI: 10.1038/s42003-022-03356-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 04/12/2022] [Indexed: 11/08/2022] Open
Abstract
The molecular mechanisms of excitation/inhibition imbalances promoting seizure generation in epilepsy patients are not fully understood. Evidence suggests that Pannexin1 (Panx1), an ATP release channel, modulates the excitability of the brain. In this report, we performed electrophysiological, behavioral, and molecular phenotyping experiments on zebrafish larvae bearing genetic or pharmacological knockouts of Panx1a and Panx1b channels, each homologous to human PANX1. When Panx1a function is lost, or both channels are under pharmacological blockade, seizures with ictal-like events and seizure-like locomotion are reduced in the presence of pentylenetetrazol. Transcriptome profiling by RNA-seq demonstrates a spectrum of distinct metabolic and cell signaling states which correlate with the loss of Panx1a. Furthermore, the pro- and anticonvulsant activities of both Panx1 channels affect ATP release and involve the purinergic receptor P2rx7. Our findings suggest a subfunctionalization of Panx1 enabling dual roles in seizures, providing a unique and comprehensive perspective to understanding seizure mechanisms in the context of this channel.
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Affiliation(s)
- Paige Whyte-Fagundes
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada.
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada.
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 1M8, Canada.
| | - Daria Taskina
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada
| | - Nickie Safarian
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada
| | - Christiane Zoidl
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada
| | - Peter L Carlen
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 1M8, Canada
- Department of Medicine, Physiology and BME, University of Toronto, 399 Bathurst St., 5w442, Toronto, ON, M5T 2S8, Canada
| | | | - Georg R Zoidl
- Department of Biology, York University, Toronto, ON, M3J1P3, Canada.
- Center of Vision Research (CVR), York University, Toronto, ON, M3J1P3, Canada.
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 1M8, Canada.
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26
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Nobili P, Shen W, Milicevic K, Bogdanovic Pristov J, Audinat E, Nikolic L. Therapeutic Potential of Astrocyte Purinergic Signalling in Epilepsy and Multiple Sclerosis. Front Pharmacol 2022; 13:900337. [PMID: 35586058 PMCID: PMC9109958 DOI: 10.3389/fphar.2022.900337] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
Epilepsy and multiple sclerosis (MS), two of the most common neurological diseases, are characterized by the establishment of inflammatory environment in the central nervous system that drives disease progression and impacts on neurodegeneration. Current therapeutic approaches in the treatments of epilepsy and MS are targeting neuronal activity and immune cell response, respectively. However, the lack of fully efficient responses to the available treatments obviously shows the need to search for novel therapeutic candidates that will not exclusively target neurons or immune cells. Accumulating knowledge on epilepsy and MS in humans and analysis of relevant animal models, reveals that astrocytes are promising therapeutic candidates to target as they participate in the modulation of the neuroinflammatory response in both diseases from the initial stages and may play an important role in their development. Indeed, astrocytes respond to reactive immune cells and contribute to the neuronal hyperactivity in the inflamed brain. Mechanistically, these astrocytic cell to cell interactions are fundamentally mediated by the purinergic signalling and involve metabotropic P2Y1 receptors in case of astrocyte interactions with neurons, while ionotropic P2X7 receptors are mainly involved in astrocyte interactions with autoreactive immune cells. Herein, we review the potential of targeting astrocytic purinergic signalling mediated by P2Y1 and P2X7 receptors to develop novel approaches for treatments of epilepsy and MS at very early stages.
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Affiliation(s)
- Paola Nobili
- Institute of Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Weida Shen
- School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Katarina Milicevic
- Center for Laser Microscopy, Institute of Physiology and Biochemistry “Ivan Djaja”, University of Belgrade, Faculty of Biology, Belgrade, Serbia
| | - Jelena Bogdanovic Pristov
- Department of Life Sciences, University of Belgrade, Institute for Multidisciplinary Research, Belgrade, Serbia
| | - Etienne Audinat
- Institute of Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Ljiljana Nikolic
- Department of Neurophysiology, University of Belgrade, Institute for Biological Research Siniša Stanković, National Institute of Republic of Serbia, Belgrade, Serbia
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Amore G, Butera A, Spoto G, Valentini G, Saia MC, Salpietro V, Calì F, Di Rosa G, Nicotera AG. KCNQ2-Related Neonatal Epilepsy Treated With Vitamin B6: A Report of Two Cases and Literature Review. Front Neurol 2022; 13:826225. [PMID: 35401395 PMCID: PMC8992372 DOI: 10.3389/fneur.2022.826225] [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: 11/30/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Potassium Voltage-Gated Channel Subfamily Q Member 2 (KCNQ2) gene has been initially associated with "Benign familial neonatal epilepsy" (BFNE). Amounting evidence arising by next-generation sequencing techniques have led to the definition of new phenotypes, such as neonatal epileptic encephalopathy (NEE), expanding the spectrum of KCNQ2-related epilepsies. Pyridoxine (PN) dependent epilepsies (PDE) are a heterogeneous group of autosomal recessive disorders associated with neonatal-onset seizures responsive to treatment with vitamin B6 (VitB6). Few cases of neonatal seizures due to KCNQ2 pathogenic variants have been reported as successfully responding to VitB6. We reported two cases of KCNQ2-related neonatal epilepsies involving a 5-year-old male with a paternally inherited heterozygous mutation (c.1639C>T; p.Arg547Trp), and a 10-year-old female with a de novo heterozygous mutation (c.740C>T; p.Ser247Leu). Both children benefited from VitB6 treatment. Although the mechanisms explaining the efficacy of VitB6 in such patients remain unclear, this treatment option in neonatal-onset seizures is easily taken into account in Neonatal Intensive Care Units (NICUs). Further studies should be conducted to better define clinical guidelines and treatment protocols.
