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Hoonakker M, Zariri A, de Brouwer L, David D, Borgman A, Sloots A. An in vitro assay for toxicity testing of Clostridium perfringens type C β-toxin. Front Immunol 2024; 15:1373411. [PMID: 38646535 PMCID: PMC11026656 DOI: 10.3389/fimmu.2024.1373411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/19/2024] [Indexed: 04/23/2024] Open
Abstract
Introduction Veterinary vaccines against Clostridium perfringens type C need to be tested for absence of toxicity, as mandated by pharmacopoeias worldwide. This toxicity testing is required at multiple manufacturing steps and relies on outdated mouse tests that involve severe animal suffering. Clostridium perfringens type C produces several toxins of which the β-toxin is the primary component responsible for causing disease. Here, we describe the successful development of a new cell-based in vitro assay that can address the specific toxicity of the β-toxin. Methods Development of the cell-based assay followed the principle of in vitro testing developed for Cl. septicum vaccines, which is based on Vero cells. We screened four cell lines and selected the THP-1 cell line, which was shown to be the most specific and sensitive for β-toxin activity, in combination with a commercially available method to determine cell viability (MTS assay) as a readout. Results The current animal test is estimated to detect 100 - 1000-fold dilutions of the Cl. perfringens type C non-inactivated antigen. When tested with an active Cl. perfringens type C antigen preparation, derived from a commercial vaccine manufacturing process, our THP-1 cell-based assay was able to detect toxin activity from undiluted to over 10000-fold dilution, showing a linear range between approximately 1000- and 10000-fold dilutions. Assay specificity for the β-toxin was confirmed with neutralizing antibodies and lack of reaction to Cl. perfringens culture medium. In addition, assay parameters demonstrated good repeatability. Conclusions Here, we have shown proof of concept for a THP-1 cell-based assay for toxicity testing of veterinary Cl. perfringens type C vaccines that is suitable for all vaccine production steps. This result represents a significant step towards the replacement of animal-based toxicity testing of this veterinary clostridial antigen. As a next step, assessment of the assay's sensitivity and repeatability and validation of the method will have to be performed in a commercial manufacturing context in order to formally implement the assay in vaccine quality control.
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Affiliation(s)
| | | | | | | | | | - Arjen Sloots
- Department of Product Characterization and Formulation, Intravacc B.V., Bilthoven, Netherlands
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2
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Zheng H, Liu Q, Zhou S, Luo H, Zhang W. Role and therapeutic targets of P2X7 receptors in neurodegenerative diseases. Front Immunol 2024; 15:1345625. [PMID: 38370420 PMCID: PMC10869479 DOI: 10.3389/fimmu.2024.1345625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/16/2024] [Indexed: 02/20/2024] Open
Abstract
The P2X7 receptor (P2X7R), a non-selective cation channel modulated by adenosine triphosphate (ATP), localizes to microglia, astrocytes, oligodendrocytes, and neurons in the central nervous system, with the most incredible abundance in microglia. P2X7R partake in various signaling pathways, engaging in the immune response, the release of neurotransmitters, oxidative stress, cell division, and programmed cell death. When neurodegenerative diseases result in neuronal apoptosis and necrosis, ATP activates the P2X7R. This activation induces the release of biologically active molecules such as pro-inflammatory cytokines, chemokines, proteases, reactive oxygen species, and excitotoxic glutamate/ATP. Subsequently, this leads to neuroinflammation, which exacerbates neuronal involvement. The P2X7R is essential in the development of neurodegenerative diseases. This implies that it has potential as a drug target and could be treated using P2X7R antagonists that are able to cross the blood-brain barrier. This review will comprehensively and objectively discuss recent research breakthroughs on P2X7R genes, their structural features, functional properties, signaling pathways, and their roles in neurodegenerative diseases and possible therapies.
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Affiliation(s)
- Huiyong Zheng
- Second Clinical Medical School, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Qiang Liu
- Second Clinical Medical School, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Siwei Zhou
- Second Clinical Medical School, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Hongliang Luo
- Gastrointestinal Surgery, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Wenjun Zhang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, China
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3
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Tewari M, Michalski S, Egan TM. Modulation of Microglial Function by ATP-Gated P2X7 Receptors: Studies in Rat, Mice and Human. Cells 2024; 13:161. [PMID: 38247852 PMCID: PMC10814008 DOI: 10.3390/cells13020161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
P2X receptors are a family of seven ATP-gated ion channels that trigger physiological and pathophysiological responses in a variety of cells. Five of the family members are sensitive to low concentrations of extracellular ATP, while the P2X6 receptor has an unknown affinity. The last subtype, the P2X7 receptor, is unique in requiring millimolar concentrations to fully activate in humans. This low sensitivity imparts the agonist with the ability to act as a damage-associated molecular pattern that triggers the innate immune response in response to the elevated levels of extracellular ATP that accompany inflammation and tissue damage. In this review, we focus on microglia because they are the primary immune cells of the central nervous system, and they activate in response to ATP or its synthetic analog, BzATP. We start by introducing purinergic receptors and then briefly consider the roles that microglia play in neurodevelopment and disease by referencing both original works and relevant reviews. Next, we move to the role of extracellular ATP and P2X receptors in initiating and/or modulating innate immunity in the central nervous system. While most of the data that we review involve work on mice and rats, we highlight human studies of P2X7R whenever possible.
