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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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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: 0] [Impact Index Per Article: 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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Quincozes-Santos A, Bobermin LD, Costa NLF, Thomaz NK, Almeida RRDS, Beys-da-Silva WO, Santi L, Rosa RL, Capra D, Coelho-Aguiar JM, DosSantos MF, Heringer M, Cirne-Lima EO, Guimarães JA, Schuler-Faccini L, Gonçalves CA, Moura-Neto V, Souza DO. The role of glial cells in Zika virus-induced neurodegeneration. Glia 2023. [PMID: 36866453 DOI: 10.1002/glia.24353] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Zika virus (ZIKV) is a strongly neurotropic flavivirus whose infection has been associated with microcephaly in neonates. However, clinical and experimental evidence indicate that ZIKV also affects the adult nervous system. In this regard, in vitro and in vivo studies have shown the ability of ZIKV to infect glial cells. In the central nervous system (CNS), glial cells are represented by astrocytes, microglia, and oligodendrocytes. In contrast, the peripheral nervous system (PNS) constitutes a highly heterogeneous group of cells (Schwann cells, satellite glial cells, and enteric glial cells) spread through the body. These cells are critical in both physiological and pathological conditions; as such, ZIKV-induced glial dysfunctions can be associated with the development and progression of neurological complications, including those related to the adult and aging brain. This review will address the effects of ZIKV infection on CNS and PNS glial cells, focusing on cellular and molecular mechanisms, including changes in the inflammatory response, oxidative stress, mitochondrial dysfunction, Ca2+ and glutamate homeostasis, neural metabolism, and neuron-glia communication. Of note, preventive and therapeutic strategies that focus on glial cells may emerge to delay and/or prevent the development of ZIKV-induced neurodegeneration and its consequences.
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Affiliation(s)
- André Quincozes-Santos
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Larissa Daniele Bobermin
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Naithan Ludian Fernandes Costa
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Natalie K Thomaz
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rômulo Rodrigo de Souza Almeida
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | | | - Lucélia Santi
- Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Rafael L Rosa
- Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Daniela Capra
- Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria Estadual de Saúde do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Juliana M Coelho-Aguiar
- Laboratório de Morfogênese Celular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Marcos Fabio DosSantos
- Laboratório de Propriedades Mecânicas e Biologia Celular, Faculdade de Odontologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Manoela Heringer
- Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria Estadual de Saúde do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | | | | | - Carlos-Alberto Gonçalves
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Vivaldo Moura-Neto
- Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria Estadual de Saúde do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.,Laboratório de Morfogênese Celular, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Diogo Onofre Souza
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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Beltran-Lobo P, Reid MJ, Jimenez-Sanchez M, Verkhratsky A, Perez-Nievas BG, Noble W. Astrocyte adaptation in Alzheimer's disease: a focus on astrocytic P2X7R. Essays Biochem 2023; 67:119-130. [PMID: 36449279 PMCID: PMC10011405 DOI: 10.1042/ebc20220079] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 12/02/2022]
Abstract
Astrocytes are key homeostatic and defensive cells of the central nervous system (CNS). They undertake numerous functions during development and in adulthood to support and protect the brain through finely regulated communication with other cellular elements of the nervous tissue. In Alzheimer's disease (AD), astrocytes undergo heterogeneous morphological, molecular and functional alterations represented by reactive remodelling, asthenia and loss of function. Reactive astrocytes closely associate with amyloid β (Aβ) plaques and neurofibrillary tangles in advanced AD. The specific contribution of astrocytes to AD could potentially evolve along the disease process and includes alterations in their signalling, interactions with pathological protein aggregates, metabolic and synaptic impairments. In this review, we focus on the purinergic receptor, P2X7R, and discuss the evidence that P2X7R activation contributes to altered astrocyte functions in AD. Expression of P2X7R is increased in AD brain relative to non-demented controls, and animal studies have shown that P2X7R antagonism improves cognitive and synaptic impairments in models of amyloidosis and tauopathy. While P2X7R activation can induce inflammatory signalling pathways, particularly in microglia, we focus here specifically on the contributions of astrocytic P2X7R to synaptic changes and protein aggregate clearance in AD, highlighting cell-specific roles of this purinoceptor activation that could be targeted to slow disease progression.
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Affiliation(s)
- Paula Beltran-Lobo
- Department of Basic and Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology and Neuroscience, 5 Cutcombe Road, London, SE5 9RX, U.K
| | - Matthew J Reid
- Department of Basic and Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology and Neuroscience, 5 Cutcombe Road, London, SE5 9RX, U.K
| | - Maria Jimenez-Sanchez
- Department of Basic and Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology and Neuroscience, 5 Cutcombe Road, London, SE5 9RX, U.K
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, U.K
- Achucarro Center for Neuroscience, IKERBASQUE, 48011 Bilbao, Spain
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, LT-01102, Vilnius, Lithuania
| | - Beatriz G Perez-Nievas
- Department of Basic and Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology and Neuroscience, 5 Cutcombe Road, London, SE5 9RX, U.K
| | - Wendy Noble
- Department of Basic and Clinical Neuroscience, King's College London, Institute of Psychiatry, Psychology and Neuroscience, 5 Cutcombe Road, London, SE5 9RX, U.K
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Yuan Y, Zhao Y, Shen M, Wang C, Dong B, Xie K, Yu Y, Yu Y. Spinal NLRP3 inflammasome activation mediates IL-1β release and contributes to remifentanil-induced postoperative hyperalgesia by regulating NMDA receptor NR1 subunit phosphorylation and GLT-1 expression in rats. Mol Pain 2022; 18:17448069221093016. [PMID: 35322721 PMCID: PMC9703502 DOI: 10.1177/17448069221093016] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Trafficking and activation of N-methyl-D-aspartate (NMDA) receptors play an important role in initiating and maintaining postoperative remifentanil-induced hyperalgesia (RIH). Activation of the NOD-like receptor protein 3 (NLRP3) inflammasome has been linked to the development of inflammatory and neuropathic pain. We hypothesized that activation of NLRP3 inflammasome mediates IL-1β release and contributes to RIH in rats by increasing NMDA receptor NR1 (NR1) subunit phosphorylation and decreasing glutamate transporter-1 (GLT-1) expression. METHODS Acute exposure to remifentanil (1.2 μg/kg/min for 60 min) was used to establish RIH in rats. Thermal and mechanical hyperalgesia were tested at baseline (24 h before remifentanil infusion) and 2, 6, 24, and 48 h after remifentanil infusion. The levels of IL-1β, GLT-1, phosphorylated NR1 (phospho-NR1), and NLRP3 inflammasome activation indicators [NLRP3, Toll-like receptor 4 (TLR4), P2X purinoceptor 7 (P2X7R), and caspase-1] were measured after the last behavioral test. A selective IL-1β inhibitor (IL-1β inhibitor antagonist; IL-1ra) or three different selective NLRP3 inflammasome activation inhibitors [(+)-naloxone (a TLR4 inhibitor), A438079 (a P2X7R inhibitor), or ac-YVADcmk (a caspase-1 inhibitor)] were intrathecally administered immediately before remifentanil infusion into rats. RESULTS Remifentanil induced significant postoperative hyperalgesia, increased IL-1β and phospho-NR1 levels and activated the NLRP3 inflammasome by increasing TLR4, P2X7R, NLRP3, and caspase-1 expression, but it decreased GLT-1 expression in the L4-L6 spinal cord segments of rats, which was markedly improved by intrathecal administration of IL-1ra, (+)-naloxone, A438079, or ac-YVADcmk. CONCLUSION NLRP3 inflammasome activation mediates IL-1β release and contributes to RIH in rats by inducing NMDA receptor NR1 subunit phosphorylation and decreasing GLT-1 expression. Inhibiting the activation of the NLRP3 inflammasome may be an effective treatment for RIH.
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Affiliation(s)
- Yuan Yuan
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Yue Zhao
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Mengxi Shen
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Chenxu Wang
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Beibei Dong
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Keliang Xie
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China
| | - Yang Yu
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China,Yang Yu, Department of Anesthesia, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin 300052, P.R. China.
| | - Yonghao Yu
- Department of Anesthesia, Tianjin Medical University General Hospital, Tianjin, China,Tianjin Institute of Anesthesiology, Tianjin, P.R. China,Yonghao Yu, Department of Anesthesia, Tianjin Medical University General Hospital, 154 Anshan Road, Tianjin 300052, P.R. China.
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6
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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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Lee DS, Kim JE. P2X7 Receptor Augments LPS-Induced Nitrosative Stress by Regulating Nrf2 and GSH Levels in the Mouse Hippocampus. Antioxidants (Basel) 2022; 11:antiox11040778. [PMID: 35453462 PMCID: PMC9025791 DOI: 10.3390/antiox11040778] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 01/27/2023] Open
Abstract
P2X7 receptor (P2X7R) regulates inducible nitric oxide synthase (iNOS) expression/activity in response to various harmful insults. Since P2X7R deletion paradoxically decreases the basal glutathione (GSH) level in the mouse hippocampus, it is likely that P2X7R may increase the demand for GSH for the maintenance of the intracellular redox state or affect other antioxidant defense systems. Therefore, the present study was designed to elucidate whether P2X7R affects nuclear factor-erythroid 2-related factor 2 (Nrf2) activity/expression and GSH synthesis under nitrosative stress in response to lipopolysaccharide (LPS)-induced neuroinflammation. In the present study, P2X7R deletion attenuated iNOS upregulation and Nrf2 degradation induced by LPS. Compatible with iNOS induction, P2X7R deletion decreased S-nitrosylated (SNO)-cysteine production under physiological and post-LPS treated conditions. P2X7R deletion also ameliorated the decreases in GSH, glutathione synthetase, GS and ASCT2 levels concomitant with the reduced S-nitrosylations of GS and ASCT2 following LPS treatment. Furthermore, LPS upregulated cystine:glutamate transporter (xCT) and glutaminase in P2X7R+/+ mice, which were abrogated by P2X7R deletion. LPS did not affect GCLC level in both P2X7R+/+ and P2X7R−/− mice. Therefore, our findings indicate that P2X7R may augment LPS-induced neuroinflammation by leading to Nrf2 degradation, aberrant glutamate-glutamine cycle and impaired cystine/cysteine uptake, which would inhibit GSH biosynthesis. Therefore, we suggest that the targeting of P2X7R, which would exert nitrosative stress with iNOS in a positive feedback manner, may be one of the important therapeutic strategies of nitrosative stress under pathophysiological conditions.