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Affiliation(s)
- Greta Amore
- Department of Human Pathology of the Adult and Developmental Age "Gaetano Barresi", Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Ambra Butera
- Department of Human Pathology of the Adult and Developmental Age "Gaetano Barresi", Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Giulia Spoto
- Department of Human Pathology of the Adult and Developmental Age "Gaetano Barresi", Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Giulia Valentini
- Department of Human Pathology of the Adult and Developmental Age "Gaetano Barresi", Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Maria Concetta Saia
- Department of Human Pathology of the Adult and Developmental Age "Gaetano Barresi", Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Vincenzo Salpietro
- Department of Neuromuscular Disorders, Institute of Neurology, University College London, London, United Kingdom.,Pediatric Neurology and Muscular Diseases Unit, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS) Istituto Giannina Gaslini, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Francesco Calì
- Oasi Research Institute-Scientific Institute for Research, Hospitalization and Healthcare (IRCCS), Troina, Italy
| | - Gabriella Di Rosa
- Department of Human Pathology of the Adult and Developmental Age "Gaetano Barresi", Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
| | - Antonio Gennaro Nicotera
- Department of Human Pathology of the Adult and Developmental Age "Gaetano Barresi", Unit of Child Neurology and Psychiatry, University of Messina, Messina, Italy
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28
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West PJ, Thomson K, Billingsley P, Pruess T, Rueda C, Saunders GW, Smith MD, Metcalf CS, Wilcox KS. Spontaneous recurrent seizures in an intra-amygdala kainate microinjection model of temporal lobe epilepsy are differentially sensitive to antiseizure drugs. Exp Neurol 2022; 349:113954. [PMID: 34922908 PMCID: PMC8815304 DOI: 10.1016/j.expneurol.2021.113954] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/14/2021] [Accepted: 12/13/2021] [Indexed: 12/15/2022]
Abstract
The discovery and development of novel antiseizure drugs (ASDs) that are effective in controlling pharmacoresistant spontaneous recurrent seizures (SRSs) continues to represent a significant unmet clinical need. The Epilepsy Therapy Screening Program (ETSP) has undertaken efforts to address this need by adopting animal models that represent the salient features of human pharmacoresistant epilepsy and employing these models for preclinical testing of investigational ASDs. One such model that has garnered increased interest in recent years is the mouse variant of the Intra-Amygdala Kainate (IAK) microinjection model of mesial temporal lobe epilepsy (MTLE). In establishing a version of this model, several methodological variables were evaluated for their effect(s) on pertinent quantitative endpoints. Although administration of a benzodiazepine 40 min after kainate (KA) induced status epilepticus (SE) is commonly used to improve survival, data presented here demonstrates similar outcomes (mortality, hippocampal damage, latency periods, and 90-day SRS natural history) between mice given midazolam and those that were not. Using a version of this model that did not interrupt SE with a benzodiazepine, a 90-day natural history study was performed and survival, latency periods, SRS frequencies and durations, and SRS clustering data were quantified. Finally, an important step towards model adoption is to assess the sensitivities or resistances of SRSs to a panel of approved and clinically used ASDs. Accordingly, the following ASDs were evaluated for their effects on SRSs in these mice: phenytoin (20 mg/kg, b.i.d.), carbamazepine (30 mg/kg, t.i.d.), valproate (240 mg/kg, t.i.d.), diazepam (4 mg/kg, b.i.d.), and phenobarbital (25 and 50 mg/kg, b.i.d.). Valproate, diazepam, and phenobarbital significantly attenuated SRS frequency relative to vehicle controls at doses devoid of observable adverse behavioral effects. Only diazepam significantly increased seizure freedom. Neither phenytoin nor carbamazepine significantly altered SRS frequency or freedom under these experimental conditions. These data demonstrate that SRSs in this IAK model of MTLE are pharmacoresistant to two representative sodium channel-inhibiting ASDs (phenytoin and carbamazepine) and partially sensitive to GABA receptor modulating ASDs (diazepam and phenobarbital) or a mixed-mechanism ASD (valproate). Accordingly, this model is being incorporated into the NINDS-funded ETSP testing platform for treatment resistant epilepsy.
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Affiliation(s)
- Peter J West
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA; Interdepartmental Neuroscience Program, University of Utah, Salt Lake City, UT 84108, USA.
| | - Kyle Thomson
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Peggy Billingsley
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Timothy Pruess
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Carlos Rueda
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Gerald W Saunders
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Misty D Smith
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA; School of Dentistry, University of Utah, Salt Lake City, UT 84108, USA
| | - Cameron S Metcalf
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Karen S Wilcox
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA; Interdepartmental Neuroscience Program, University of Utah, Salt Lake City, UT 84108, USA
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Beyond Seizure Control: Treating Comorbidities in Epilepsy via Targeting of the P2X7 Receptor. Int J Mol Sci 2022; 23:ijms23042380. [PMID: 35216493 PMCID: PMC8875404 DOI: 10.3390/ijms23042380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/17/2022] Open
Abstract
Epilepsy is one of the most common chronic diseases of the central nervous system (CNS). Treatment of epilepsy remains, however, a clinical challenge with over 30% of patients not responding to current pharmacological interventions. Complicating management of treatment, epilepsy comes with multiple comorbidities, thereby further reducing the quality of life of patients. Increasing evidence suggests purinergic signalling via extracellularly released ATP as shared pathological mechanisms across numerous brain diseases. Once released, ATP activates specific purinergic receptors, including the ionotropic P2X7 receptor (P2X7R). Among brain diseases, the P2X7R has attracted particular attention as a therapeutic target. The P2X7R is an important driver of inflammation, and its activation requires high levels of extracellular ATP to be reached under pathological conditions. Suggesting the therapeutic potential of drugs targeting the P2X7R for epilepsy, P2X7R expression increases following status epilepticus and during epilepsy, and P2X7R antagonism modulates seizure severity and epilepsy development. P2X7R antagonism has, however, also been shown to be effective in treating conditions most commonly associated with epilepsy such as psychiatric disorders and cognitive deficits, which suggests that P2X7R antagonisms may provide benefits beyond seizure control. This review summarizes the evidence suggesting drugs targeting the P2X7R as a novel treatment strategy for epilepsy with a particular focus of its potential impact on epilepsy-associated comorbidities.
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P2X7 Receptor Antagonist Reduces Fibrosis and Inflammation in a Mouse Model of Alpha-Sarcoglycan Muscular Dystrophy. Pharmaceuticals (Basel) 2022; 15:ph15010089. [PMID: 35056146 PMCID: PMC8777980 DOI: 10.3390/ph15010089] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/05/2022] [Accepted: 01/11/2022] [Indexed: 02/08/2023] Open
Abstract
Limb-girdle muscular dystrophy R3, a rare genetic disorder affecting the limb proximal muscles, is caused by mutations in the α-sarcoglycan gene (Sgca) and aggravated by an immune-mediated damage, finely modulated by the extracellular (e)ATP/purinoceptors axis. Currently, no specific drugs are available. The aim of this study was to evaluate the therapeutic effectiveness of a selective P2X7 purinoreceptor antagonist, A438079. Sgca knockout mice were treated with A438079 every two days at 3 mg/Kg for 24 weeks. The P2X7 antagonist improved clinical parameters by ameliorating mice motor function and decreasing serum creatine kinase levels. Histological analysis of muscle morphology indicated a significant reduction of the percentage of central nuclei, of fiber size variability and of the extent of local fibrosis and inflammation. A cytometric characterization of the muscle inflammatory infiltrates showed that A438079 significantly decreased innate immune cells and upregulated the immunosuppressive regulatory T cell subpopulation. In α-sarcoglycan null mice, the selective P2X7 antagonist A438079 has been shown to be effective to counteract the progression of the dystrophic phenotype and to reduce the inflammatory response. P2X7 antagonism via selective inhibitors could be included in the immunosuppressant strategies aimed to dampen the basal immune-mediated damage and to favor a better engraftment of gene-cell therapies.
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31
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Abstract
Purinergic signaling is increasingly recognized to play a role during the generation of hyperexcitable networks in the brain. Among the purinergic receptors, the ionotropic ATP-gated P2X7 receptor has attracted particular attention as a possible drug target for epilepsy. P2X7 receptor expression is increased in the brain of experimental models of epilepsy and in patients and, P2X7 receptor antagonism modulates seizure severity and epilepsy development. To date, studies analyzing the role of the P2X7 receptor during epilepsy have mainly focused on temporal lobe epilepsy, the most common form of acquired epilepsy in adults which is particularly prone to drug refractoriness.Animal models of seizures and epilepsy are an essential tool in the identification of novel anticonvulsive and antiepileptogenic drug targets and much data demonstrating a role for the P2X7 receptor during epilepsy have been obtained by using these models. The aim of the present book chapter is to provide a detailed description of two commonly used mouse models of temporal lobe epilepsy, which are the intra-amygdala kainic acid model of status epilepticus and the controlled cortical impact model of traumatic brain injury. This chapter concludes with a brief description of how these models can be used to investigate the impact of targeting the P2X7 receptor on acute seizures, epilepsy development and established epilepsy .
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Affiliation(s)
- Mariana Alves
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Laura de Diego-Garcia
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
- Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.