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4
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Huang L, Mut-Arbona P, Varga B, Török B, Brunner J, Arszovszki A, Iring A, Kisfali M, Vizi ES, Sperlágh B. P2X7 purinergic receptor modulates dentate gyrus excitatory neurotransmission and alleviates schizophrenia-like symptoms in mouse. iScience 2023; 26:107560. [PMID: 37649698 PMCID: PMC10462828 DOI: 10.1016/j.isci.2023.107560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/11/2023] [Accepted: 08/02/2023] [Indexed: 09/01/2023] Open
Abstract
ATP-gated P2X7 receptors (P2X7Rs) play a crucial role in brain disorders. However, how they affect normal and pathological synaptic transmission is still largely unclear. Here, by using whole-cell patch-clamp technique to record AMPA- and NMDA receptor-mediated excitatory postsynaptic currents (s/mEPSCs) in dentate gyrus granule cells (DG GCs), we revealed a modulation by P2X7Rs of presynaptic sites, especially originated from entorhinal cortex (EC)-GC path but not the mossy cell (MC)-GC path. The involvement of P2X7Rs was confirmed using a pharmacological approach. Additionally, the acute activation of P2X7Rs directly elevated calcium influx from EC-GC terminals. In postnatal phencyclidine (PCP)-induced mouse model of schizophrenia, we observed that P2X7R deficiency restored the EC-GC synapse alteration and alleviated PCP-induced symptoms. To summarize, P2X7Rs participate in the modulation of GC excitatory neurotransmission in the DG via EC-GC pathway, contributing to pathological alterations of neuronal functions leading to neurodevelopmental disorders.
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Affiliation(s)
- Lumei Huang
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
- János Szentágothai Doctoral School, Semmelweis University, 1085 Budapest, Hungary
| | - Paula Mut-Arbona
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
- János Szentágothai Doctoral School, Semmelweis University, 1085 Budapest, Hungary
| | - Bernadett Varga
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
- János Szentágothai Doctoral School, Semmelweis University, 1085 Budapest, Hungary
| | - Bibiana Török
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - János Brunner
- Laboratory of Cellular Neuropharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Antonia Arszovszki
- Laboratory of Cellular Neuropharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - András Iring
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Máté Kisfali
- Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - E. Sylvester Vizi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
- János Szentágothai Doctoral School, Semmelweis University, 1085 Budapest, Hungary
| | - Beáta Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, 1083 Budapest, Hungary
- János Szentágothai Doctoral School, Semmelweis University, 1085 Budapest, Hungary
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5
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Lee WE, Genetzakis E, Figtree GA. Novel Strategies in the Early Detection and Treatment of Endothelial Cell-Specific Mitochondrial Dysfunction in Coronary Artery Disease. Antioxidants (Basel) 2023; 12:1359. [PMID: 37507899 PMCID: PMC10376062 DOI: 10.3390/antiox12071359] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 06/26/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
Although elevated cholesterol and other recognised cardiovascular risk factors are important in the development of coronary artery disease (CAD) and heart attack, the susceptibility of humans to this fatal process is distinct from other animals. Mitochondrial dysfunction of cells in the arterial wall, particularly the endothelium, has been strongly implicated in the pathogenesis of CAD. In this manuscript, we review the established evidence and mechanisms in detail and explore the potential opportunities arising from analysing mitochondrial function in patient-derived cells such as endothelial colony-forming cells easily cultured from venous blood. We discuss how emerging technology and knowledge may allow us to measure mitochondrial dysfunction as a potential biomarker for diagnosis and risk management. We also discuss the "pros and cons" of animal models of atherosclerosis, and how patient-derived cell models may provide opportunities to develop novel therapies relevant for humans. Finally, we review several targets that potentially alleviate mitochondrial dysfunction working both via direct and indirect mechanisms and evaluate the effect of several classes of compounds in the cardiovascular context.