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High, in Contrast to Low Levels of Acute Stress Induce Depressive-like Behavior by Involving Astrocytic, in Addition to Microglial P2X7 Receptors in the Rodent Hippocampus. Int J Mol Sci 2022; 23:ijms23031904. [PMID: 35163829 PMCID: PMC8836505 DOI: 10.3390/ijms23031904] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/27/2022] [Accepted: 02/01/2022] [Indexed: 12/30/2022] Open
Abstract
Extracellular adenosine 5'-triphosphate (ATP) in the brain is suggested to be an etiological factor of major depressive disorder (MDD). It has been assumed that stress-released ATP stimulates P2X7 receptors (Rs) at the microglia, thereby causing neuroinflammation; however, other central nervous system (CNS) cell types such as astrocytes also possess P2X7Rs. In order to elucidate the possible involvement of the MDD-relevant hippocampal astrocytes in the development of a depressive-like state, we used various behavioral tests (tail suspension test [TST], forced swim test [FST], restraint stress, inescapable foot shock, unpredictable chronic mild stress [UCMS]), as well as fluorescence immunohistochemistry, and patch-clamp electrophysiology in wild-type (WT) and genetically manipulated rodents. The TST and FST resulted in learned helplessness manifested as a prolongation of the immobility time, while inescapable foot shock caused lower sucrose consumption as a sign of anhedonia. We confirmed the participation of P2X7Rs in the development of the depressive-like behaviors in all forms of acute (TST, FST, foot shock) and chronic stress (UCMS) in the rodent models used. Further, pharmacological agonists and antagonists acted in a different manner in rats and mice due to their diverse potencies at the respective receptor orthologs. In hippocampal slices of mice and rats, only foot shock increased the current responses to locally applied dibenzoyl-ATP (Bz-ATP) in CA1 astrocytes; in contrast, TST and restraint depressed these responses. Following stressful stimuli, immunohistochemistry demonstrated an increased co-localization of P2X7Rs with a microglial marker, but no change in co-localization with an astroglial marker. Pharmacological damage to the microglia and astroglia has proven the significance of the microglia for mediating all types of depression-like behavioral reactions, while the astroglia participated only in reactions induced by strong stressors, such as foot shock. Because, in addition to acute stressors, their chronic counterparts induce a depressive-like state in rodents via P2X7R activation, we suggest that our data may have relevance for the etiology of MDD in humans.
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Debom GN, Rubenich DS, Braganhol E. Adenosinergic Signaling as a Key Modulator of the Glioma Microenvironment and Reactive Astrocytes. Front Neurosci 2022; 15:648476. [PMID: 35069091 PMCID: PMC8766410 DOI: 10.3389/fnins.2021.648476] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 12/03/2021] [Indexed: 12/13/2022] Open
Abstract
Astrocytes are numerous glial cells of the central nervous system (CNS) and play important roles in brain homeostasis. These cells can directly communicate with neurons by releasing gliotransmitters, such as adenosine triphosphate (ATP) and glutamate, into the multipartite synapse. Moreover, astrocytes respond to tissue injury in the CNS environment. Recently, astrocytic heterogeneity and plasticity have been discussed by several authors, with studies proposing a spectrum of astrocytic activation characterized by A1/neurotoxic and A2/neuroprotective polarization extremes. The fundamental roles of astrocytes in communicating with other cells and sustaining homeostasis are regulated by purinergic signaling. In the CNS environment, the gliotransmitter ATP acts cooperatively with other glial signaling molecules, such as cytokines, which may impact CNS functions by facilitating/inhibiting neurotransmitter release. Adenosine (ADO), the main product of extracellular ATP metabolism, is an important homeostatic modulator and acts as a neuromodulator in synaptic transmission via P1 receptor sensitization. Furthermore, purinergic signaling is a key factor in the tumor microenvironment (TME), as damaged cells release ATP, leading to ADO accumulation in the TME through the ectonucleotidase cascade. Indeed, the enzyme CD73, which converts AMP to ADO, is overexpressed in glioblastoma cells; this upregulation is associated with tumor aggressiveness. Because of the crucial activity of CD73 in these cells, extracellular ADO accumulation in the TME contributes to sustaining glioblastoma immune escape while promoting A2-like activation. The present review describes the importance of ADO in modulating astrocyte polarization and simultaneously promoting tumor growth. We also discuss whether targeting of CD73 to block ADO production can be used as an alternative cancer therapy.
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Affiliation(s)
- Gabriela N Debom
- Programa de Pós-graduação em Biociências, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil
| | - Dominique S Rubenich
- Programa de Pós-graduação em Biociências, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil
| | - Elizandra Braganhol
- Programa de Pós-graduação em Biociências, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil.,Instituto de Cardiologia do Rio Grande do Sul, Instituto de Cardiologia - Fundação Universitária de Cardiologia, Porto Alegre, Brazil
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10
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Ren WJ, Illes P. Involvement of P2X7 receptors in chronic pain disorders. Purinergic Signal 2021; 18:83-92. [PMID: 34799827 PMCID: PMC8850523 DOI: 10.1007/s11302-021-09796-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/11/2021] [Indexed: 02/07/2023] Open
Abstract
Chronic pain is caused by cellular damage with an obligatory inflammatory component. In response to noxious stimuli, high levels of ATP leave according to their concentration gradient, the intracellular space through discontinuities generated in the plasma membrane or diffusion through pannexin-1 hemichannels, and activate P2X7Rs localized at peripheral and central immune cells. Because of the involvement of P2X7Rs in immune functions and especially the initiation of macrophage/microglial and astrocytic secretion of cytokines, chemokines, prostaglandins, proteases, reactive oxygen, and nitrogen species as well as the excitotoxic glutamate/ATP, this receptor type has a key role in chronic pain processes. Microglia are equipped with a battery of pattern recognition receptors that detect pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharide (LPS) from bacterial infections or danger associated molecular patterns (DAMPs) such as ATP. The co-stimulation of these receptors leads to the activation of the NLRP3 inflammasome and interleukin-1β (IL-1β) release. In the present review, we invite you to a journey through inflammatory and neuropathic pain, primary headache, and regulation of morphine analgesic tolerance, in the pathophysiology of which P2X7Rs are centrally involved. P2X7R bearing microglia and astrocyte-like cells playing eminent roles in chronic pain will be also discussed.
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Affiliation(s)
- Wen-Jing Ren
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
| | - Peter Illes
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China.
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04109, Leipzig, Germany.
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11
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Xu Q, Ford NC, He S, Huang Q, Anderson M, Chen Z, Yang F, Crawford LK, Caterina MJ, Guan Y, Dong X. Astrocytes contribute to pain gating in the spinal cord. SCIENCE ADVANCES 2021; 7:eabi6287. [PMID: 34730998 PMCID: PMC8565904 DOI: 10.1126/sciadv.abi6287] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
Various pain therapies have been developed on the basis of the gate control theory of pain, which postulates that nonpainful sensory inputs mediated by large-diameter afferent fibers (Aβ-fibers) can attenuate noxious signals relayed to the brain. To date, this theory has focused only on neuronal mechanisms. Here, we identified an unprecedented function of astrocytes in the gating of nociceptive signals transmitted by neurokinin 1 receptor–positive (NK1R+) projection neurons in the spinal cord. Electrical stimulation of peripheral Aβ-fibers in naïve mice activated spinal astrocytes, which in turn induced long-term depression (LTD) in NK1R+ neurons and antinociception through activation of endogenous adenosinergic mechanisms. Suppression of astrocyte activation by pharmacologic, chemogenetic, and optogenetic manipulations blocked the induction of LTD in NK1R+ neurons and pain inhibition by Aβ-fiber stimulation. Collectively, our study introduces astrocytes as an important component of pain gating by activation of Aβ-fibers, which thus exert nonneuronal control of pain.
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Affiliation(s)
- Qian Xu
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Neil C. Ford
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shaoqiu He
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Qian Huang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael Anderson
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zhiyong Chen
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Fei Yang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - LaTasha K. Crawford
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael J. Caterina
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurological Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurological Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neurological Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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12
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Huang H, Zheng S, Chen M, Xie L, Li Z, Guo M, Wang J, Lu M, Zhu X. The potential of the P2X7 receptor as a therapeutic target in a sub-chronic PCP-induced rodent model of schizophrenia. J Chem Neuroanat 2021; 116:101993. [PMID: 34147620 DOI: 10.1016/j.jchemneu.2021.101993] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/17/2021] [Accepted: 06/15/2021] [Indexed: 01/27/2023]
Abstract
OBJECTIVE We studied the role of the P2X7 receptor on cognitive dysfunction in a mouse model of schizophrenia. METHODS An adult mouse model was established by treatment with phencyclidine (PCP), an N-methyl-D-aspartate (NMDA) receptor antagonist. Young mice were divided into three groups: 1) the control (saline-injected) group; 2) experimental 5 mg/kg PCP-injected group; and 3) experimental 10 mg/kg PCP-injected group. The mice were subjected to the open-field and Morris water maze tests at 7 weeks. After intraperitoneal injection of the P2X7 receptor antagonist JNJ-47965567, the behaviour tests were performed again. Samples were taken after testing. The P2X7 receptor protein and mRNA expression levels were detected by immunohistochemistry, Western blotting and PCR. RESULTS This study revealed that the infant sub-chronic PCP mice model showed severe spatial learning and memory impairment in the Morris water maze and schizophrenia-like symptoms (hypermotor behaviour) in the open-field test. The P2X7 receptor protein was highly expressed in the sub-chronic PCP mouse model and more highly expressed in the hippocampus than the prefrontal lobe. After the P2X7 receptor was blocked with JNJ-47965567, P2X7 receptor protein and mRNA expression in the frontal lobe were significantly increased, and the spatial memory impairment and hypermotor behaviour induced by PCP were reversed. CONCLUSION PCP-induced cognitive impairment can be significantly improved by antagonizing the P2X7 receptor. Therefore, we believe that the P2X7 receptor plays an important role in the cognition of schizophrenic-like mice.
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Affiliation(s)
- Hui Huang
- Department of Neurosurgery, Second Affiliation Hospital, Nanchang University, Nanchang, Jiangxi, China; Institute of Neuroscience, Nanchang University, Nanchang, Jiangxi, China
| | - Suyue Zheng
- Department of Neurosurgery, First Affiliation Hospital, Nanchang University, Nanchang, Jiangxi, China
| | - Min Chen
- Department of Neurosurgery, Second Affiliation Hospital, Nanchang University, Nanchang, Jiangxi, China; Institute of Neuroscience, Nanchang University, Nanchang, Jiangxi, China
| | - Liyuan Xie
- Department of Neurosurgery, Second Affiliation Hospital, Nanchang University, Nanchang, Jiangxi, China; Institute of Neuroscience, Nanchang University, Nanchang, Jiangxi, China
| | - Ziyi Li
- Department of Neurosurgery, Second Affiliation Hospital, Nanchang University, Nanchang, Jiangxi, China; Institute of Neuroscience, Nanchang University, Nanchang, Jiangxi, China
| | - Min Guo
- Psychosomatic Medicine, Second Affiliation Hospital, Nanchang University, Nanchang, Jiangxi, China
| | - Jianhong Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences, Kunming Institute of Zoology, Kunming, Yunnan, China
| | - Mingwei Lu
- Department of Neurosurgery, Second Affiliation Hospital, Nanchang University, Nanchang, Jiangxi, China; Institute of Neuroscience, Nanchang University, Nanchang, Jiangxi, China.
| | - Xingen Zhu
- Department of Neurosurgery, Second Affiliation Hospital, Nanchang University, Nanchang, Jiangxi, China; Institute of Neuroscience, Nanchang University, Nanchang, Jiangxi, China.