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32
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Beamer E, Morgan J, Alves M, Méndez AM, Morris G, Zimmer B, Conte G, de Diego-Garcia L, Alarcón-Vila C, Ng NKY, Madden S, Calzaferri F, de Los Rios C, Garcia AG, Hamacher M, Dinkel K, Pelegrin P, Henshall DC, Nicke A, Engel T. Increased expression of the ATP-gated P2X7 receptor reduces responsiveness to anti-convulsants during status epilepticus in mice. Br J Pharmacol 2021; 179:2986-3006. [PMID: 34962289 DOI: 10.1111/bph.15785] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/29/2021] [Accepted: 12/14/2021] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Refractory status epilepticus is a clinical emergency associated with high mortality and morbidity. Increasing evidence suggests neuroinflammation contributes to the development of drug-refractoriness during status epilepticus. The aim of the present study was to determine the contribution of the ATP-gated P2X7 receptor (P2X7R), previously linked to both inflammation and increased hyperexcitability, to drug-refractory status epilepticus and its therapeutic potential. EXPERIMENTAL APPROACH Status epilepticus was induced via a unilateral microinjection of kainic acid into the amygdala in adult mice. Severity of status epilepticus was compared in animals with overexpressing or knock-out of the P2X7R, after inflammatory priming by the pre-injection of bacterial lipopolysaccharide (LPS) and in mice treated with P2X7R-targeting and anti-inflammatory drugs. KEY RESULTS P2X7R overexpressing mice were unresponsive to several anticonvulsants (lorazepam, midazolam, phenytoin and carbamazepine) during status epilepticus. P2X7R expression was increased in microglia during status epilepticus, at a time-point when responses to anticonvulsant are reduced. P2X7R overexpression led to a pro-inflammatory phenotype in microglia during status epilepticus and the anti-inflammatory drug minocycline restored normal responsiveness to anticonvulsants in P2X7R overexpressing mice. Pre-treatment of wildtype mice with LPS increased P2X7R levels in the brain and reduced responsiveness to anticonvulsants during status epilepticus, which was overcome by either a genetic deletion of the P2X7R or the administration of the P2X7R antagonists AFC-5128 or ITH15004. CONCLUSION AND IMPLICATIONS Our results demonstrate that P2X7R-induced pro-inflammatory effects contribute to resistance to pharmacotherapy during status epilepticus and suggest therapies targeting the P2X7R as novel adjunctive treatments for drug-refractory status epilepticus.
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Affiliation(s)
- Edward Beamer
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland.,School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - James Morgan
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland.,Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Mariana Alves
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland
| | - Aida Menéndez Méndez
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland
| | - Gareth Morris
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland.,FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | - Béla Zimmer
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Giorgia Conte
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland
| | - Laura de Diego-Garcia
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland
| | - Cristina Alarcón-Vila
- Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), Hospital Clínico Universitario Virgen de la Arrixaca, Carretera Buenavista s/n. 30120 El Palmar, Murcia, Spain
| | - Nico Ka Yiu Ng
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland
| | - Stephen Madden
- Data Science Centre, RCSI University of Medicine & Health Sciences, Dublin, Ireland
| | - Francesco Calzaferri
- Instituto-Fundación Teofilo Hernando and Departamento de Farmacologia, Facultad de Medicina, Universidad Autonoma de Madrid, C/Arzobispo Morcillo 4, Madrid, Spain
| | - Cristobal de Los Rios
- Instituto-Fundación Teofilo Hernando and Departamento de Farmacologia, Facultad de Medicina, Universidad Autonoma de Madrid, C/Arzobispo Morcillo 4, Madrid, Spain.,Instituto de Investigacion Sanitaria, Hospital Universitario de La Princesa, C/Diego de Leon, 62, 1a Planta, Madrid, Spain
| | - Antonio G Garcia
- Instituto-Fundación Teofilo Hernando and Departamento de Farmacologia, Facultad de Medicina, Universidad Autonoma de Madrid, C/Arzobispo Morcillo 4, Madrid, Spain.,Instituto de Investigacion Sanitaria, Hospital Universitario de La Princesa, C/Diego de Leon, 62, 1a Planta, Madrid, Spain
| | - Michael Hamacher
- Affectis Pharmaceuticals AG, Otto-Hahn-Straße 15, Dortmund, Germany
| | - Klaus Dinkel
- Lead Discovery Center GmbH, Otto-Hahn-Straße 15, Dortmund, Germany
| | - Pablo Pelegrin
- Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), Hospital Clínico Universitario Virgen de la Arrixaca, Carretera Buenavista s/n. 30120 El Palmar, Murcia, Spain.,Department of Biochemistry and Molecular Biology B and Immunology, University of Murcia, Murcia, Spain
| | - David C Henshall
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland.,FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Tobias Engel
- Department of Physiology & Medical Physics, RCSI University of Medicine & Health Sciences, Dublin, Ireland.,FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, Dublin, Ireland
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Conte G, Menéndez-Méndez A, Bauer S, El-Naggar H, Alves M, Nicke A, Delanty N, Rosenow F, Henshall DC, Engel T. Circulating P2X7 Receptor Signaling Components as Diagnostic Biomarkers for Temporal Lobe Epilepsy. Cells 2021; 10:cells10092444. [PMID: 34572093 PMCID: PMC8467140 DOI: 10.3390/cells10092444] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 12/20/2022] Open
Abstract
Circulating molecules have potential as biomarkers to support the diagnosis of epilepsy and to assist with differential diagnosis, for example, in conditions resembling epilepsy, such as in psychogenic non-epileptic seizures (PNES). The P2X7 receptor (P2X7R) is an important regulator of inflammation and mounting evidence supports its activation in the brain during epilepsy. Whether the P2X7R or P2X7R-dependent signaling molecules can be used as biomarkers of epilepsy has not been reported. P2X7R levels were analyzed by quantitative ELISA using plasma samples from controls and patients with temporal lobe epilepsy (TLE) or PNES. Moreover, blood cell P2X7R expression and P2X7R-dependent cytokine signature was measured following status epilepticus in P2X7R-EGFP reporter, wildtype, and P2X7R-knockout mice. P2X7R plasma levels were higher in TLE patients when compared with controls and patients with PNES. Plasma levels of the broad inflammatory marker protein C-Reactive protein (CRP) were similar between the three groups. Using P2X7R-EGFP reporter mice, we identified monocytes as the main blood cell type expressing P2X7R after experimentally evoked seizures. Finally, cytokine array analysis in P2X7R-deficient mice identified KC/GRO as a potential P2X7R-dependent plasma biomarker following status epilepticus and during epilepsy. Our data suggest that P2X7R signaling components may be a promising subclass of circulating biomarkers to support the diagnosis of epilepsy.
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Affiliation(s)
- Giorgia Conte
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland; (G.C.); (A.M.-M.); (M.A.); (D.C.H.)
| | - Aida Menéndez-Méndez
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland; (G.C.); (A.M.-M.); (M.A.); (D.C.H.)
| | - Sebastian Bauer
- Epilepsy Center Hessen, Department of Neurology, Philipps-University Marburg, Baldingerstr, 35043 Marburg, Germany; (S.B.); (F.R.)
- Epilepsy Center Frankfurt Rhine-Main, Center of Neurology and Neurosurgery, Goethe-University Frankfurt, University Hospital Frankfurt, Schleusenweg 2-16 (Haus 95), 60528 Frankfurt am Main, Germany
- LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University Frankfurt, Schleusenweg 2-16, 60528 Frankfurt am Main, Germany
| | - Hany El-Naggar
- Neurological Services, Beaumont Hospital, D09 V2N0 Dublin, Ireland; (H.E.-N.); (N.D.)
| | - Mariana Alves
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland; (G.C.); (A.M.-M.); (M.A.); (D.C.H.)
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336 Munich, Germany;
| | - Norman Delanty
- Neurological Services, Beaumont Hospital, D09 V2N0 Dublin, Ireland; (H.E.-N.); (N.D.)
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Felix Rosenow
- Epilepsy Center Hessen, Department of Neurology, Philipps-University Marburg, Baldingerstr, 35043 Marburg, Germany; (S.B.); (F.R.)