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Affiliation(s)
- Weiqian E. Lee
- Kolling Institute, University of Sydney, Sydney, NSW 2006, Australia; (W.E.L.); (E.G.)
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia
| | - Elijah Genetzakis
- Kolling Institute, University of Sydney, Sydney, NSW 2006, Australia; (W.E.L.); (E.G.)
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia
| | - Gemma A. Figtree
- Kolling Institute, University of Sydney, Sydney, NSW 2006, Australia; (W.E.L.); (E.G.)
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia
- Department of Cardiology, Royal North Shore Hospital, Northern Sydney Local Health District, Sydney, NSW 2065, Australia
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6
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Raval NR, Wetherill RR, Wiers CE, Dubroff JG, Hillmer AT. Positron Emission Tomography of Neuroimmune Responses in Humans: Insights and Intricacies. Semin Nucl Med 2023; 53:213-229. [PMID: 36270830 DOI: 10.1053/j.semnuclmed.2022.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 08/30/2022] [Indexed: 11/06/2022]
Abstract
The brain's immune system plays a critical role in responding to immune challenges and maintaining homeostasis. However, dysregulated neuroimmune function contributes to neurodegenerative disease and neuropsychiatric conditions. In vivo positron emission tomography (PET) imaging of the neuroimmune system has facilitated a greater understanding of its physiology and the pathology of some neuropsychiatric conditions. This review presents an in-depth look at PET findings from human neuroimmune function studies, highlighting their importance in current neuropsychiatric research. Although the majority of human PET studies feature radiotracers targeting the translocator protein 18 kDa (TSPO), this review also considers studies with other neuroimmune targets, including monoamine oxidase B, cyclooxygenase-1 and cyclooxygenase-2, nitric oxide synthase, and the purinergic P2X7 receptor. Promising new targets, such as colony-stimulating factor 1, Sphingosine-1-phosphate receptor 1, and the purinergic P2Y12 receptor, are also discussed. The significance of validating neuroimmune targets and understanding their function and expression is emphasized in this review to better identify and interpret PET results.
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Affiliation(s)
- Nakul R Raval
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; Yale PET Center, Yale University, New Haven, CT
| | - Reagan R Wetherill
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Corinde E Wiers
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA; Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Jacob G Dubroff
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ansel T Hillmer
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT; Yale PET Center, Yale University, New Haven, CT; Department of Psychiatry, Yale University, New Haven, CT.
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7
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Simões JL, Sobierai LD, Leal IF, Dos Santos MV, Coiado JV, Bagatini MD. Action of the Purinergic and Cholinergic Anti-inflammatory Pathways on Oxidative Stress in Patients with Alzheimer's Disease in the Context of the COVID-19 Pandemic. Neuroscience 2023; 512:110-132. [PMID: 36526078 PMCID: PMC9746135 DOI: 10.1016/j.neuroscience.2022.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 12/15/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of the 2019 coronavirus disease (COVID-19), has affected more than 20 million people in Brazil and caused a global health emergency. This virus has the potential to affect various parts of the body and compromise metabolic functions. The virus-mediated neural inflammation of the nervous system is due to a storm of cytokines and oxidative stress, which are the clinical features of Alzheimer's disease (AD). This neurodegenerative disease is aggravated in cases involving SARS-CoV-2 and its inflammatory biomarkers, accelerating accumulation of β-amyloid peptide, hyperphosphorylation of tau protein, and production of reactive oxygen species, which lead to homeostasis imbalance. The cholinergic system, through neurons and the neurotransmitter acetylcholine (ACh), modulates various physiological pathways, such as the response to stress, sleep and wakefulness, sensory information, and the cognitive system. Patients with AD have low concentrations of ACh; hence, therapeutic methods are aimed at adjusting the ACh titers available to the body for maintaining functionality. Herein, we focused on acetylcholinesterase inhibitors, responsible for the degradation of ACh in the synaptic cleft, and muscarinic and nicotinic receptor agonists of the cholinergic system owing to the therapeutic potential of the cholinergic anti-inflammatory pathway in AD associated with SARS-CoV-2 infection.