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13
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Zhao YF, Tang Y, Illes P. Astrocytic and Oligodendrocytic P2X7 Receptors Determine Neuronal Functions in the CNS. Front Mol Neurosci 2021; 14:641570. [PMID: 33642994 PMCID: PMC7906075 DOI: 10.3389/fnmol.2021.641570] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 01/19/2021] [Indexed: 12/20/2022] Open
Abstract
P2X7 receptors are members of the ATP-gated cationic channel family with a preferential localization at the microglial cells, the resident macrophages of the brain. However, these receptors are also present at neuroglia (astrocytes, oligodendrocytes) although at a considerably lower density. They mediate necrosis/apoptosis by the release of pro-inflammatory cytokines/chemokines, reactive oxygen species (ROS) as well as the excitotoxic (glio)transmitters glutamate and ATP. Besides mediating cell damage i.e., superimposed upon chronic neurodegenerative processes in Alzheimer’s Disease, Parkinson’s Disease, multiple sclerosis, and amyotrophic lateral sclerosis, they may also participate in neuroglial signaling to neurons under conditions of high ATP concentrations during any other form of neuroinflammation/neurodegeneration. It is a pertinent open question whether P2X7Rs are localized on neurons, or whether only neuroglia/microglia possess this receptor-type causing indirect effects by releasing the above-mentioned signaling molecules. We suggest as based on molecular biology and functional evidence that neurons are devoid of P2X7Rs although the existence of neuronal P2X7Rs cannot be excluded with absolute certainty.
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Affiliation(s)
- Ya-Fei Zhao
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yong Tang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China.,International Collaborative Center on Big Science Plan for Purine 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 Purine Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, China.,Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
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14
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Presynaptic Inhibition of Pain and Touch in the Spinal Cord: From Receptors to Circuits. Int J Mol Sci 2021; 22:ijms22010414. [PMID: 33401784 PMCID: PMC7795800 DOI: 10.3390/ijms22010414] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 02/07/2023] Open
Abstract
Sensory primary afferent fibers, conveying touch, pain, itch, and proprioception, synapse onto spinal cord dorsal horn neurons. Primary afferent central terminals express a wide variety of receptors that modulate glutamate and peptide release. Regulation of the amount and timing of neurotransmitter release critically affects the integration of postsynaptic responses and the coding of sensory information. The role of GABA (γ-aminobutyric acid) receptors expressed on afferent central terminals is particularly important in sensory processing, both in physiological conditions and in sensitized states induced by chronic pain. During the last decade, techniques of opto- and chemogenetic stimulation and neuronal selective labeling have provided interesting insights on this topic. This review focused on the recent advances about the modulatory effects of presynaptic GABAergic receptors in spinal cord dorsal horn and the neural circuits involved in these mechanisms.
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15
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Ollà I, Santos-Galindo M, Elorza A, Lucas JJ. P2X7 Receptor Upregulation in Huntington's Disease Brains. Front Mol Neurosci 2020; 13:567430. [PMID: 33122998 PMCID: PMC7573237 DOI: 10.3389/fnmol.2020.567430] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/28/2020] [Indexed: 01/02/2023] Open
Abstract
Huntington’s disease (HD) is a fatal degenerative disorder affecting the nervous system. It is characterized by motor, cognitive, and psychiatric dysfunctions, with a late onset and an autosomal dominant pattern of inheritance. HD-causing mutation consists in an expansion of repeated CAG triplets in the huntingtin gene (HTT), encoding for an expanded polyglutamine (polyQ) stretch in the huntingtin protein (htt). The mutation causes neuronal dysfunction and loss through multiple mechanisms, affecting both the nucleus and cytoplasm. P2X7 receptor (P2X7R) emerged as a major player in neuroinflammation, since ATP – its endogenous ligand – is massively released under this condition. Indeed, P2X7R stimulation in the central nervous system (CNS) is known to enhance the release of pro-inflammatory cytokines from microglia and of neurotransmitters from neuronal presynaptic terminals, as well as to promote apoptosis. Previous experiments performed with neurons expressing the mutant huntingtin and exploiting HD mouse models demonstrated a role of P2X7R in HD. On the basis of those results, here, we explore for the first time the status of P2X7R in HD patients’ brain. We report that in HD postmortem striatum, as earlier observed in HD mice, the protein levels of the full-length form of P2X7R, also named P2X7R-A, are upregulated. In addition, the exclusively human naturally occurring variant lacking the C-terminus region, P2X7R-B, is upregulated as well. As we show here, this augmented protein levels can be explained by elevated mRNA levels. Furthermore, in HD patients’ striatum, P2X7R shows not only an augmented total transcript level but also an alteration of its splicing. Remarkably, P2X7R introns 10 and 11 are more retained in HD patients when compared with controls. Taken together, our data confirm that P2X7R is altered in brains of HD subjects and strengthen the notion that P2X7R may represent a potential therapeutic target for HD.
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Affiliation(s)
- Ivana Ollà
- Centro de Biología Molecular 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid, Spain.,Networking Research Centre on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - María Santos-Galindo
- Centro de Biología Molecular 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid, Spain.,Networking Research Centre on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Ainara Elorza
- Centro de Biología Molecular 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid, Spain.,Networking Research Centre on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - José J Lucas
- Centro de Biología Molecular 'Severo Ochoa' (CBMSO) CSIC/UAM, Madrid, Spain.,Networking Research Centre on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
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16
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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: 66] [Impact Index Per Article: 16.5] [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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Estrada JA, Ducrocq GP, Kim JS, Kaufman MP. Intrathecal injection of brilliant blue G, a P2X7 antagonist, attenuates the exercise pressor reflex in rats. Am J Physiol Regul Integr Comp Physiol 2020; 319:R223-R232. [PMID: 32609538 DOI: 10.1152/ajpregu.00093.2020] [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] [Indexed: 12/11/2022]
Abstract
Purinergic 2X (P2X) receptors on the endings of group III and IV afferents play a role in evoking the exercise pressor reflex. Particular attention has been paid to P2X3 receptors because their blockade in the periphery attenuated this reflex. In contrast, nothing is known about the role played by P2X receptors in the spinal cord in evoking the exercise pressor reflex in rats. P2X7 receptors, in particular, may be especially important in this regard because they are found in abundance on spinal glial cells and may communicate with neurons to effect reflexes controlling cardiovascular function. Consequently, we investigated the role played by spinal P2X7 receptors in evoking the exercise pressor reflex in decerebrated rats. We found that intrathecal injection of the P2X7 antagonist brilliant blue G (BBG) attenuated the exercise pressor reflex (blood pressure index: 294 ± 112 mmHg·s before vs. 7 ± 32 mmHg·s after; P < 0.05). Likewise, intrathecal injection of minocycline, which inhibits microglial cell output, attenuated the reflex. In contrast, intrathecal injection of BBG did not attenuate the pressor response evoked by intracarotid injection of sodium cyanide, a maneuver that stimulated carotid chemoreceptors. Moreover, injections of BBG either into the arterial supply of the contracting hindlimb muscles or into the jugular vein did not attenuate the exercise pressor reflex. Our findings support the hypothesis that P2X7 receptors on microglial cells within the spinal cord play a role in evoking the exercise pressor reflex.
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Affiliation(s)
- Juan A Estrada
- Heart and Vascular Institute, Penn State College of Medicine, Hershey, Pennsylvania
| | - Guillaume P Ducrocq
- Heart and Vascular Institute, Penn State College of Medicine, Hershey, Pennsylvania
| | - Joyce S Kim
- Heart and Vascular Institute, Penn State College of Medicine, Hershey, Pennsylvania
| | - Marc P Kaufman
- Heart and Vascular Institute, Penn State College of Medicine, Hershey, Pennsylvania
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18
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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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Deletion of P2X7 Receptor Decreases Basal Glutathione Level by Changing Glutamate-Glutamine Cycle and Neutral Amino Acid Transporters. Cells 2020; 9:cells9040995. [PMID: 32316268 PMCID: PMC7226967 DOI: 10.3390/cells9040995] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/07/2020] [Accepted: 04/14/2020] [Indexed: 12/24/2022] Open
Abstract
Glutathione (GSH) is an endogenous tripeptide antioxidant that consists of glutamate-cysteine-glycine. GSH content is limited by the availability of glutamate and cysteine. Furthermore, glutamine is involved in the regulation of GSH synthesis via the glutamate–glutamine cycle. P2X7 receptor (P2X7R) is one of the cation-permeable ATP ligand-gated ion channels, which is involved in neuronal excitability, neuroinflammation and astroglial functions. In addition, P2X7R activation decreases glutamate uptake and glutamine synthase (GS) expression/activity. In the present study, we found that P2X7R deletion decreased the basal GSH level without altering GSH synthetic enzyme expressions in the mouse hippocampus. P2X7R deletion also increased expressions of GS and ASCT2 (a glutamine:cysteine exchanger), but diminished the efficacy of N-acetylcysteine (NAC, a GSH precursor) in the GSH level. SIN-1 (500 μM, a generator nitric oxide, superoxide and peroxynitrite), which facilitates the cystine–cysteine shuttle mediated by xCT (a glutamate/cystein:cystine/NAC antiporter), did not affect basal GSH concentration in WT and P2X7R knockout (KO) mice. However, SIN-1 effectively reduced the efficacy of NAC in GSH synthesis in WT mice, but not in P2X7R KO mice. Therefore, our findings indicate that P2X7R may be involved in the maintenance of basal GSH levels by regulating the glutamate–glutamine cycle and neutral amino acid transports under physiological conditions, which may be the defense mechanism against oxidative stress during P2X7R activation.