- Epilepsy Center Frankfurt Rhine-Main, Center of Neurology and Neurosurgery, Goethe-University Frankfurt, University Hospital Frankfurt, Schleusenweg 2-16 (Haus 95), 60528 Frankfurt am Main, Germany
- LOEWE Center for Personalized Translational Epilepsy Research (CePTER), Goethe-University Frankfurt, Schleusenweg 2-16, 60528 Frankfurt am Main, Germany
| | - David C. Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland; (G.C.); (A.M.-M.); (M.A.); (D.C.H.)
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland; (G.C.); (A.M.-M.); (M.A.); (D.C.H.)
- FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
- Correspondence:
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34
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Engel T, Smith J, Alves M. Targeting Neuroinflammation via Purinergic P2 Receptors for Disease Modification in Drug-Refractory Epilepsy. J Inflamm Res 2021; 14:3367-3392. [PMID: 34305404 PMCID: PMC8298823 DOI: 10.2147/jir.s287740] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 06/12/2021] [Indexed: 12/27/2022] Open
Abstract
Treatment of epilepsy remains a clinical challenge, with >30% of patients not responding to current antiseizure drugs (ASDs). Moreover, currently available ASDs are merely symptomatic without altering significantly the progression of the disease. Inflammation is increasingly recognized as playing an important role during the generation of hyperexcitable networks in the brain. Accordingly, the suppression of chronic inflammation has been suggested as a promising therapeutic strategy to prevent epileptogenesis and to treat drug-refractory epilepsy. As a consequence, a strong focus of ongoing research is identification of the mechanisms that contribute to sustained inflammation in the brain during epilepsy and whether these can be targeted. ATP is released in response to several pathological stimuli, including increased neuronal activity within the central nervous system, where it functions as a neuro- and gliotransmitter. Once released, ATP activates purinergic P2 receptors, which are divided into metabotropic P2Y and ionotropic P2X receptors, driving inflammatory processes. Evidence from experimental models and patients demonstrates widespread expression changes of both P2Y and P2X receptors during epilepsy, and critically, drugs targeting both receptor subtypes, in particular the P2Y1 and P2X7 subtypes, have been shown to possess both anticonvulsive and antiepileptic potential. This review provides a detailed summary of the current evidence suggesting ATP-gated receptors as novel drug targets for epilepsy and discusses how P2 receptor–driven inflammation may contribute to the generation of seizures and the development of epilepsy.
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Affiliation(s)
- Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland.,FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland
| | - Jonathon Smith
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland.,FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland
| | - Mariana Alves
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D02 YN77, Ireland
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Beamer E, Kuchukulla M, Boison D, Engel T. ATP and adenosine-Two players in the control of seizures and epilepsy development. Prog Neurobiol 2021; 204:102105. [PMID: 34144123 DOI: 10.1016/j.pneurobio.2021.102105] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/07/2021] [Accepted: 06/09/2021] [Indexed: 02/08/2023]
Abstract
Despite continuous advances in understanding the underlying pathogenesis of hyperexcitable networks and lowered seizure thresholds, the treatment of epilepsy remains a clinical challenge. Over one third of patients remain resistant to current pharmacological interventions. Moreover, even when effective in suppressing seizures, current medications are merely symptomatic without significantly altering the course of the disease. Much effort is therefore invested in identifying new treatments with novel mechanisms of action, effective in drug-refractory epilepsy patients, and with the potential to modify disease progression. Compelling evidence has demonstrated that the purines, ATP and adenosine, are key mediators of the epileptogenic process. Extracellular ATP concentrations increase dramatically under pathological conditions, where it functions as a ligand at a host of purinergic receptors. ATP, however, also forms a substrate pool for the production of adenosine, via the action of an array of extracellular ATP degrading enzymes. ATP and adenosine have assumed largely opposite roles in coupling neuronal excitability to energy homeostasis in the brain. This review integrates and critically discusses novel findings regarding how ATP and adenosine control seizures and the development of epilepsy. This includes purine receptor P1 and P2-dependent mechanisms, release and reuptake mechanisms, extracellular and intracellular purine metabolism, and emerging receptor-independent effects of purines. Finally, possible purine-based therapeutic strategies for seizure suppression and disease modification are discussed.
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Affiliation(s)
- Edward Beamer
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; Centre for Bioscience, Manchester Metropolitan University, John Dalton Building, All Saints Campus, Manchester M15 6BH, UK
| | - Manvitha Kuchukulla
- Department of Neurosurgery, Robert Wood Johnson & New Jersey Medical Schools, Rutgers University, Piscataway, NJ 08854, USA
| | - Detlev Boison
- Department of Neurosurgery, Robert Wood Johnson & New Jersey Medical Schools, Rutgers University, Piscataway, NJ 08854, USA.
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin D02 YN77, Ireland; FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin D02 YN77, Ireland.
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Di Nunzio M, Di Sapia R, Sorrentino D, Kebede V, Cerovic M, Gullotta GS, Bacigaluppi M, Audinat E, Marchi N, Ravizza T, Vezzani A. Microglia proliferation plays distinct roles in acquired epilepsy depending on disease stages. Epilepsia 2021; 62:1931-1945. [PMID: 34128226 DOI: 10.1111/epi.16956] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/21/2021] [Accepted: 05/23/2021] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Microgliosis occurs in animal models of acquired epilepsy and in patients. It includes cell proliferation that is associated with seizure frequency and decreased neuronal cells in human epilepsy. The role of microglia proliferation in the development of acquired epilepsy is unknown; thus, we examined its contribution to spontaneous seizure, neurodegeneration, and cognitive deficits in different disease phases. METHODS We used a model of acquired epilepsy triggered by intra-amygdala kainic acid in C57BL6N adult male mice. Mice were electroencephalographically (EEG) monitored (24/7) during status epilepticus and in early and chronic disease. Microglia proliferation was blocked by GW2580, a selective CSF1 receptor inhibitor, supplemented in the diet for 21 days from status epilepticus onset. Then, mice were returned to placebo diet until experiment completion. Control mice were exposed to status epilepticus and fed with placebo diet. Experimental mice were tested in the novel object recognition test (NORT) and in Barnes maze, and compared to control and sham mice. At the end of the behavioral test, mice were killed for brain histopathological analysis. Additionally, seizure baseline was monitored in chronic epileptic mice, then mice were fed for 14 days with GW2580 or placebo diet under 24/7 EEG recording. RESULTS GW2580 prevented microglia proliferation in mice undergoing epilepsy, whereas it did not affect microglia or basal excitatory neurotransmission in the hippocampus of naive mice. Mice with occluded microglia proliferation during early disease development underwent status epilepticus and subsequent epilepsy similar to placebo diet mice, and were similarly impaired in NORT, with improvement in Barnes maze. GW2580-treated mice displayed neuroprotection in the hippocampus. In contrast, blockade of microglia proliferation in chronic epileptic mice resulted in spontaneous seizure reduction versus placebo mice. SIGNIFICANCE Microglia proliferation during early disease contributes to neurodegeneration, whereas in late chronic disease it contributes to seizures. Timely pharmacological interference with microglia proliferation may offer a potential target for improving disease outcomes.