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Affiliation(s)
- Júlia L.B. Simões
- Medical School, Federal University of Fronteira Sul, Chapecó, SC, Brazil
| | | | - Inayá F. Leal
- Medical School, Federal University of Fronteira Sul, Chapecó, SC, Brazil
| | | | - João Victor Coiado
- Medical School, Federal University of Fronteira Sul, Chapecó, SC, Brazil
| | - Margarete D. Bagatini
- Graduate Program in Biomedical Sciences, Federal University of Fronteira Sul, Chapecó, SC, Brazil,Corresponding author
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8
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Yang R, Shi L, Si H, Hu Z, Zou L, Li L, Xu X, Schmalzing G, Nie H, Li G, Liu S, Liang S, Xu C. Gallic Acid Improves Comorbid Chronic Pain and Depression Behaviors by Inhibiting P2X7 Receptor-Mediated Ferroptosis in the Spinal Cord of Rats. ACS Chem Neurosci 2023; 14:667-676. [PMID: 36719132 DOI: 10.1021/acschemneuro.2c00532] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Ferroptosis is an inflammatory programmed cell death process that is dependent on iron deposition and lipid peroxidation. The P2X7 receptor not only is involved in the pain process but also is closely related to the onset of depression. Gallic acid (3,4,5-trihydroxybenzoic acid), which is naturally found in a variety of plants, exhibits anti-inflammatory, antioxidant, and analgesic effects. This study established a rat model with the comorbidity of chronic constrictive injury (CCI) plus chronic unpredictable mild stress (CUMS) to explore the role and mechanism of gallic acid in the treatment of pain and depression comorbidity. Our experimental results showed that pain and depression-like behaviors were more obvious in the chronic constriction injury (CCI) plus chronic unpredictable mild stimulation (CUMS) group than they were in the sham operation group, and the P2X7-reactive oxygen species (ROS) signaling pathway was activated. The tissue iron concentration was increased, and mitochondrial damage was observed in the CCI plus CUMS group. These results were alleviated with gallic acid treatment. Therefore, we speculate that gallic acid inhibits the ferroptosis of the spinal microglia by regulating the P2X7-ROS signaling pathway and relieves the behavioral changes in rats with comorbid pain and depression.
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Affiliation(s)
- Runan Yang
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
| | - Liran Shi
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,The People's Hospital of Jiawang of Xuzhou, Xuzhou, Jiangsu 221011, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
| | - Han Si
- Nursing College, Medical College of Nanchang University, Nanchang, Jiangxi 330006, P. R. China
| | - Zihui Hu
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
| | - Lifang Zou
- Center of Hematology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Clinical Research Center for Hematologic Disease of Jiangxi Province, Nanchang, Jiangxi 330006, P. R. China
| | - Lin Li
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
| | - Xiumei Xu
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
| | - Günther Schmalzing
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen 52062, Germany
| | - Hong Nie
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, P. R. China
| | - Guilin Li
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
| | - Shuangmei Liu
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
| | - Shangdong Liang
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
| | - Changshui Xu
- Neuropharmacology Laboratory of Physiology Department, Medical School of Nanchang University, Nanchang, Jiangxi 330006, P. R. China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, Jiangxi 330006, P. R. China
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9
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P2X7 receptor activation mediates superoxide dismutase 1 (SOD1) release from murine NSC-34 motor neurons. Purinergic Signal 2022; 18:451-467. [PMID: 35478453 PMCID: PMC9832181 DOI: 10.1007/s11302-022-09863-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/05/2022] [Indexed: 01/15/2023] Open
Abstract
Mutant superoxide dismutase 1 (SOD1) can be constitutively released from motor neurons and transmitted to naïve motor neurons to promote the progression of amyotrophic lateral sclerosis (ALS). However, the biological impacts of this process and the precise mechanisms of SOD1 release remain to be fully resolved. Using biochemical and fluorescent techniques, this study aimed to determine if P2X7 receptor activation could induce mutant SOD1 release from motor neurons and whether this released SOD1 could be transmitted to motor neurons or microglia to mediate effects associated with neurodegeneration in ALS. Aggregated SOD1G93A, released from murine NSC-34 motor neurons transiently transfected with SOD1G93A, could be transmitted to naïve NSC-34 cells and murine EOC13 microglia to induce endoplasmic reticulum (ER) stress and tumour necrosis factor-alpha (TNFα) release, respectively. Immunoblotting revealed NSC-34 cells expressed P2X7. Extracellular ATP induced cation dye uptake into these cells, which was blocked by the P2X7 antagonist AZ10606120, demonstrating these cells express functional P2X7. Moreover, ATP induced the rapid release of aggregated SOD1G93A from NSC-34 cells transiently transfected with SOD1G93A, a process blocked by AZ10606120 and revealing a role for P2X7 in this process. ATP-induced SOD1G93A release coincided with membrane blebbing. Finally, aggregated SOD1G93A released via P2X7 activation could also be transmitted to NSC-34 and EOC13 cells to induce ER stress and TNFα release, respectively. Collectively, these results identify a novel role for P2X7 in the prion-like propagation of SOD1 in ALS and provide a possible explanation for the therapeutic benefits of P2X7 antagonism previously observed in ALS SOD1G93A mice.