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20
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Munoz FM, Patel PA, Gao X, Mei Y, Xia J, Gilels S, Hu H. Reactive oxygen species play a role in P2X7 receptor-mediated IL-6 production in spinal astrocytes. Purinergic Signal 2020; 16:97-107. [PMID: 32146607 DOI: 10.1007/s11302-020-09691-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 02/11/2020] [Indexed: 01/29/2023] Open
Abstract
Astrocytes mediate a remarkable variety of cellular functions, including gliotransmitter release. Under pathological conditions, high concentrations of the purinergic receptor agonist adenosine triphosphate (ATP) are released into the extracellular space leading to the activation of the purinergic P2X7 receptor, which in turn can initiate signaling cascades. It is well-established that reactive oxygen species (ROS) increase in macrophages and microglia following P2X7 receptor activation. However, direct evidence that activation of P2X7 receptor leads to ROS production in astrocytes is lacking to date. While it is known that P2X7R activation induces cytokine production, the mechanism involved in this process is unclear. In the present study, we demonstrated that P2X7 receptor activation induced ROS production in spinal astrocytes in a concentration-dependent manner. We also found that P2X7R-mediated ROS production is at least partially through NADPH oxidase. In addition, our ELISA data show that P2X7R-induced IL-6 release was dependent on NADPH oxidase-mediated production of ROS. Collectively, these results reveal that activation of the P2X7 receptor on spinal astrocytes increases ROS production through NADPH oxidase, subsequently leading to IL-6 release. Our results reveal a role of ROS in the P2X7 signaling pathway in mouse spinal cord astrocytes and may indicate a potential mechanism for the astrocytic P2X7 receptor in chronic pain.
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Affiliation(s)
- Frances M Munoz
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Priya A Patel
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Xinghua Gao
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, China
| | - Yixiao Mei
- Department of Anesthesiology, Rutgers New Jersey Medical School, 185 S. Orange Ave., Newark, NJ, 07103, USA
| | - Jingsheng Xia
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Sofia Gilels
- Department of Anesthesiology, Rutgers New Jersey Medical School, 185 S. Orange Ave., Newark, NJ, 07103, USA
| | - Huijuan Hu
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, USA. .,Department of Anesthesiology, Rutgers New Jersey Medical School, 185 S. Orange Ave., Newark, NJ, 07103, USA.
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21
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Abstract
P2X7 is a nonselective cation channel activated by extracellular ATP. P2X7 activation contributes to the proinflammatory response to injury or bacterial invasion and mediates apoptosis. Recently, P2X7 function has been linked to chronic inflammatory and neuropathic pain. P2X7 may contribute to pain modulation both by effects on peripheral tissue injury underlying clinical pain states, and through alterations in central nervous system processing, as suggested by animal models. To further test its role in pain sensitivity, we examined whether variation within the P2RX7 gene, which encodes the P2X7 receptor, was associated with experimentally induced pain in human patients. Experimental pain was assessed in Tromsø 6, a longitudinal and cross-sectional population-based study (N = 3016), and the BrePainGen cohort, consisting of patients who underwent breast cancer surgery (N = 831). For both cohorts, experimental pain intensity and tolerance were assessed with the cold-pressor test. In addition, multisite chronic pain was assessed in Tromsø 6 and pain intensity 1 week after surgery was assessed in BrePainGen. We tested whether the single-nucleotide polymorphism rs7958311, previously implicated in clinical pain, was associated with experimental and clinical pain phenotypes. In addition, we examined effects of single-nucleotide polymorphisms rs208294 and rs208296, for which previous results have been equivocal. Rs7958311 was associated with experimental pain intensity in the meta-analysis of both cohorts. Significant associations were also found for multisite pain and postoperative pain. Our results strengthen the existing evidence and suggest that P2X7 and genetic variation in the P2RX7-gene may be involved in the modulation of human pain sensitivity.
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Arslan G, Avci B, Kocacan SE, Rzayev E, Ayyildiz M, Agar E. The interaction between P2X7Rs and T-type calcium ion channels in penicillin-induced epileptiform activity. Neuropharmacology 2019; 149:1-12. [PMID: 30695710 DOI: 10.1016/j.neuropharm.2019.01.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 01/02/2019] [Accepted: 01/24/2019] [Indexed: 02/06/2023]
Abstract
Limited information exists on the link between purinergic class P2X7 receptors (P2X7Rs) and calcium ion channels in epilepsy; no data has been reported regarding the interaction between P2X7Rs and T-type calcium ion channels in epilepsy. Thus, this study is an evaluation of the role that T-type calcium ion channels play in the effect of P2X7Rs on penicillin-induced epileptiform activity. In the first set of experiments, P2X7R agonist BzATP (at 25-, 50-, 100- and 200-μg doses), P2X7R antagonist A-438079 (at 5-, 10-, 20- and 40-μg doses) and T-type calcium ion channel antagonist, NNC-550396 were administered for electrophysiological analyses 30 min after penicillin injection (2.5 μl, 500 IU). In the second set of experiments, the effective doses of these substances were used for biochemical analyses. Malondialdehyde (MDA), advanced oxidation protein product (AOPP), glutathione (GSH), glutathione reductase (GR), glutathione peroxide (GPx), catalase (CAT) and superoxide dismutase (SOD) levels were measured in the cerebrum, cerebellum and brainstem of rats. BzATP (100 μg, icv) increased the mean frequency of epileptiform activity, whereas A-438079 (40 μg, icv) and NNC-550396 (30 μg, ic) reduced it. Both A-438079 and NNC-550396 reversed BzATP's proconvulsant action. BzATP increased lipid peroxidation and protein oxidation; it also altered other antioxidant enzymes measured in this study, which were all then reversed via A-438079 and NNC-550396, at least in the cerebrum. The electrophysiological and biochemical analysis of present study suggest that P2X7Rs and its interaction with T-type calcium ion channels play an important role in the experimental model of epilepsy.
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Affiliation(s)
- Gokhan Arslan
- Department of Physiology, Medical School, University of Ondokuz Mayis, Samsun, Turkey
| | - Bahattin Avci
- Department of Biochemistry, Medical School, University of Ondokuz Mayis, Samsun, Turkey
| | - Süleyman Emre Kocacan
- Department of Physiology, Medical School, University of Ondokuz Mayis, Samsun, Turkey
| | - Emil Rzayev
- Department of Biochemistry, Medical School, University of Ondokuz Mayis, Samsun, Turkey
| | - Mustafa Ayyildiz
- Department of Physiology, Medical School, University of Ondokuz Mayis, Samsun, Turkey
| | - Erdal Agar
- Department of Physiology, Medical School, University of Ondokuz Mayis, Samsun, Turkey.
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Miras-Portugal MT, Queipo MJ, Gil-Redondo JC, Ortega F, Gómez-Villafuertes R, Gualix J, Delicado EG, Pérez-Sen R. P2 receptor interaction and signalling cascades in neuroprotection. Brain Res Bull 2018; 151:74-83. [PMID: 30593879 DOI: 10.1016/j.brainresbull.2018.12.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/27/2018] [Accepted: 12/19/2018] [Indexed: 02/08/2023]
Abstract
Nucleotides can contribute to the survival of different glial and neuronal models at the nervous system via activation of purinergic P2X and P2Y receptors. Their activation counteracts different proapoptotic events, such as excitotoxicity, mitochondrial impairment, oxidative stress and DNA damage, which concur to elicit cell loss in different processes of neurodegeneration and brain injury. Thus, it is frequent to find that different neuroprotective mediators converge in the activation of the same intracellular survival pathways to protect cells from death. The present review focuses on the role of P2Y1 and P2Y13 metabotropic receptors, and P2X7 ionotropic receptors to regulate the balance between survival and apoptosis. In particular, we analyze the intracellular pathways involved in the signaling of these nucleotide receptors to elicit survival, including calcium/PLC, PI3K/Akt/GSK3, MAPK cascades, and the expression of antioxidant and antiapoptotic genes. This review emphasizes the novel contribution of nucleotide receptors to maintain cell homeostasis through the regulation of MAP kinases and phosphatases. Unraveling the different roles found for nucleotide receptors in different models and cellular contexts may be crucial to delineate future therapeutic applications based on targeting nucleotide receptors for neuroprotection.
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Affiliation(s)
- Mª Teresa Miras-Portugal
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Instituto Universitario de Investigación en Neuroquímica (IUIN), Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdiSSC), Universidad Complutense Madrid, 28040 Madrid, Spain
| | - Mª José Queipo
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Instituto Universitario de Investigación en Neuroquímica (IUIN), Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdiSSC), Universidad Complutense Madrid, 28040 Madrid, Spain
| | - Juan Carlos Gil-Redondo
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Instituto Universitario de Investigación en Neuroquímica (IUIN), Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdiSSC), Universidad Complutense Madrid, 28040 Madrid, Spain
| | - Felipe Ortega
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Instituto Universitario de Investigación en Neuroquímica (IUIN), Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdiSSC), Universidad Complutense Madrid, 28040 Madrid, Spain
| | - Rosa Gómez-Villafuertes
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Instituto Universitario de Investigación en Neuroquímica (IUIN), Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdiSSC), Universidad Complutense Madrid, 28040 Madrid, Spain
| | - Javier Gualix
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Instituto Universitario de Investigación en Neuroquímica (IUIN), Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdiSSC), Universidad Complutense Madrid, 28040 Madrid, Spain
| | - Esmerilda G Delicado
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Instituto Universitario de Investigación en Neuroquímica (IUIN), Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdiSSC), Universidad Complutense Madrid, 28040 Madrid, Spain.
| | - Raquel Pérez-Sen
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Instituto Universitario de Investigación en Neuroquímica (IUIN), Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdiSSC), Universidad Complutense Madrid, 28040 Madrid, Spain.
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24
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Koole M, Schmidt ME, Hijzen A, Ravenstijn P, Vandermeulen C, Van Weehaeghe D, Serdons K, Celen S, Bormans G, Ceusters M, Zhang W, Van Nueten L, Kolb H, de Hoon J, Van Laere K. 18F-JNJ-64413739, a Novel PET Ligand for the P2X7 Ion Channel: Radiation Dosimetry, Kinetic Modeling, Test-Retest Variability, and Occupancy of the P2X7 Antagonist JNJ-54175446. J Nucl Med 2018; 60:683-690. [PMID: 30262518 DOI: 10.2967/jnumed.118.216747] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 09/18/2018] [Indexed: 12/27/2022] Open
Abstract
The P2X7 receptor (P2X7R) is an adenosine triphosphate-gated ion channel that is predominantly expressed on microglial cells in the central nervous system. We report the clinical qualification of P2X7-specific PET ligand 18F-JNJ-64413739 in healthy volunteers, including dosimetry, kinetic modeling, test-retest variability, and blocking by the P2X7 antagonist JNJ-54175446. Methods: Whole-body dosimetry was performed in 3 healthy male subjects by consecutive whole-body PET/CT scanning, estimation of the normalized cumulated activity, and calculation of the effective dose using OLINDA (v1.1). Next, 5 healthy male subjects underwent a 120-min dynamic 18F-JNJ-64413739 PET/MRI scan with arterial blood sampling to determine the appropriate kinetic model. For this purpose, 1- and 2-tissue compartment models and Logan graphic analysis (LGA) were evaluated for estimating regional volumes of distribution (VT). PET/MRI scanning was repeated in 4 of these subjects to evaluate medium-term test-retest variability (interscan interval, 26-97 d). For the single-dose occupancy study, 8 healthy male subjects underwent baseline and postdose 18F-JNJ-64413739 PET/MRI scans 4-6 h after the administration of a single oral dose of JNJ-54175446 (dose range, 5-300 mg). P2X7 occupancies were estimated using a Lassen plot and regional baseline and postdose VT Results: The average (mean ± SD) effective dose was 22.0 ± 1.0 μSv/MBq. The 2-tissue compartment model was the most appropriate kinetic model, with LGA showing very similar results. Regional 2-tissue compartment model VT values were about 3 and were rather homogeneous across all brain regions, with slightly higher estimates for the thalamus, striatum, and brain stem. Between-subject VT variability was relatively high, with cortical VT showing an approximate 3-fold range across subjects. As for time stability, the acquisition time could be reduced to 90 min. The average regional test-retest variability values were 10.7% ± 2.2% for 2-tissue compartment model VT and 11.9% ± 2.2% for LGA VT P2X7 occupancy approached saturation for single doses of JNJ-54175446 higher than 50 mg, and no reference region could be identified. Conclusion: 18F-JNJ-64413739 is a suitable PET ligand for the quantification of P2X7R expression in the human brain. It can be used to provide insight into P2X7R expression in health and disease, to evaluate target engagement by P2X7 antagonists, and to guide dose selection.