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Affiliation(s)
- Martina Di Nunzio
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Rossella Di Sapia
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Diletta Sorrentino
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Valentina Kebede
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Milica Cerovic
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Giorgia S Gullotta
- Neuroimmunology Unit, Institute of Experimental Neurology, San Raffaele Hospital and Vita-Salute San Raffaele University, Milan, Italy
| | - Marco Bacigaluppi
- Neuroimmunology Unit, Institute of Experimental Neurology, San Raffaele Hospital and Vita-Salute San Raffaele University, Milan, Italy
| | - Etienne Audinat
- Institute of Functional Genomics (UMR 5203 CNRS - U 1191 INSERM), University of Montpellier, Montpellier, France
| | - Nicola Marchi
- Institute of Functional Genomics (UMR 5203 CNRS - U 1191 INSERM), University of Montpellier, Montpellier, France
| | - Teresa Ravizza
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Annamaria Vezzani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
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Functional P2X 7 Receptors in the Auditory Nerve of Hearing Rodents Localize Exclusively to Peripheral Glia. J Neurosci 2021; 41:2615-2629. [PMID: 33563723 DOI: 10.1523/jneurosci.2240-20.2021] [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: 08/26/2020] [Revised: 12/03/2020] [Accepted: 01/09/2021] [Indexed: 11/21/2022] Open
Abstract
P2X7 receptors (P2X7Rs) are associated with numerous pathophysiological mechanisms, and this promotes them as therapeutic targets for certain neurodegenerative conditions. However, the identity of P2X7R-expressing cells in the nervous system remains contentious. Here, we examined P2X7R functionality in auditory nerve cells from rodents of either sex, and determined their functional and anatomic expression pattern. In whole-cell recordings from rat spiral ganglion cultures, the purinergic agonist 2',3'-O-(4-benzoylbenzoyl)-ATP (BzATP) activated desensitizing currents in spiral ganglion neurons (SGNs) but non-desensitizing currents in glia that were blocked by P2X7R-specific antagonists. In imaging experiments, BzATP gated sustained Ca2+ entry into glial cells. BzATP-gated uptake of the fluorescent dye YO-PRO-1 was reduced and slowed by P2X7R-specific antagonists. In rats, P2X7Rs were immuno-localized predominantly within satellite glial cells (SGCs) and Schwann cells (SCs). P2X7R expression was not detected in the portion of the auditory nerve within the central nervous system. Mouse models allowed further exploration of the distribution of cochlear P2X7Rs. In GENSAT reporter mice, EGFP expression driven via the P2rx7 promoter was evident in SGCs and SCs but was undetectable in SGNs. A second transgenic model showed a comparable cellular distribution of EGFP-tagged P2X7Rs. In wild-type mice the discrete glial expression was confirmed using a P2X7-specific nanobody construct. Our study shows that P2X7Rs are expressed by peripheral glial cells, rather than by afferent neurons. Description of functional signatures and cellular distributions of these enigmatic proteins in the peripheral nervous system (PNS) will help our understanding of ATP-dependent effects contributing to hearing loss and other sensory neuropathies.SIGNIFICANCE STATEMENT P2X7 receptors (P2X7Rs) have been the subject of much scrutiny in recent years. They have been promoted as therapeutic targets in a number of diseases of the nervous system, yet the specific cellular location of these receptors remains the subject of intense debate. In the auditory nerve, connecting the inner ear to the brainstem, we show these multimodal ATP-gated channels localize exclusively to peripheral glial cells rather than the sensory neurons, and are not evident in central glia. Physiologic responses in the peripheral glia display classical hallmarks of P2X7R activation, including the formation of ion-permeable and also macromolecule-permeable pores. These qualities suggest these proteins could contribute to glial-mediated inflammatory processes in the auditory periphery under pathologic disease states.
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Dias L, Lopes CR, Gonçalves FQ, Nunes A, Pochmann D, Machado NJ, Tomé AR, Agostinho P, Cunha RA. Crosstalk Between ATP-P 2X7 and Adenosine A 2A Receptors Controlling Neuroinflammation in Rats Subject to Repeated Restraint Stress. Front Cell Neurosci 2021; 15:639322. [PMID: 33732112 PMCID: PMC7957057 DOI: 10.3389/fncel.2021.639322] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/08/2021] [Indexed: 01/02/2023] Open
Abstract
Depressive conditions precipitated by repeated stress are a major socio-economical burden in Western countries. Previous studies showed that ATP-P2X7 receptors (P2X7R) and adenosine A2A receptors (A2AR) antagonists attenuate behavioral modifications upon exposure to repeated stress. Since it is unknown if these two purinergic modulation systems work independently, we now investigated a putative interplay between P2X7R and A2AR. Adult rats exposed to restraint stress for 14 days displayed an anxious (thigmotaxis, elevated plus maze), depressive (anhedonia, increased immobility), and amnesic (modified Y maze, object displacement) profile, together with increased expression of Iba-1 (a marker of microglia “activation”) and interleukin-1β (IL1β) and tumor necrosis factor α (TNFα; proinflammatory cytokines) and an up-regulation of P2X7R (mRNA) and A2AR (receptor binding) in the hippocampus and prefrontal cortex. All these features were attenuated by the P2X7R-preferring antagonist brilliant blue G (BBG, 45 mg/kg, i.p.) or by caffeine (0.3 g/L, p.o.), which affords neuroprotection through A2AR blockade. Notably, BBG attenuated A2AR upregulation and caffeine attenuated P2X7R upregulation. In microglial N9 cells, the P2X7R agonist BzATP (100 μM) or the A2AR agonist CGS26180 (100 nM) increased calcium levels, which was abrogated by the P2X7R antagonist JNJ47965567 (1 μM) and by the A2AR antagonist SCH58261 (50 nM), respectively; notably JNJ47965567 prevented the effect of CGS21680 and the effect of BzATP was attenuated by SCH58261 and increased by CGS21680. These results provide the first demonstration of a functional interaction between P2X7R and A2AR controlling microglia reactivity likely involved in behavioral adaptive responses to stress and are illustrative of a cooperation between the two arms of the purinergic system in the control of brain function.
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Affiliation(s)
- Liliana Dias
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Cátia R Lopes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Francisco Q Gonçalves
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ana Nunes
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Daniela Pochmann
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Nuno J Machado
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Angelo R Tomé
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - Paula Agostinho
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
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Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
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Deviant reporter expression and P2X4 passenger gene overexpression in the soluble EGFP BAC transgenic P2X7 reporter mouse model. Sci Rep 2020; 10:19876. [PMID: 33199725 PMCID: PMC7669894 DOI: 10.1038/s41598-020-76428-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/23/2020] [Indexed: 12/11/2022] Open
Abstract
The ATP-gated P2X7 receptor is highly expressed in microglia and has been involved in diverse brain diseases. P2X7 effects were also described in neurons and astrocytes but its localisation and function in these cell types has been challenging to demonstrate in situ. BAC transgenic mouse lines have greatly advanced neuroscience research and two BAC-transgenic P2X7 reporter mouse models exist in which either a soluble EGFP (sEGFP) or an EGFP-tagged P2X7 receptor (P2X7-EGFP) is expressed under the control of a BAC-derived P2rx7 promoter. Here we evaluate both mouse models and find striking differences in both P2X expression levels and EGFP reporter expression patterns. Most remarkably, the sEGFP model overexpresses a P2X4 passenger gene and sEGFP shows clear neuronal localisation but appears to be absent in microglia. Preliminary functional analysis in a status epilepticus model suggests functional consequences of the observed P2X receptor overexpression. In summary, an aberrant EGFP reporter pattern and possible effects of P2X4 and/or P2X7 protein overexpression need to be considered when working with this model. We further discuss reasons for the observed differences and possible caveats in BAC transgenic approaches.