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10
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Alberto AVP, Ferreira NCDS, Bonavita AGC, Nihei OK, de Farias FP, Bisaggio RDC, de Albuquerque C, Savino W, Coutinho‐Silva R, Persechini PM, Alves LA. Physiologic roles of P2 receptors in leukocytes. J Leukoc Biol 2022; 112:983-1012. [PMID: 35837975 PMCID: PMC9796137 DOI: 10.1002/jlb.2ru0421-226rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/13/2022] [Indexed: 01/01/2023] Open
Abstract
Since their discovery in the 1970s, purinergic receptors have been shown to play key roles in a wide variety of biologic systems and cell types. In the immune system, purinergic receptors participate in innate immunity and in the modulation of the adaptive immune response. In particular, P2 receptors, which respond to extracellular nucleotides, are widely expressed on leukocytes, causing the release of cytokines and chemokines and the formation of inflammatory mediators, and inducing phagocytosis, degranulation, and cell death. The activity of these receptors is regulated by ectonucleotidases-expressed in these same cell types-which regulate the availability of nucleotides in the extracellular environment. In this article, we review the characteristics of the main purinergic receptor subtypes present in the immune system, focusing on the P2 family. In addition, we describe the physiologic roles of the P2 receptors already identified in leukocytes and how they can positively or negatively modulate the development of infectious diseases, inflammation, and pain.
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Affiliation(s)
- Anael Viana Pinto Alberto
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
| | | | | | - Oscar Kenji Nihei
- Center of Education and LetterState University of the West of ParanáFoz do IguaçuPRBrazil
| | | | - Rodrigo da Cunha Bisaggio
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Federal Institute of Education, Science, and Technology of Rio de JaneiroRio de JaneiroRJBrazil
| | | | - Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Brazilian National Institute of Science and Technology on NeuroimmunomodulationRio de Janeiro Research Network on NeuroinflammationRio de JaneiroRJBrazil
| | - Robson Coutinho‐Silva
- Laboratory of Immunophysiology, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Pedro Muanis Persechini
- Laboratory of Immunobiophysics, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Luiz Anastacio Alves
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
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11
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Mckenzie ADJ, Garrett TR, Werry EL, Kassiou M. Purinergic P2X 7 Receptor: A Therapeutic Target in Amyotrophic Lateral Sclerosis. ACS Chem Neurosci 2022; 13:1479-1490. [PMID: 35512313 DOI: 10.1021/acschemneuro.2c00133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by upper and lower motor neuron loss. The pathomechanisms of ALS are still poorly understood with current hypotheses involving genetic mutations, excitotoxicity, and reactive oxygen species formation. In the absence of a disease-altering clinically approved therapeutic, there is an ever-increasing need to identify new targets to develop drugs that delay disease onset and/or progression. The purinergic P2X7 receptor (P2X7R) has been implicated widely across the ALS realm, providing a potential therapeutic strategy. This review summarizes the current understanding of ALS, the P2X7R and its role in ALS, the current landscape of P2X7R antagonists, and the in vivo potential of these antagonists in preclinical ALS models.