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Affiliation(s)
- Michel Koole
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium.,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | | | - Anja Hijzen
- Janssen Research and Development, Beerse, Belgium
| | | | - Corinne Vandermeulen
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium; and
| | - Donatienne Van Weehaeghe
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium
| | - Kim Serdons
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium
| | - Sofie Celen
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, KU Leuven, Leuven, Belgium
| | | | - Wei Zhang
- Janssen Research and Development, Beerse, Belgium
| | | | | | - Jan de Hoon
- Center for Clinical Pharmacology, University Hospitals Leuven, Leuven, Belgium; and
| | - Koen Van Laere
- Division of Nuclear Medicine and Molecular Imaging, University Hospitals Leuven, Leuven, Belgium .,Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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25
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Abstract
Due to strong electrical coupling, syncytial isopotentiality emerges as a physiological mechanism that coordinates astrocytes into a highly efficient system in brain homeostasis. Although this electrophysiological phenomenon has now been observed in astrocyte networks established by different astrocyte subtypes, the spinal cord remains a brain region that is still unexplored. In ALDH1L1-eGFP transgenic mice, astrocytes can be visualized by confocal microscopy and the spinal cord astrocytes in grey matter are organized in a distinctive pattern. Namely, each astrocyte resides with more directly coupled neighbors at shorter interastrocytic distances compared to protoplasmic astrocytes in the hippocampal CA1 region. In whole-cell patch clamp recording, the spinal cord grey matter astrocytes exhibit passive K+ conductance and a highly hyperpolarized membrane potential of −80 mV. To answer whether syncytial isopotentiality is a shared feature of astrocyte networks in the spinal cord, the K+ content in a physiological recording solution was substituted by equimolar Na+ for whole-cell recording in spinal cord slices. In uncoupled single astrocytes, this substitution of endogenous K+ with Na+ is known to depolarize astrocytes to around 0 mV as predicted by Goldman–Hodgkin–Katz (GHK) equation. In contrast, the existence of syncytial isopotentiality is indicated by a disobedience of the GHK predication as the recorded astrocyte’s membrane potential remains at a quasi-physiological level that is comparable to its neighbors due to strong electrical coupling. We showed that the strength of syncytial isopotentiality in spinal cord grey matter is significantly stronger than that of astrocyte network in the hippocampal CA1 region. Thus, this study corroborates the notion that syncytial isopotentiality most likely represents a system-wide electrical feature of astrocytic networks throughout the brain.
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26
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P2X7 Receptors Mediate CO-Induced Alterations in Gene Expression in Cultured Cortical Astrocytes—Transcriptomic Study. Mol Neurobiol 2018; 56:3159-3174. [DOI: 10.1007/s12035-018-1302-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 08/06/2018] [Indexed: 01/31/2023]
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27
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Khan MT, Deussing J, Tang Y, Illes P. Astrocytic rather than neuronal P2X7 receptors modulate the function of the tri-synaptic network in the rodent hippocampus. Brain Res Bull 2018; 151:164-173. [PMID: 30098388 DOI: 10.1016/j.brainresbull.2018.07.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/21/2018] [Accepted: 07/25/2018] [Indexed: 12/12/2022]
Abstract
Whole-cell patch clamp recordings demonstrated that in the dentate gyrus (DG) as well as in the CA3 area of mouse hippocampal slices the prototypic P2X7 receptor (R) agonist dibenzoyl-ATP (Bz-ATP) induced inward current responses both in neurons and astrocytes. Whereas the selective P2X7R antagonist A438079 strongly inhibited both neuronal and astrocytic currents, a combination of ionotropic glutamate receptor (CNQX, AP-5) and GABAA-R (gabazine) antagonists depressed the Bz-ATP-induced current responses in the DG (granule cells) and CA3 neurons only. It was concluded that Bz-ATP activated astrocytic P2X7Rs and thereby released glutamate and GABA to stimulate nearby neurons. The residual A438079-resistant current response of astrocytes was suggested to be due to the stimulation of P2XRs of the non-P2X7-type. Further, we searched for presynaptic P2X7Rs at the axon terminals of DG and CA3 pyramidal neurons innervating CA3 and CA1 cells, respectively. Bz-ATP potentiated the frequency of spontaneous postsynaptic currents (sPSCs) in CA1 but not CA3 pyramidal cells. However, the Bz-ATP effect in CA1 cells was inhibited by gabazine or the astrocytic toxin fluorocitrate suggesting stimulation of P2X7Rs at stratum radiatum astrocytes located near to interneurons and synapsing onto CA1 neurons. Our data suggest that functional P2X7Rs are missing at neurons in the tri-synaptic network of the rodent hippocampus, but are present at nearby astrocytes indirectly regulating network activity.
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Affiliation(s)
- Muhammad Tahir Khan
- Rudolf-Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany
| | - Jan Deussing
- Department of Molecular Neurogenetics, Max-Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Peter Illes
- Rudolf-Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany; Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China.
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28
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Grace PM, Strand KA, Galer EL, Rice KC, Maier SF, Watkins LR. Protraction of neuropathic pain by morphine is mediated by spinal damage associated molecular patterns (DAMPs) in male rats. Brain Behav Immun 2018; 72:45-50. [PMID: 28860068 PMCID: PMC5832500 DOI: 10.1016/j.bbi.2017.08.018] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 08/28/2017] [Indexed: 11/27/2022] Open
Abstract
We have recently reported that a short course of morphine, starting 10days after sciatic chronic constriction injury (CCI), prolonged the duration of mechanical allodynia for months after morphine ceased. Maintenance of this morphine-induced persistent sensitization was dependent on spinal NOD-like receptor protein 3 (NLRP3) inflammasomes-protein complexes that proteolytically activate interleukin-1β (IL-1β) via caspase-1. However, it is still unclear how NLRP3 inflammasome signaling is maintained long after morphine is cleared. Here, we demonstrate that spinal levels of the damage associated molecular patterns (DAMPs) high mobility group box 1 (HMGB1) and biglycan are elevated during morphine-induced persistent sensitization in male rats; that is, 5weeks after cessation of morphine dosing. We also show that HMGB1 and biglycan levels are at least partly dependent on the initial activation of caspase-1, as well as Toll like receptor 4 (TLR4) and the purinergic receptor P2X7R-receptors responsible for priming and activation of NLRP3 inflammasomes. Finally, pharmacological attenuation of the DAMPs HMGB1, biglycan, heat shock protein 90 and fibronectin persistently reversed morphine-prolonged allodynia. We conclude that after peripheral nerve injury, morphine treatment results in persistent DAMP release via TLR4, P2X7R and caspase-1, which are involved in formation/activation of NLRP3 inflammasomes. These DAMPs are responsible for maintaining persistent allodynia, which may be due to engagement of a positive feedback loop, in which NLRP3 inflammasomes are persistently activated by DAMPs signaling at TLR4 and P2X7R.
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Affiliation(s)
- Peter M. Grace
- Department of Psychology and Neuroscience, and The Center for Neuroscience, University of Colorado, Boulder, CO, USA,Discipline of Pharmacology, School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - Keith A. Strand
- Department of Psychology and Neuroscience, and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Erika L. Galer
- Department of Psychology and Neuroscience, and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Kenner C. Rice
- Drug Design and Synthesis Section, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA
| | - Steven F. Maier
- Department of Psychology and Neuroscience, and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
| | - Linda R. Watkins
- Department of Psychology and Neuroscience, and The Center for Neuroscience, University of Colorado, Boulder, CO, USA
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29
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Merighi A. The histology, physiology, neurochemistry and circuitry of the substantia gelatinosa Rolandi (lamina II) in mammalian spinal cord. Prog Neurobiol 2018; 169:91-134. [PMID: 29981393 DOI: 10.1016/j.pneurobio.2018.06.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 06/07/2018] [Accepted: 06/30/2018] [Indexed: 02/06/2023]
Abstract
The substantia gelatinosa Rolandi (SGR) was first described about two centuries ago. In the following decades an enormous amount of information has permitted us to understand - at least in part - its role in the initial processing of pain and itch. Here, I will first provide a comprehensive picture of the histology, physiology, and neurochemistry of the normal SGR. Then, I will analytically discuss the SGR circuits that have been directly demonstrated or deductively envisaged in the course of the intensive research on this area of the spinal cord, with particular emphasis on the pathways connecting the primary afferent fibers and the intrinsic neurons. The perspective existence of neurochemically-defined sets of primary afferent neurons giving rise to these circuits will be also discussed, with the proposition that a cross-talk between different subsets of peptidergic fibers may be the structural and functional substrate of additional gating mechanisms in SGR. Finally, I highlight the role played by slow acting high molecular weight modulators in these gating mechanisms.
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Affiliation(s)
- Adalberto Merighi
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, I-10095 Grugliasco (TO), Italy.
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Towards a Novel Class of Multitarget-Directed Ligands: Dual P2X7-NMDA Receptor Antagonists. Molecules 2018; 23:molecules23010230. [PMID: 29361735 PMCID: PMC6017257 DOI: 10.3390/molecules23010230] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 01/15/2018] [Accepted: 01/16/2018] [Indexed: 01/09/2023] Open
Abstract
Multi-target-directed ligands (MTDLs) offer new hope for the treatment of multifactorial complex diseases such as Alzheimer's Disease (AD). Herein, we present compounds aimed at targeting the NMDA and the P2X7 receptors, which embody a different approach to AD therapy. On one hand, we are seeking to delay neurodegeneration targeting the glutamatergic NMDA receptors; on the other hand, we also aim to reduce neuroinflammation, targeting P2X7 receptors. Although the NMDA receptor is a widely recognized therapeutic target in treating AD, the P2X7 receptor remains largely unexplored for this purpose; therefore, the dual inhibitor presented herein-which is open to further optimization-represents the first member of a new class of MTDLs.