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41
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Evolving targets for anti-epileptic drug discovery. Eur J Pharmacol 2020; 887:173582. [DOI: 10.1016/j.ejphar.2020.173582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 12/27/2022]
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Conte G, Parras A, Alves M, Ollà I, De Diego-Garcia L, Beamer E, Alalqam R, Ocampo A, Mendez R, Henshall DC, Lucas JJ, Engel T. High concordance between hippocampal transcriptome of the mouse intra-amygdala kainic acid model and human temporal lobe epilepsy. Epilepsia 2020; 61:2795-2810. [PMID: 33070315 DOI: 10.1111/epi.16714] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/11/2020] [Accepted: 09/11/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Pharmacoresistance and the lack of disease-modifying actions of current antiseizure drugs persist as major challenges in the treatment of epilepsy. Experimental models of chemoconvulsant-induced status epilepticus remain the models of choice to discover potential antiepileptogenic drugs, but doubts remain as to the extent to which they model human pathophysiology. The aim of the present study was to compare the molecular landscape of the intra-amygdala kainic acid model of status epilepticus in mice with findings in resected brain tissue from patients with drug-resistant temporal lobe epilepsy (TLE). METHODS Status epilepticus was induced via intra-amygdala microinjection of kainic acid in C57BL/6 mice, and gene expression was analyzed via microarrays in hippocampal tissue at acute and chronic time-points. Results were compared to reference datasets in the intraperitoneal pilocarpine and intrahippocampal kainic acid model and to human resected brain tissue (hippocampus and cortex) from patients with drug-resistant TLE. RESULTS Intra-amygdala kainic acid injection in mice triggered extensive dysregulation of gene expression that was ~3-fold greater shortly after status epilepticus (2729 genes) when compared to epilepsy (412). Comparison to samples from patients with TLE revealed a particularly high correlation of gene dysregulation during established epilepsy. Pathway analysis found suppression of calcium signaling to be highly conserved across different models of epilepsy and patients. cAMP response element-binding protein (CREB) was predicted as one of the main upstream transcription factors regulating gene expression during acute and chronic phases, and inhibition of CREB reduced seizure severity in the intra-amygdala kainic acid model. SIGNIFICANCE Our findings suggest the intra-amygdala kainic acid model faithfully replicates key molecular features of human drug-resistant TLE and provides potential rational target approaches for disease-modification through new insights into the unique and shared gene expression landscape in experimental epilepsy.
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Affiliation(s)
- Giorgia Conte
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Alberto Parras
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Severo Ochoa Center for Molecular Biology-CBMSO, CSIC/UAM, Madrid, Spain.,Networking Research Center on Neurodegenerative Diseases-CiberNed, Carlos III Institute of Health, Madrid, Spain
| | - Mariana Alves
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Ivana Ollà
- Severo Ochoa Center for Molecular Biology-CBMSO, CSIC/UAM, Madrid, Spain.,Networking Research Center on Neurodegenerative Diseases-CiberNed, Carlos III Institute of Health, Madrid, Spain
| | - Laura De Diego-Garcia
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Edward Beamer
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,Department of Science and Engineering, John Dalton Building, All Saints Campus, Metropolitan University, Manchester, UK
| | - Razi Alalqam
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Alejandro Ocampo
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Raúl Mendez
- Institute for Research in Biomedicine, Barcelona Institute of Science and Technology, Barcelona, Spain.,Catalan Institution for Research and Advanced Studies, Barcelona, Spain
| | - David C Henshall
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - José J Lucas
- Severo Ochoa Center for Molecular Biology-CBMSO, CSIC/UAM, Madrid, Spain.,Networking Research Center on Neurodegenerative Diseases-CiberNed, Carlos III Institute of Health, Madrid, Spain
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland.,FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
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Characterization of the Expression of the ATP-Gated P2X7 Receptor Following Status Epilepticus and during Epilepsy Using a P2X7-EGFP Reporter Mouse. Neurosci Bull 2020; 36:1242-1258. [PMID: 32895896 DOI: 10.1007/s12264-020-00573-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 07/08/2020] [Indexed: 12/18/2022] Open
Abstract
Mounting evidence suggests that the ATP-gated P2X7 receptor contributes to increased hyperexcitability in the brain. While increased expression of P2X7 in the hippocampus and cortex following status epilepticus and during epilepsy has been repeatedly demonstrated, the cell type-specific expression of P2X7 and its expression in extra-hippocampal brain structures remains incompletely explored. In this study, P2X7 expression was visualized by using a transgenic mouse model overexpressing P2X7 fused to the fluorescent protein EGFP. The results showed increased P2X7-EGFP expression after status epilepticus induced by intra-amygdala kainic acid and during epilepsy in different brain regions including the hippocampus, cortex, striatum, thalamus and cerebellum, and this was most evident in microglia and oligodendrocytes. Co-localization of P2X7-EGFP with cell type-specific markers was not detected in neurons or astrocytes. These data suggest that P2X7 activation is a common pathological hallmark across different brain structures, possibly contributing to brain inflammation and neurodegeneration following acute seizures and during epilepsy.
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P2X7 Receptors Amplify CNS Damage in Neurodegenerative Diseases. Int J Mol Sci 2020; 21:ijms21175996. [PMID: 32825423 PMCID: PMC7504621 DOI: 10.3390/ijms21175996] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 12/11/2022] Open
Abstract
ATP is a (co)transmitter and signaling molecule in the CNS. It acts at a multitude of ligand-gated cationic channels termed P2X to induce rapid depolarization of the cell membrane. Within this receptor-channel family, the P2X7 receptor (R) allows the transmembrane fluxes of Na+, Ca2+, and K+, but also allows the slow permeation of larger organic molecules. This is supposed to cause necrosis by excessive Ca2+ influx, as well as depletion of intracellular ions and metabolites. Cell death may also occur by apoptosis due to the activation of the caspase enzymatic cascade. Because P2X7Rs are localized in the CNS preferentially on microglia, but also at a lower density on neuroglia (astrocytes, oligodendrocytes) the stimulation of this receptor leads to the release of neurodegeneration-inducing bioactive molecules such as pro-inflammatory cytokines, chemokines, proteases, reactive oxygen and nitrogen molecules, and the excitotoxic glutamate/ATP. Various neurodegenerative reactions of the brain/spinal cord following acute harmful events (mechanical CNS damage, ischemia, status epilepticus) or chronic neurodegenerative diseases (neuropathic pain, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, amyotrophic lateral sclerosis) lead to a massive release of ATP via the leaky plasma membrane of neural tissue. This causes cellular damage superimposed on the original consequences of neurodegeneration. Hence, blood-brain-barrier permeable pharmacological antagonists of P2X7Rs with excellent bioavailability are possible therapeutic agents for these diseases. The aim of this review article is to summarize our present state of knowledge on the involvement of P2X7R-mediated events in neurodegenerative illnesses endangering especially the life quality and duration of the aged human population.
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Conte G, Nguyen NT, Alves M, de Diego-Garcia L, Kenny A, Nicke A, Henshall DC, Jimenez-Mateos EM, Engel T. P2X7 Receptor-Dependent microRNA Expression Profile in the Brain Following Status Epilepticus in Mice. Front Mol Neurosci 2020; 13:127. [PMID: 32982684 PMCID: PMC7485385 DOI: 10.3389/fnmol.2020.00127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/26/2020] [Indexed: 12/17/2022] Open
Abstract
The ionotropic ATP-gated P2X7 receptor is an important contributor to inflammatory signaling cascades via the release of Interleukin-1β, as well as having roles in cell death, neuronal plasticity and the release of neurotransmitters. Accordingly, there is interest in targeting the P2X7 receptor for the treatment of epilepsy. However, the signaling pathways downstream of P2X7 receptor activation remain incompletely understood. Notably, recent studies showed that P2X7 receptor expression is controlled, in part, by microRNAs (miRNAs). Here, we explored P2X7 receptor-dependent microRNA expression by comparing microRNA expression profiles of wild-type (wt) and P2X7 receptor knockout mice before and after status epilepticus. Genome-wide microRNA profiling was performed using hippocampi from wt and P2X7 receptor knockout mice following status epilepticus induced by intra-amygdala kainic acid. This revealed that the genetic deletion of the P2X7 receptor results in distinct patterns of microRNA expression. Specifically, we found that in vehicle-injected control mice, the lack of the P2X7 receptor resulted in the up-regulation of 50 microRNAs and down-regulation of 35 microRNAs. Post-status epilepticus, P2X7 receptor deficiency led to the up-regulation of 44 microRNAs while 13 microRNAs were down-regulated. Moreover, there was only limited overlap among identified P2X7 receptor-dependent microRNAs between control conditions and post-status epilepticus, suggesting that the P2X7 receptor regulates the expression of different microRNAs during normal physiology and pathology. Bioinformatic analysis revealed that genes targeted by P2X7 receptor-dependent microRNAs were particularly overrepresented in pathways involved in intracellular signaling, inflammation, and cell death; processes that have been repeatedly associated with P2X7 receptor activation. Moreover, whereas genes involved in signaling pathways and inflammation were common among up- and down-regulated P2X7 receptor-dependent microRNAs during physiological and pathological conditions, genes associated with cell death seemed to be restricted to up-regulated microRNAs during both physiological conditions and post-status epilepticus. Taken together, our results demonstrate that the P2X7 receptor impacts on the expression profile of microRNAs in the brain, thereby possibly contributing to both the maintenance of normal cellular homeostasis and pathological processes.