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Affiliation(s)
- André D. J. Mckenzie
- School of Chemistry, Faculty of Science, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Taylor R. Garrett
- School of Chemistry, Faculty of Science, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Eryn L. Werry
- School of Chemistry, Faculty of Science, University of Sydney, Sydney, New South Wales 2006, Australia
- Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Michael Kassiou
- School of Chemistry, Faculty of Science, University of Sydney, Sydney, New South Wales 2006, Australia
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12
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Chiang CH, Cheng CY, Lien YT, Huang KC, Lin WW. P2X7 Activation Enhances Lipid Accumulation During Adipocytes Differentiation Through Suppressing the Expression of Sirtuin-3, Sirtuin-5, and Browning Genes. Front Pharmacol 2022; 13:852858. [PMID: 35462937 PMCID: PMC9019299 DOI: 10.3389/fphar.2022.852858] [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: 01/11/2022] [Accepted: 03/18/2022] [Indexed: 11/24/2022] Open
Abstract
P2X7 signaling has been explored in adipose tissue because of its potential to promote ATP-activated inflammatory cascades during obesogenic environments. However, limited literature has investigated the role of the P2X7 receptor in lipid metabolism during adipocyte differentiation. This study sought to explore the regulatory roles of P2X7 in adipocytes. This study utilized the in vitro 3T3-L1 differentiation model. Lipid accumulation, intracellular triglyceride, and extracellular glycerol were determined. The selective P2X7 agonist BzATP and antagonist A438079 were administered to investigate the functions of P2X7. We found that the expression of P2X7 and the lipid accumulation increased during adipocyte differentiation from D0 to D4. When administered at D0/D2, A438079 attenuated, while BzATP enhanced the degree of lipid accumulation during adipocyte differentiation. Neither did BzATP and A438079 administration affect the expression of PPARγ and C/EBPα genes that increased at D4. In addition, both intracellular triglyceride and extracellular glycerol levels at D4 were reduced by A438079 treatment and enhanced by BzATP administration. When administered at stage 2 of adipocyte differentiation, BzATP consistently enhanced lipid accumulation and intracellular triglyceride and extracellular glycerol levels without affecting mRNA and protein levels of PPARγ and C/EBPα that increased at D4. However, treating A438079 or BzATP at D4 did not affect intracellular triglyceride formation and extracellular glycerol release in differentiated adipocytes at D7. Notably, BzATP administration at stage 2 exerted a concentration-dependent inhibition on the enhanced expression of PRDM16, PGC-1α, and UCP-1 at D4. Furthermore, BzATP administration at D0/D2 inhibited the protein and mRNA levels of sirtuin-3/5 at D4. BzATP treatment at stage 2 also suppressed the mRNA levels of sirtuin-3/5 genes upregulated by insulin. In conclusion, this study demonstrated P2X7 enhances lipid accumulation during adipogenesis by suppressing the expression of sirtuin-3/5 and the browning genes.
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Affiliation(s)
- Chien-Hsieh Chiang
- Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Family Medicine, National Taiwan University Hospital & College of Medicine, Taipei, Taiwan
| | - Ching-Yuan Cheng
- Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yi-Ting Lien
- Department of Family Medicine, National Taiwan University Hospital & College of Medicine, Taipei, Taiwan
| | - Kuo-Chin Huang
- Department of Family Medicine, National Taiwan University Hospital & College of Medicine, Taipei, Taiwan
| | - Wan-Wan Lin
- Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, Taiwan.,Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan
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13
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Pregnant Women and Endocrine Disruptors: Role of P2X7 Receptor and Mitochondrial Alterations in Placental Cell Disorders. Cells 2022; 11:cells11030495. [PMID: 35159304 PMCID: PMC8834275 DOI: 10.3390/cells11030495] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 01/28/2022] [Accepted: 01/29/2022] [Indexed: 02/07/2023] Open
Abstract
In pregnant women, the lungs, skin and placenta are exposed daily to endocrine-disrupting chemicals (EDCs). EDCs induce multiple adverse effects, not only on endocrine organs, but also on non-endocrine organs, with the P2X7 cell death receptor being potentially the common key element. Our objective was first to investigate mechanisms of EDCs toxicity in both endocrine and non-endocrine cells through P2X7 receptor activation, and second, to compare the level of activation in lung, skin and placental cells. In addition, apoptosis in placental cells was studied because the placenta is the most exposed organ to EDCs and has essential endocrine functions. A total of nine EDCs were evaluated on three human cell models. We observed that the P2X7 receptor was not activated by EDCs in lung non-endocrine cells but was activated in skin and placenta cells, with the highest activation in placenta cells. P2X7 receptor activation and apoptosis are pathways shared by all tested EDCs in endocrine placental cells. P2X7 receptor activation along with apoptosis induction could be key elements in understanding endocrine placental and skin disorders induced by EDCs.
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14
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Wu P, Zhou G, Wu X, Lv R, Yao J, Wen Q. P2X7 receptor induces microglia polarization to the M1 phenotype in cancer-induced bone pain rat models. Mol Pain 2022; 18:17448069211060962. [PMID: 35057643 PMCID: PMC8961217 DOI: 10.1177/17448069211060962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Background The transition from pro-inflammatory M1 phenotype to anti-inflammatory M2
phenotype presents a novel therapeutic strategy for chronic pain. Objective We investigated the role of microglia polarization in cancer-induced bone
pain (CIBP), as well as the role of the P2X7 receptor in modulating M1 to M2
polarization. Methods Walker-256 breast cancer cells were administered into tibias of female rats
to induce bone cancer–associated cancer. Results During bone cancer development, the P2X7 receptor and M1 microglia markers
were upregulated. In contrast, inhibition of the P2X7 receptor by BBG, a
blood-brain barrier-permeable P2X7R-specific antagonist, alleviated the pain
and promoted microglia polarization toward the M2 phenotype, while
suppressing the M1 phenotype in vivo and in
vitro. Conclusion P2X7 receptor-mediated spinal microglia polarization is involved in
alleviation of CIBP. Therefore, P2X7R is a potential option for CIBP
treatment.