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31
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Site-Specific Regulation of P2X7 Receptor Function in Microglia Gates Morphine Analgesic Tolerance. J Neurosci 2017; 37:10154-10172. [PMID: 28924009 DOI: 10.1523/jneurosci.0852-17.2017] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 09/03/2017] [Indexed: 01/12/2023] Open
Abstract
Tolerance to the analgesic effects of opioids is a major problem in chronic pain management. Microglia are implicated in opioid tolerance, but the core mechanisms regulating their response to opioids remain obscure. By selectively ablating microglia in the spinal cord using a saporin-conjugated antibody to Mac1, we demonstrate a causal role for microglia in the development, but not maintenance, of morphine tolerance in male rats. Increased P2X7 receptor (P2X7R) activity is a cardinal feature of microglial activation, and in this study we found that morphine potentiates P2X7R-mediated Ca2+ responses in resident spinal microglia acutely isolated from morphine tolerant rats. The increased P2X7R function was blocked in cultured microglia by PP2, a Src family protein tyrosine kinase inhibitor. We identified Src family kinase activation mediated by μ-receptors as a key mechanistic step required for morphine potentiation of P2X7R function. Furthermore, we show by site-directed mutagenesis that tyrosine (Y382-384) within the P2X7R C-terminus is differentially modulated by repeated morphine treatment and has no bearing on normal P2X7R function. Intrathecal administration of a palmitoylated peptide corresponding to the Y382-384 site suppressed morphine-induced microglial reactivity and preserved the antinociceptive effects of morphine in male rats. Thus, site-specific regulation of P2X7R function mediated by Y382-384 is a novel cellular determinant of the microglial response to morphine that critically underlies the development of morphine analgesic tolerance.SIGNIFICANCE STATEMENT Controlling pain is one of the most difficult challenges in medicine and its management is a requirement of a large diversity of illnesses. Although morphine and other opioids offer dramatic and impressive relief of pain, their impact is truncated by loss of efficacy (analgesic tolerance). Understanding why this occurs and how to prevent it are of critical importance in improving pain therapies. We uncovered a novel site (Y382-384) within the P2X7 receptor that can be targeted to blunt the development of morphine analgesic tolerance, without affecting normal P2X7 receptor function. Our findings provide a critical missing mechanistic piece, site-specific modulation by Y382-384, that unifies P2X7R function to the activation of spinal microglia and the development of morphine tolerance.
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32
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Neuronal P2X7 Receptors Revisited: Do They Really Exist? J Neurosci 2017; 37:7049-7062. [PMID: 28747388 DOI: 10.1523/jneurosci.3103-16.2017] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/22/2017] [Accepted: 05/24/2017] [Indexed: 12/13/2022] Open
Abstract
P2X7 receptors (Rs) constitute a subclass of ATP-sensitive ionotropic receptors (P2X1-P2X7). P2X7Rs have many distinguishing features, mostly based on their long intracellular C terminus regulating trafficking to the cell membrane, protein-protein interactions, and post-translational modification. Their C-terminal tail is especially important in enabling the transition from the nonselective ion channel mode to a membrane pore allowing the passage of large molecules. There is an ongoing dispute on the existence of neuronal P2X7Rs with consequences for our knowledge on their involvement in neuroinflammation, aggravating stroke, temporal lobe epilepsy, neuropathic pain, and various neurodegenerative diseases. Whereas early results appeared to support the operation of P2X7Rs at neurons, more recently glial P2X7Rs are increasingly considered as indirect causes of neuronal effects. Specific tools for P2X7Rs are of limited value because of the poor selectivity of agonists, and the inherent failure of antibodies to differentiate between the large number of active and inactive splice variants, or gain-of-function and loss-of-function small nucleotide polymorphisms of the receptor. Unfortunately, the available P2RX7 knock-out mice generated by pharmaceutical companies possess certain splice variants, which evade inactivation. In view of the recently discovered bidirectional dialogue between astrocytes and neurons (and even microglia and neurons), we offer an alternative explanation for previous data, which assumedly support the existence of P2X7Rs at neurons. We think that the unbiased reader will follow our argumentation on astrocytic or microglial P2X7Rs being the primary targets of pathologically high extracellular ATP concentrations, although a neuronal localization of these receptors cannot be fully excluded either.
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Neuronal P2X7 Receptor: Involvement in Neuronal Physiology and Pathology. J Neurosci 2017; 37:7063-7072. [PMID: 28747389 DOI: 10.1523/jneurosci.3104-16.2017] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/12/2017] [Accepted: 05/16/2017] [Indexed: 12/28/2022] Open
Abstract
The proposed presence of P2X7 receptor (P2X7R) in neurons has been the source of some contention. Initial studies suggested an absence of P2X7R mRNA in neurons, and the apparent nonspecificity of the antibodies used to identify P2X7R raised further doubts. However, subsequent studies using new pharmacological and biomolecular tools provided conclusive evidence supporting the existence of functional P2X7Rs in neurons. The P2X7 receptor has since been shown to play a leading role in multiple aspects of neuronal physiology, including axonal elongation and branching and neurotransmitter release. P2X7R has also been implicated in neuronal pathologies, in which it may influence neuronal survival. Together, this body of research suggests that P2X7R may constitute an important therapeutic target for a variety of neurological disorders.
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34
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Abstract
This study was aimed at exploring the effects of P2X7 receptor on BV2 microglia cell injury induced by glycoprotein gp120 (gp120) and its underlying mechanisms. We used the MTS method to study the influence of different gp120 concentrations on BV2 microglia cells, and to test the degree of cell injury in each gp120 treatment group; quantitative real-time PCR (qPCR) and Western blot were used to detect the P2X7 mRNA and receptor protein expressions. Immunocytochemistry and Western blot were used to detect the P2X7 receptor expression and P65 NF-κB, respectively. We also measured the content of TNFα, IL-1β, nitric oxide (NO) and reactive oxygen species (ROS). We found that the cell survival rate generally decreased as gp120 concentration increased, and the cell survival rate of the gp120 + Brilliant Blue G (BBG) group was higher than that of the gp120 group. Western blot and qPCR results showed that the expressions of P2X7 receptor protein and mRNA were positively dose-dependent with gp120 concentration; the results of immunocytochemistry and Western blot showed that the expressions of P2X7 receptor and P65 NF-κB in the gp120 group increased significantly compared to those of the control (Ctrl) group, but those in the gp120+BBG group decreased. Taken together, these results confirmed that the P2X7 receptor is involved in gp120-induced BV2 microglial cell injury and that the underlying mechanism may be associated with the over-activation of microglia caused by P2X7 receptor up-regulation, which leads to abundant release of inflammatory factors which exert toxic effects on the cells.
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Gao P, Ding X, Khan TM, Rong W, Franke H, Illes P. P2X7 receptor-sensitivity of astrocytes and neurons in the substantia gelatinosa of organotypic spinal cord slices of the mouse depends on the length of the culture period. Neuroscience 2017; 349:195-207. [PMID: 28237817 DOI: 10.1016/j.neuroscience.2017.02.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 02/14/2017] [Accepted: 02/15/2017] [Indexed: 02/08/2023]
Abstract
The whole-cell patch-clamp technique was used to record current responses to AMPA, N-methyl-d-aspartate (NMDA), muscimol and dibenzoyl-ATP (Bz-ATP) in superficial (reactive/gliotic) substantia gelatinosa (SG) astrocytes and neurons of spinal cord slices kept for different periods of time in organotypic culture. Currents induced by AMPA, NMDA and muscimol confirmed the existence of their specific receptors in 2-week-old neurons; astrocytes cultured for the same period of time responded to AMPA and muscimol, but not to NMDA. AMPA had a larger effect on 2-week-old astrocytes than on the 1-week-old ones, in spite of a similar sensitivity of the age-matched neurons to this amino acid. The effect of the prototypic P2X7 receptor agonist Bz-ATP on superficial astrocytes and neurons depended on the drug concentration applied and increased in parallel with the lengthening of the culture period. The amplitudes of Bz-ATP currents of deep (resting) astrocytes were age-independent. Neurons located in deep layers exhibited after 1week of culturing much larger Bz-ATP currents than the superficial ones of the same age. In conclusion, whereas resting astrocytes had culture period-independent P2X7 receptor-sensitivity, reactive/gliotic astrocytes exhibited P2X7 receptor-sensitivity increasing in parallel with the prolongation of the time spent in culture. The results with Bz-ATP agree with the facilitation of AMPA-induced currents in reactive astrocytes during development, and with the hypothesis that extracellular ATP is an ontogenetically early transmitter/signaling molecule in the CNS.
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Affiliation(s)
- Po Gao
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, 04107 Leipzig, Germany; Department of Physiology, Shanghai Jiaotong University School of Medicine, 200025 Shanghai, China
| | - Xiaowei Ding
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, 04107 Leipzig, Germany; Department of Physiology, Shanghai Jiaotong University School of Medicine, 200025 Shanghai, China
| | - Tahir Muhammad Khan
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, 04107 Leipzig, Germany
| | - Weifang Rong
- Department of Physiology, Shanghai Jiaotong University School of Medicine, 200025 Shanghai, China
| | - Heike Franke
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, 04107 Leipzig, Germany
| | - Peter Illes
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, 04107 Leipzig, Germany.
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36
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Freitas HR, Reis RADM. Glutathione induces GABA release through P2X 7R activation on Müller glia. NEUROGENESIS 2017; 4:e1283188. [PMID: 28229088 DOI: 10.1080/23262133.2017.1283188] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/25/2016] [Accepted: 01/10/2017] [Indexed: 01/04/2023]
Abstract
The retinal tissue of warm-blooded vertebrates performs surprisingly complex and accurate transduction of visual information. To achieve precision, a multilayered neuroglia structure is established throughout the embryonic development, and the presence of radial Müller (glial) cells ensure differentiation, growth and survival for the neuronal elements within retinal environment. It is assumed that Müller cells serve as a dynamic reservoir of progenitors, capable of expressing transcription factors, differentiating and proliferating as either neuronal or glial cells depending on extrinsic cues. In the postnatal period, Müller glia may re-enter cell cycle and produce new retinal neurons in response to acute damage. In this context, glutathione (GSH), a virtually ubiquitous tripeptide antioxidant, which is found at milimolar concentrations in central glial cells, plays a vital role as a reducing agent, buffering radical oxygen species (ROS) and preventing cell death in severely injured retinal tissues. Despite its antioxidant role, data also point to GSH as a signaling agent, suggesting that GABA release and P2X7R-mediated calcium inwards occur in Müller cells in a GSH-enriched environment. These phenomena indicate a novel mechanistic response to damage in the vertebrate retinal tissue, particularly in neuron-glia networks.