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Affiliation(s)
- Giorgia Conte
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Ngoc T Nguyen
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland.,FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Mariana Alves
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Laura de Diego-Garcia
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Aidan Kenny
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland.,FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
| | - Eva M Jimenez-Mateos
- Discipline of Physiology, School of Medicine, Trinity College Ireland, The University of Dublin, Dublin, Ireland
| | - Tobias Engel
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland.,FutureNeuro, Science Foundation Ireland (SFI) Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
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46
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Neiva R, Caulino-Rocha A, Ferreirinha F, Lobo MG, Correia-de-Sá P. Non-genomic Actions of Methylprednisolone Differentially Influence GABA and Glutamate Release From Isolated Nerve Terminals of the Rat Hippocampus. Front Mol Neurosci 2020; 13:146. [PMID: 32848604 PMCID: PMC7419606 DOI: 10.3389/fnmol.2020.00146] [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: 08/04/2019] [Accepted: 07/14/2020] [Indexed: 12/31/2022] Open
Abstract
Corticosteroids exert a dual role in eukaryotic cells through their action via (1) intracellular receptors (slow genomic responses), or (2) membrane-bound receptors (fast non-genomic responses). Highly vulnerable regions of the brain, like the hippocampus, express high amounts of corticosteroid receptors, yet their actions on ionic currents and neurotransmitters release are still undefined. Here, we investigated the effect of methylprednisolone (MP) on GABA and glutamate (Glu) release from isolated nerve terminals of the rat hippocampus. MP favored both spontaneous and depolarization-evoked [14C]Glu release from rat hippocampal nerve terminals, without affecting [3H]GABA outflow. Facilitation of [14C]Glu release by MP is mediated by a Na+-dependent Ca2+-independent non-genomic mechanism relying on the activation of membrane-bound glucocorticoid (GR) and mineralocorticoid (MR) receptors sensitive to their antagonists mifepristone and spironolactone, respectively. The involvement of Na+-dependent high-affinity EAAT transport reversal was inferred by blockage of MP-induced [14C]Glu release by DL-TBOA. Depolarization-evoked [3H]GABA release in the presence of MP was partially attenuated by the selective P2X7 receptor antagonist A-438079, but this compound did not affect the release of [14C]Glu. Data indicate that MP differentially affects GABA and glutamate release from rat hippocampal nerve terminals via fast non-genomic mechanisms putatively involving the activation of membrane-bound corticosteroid receptors. Facilitation of Glu release strengthen previous assumptions that MP may act as a cognitive enhancer in rats, while crosstalk with ATP-sensitive P2X7 receptors may promote a therapeutically desirable GABAergic inhibitory control during paroxysmal epileptic crisis that might be particularly relevant when extracellular Ca2+ levels decrease below the threshold required for transmitter release.
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Affiliation(s)
- Rafael Neiva
- Laboratório de Farmacologia e Neurobiologia - Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - Ana Caulino-Rocha
- Laboratório de Farmacologia e Neurobiologia - Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - Fátima Ferreirinha
- Laboratório de Farmacologia e Neurobiologia - Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - Maria Graça Lobo
- Laboratório de Farmacologia e Neurobiologia - Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia - Departamento de Imuno-Fisiologia e Farmacologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
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47
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Hong S, Xin Y, JiaWen W, ShuQin Z, GuiLian Z, HaiQin W, Zhen G, HongWei R, YongNan L. The P2X7 receptor in activated microglia promotes depression- and anxiety-like behaviors in lithium -pilocarpine induced epileptic rats. Neurochem Int 2020; 138:104773. [PMID: 32531197 DOI: 10.1016/j.neuint.2020.104773] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/17/2020] [Accepted: 05/20/2020] [Indexed: 12/14/2022]
Abstract
Depressive and anxious behaviors are the most common psychiatric symptoms of epilepsy, and may aggravate the epileptic condition and affect the patient's quality of life. Accumulating data obtained from both experimental animal models and patients have convincingly shown a critical role of P2X7 receptor (P2X7R) during depression and anxiety. Our study showed for the first time that the P2X7R is involved in promoting depression- and anxiety-like behaviors in lithium pilocarpine-induced epileptic rats. More importantly, direct anti-depressive and anti-anxiety effects were produced by the P2X7R antagonist Brilliant Blue G (BBG) is in this study, and the effect was similar to that of the classic anti-depressant and anti-anxiety drug fluoxetine. We also found that BBG did not affect the development of spontaneous recurrent seizures (SRS) and had a neuroprotective effect via inhibition of microglial activation after status epilepticus (SE). Thus, our data provide evidence that the P2X7R in activated microglia promotes depression- and anxiety-like behaviors in lithium-pilocarpine induced epileptic rats. Since previous studies have indicated that some anti-depression and anti-anxiety drugs may exacerbate seizures, our data support that the P2X7R is a promising therapeutic target for epilepsy associated with depression and anxiety.
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Affiliation(s)
- Sun Hong
- Department of Neurology, The Second Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China.
| | - Yu Xin
- Department of Neurology, People's Liberation Army 401 Hospital, Qingdao, Shandong, 266071, China
| | - Wu JiaWen
- Department of Dermatology, The Second Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China
| | - Zhan ShuQin
- Department of Neurology, The Second Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China
| | - Zhang GuiLian
- Department of Neurology, The Second Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China
| | - Wu HaiQin
- Department of Neurology, The Second Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China
| | - Gao Zhen
- Department of Neurology, The Second Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China
| | - Reng HongWei
- Department of Neurology, The Second Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, 710004, Shaanxi Province, China
| | - Li YongNan
- Department of Neurology, The Fourth Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, China
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48
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Gawel K, Kukula-Koch W, Nieoczym D, Stepnik K, van der Ent W, Banono NS, Tarabasz D, Turski WA, Esguerra CV. The Influence of Palmatine Isolated from Berberis sibirica Radix on Pentylenetetrazole-Induced Seizures in Zebrafish. Cells 2020; 9:cells9051233. [PMID: 32429356 PMCID: PMC7290958 DOI: 10.3390/cells9051233] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/11/2020] [Accepted: 05/14/2020] [Indexed: 12/15/2022] Open
Abstract
Palmatine (PALM) and berberine (BERB) are widely identified isoquinoline alkaloids among the representatives of the Berberidaceae botanical family. The antiseizure activity of BERB was shown previously in experimental epilepsy models. We assessed the effect of PALM in a pentylenetetrazole (PTZ)-induced seizure assay in zebrafish, with BERB as an active reference compound. Both alkaloids were isolated from the methanolic root extract of Berberis sibirica by counter-current chromatography, and their ability to cross the blood–brain barrier was determined via quantitative structure–activity relationship assay. PALM exerted antiseizure activity, as confirmed by electroencephalographic analysis, and decreased c-fos and bdnf levels in PTZ-treated larvae. In a behavioral assay, PALM dose-dependently decreased PTZ-induced hyperlocomotion. The combination of PALM and BERB in ED16 doses revealed hyperadditive activity towards PTZ-induced hyperlocomotion. Notably, we have indicated that both alkaloids may exert their anticonvulsant activity through different mechanisms of action. Additionally, the combination of both alkaloids in a 1:2.17 ratio (PALM: BERB) mimicked the activity of the pure extract, which indicates that these two active compounds are responsible for its anticonvulsive activity. In conclusion, our study reveals for the first time the anticonvulsant activity of PALM and suggests the combination of PALM and BERB may have higher therapeutic value than separate usage of these compounds.