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Affiliation(s)
- Ping Wu
- Department of Anesthesiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Guohua Zhou
- Anesthesiology Department, Dalian Medical University, Dalian, China
| | - Xiaoqi Wu
- Anesthesiology Department, Dalian Medical University, Dalian, China
| | - Run Lv
- Department of Anesthesiology, The first hospital of Hebei Medical University, Shijiazhuang, China
| | - Jiaqi Yao
- Department of Anesthesiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Qingping Wen
- Department of Anesthesiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
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15
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NLRP3 Inflammasome in Diabetic Cardiomyopathy and Exercise Intervention. Int J Mol Sci 2021; 22:ijms222413228. [PMID: 34948026 PMCID: PMC8707657 DOI: 10.3390/ijms222413228] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/24/2021] [Accepted: 12/06/2021] [Indexed: 12/12/2022] Open
Abstract
Diabetic cardiomyopathy (DCM), as a common complication of diabetes, is characterized by chronic low-grade inflammation. The NLRP3 inflammasome is a key sensor mediating innate immune and inflammatory responses. However, the mechanisms initiating and promoting NLRP3 inflammasome activation in DCM is largely unexplored. The aim of the present review is to describe the link between NLRP3 inflammasome and DCM, and to provide evidence highlighting the importance of exercise training in DCM intervention. Collectively, this evidence suggests that DCM is an inflammatory disease aggravated by NLRP3 inflammasome-mediated release of IL-1β and IL-18. In addition, chronic exercise intervention is an effective preventive and therapeutic method to alleviate DCM via modulating the NLRP3 inflammasome.
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16
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García-Rodríguez C, Bravo-Tobar ID, Duarte Y, Barrio LC, Sáez JC. Contribution of non-selective membrane channels and receptors in epilepsy. Pharmacol Ther 2021; 231:107980. [PMID: 34481811 DOI: 10.1016/j.pharmthera.2021.107980] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/14/2022]
Abstract
Overcoming refractory epilepsy's resistance to the combination of antiepileptic drugs (AED), mitigating side effects, and preventing sudden unexpected death in epilepsy are critical goals for therapy of this disorder. Current therapeutic strategies are based primarily on neurocentric mechanisms, overlooking the participation of astrocytes and microglia in the pathophysiology of epilepsy. This review is focused on a set of non-selective membrane channels (permeable to ions and small molecules), including channels and ionotropic receptors of neurons, astrocytes, and microglia, such as: the hemichannels formed by Cx43 and Panx1; the purinergic P2X7 receptors; the transient receptor potential vanilloid (TRPV1 and TRPV4) channels; calcium homeostasis modulators (CALHMs); transient receptor potential canonical (TRPC) channels; transient receptor potential melastatin (TRPM) channels; voltage-dependent anion channels (VDACs) and volume-regulated anion channels (VRACs), which all have in common being activated by epileptic activity and the capacity to exacerbate seizure intensity. Specifically, we highlight evidence for the activation of these channels/receptors during epilepsy including neuroinflammation and oxidative stress, discuss signaling pathways and feedback mechanisms, and propose the functions of each of them in acute and chronic epilepsy. Studying the role of these non-selective membrane channels in epilepsy and identifying appropriate blockers for one or more of them could provide complementary therapies to better alleviate the disease.
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Affiliation(s)
- Claudia García-Rodríguez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile.
| | - Iván D Bravo-Tobar
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile
| | - Yorley Duarte
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Luis C Barrio
- Hospital Ramon y Cajal-IRYCIS, Centro de Tecnología Biomédica de la Universidad Politécnica, Madrid, Spain
| | - Juan C Sáez
- Instituto de Neurociencia, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Chile.