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Affiliation(s)
- Hércules Rezende Freitas
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro, Brazil
| | - Ricardo A de Melo Reis
- Laboratório de Neuroquímica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro , Rio de Janeiro, Brazil
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37
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Kronschläger MT, Drdla-Schutting R, Gassner M, Honsek SD, Teuchmann HL, Sandkühler J. Gliogenic LTP spreads widely in nociceptive pathways. Science 2016; 354:1144-1148. [PMID: 27934764 PMCID: PMC6145441 DOI: 10.1126/science.aah5715] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 11/01/2016] [Indexed: 12/30/2022]
Abstract
Learning and memory formation involve long-term potentiation (LTP) of synaptic strength. A fundamental feature of LTP induction in the brain is the need for coincident pre- and postsynaptic activity. This restricts LTP expression to activated synapses only (homosynaptic LTP) and leads to its input specificity. In the spinal cord, we discovered a fundamentally different form of LTP that is induced by glial cell activation and mediated by diffusible, extracellular messengers, including d-serine and tumor necrosis factor (TNF), and that travel long distances via the cerebrospinal fluid, thereby affecting susceptible synapses at remote sites. The properties of this gliogenic LTP resolve unexplained findings of memory traces in nociceptive pathways and may underlie forms of widespread pain hypersensitivity.
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Affiliation(s)
- M T Kronschläger
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - R Drdla-Schutting
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - M Gassner
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - S D Honsek
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - H L Teuchmann
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - J Sandkühler
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
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38
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Koványi B, Csölle C, Calovi S, Hanuska A, Kató E, Köles L, Bhattacharya A, Haller J, Sperlágh B. The role of P2X7 receptors in a rodent PCP-induced schizophrenia model. Sci Rep 2016; 6:36680. [PMID: 27824163 PMCID: PMC5099752 DOI: 10.1038/srep36680] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 10/18/2016] [Indexed: 02/07/2023] Open
Abstract
P2X7 receptors (P2X7Rs) are ligand-gated ion channels sensitive to extracellular ATP. Here we examined for the first time the role of P2X7R in an animal model of schizophrenia. Using the PCP induced schizophrenia model we show that both genetic deletion and pharmacological inhibition of P2X7Rs alleviate schizophrenia-like behavioral alterations. In P2rx7+/+ mice, PCP induced hyperlocomotion, stereotype behavior, ataxia and social withdrawal. In P2X7 receptor deficient mice (P2rx7−/−), the social interactions were increased, whereas the PCP induced hyperlocomotion and stereotype behavior were alleviated. The selective P2X7 receptor antagonist JNJ-47965567 partly replicated the effect of gene deficiency on PCP-induced behavioral changes and counteracted PCP-induced social withdrawal. We also show that PCP treatment upregulates and increases the functional responsiveness of P2X7Rs in the prefrontal cortex of young adult animals. The amplitude of NMDA evoked currents recorded from layer V pyramidal neurons of cortical slices were slightly decreased by both genetic deletion of P2rx7 and by JNJ-47965567. PCP induced alterations in mRNA expression encoding schizophrenia-related genes, such as NR2A, NR2B, neuregulin 1, NR1 and GABA α1 subunit were absent in the PFC of young adult P2rx7−/− animals. Our findings point to P2X7R as a potential therapeutic target in schizophrenia.
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Affiliation(s)
- Bence Koványi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences (IEM HAS), H-1450 Budapest, Hungary.,János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, Hungary
| | - Cecilia Csölle
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences (IEM HAS), H-1450 Budapest, Hungary
| | - Stefano Calovi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences (IEM HAS), H-1450 Budapest, Hungary
| | - Adrienn Hanuska
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, H-1089 Budapest, Hungary
| | - Erzsébet Kató
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, H-1089 Budapest, Hungary
| | - László Köles
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, H-1089 Budapest, Hungary
| | | | - József Haller
- Department of Behavioral Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences (IEM HAS), H-1450, Budapest, Hungary
| | - Beáta Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences (IEM HAS), H-1450 Budapest, Hungary
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Morphine paradoxically prolongs neuropathic pain in rats by amplifying spinal NLRP3 inflammasome activation. Proc Natl Acad Sci U S A 2016; 113:E3441-50. [PMID: 27247388 DOI: 10.1073/pnas.1602070113] [Citation(s) in RCA: 258] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Opioid use for pain management has dramatically increased, with little assessment of potential pathophysiological consequences for the primary pain condition. Here, a short course of morphine, starting 10 d after injury in male rats, paradoxically and remarkably doubled the duration of chronic constriction injury (CCI)-allodynia, months after morphine ceased. No such effect of opioids on neuropathic pain has previously been reported. Using pharmacologic and genetic approaches, we discovered that the initiation and maintenance of this multimonth prolongation of neuropathic pain was mediated by a previously unidentified mechanism for spinal cord and pain-namely, morphine-induced spinal NOD-like receptor protein 3 (NLRP3) inflammasomes and associated release of interleukin-1β (IL-1β). As spinal dorsal horn microglia expressed this signaling platform, these cells were selectively inhibited in vivo after transfection with a novel Designer Receptor Exclusively Activated by Designer Drugs (DREADD). Multiday treatment with the DREADD-specific ligand clozapine-N-oxide prevented and enduringly reversed morphine-induced persistent sensitization for weeks to months after cessation of clozapine-N-oxide. These data demonstrate both the critical importance of microglia and that maintenance of chronic pain created by early exposure to opioids can be disrupted, resetting pain to normal. These data also provide strong support for the recent "two-hit hypothesis" of microglial priming, leading to exaggerated reactivity after the second challenge, documented here in the context of nerve injury followed by morphine. This study predicts that prolonged pain is an unrealized and clinically concerning consequence of the abundant use of opioids in chronic pain.
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40
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Marignier R, Ruiz A, Cavagna S, Nicole A, Watrin C, Touret M, Parrot S, Malleret G, Peyron C, Benetollo C, Auvergnon N, Vukusic S, Giraudon P. Neuromyelitis optica study model based on chronic infusion of autoantibodies in rat cerebrospinal fluid. J Neuroinflammation 2016; 13:111. [PMID: 27193196 PMCID: PMC4872335 DOI: 10.1186/s12974-016-0577-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/10/2016] [Indexed: 11/19/2022] Open
Abstract
Background Devic’s neuromyelitis optica (NMO) is an autoimmune astrocytopathy, associated with central nervous system inflammation, demyelination, and neuronal injury. Several studies confirmed that autoantibodies directed against aquaporin-4 (AQP4-IgG) are relevant in the pathogenesis of NMO, mainly through complement-dependent toxicity leading to astrocyte death. However, the effect of the autoantibody per se and the exact role of intrathecal AQP4-IgG are still controversial. Methods To explore the intrinsic effect of intrathecal AQP4-IgG, independent from additional inflammatory effector mechanisms, and to evaluate its clinical impact, we developed a new animal model, based on a prolonged infusion of purified immunoglobulins from NMO patient (IgGAQP4+, NMO-rat) and healthy individual as control (Control-rat) in the cerebrospinal fluid (CSF) of live rats. Results We showed that CSF infusion of purified immunoglobulins led to diffusion in the brain, spinal cord, and optic nerves, the targeted structures in NMO. This was associated with astrocyte alteration in NMO-rats characterized by loss of aquaporin-4 expression in the spinal cord and the optic nerves compared to the Control-rats (p = 0.001 and p = 0.02, respectively). In addition, glutamate uptake tested on vigil rats was dramatically reduced in NMO-rats (p = 0.001) suggesting that astrocytopathy occurred in response to AQP4-IgG diffusion. In parallel, myelin was altered, as shown by the decrease of myelin basic protein staining by up to 46 and 22 % in the gray and white matter of the NMO-rats spinal cord, respectively (p = 0.03). Loss of neurofilament positive axons in NMO-rats (p = 0.003) revealed alteration of axonal integrity. Then, we investigated the clinical consequences of such alterations on the motor behavior of the NMO-rats. In a rotarod test, NMO-rats performance was lower compared to the controls (p = 0.0182). AQP4 expression, and myelin and axonal integrity were preserved in AQP4-IgG-depleted condition. We did not find a major immune cell infiltration and microglial activation nor complement deposition in the central nervous system, in our model. Conclusions We establish a link between motor-deficit, NMO-like lesions and astrocytopathy mediated by intrathecal AQP4-IgG. Our study validates the concept of the intrinsic effect of autoantibody against surface antigens and offers a model for testing antibody and astrocyte-targeted therapies in NMO. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0577-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- R Marignier
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France. .,Université Lyon 1, Université de Lyon, Lyon, France. .,Service de Neurologie A, Eugène Devic EDMUS Foundation Against Multiple Sclerosis, Observatoire Français de la Sclérose en Plaques, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, 59 Boulevard Pinel, 69677, Lyon-Bron cedex, France.
| | - A Ruiz
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - S Cavagna
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - A Nicole
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France
| | - C Watrin
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - M Touret
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - S Parrot
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - G Malleret
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - C Peyron
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - C Benetollo
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - N Auvergnon
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
| | - S Vukusic
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France.,Service de Neurologie A, Eugène Devic EDMUS Foundation Against Multiple Sclerosis, Observatoire Français de la Sclérose en Plaques, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, 59 Boulevard Pinel, 69677, Lyon-Bron cedex, France
| | - P Giraudon
- INSERM U1028, CNRS UMR 5292, Center for Research in Neuroscience of Lyon, Lyon, France.,Université Lyon 1, Université de Lyon, Lyon, France
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Mittal R, Chan B, Grati M, Mittal J, Patel K, Debs LH, Patel AP, Yan D, Chapagain P, Liu XZ. Molecular Structure and Regulation of P2X Receptors With a Special Emphasis on the Role of P2X2 in the Auditory System. J Cell Physiol 2015; 231:1656-70. [PMID: 26627116 DOI: 10.1002/jcp.25274] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 12/01/2015] [Indexed: 12/23/2022]
Abstract
The P2X purinergic receptors are cation-selective channels gated by extracellular adenosine 5'-triphosphate (ATP). These purinergic receptors are found in virtually all mammalian cell types and facilitate a number of important physiological processes. Within the past few years, the characterization of crystal structures of the zebrafish P2X4 receptor in its closed and open states has provided critical insights into the mechanisms of ligand binding and channel activation. Understanding of this gating mechanism has facilitated to design and interpret new modeling and structure-function experiments to better elucidate how different agonists and antagonists can affect the receptor with differing levels of potency. This review summarizes the current knowledge on the structure, activation, allosteric modulators, function, and location of the different P2X receptors. Moreover, an emphasis on the P2X2 receptors has been placed in respect to its role in the auditory system. In particular, the discovery of three missense mutations in P2X2 receptors could become important areas of study in the field of gene therapy to treat progressive and noise-induced hearing loss. J. Cell. Physiol. 231: 1656-1670, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Brandon Chan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - M'hamed Grati
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Jeenu Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Kunal Patel
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Luca H Debs
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Amit P Patel
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Prem Chapagain
- Department of Physics, Florida International University, Miami, Florida.,Biomolecular Science Institute, Florida International University, Miami, Florida
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida.,Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida.,Department of Biochemistry, University of Miami Miller School of Medicine, Miami, Florida
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42
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Köles L, Kató E, Hanuska A, Zádori ZS, Al-Khrasani M, Zelles T, Rubini P, Illes P. Modulation of excitatory neurotransmission by neuronal/glial signalling molecules: interplay between purinergic and glutamatergic systems. Purinergic Signal 2015; 12:1-24. [PMID: 26542977 DOI: 10.1007/s11302-015-9480-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/26/2015] [Indexed: 12/29/2022] Open
Abstract
Glutamate is the main excitatory neurotransmitter of the central nervous system (CNS), released both from neurons and glial cells. Acting via ionotropic (NMDA, AMPA, kainate) and metabotropic glutamate receptors, it is critically involved in essential regulatory functions. Disturbances of glutamatergic neurotransmission can be detected in cognitive and neurodegenerative disorders. This paper summarizes the present knowledge on the modulation of glutamate-mediated responses in the CNS. Emphasis will be put on NMDA receptor channels, which are essential executive and integrative elements of the glutamatergic system. This receptor is crucial for proper functioning of neuronal circuits; its hypofunction or overactivation can result in neuronal disturbances and neurotoxicity. Somewhat surprisingly, NMDA receptors are not widely targeted by pharmacotherapy in clinics; their robust activation or inhibition seems to be desirable only in exceptional cases. However, their fine-tuning might provide a promising manipulation to optimize the activity of the glutamatergic system and to restore proper CNS function. This orchestration utilizes several neuromodulators. Besides the classical ones such as dopamine, novel candidates emerged in the last two decades. The purinergic system is a promising possibility to optimize the activity of the glutamatergic system. It exerts not only direct and indirect influences on NMDA receptors but, by modulating glutamatergic transmission, also plays an important role in glia-neuron communication. These purinergic functions will be illustrated mostly by depicting the modulatory role of the purinergic system on glutamatergic transmission in the prefrontal cortex, a CNS area important for attention, memory and learning.