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Affiliation(s)
- Kinga Gawel
- Chemical Neuroscience Group, Faculty of Medicine, Centre for Molecular Medicine Norway, University of Oslo, Gaustadalléen 21, 0349 Oslo, Norway; (W.v.d.E.); (N.S.B.); (C.V.E.)
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego Str. 8b, 20-090 Lublin, Poland;
- Correspondence: ; Tel.: +48-81448-6454
| | - Wirginia Kukula-Koch
- Chair and Department of Pharmacognosy, Medical University of Lublin, 1, Chodzki Str. 1, 20-093 Lublin, Poland; (W.K.-K.); (D.T.)
| | - Dorota Nieoczym
- Department of Animal Physiology and Pharmacology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka Str. 19, 20-033 Lublin, Poland;
| | - Katarzyna Stepnik
- Department of Physical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University, Pl. M. Curie-Skłodowskiej 3/243, 20-031 Lublin, Poland;
| | - Wietske van der Ent
- Chemical Neuroscience Group, Faculty of Medicine, Centre for Molecular Medicine Norway, University of Oslo, Gaustadalléen 21, 0349 Oslo, Norway; (W.v.d.E.); (N.S.B.); (C.V.E.)
| | - Nancy Saana Banono
- Chemical Neuroscience Group, Faculty of Medicine, Centre for Molecular Medicine Norway, University of Oslo, Gaustadalléen 21, 0349 Oslo, Norway; (W.v.d.E.); (N.S.B.); (C.V.E.)
| | - Dominik Tarabasz
- Chair and Department of Pharmacognosy, Medical University of Lublin, 1, Chodzki Str. 1, 20-093 Lublin, Poland; (W.K.-K.); (D.T.)
| | - Waldemar A. Turski
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego Str. 8b, 20-090 Lublin, Poland;
| | - Camila V. Esguerra
- Chemical Neuroscience Group, Faculty of Medicine, Centre for Molecular Medicine Norway, University of Oslo, Gaustadalléen 21, 0349 Oslo, Norway; (W.v.d.E.); (N.S.B.); (C.V.E.)
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49
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Wesselingh R, Butzkueven H, Buzzard K, Tarlinton D, O'Brien TJ, Monif M. Seizures in autoimmune encephalitis: Kindling the fire. Epilepsia 2020; 61:1033-1044. [DOI: 10.1111/epi.16515] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 04/07/2020] [Accepted: 04/07/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Robb Wesselingh
- Department of Neurosciences Central Clinical School Faculty of Medicine, Nursing, and Health Sciences Monash University Melbourne Victoria Australia
- Department of Neurology Alfred Health Melbourne Victoria Australia
| | - Helmut Butzkueven
- Department of Neurosciences Central Clinical School Faculty of Medicine, Nursing, and Health Sciences Monash University Melbourne Victoria Australia
- Department of Neurology Alfred Health Melbourne Victoria Australia
| | - Katherine Buzzard
- Department of Neurology Melbourne Health Parkville Victoria Australia
- Department of Neurology Eastern Health Box Hill Victoria Australia
| | - David Tarlinton
- Department of Immunology Central Clinical School Faculty of Medicine, Nursing, and Health Sciences Monash University Melbourne Victoria Australia
| | - Terence J. O'Brien
- Department of Neurosciences Central Clinical School Faculty of Medicine, Nursing, and Health Sciences Monash University Melbourne Victoria Australia
- Department of Neurology Alfred Health Melbourne Victoria Australia
| | - Mastura Monif
- Department of Neurosciences Central Clinical School Faculty of Medicine, Nursing, and Health Sciences Monash University Melbourne Victoria Australia
- Department of Neurology Alfred Health Melbourne Victoria Australia
- Department of Neurology Melbourne Health Parkville Victoria Australia
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50
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Doǧan E, Aygün H, Arslan G, Rzayev E, Avcı B, Ayyıldız M, Ağar E. The Role of NMDA Receptors in the Effect of Purinergic P2X7 Receptor on Spontaneous Seizure Activity in WAG/Rij Rats With Genetic Absence Epilepsy. Front Neurosci 2020; 14:414. [PMID: 32435183 PMCID: PMC7218146 DOI: 10.3389/fnins.2020.00414] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/06/2020] [Indexed: 12/14/2022] Open
Abstract
P2X7 receptors (P2X7Rs) are ATP sensitive cation channels and have been shown to be effective in various epilepsy models. Absence epilepsy is a type of idiopathic, generalized, non-convulsive epilepsy. Limited data exist on the role of P2X7Rs and no data has been reported regarding the interaction between P2X7Rs and glutamate receptor NMDA in absence epilepsy. Thus, this study was designed to investigate the role of P2X7 and NMDA receptors and their possible interaction in WAG/Rij rats with absence epilepsy. Permanent cannula and electrodes were placed on the skulls of the animals. After the healing period of the electrode and cannula implantation, ECoG recordings were obtained during 180 min before and after drug injections. P2X7R agonist BzATP, at doses of 50 μg and 100 μg (intracerebroventricular; i.c.v.) and antagonist A-438079, at doses of 20 μg and 40 μg (i.c.v.) were administered alone or prior to memantine (5 mg/kg, intraperitoneal; i.p.) injection. The total number (in every 20 min), the mean duration, and the amplitude of spike-wave discharges (SWDs) were calculated and compared. Rats were decapitated and the right and left hemisphere, cerebellum, and brainstem were separated for the measurements of the advanced oxidation protein product (AOPP), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), glutathione peroxide (GPx), and glutathione reductase (GR). BzATP and A-438079 did not alter measured SWDs parameters, whereas memantine reduced them, which is considered anticonvulsant. BzATP did not alter the anticonvulsant effect of memantine, while A-438079 decreased the effect of memantine. Administration of BzATP increased the levels of SOD and GR in cerebrum hemispheres. A-438079 did not alter any of the biochemical parameters. Memantine reduced the levels of MDA, GSH, and GR while increased the level of CAT in the cerebrum. Administration of BzATP before memantine abolished the effect of memantine on MDA levels. The evidence from this study suggests that P2X7Rs does not directly play a role in the formation of absence seizures. P2X7Rs agonist, reduced the antioxidant activity of memantine whereas agonist of P2X7Rs reduced the anticonvulsant action of memantine, suggesting a partial interaction between P2X7 and NMDA receptors in absence epilepsy model.
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Affiliation(s)
- Elif Doǧan
- Department of Physiology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Hatice Aygün
- Department of Physiology, Faculty of Medicine, Gaziosmanpasa University, Tokat, Turkey
| | - Gökhan Arslan
- Department of Physiology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Emil Rzayev
- Department of Clinical Biochemistry, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Bahattin Avcı
- Department of Clinical Biochemistry, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Mustafa Ayyıldız
- Department of Physiology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
| | - Erdal Ağar
- Department of Physiology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Turkey
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