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Affiliation(s)
- László Köles
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary.
| | - Erzsébet Kató
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Adrienn Hanuska
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Zoltán S Zádori
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Mahmoud Al-Khrasani
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Patrizia Rubini
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, 04107, Leipzig, Germany
| | - Peter Illes
- Rudolf-Boehm-Institute of Pharmacology and Toxicology, University of Leipzig, 04107, Leipzig, Germany.
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Frenguelli BG, Wall MJ. Combined electrophysiological and biosensor approaches to study purinergic regulation of epileptiform activity in cortical tissue. J Neurosci Methods 2015; 260:202-14. [PMID: 26381061 DOI: 10.1016/j.jneumeth.2015.09.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 09/05/2015] [Accepted: 09/07/2015] [Indexed: 12/16/2022]
Abstract
BACKGROUND Cortical brain slices offer a readily accessible experimental model of a region of the brain commonly affected by epilepsy. The diversity of recording techniques, seizure-promoting protocols and mutant mouse models provides a rich diversity of avenues of investigation, which is facilitated by the regular arrangement of distinct neuronal populations and afferent fibre pathways, particularly in the hippocampus. NEW METHOD AND RESULTS We have been interested in the regulation of seizure activity in hippocampal and neocortical slices by the purines, adenosine and ATP. Via the use of microelectrode biosensors we have been able to measure the release of these important neuroactive compounds simultaneously with on-going epileptiform activity, even of brief durations. In addition, detailed numerical analysis and computational modelling has produced new insights into the kinetics and spatial distribution of elevations in purine concentration that occur during seizure activity. COMPARISON AND CONCLUSIONS Such an approach allows the spatio-temporal characteristics of neurotransmitter/neuromodulator release to be directly correlated with electrophysiological measures of synaptic and seizure activity, and can provide greater insight into the role of purines in epilepsy.
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Affiliation(s)
| | - Mark J Wall
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
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Illes P, Verkhratsky A. Purinergic neurone-glia signalling in cognitive-related pathologies. Neuropharmacology 2015; 104:62-75. [PMID: 26256423 DOI: 10.1016/j.neuropharm.2015.08.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/19/2015] [Accepted: 08/03/2015] [Indexed: 12/31/2022]
Abstract
Neuroglia, represented by astrocytes, oligodendrocytes, NG glia and microglia are homeostatic, myelinating and defensive cells of the brain. Neuroglial cells express various combinations of purinoceptors, which contribute to multiple intercellular signalling pathways in the healthy and diseased nervous system. Neurological diseases are invariably associated with profound neuroglial remodelling, which is manifest by reactive gliosis, pathological remodelling and functional atrophy of various types of glial cells. Gliopathology is disease and region specific and produces multiple glial phenotypes that may be neuroprotective or neurotoxic. In this review we summarise recent knowledge on the role of glial purinergic signalling in cognitive-related neurological diseases. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- Peter Illes
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany.
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain; University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia.
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Lord B, Aluisio L, Shoblock JR, Neff RA, Varlinskaya EI, Ceusters M, Lovenberg TW, Carruthers N, Bonaventure P, Letavic MA, Deak T, Drinkenburg W, Bhattacharya A. Pharmacology of a novel central nervous system-penetrant P2X7 antagonist JNJ-42253432. J Pharmacol Exp Ther 2014; 351:628-41. [PMID: 25271258 DOI: 10.1124/jpet.114.218487] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In the central nervous system, the ATP-gated Purinergic receptor P2X ligand-gated ion channel 7 (P2X7) is expressed in glial cells and modulates neurophysiology via release of gliotransmitters, including the proinflammatory cytokine interleukin (IL)-1β. In this study, we characterized JNJ-42253432 [2-methyl-N-([1-(4-phenylpiperazin-1-yl)cyclohexyl]methyl)-1,2,3,4-tetrahydroisoquinoline-5-carboxamide] as a centrally permeable (brain-to-plasma ratio of 1), high-affinity P2X7 antagonist with desirable pharmacokinetic and pharmacodynamic properties for in vivo testing in rodents. JNJ-42253432 is a high-affinity antagonist for the rat (pKi 9.1 ± 0.07) and human (pKi 7.9 ± 0.08) P2X7 channel. The compound blocked the ATP-induced current and Bz-ATP [2'(3')-O-(4-benzoylbenzoyl)adenosine-5'-triphosphate tri(triethylammonium)]-induced release of IL-1β in a concentration-dependent manner. When dosed in rats, JNJ-42253432 occupied the brain P2X7 channel with an ED50 of 0.3 mg/kg, corresponding to a mean plasma concentration of 42 ng/ml. The compound blocked the release of IL-1β induced by Bz-ATP in freely moving rat brain. At higher doses/exposure, JNJ-42253432 also increased serotonin levels in the rat brain, which is due to antagonism of the serotonin transporter (SERT) resulting in an ED50 of 10 mg/kg for SERT occupancy. JNJ-42253432 reduced electroencephalography spectral power in the α-1 band in a dose-dependent manner; the compound also attenuated amphetamine-induced hyperactivity. JNJ-42253432 significantly increased both overall social interaction and social preference, an effect that was independent of stress induced by foot-shock. Surprisingly, there was no effect of the compound on either neuropathic pain or inflammatory pain behaviors. In summary, in this study, we characterize JNJ-42253432 as a novel brain-penetrant P2X7 antagonist with high affinity and selectivity for the P2X7 channel.
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Affiliation(s)
- Brian Lord
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Leah Aluisio
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - James R Shoblock
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Robert A Neff
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Elena I Varlinskaya
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Marc Ceusters
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Timothy W Lovenberg
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Nicholas Carruthers
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Pascal Bonaventure
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Michael A Letavic
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Terrence Deak
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Wilhelmus Drinkenburg
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
| | - Anindya Bhattacharya
- Neuroscience Therapeutic Area, Janssen Research & Development, LLC, San Diego, California (B.L., L.A., J.R.S., R.A.N., T.W.L., N.C., P.B., M.A.L., A.B.); Neuroscience Therapeutic Area, Janssen Research & Development, Division of Janssen Pharmaceutica NV, Beerse, Belgium (M.C., W.D.); and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-State University of New York, Binghamton, New York (E.I.V., T.D.)
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Sperlágh B, Illes P. P2X7 receptor: an emerging target in central nervous system diseases. Trends Pharmacol Sci 2014; 35:537-47. [PMID: 25223574 DOI: 10.1016/j.tips.2014.08.002] [Citation(s) in RCA: 288] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/07/2014] [Accepted: 08/14/2014] [Indexed: 12/19/2022]
Abstract
The ATP-sensitive homomeric P2X7 receptor (P2X7R) has received particular attention as a potential drug target because of its widespread involvement in inflammatory diseases as a key regulatory element of the inflammasome complex. However, it has only recently become evident that P2X7Rs also play a pivotal role in central nervous system (CNS) pathology. There is an explosion of data indicating that genetic deletion and pharmacological blockade of P2X7Rs alter responsiveness in animal models of neurological disorders, such as stroke, neurotrauma, epilepsy, neuropathic pain, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Alzheimer's disease, Parkinson's disease, and Huntington's disease. Moreover, recent studies suggest that P2X7Rs regulate the pathophysiology of psychiatric disorders, including mood disorders, implicating P2X7Rs as drug targets in a variety of CNS pathology.
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Affiliation(s)
- Beáta Sperlágh
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1450 Budapest, Hungary.
| | - Peter Illes
- Rudolf Boehm Institute of Pharmacology and Toxicology, University of Leipzig, D-04107 Leipzig, Germany
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Role of astrocytes in memory and psychiatric disorders. ACTA ACUST UNITED AC 2014; 108:240-51. [PMID: 25169821 DOI: 10.1016/j.jphysparis.2014.08.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 04/12/2014] [Accepted: 08/18/2014] [Indexed: 01/10/2023]
Abstract
Over the past decade, the traditional description of astrocytes as being merely accessories to brain function has shifted to one in which their role has been pushed into the forefront of importance. Current views suggest that astrocytes:(1) are excitable through calcium fluctuations and respond to neurotransmitters released at synapses; (2) communicate with each other via calcium waves and release their own gliotransmitters which are essential for synaptic plasticity; (3) activate hundreds of synapses at once, thereby synchronizing neuronal activity and activating or inhibiting complete neuronal networks; (4) release vasoactive substances to the smooth muscle surrounding blood vessels enabling the coupling of circulation (blood flow) to local brain activity; and (5) release lactate in an activity-dependent manner in order to supply neuronal metabolic demand. In consequence, the role of astrocytes and astrocytic gliotransmitters is now believed to be critical for higher brain function and recently, evidence begins to gather suggesting that astrocytes are pivotal for learning and memory. All of the above are reviewed here while focusing on the role of astrocytes in memory and psychiatric disorders.
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