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17
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Jassim AH, Inman DM, Mitchell CH. Crosstalk Between Dysfunctional Mitochondria and Inflammation in Glaucomatous Neurodegeneration. Front Pharmacol 2021; 12:699623. [PMID: 34366851 PMCID: PMC8334009 DOI: 10.3389/fphar.2021.699623] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/22/2021] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial dysfunction and excessive inflammatory responses are both sufficient to induce pathology in age-dependent neurodegenerations. However, emerging evidence indicates crosstalk between damaged mitochondrial and inflammatory signaling can exacerbate issues in chronic neurodegenerations. This review discusses evidence for the interaction between mitochondrial damage and inflammation, with a focus on glaucomatous neurodegeneration, and proposes that positive feedback resulting from this crosstalk drives pathology. Mitochondrial dysfunction exacerbates inflammatory signaling in multiple ways. Damaged mitochondrial DNA is a damage-associated molecular pattern, which activates the NLRP3 inflammasome; priming and activation of the NLRP3 inflammasome, and the resulting liberation of IL-1β and IL-18 via the gasdermin D pore, is a major pathway to enhance inflammatory responses. The rise in reactive oxygen species induced by mitochondrial damage also activates inflammatory pathways, while blockage of Complex enzymes is sufficient to increase inflammatory signaling. Impaired mitophagy contributes to inflammation as the inability to turnover mitochondria in a timely manner increases levels of ROS and damaged mtDNA, with the latter likely to stimulate the cGAS-STING pathway to increase interferon signaling. Mitochondrial associated ER membrane contacts and the mitochondria-associated adaptor molecule MAVS can activate NLRP3 inflammasome signaling. In addition to dysfunctional mitochondria increasing inflammation, the corollary also occurs, with inflammation reducing mitochondrial function and ATP production; the resulting downward spiral accelerates degeneration. Evidence from several preclinical models including the DBA/2J mouse, microbead injection and transient elevation of IOP, in addition to patient data, implicates both mitochondrial damage and inflammation in glaucomatous neurodegeneration. The pressure-dependent hypoxia and the resulting metabolic vulnerability is associated with mitochondrial damage and IL-1β release. Links between mitochondrial dysfunction and inflammation can occur in retinal ganglion cells, microglia cells and astrocytes. In summary, crosstalk between damaged mitochondria and increased inflammatory signaling enhances pathology in glaucomatous neurodegeneration, with implications for other complex age-dependent neurodegenerations like Alzheimer's and Parkinson's disease.
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Affiliation(s)
- Assraa Hassan Jassim
- Department of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA, United States
| | - Denise M. Inman
- Department of Pharmaceutical Sciences, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Claire H. Mitchell
- Department of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA, United States
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, United States
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, United States
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18
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P2X7 receptor in multifaceted cellular signalling and its relevance as a potential therapeutic target in different diseases. Eur J Pharmacol 2021; 906:174235. [PMID: 34097884 DOI: 10.1016/j.ejphar.2021.174235] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 05/28/2021] [Accepted: 06/02/2021] [Indexed: 02/07/2023]
Abstract
P2X7 receptor, a purinergic receptor family member, is abundantly expressed on many cells, including immune, muscle, bone, neuron, and glia. It acts as an ATP-activated cation channel that permits the influx of Ca2+, Na+ and efflux of K+ ions. The P2X7 receptor plays crucial roles in many physiological processes including cytokine and chemokine secretion, NLRP3 inflammasome activation, cellular growth and differentiation, locomotion, wound healing, transcription factors activation, cell death and T-lymphocyte survival. Past studies have demonstrated the up-regulation and direct association of this receptor in many pathophysiological conditions such as cancer, diabetics, arthritis, tuberculosis (TB) and inflammatory diseases. Hence, targeting this receptor is considered a worthwhile approach to lessen the afflictions associated with the disorders mentioned above by understanding the receptor architecture and downstream signalling processes. Here, in the present review, we have dissected the structural and functional aspects of the P2X7 receptor, emphasizing its role in various diseased conditions. This information will provide in-depth knowledge about the receptor and help to develop apt curative methodologies for the betterment of humanity in the coming years.
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19
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Shokoples BG, Paradis P, Schiffrin EL. P2X7 Receptors: An Untapped Target for the Management of Cardiovascular Disease. Arterioscler Thromb Vasc Biol 2020; 41:186-199. [PMID: 32998520 PMCID: PMC7752223 DOI: 10.1161/atvbaha.120.315116] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic low-grade inflammation contributes to the development of several diseases, including cardiovascular disease. Adequate strategies to target inflammation in cardiovascular disease are in their infancy and remain an avenue of great interest. The purinergic receptor P2X7 is a ubiquitously expressed receptor that predominately mediates inflammation and cellular death. P2X7 is a ligand-gated cation channel that is activated in response to high concentrations of extracellular ATP, triggering the assembly and activation of the NLRP3 (nuclear oligomerization domain like receptor family pyrin domain containing 3) inflammasome and subsequent release of proinflammatory cytokines IL (interleukin)-1β and IL-18. Increased P2X7 activation and IL-1β and IL-18 concentrations have been implicated in the development of many cardiovascular conditions including hypertension, atherosclerosis, ischemia/reperfusion injury, and heart failure. P2X7 receptor KO (knockout) mice exhibit a significant attenuation of the inflammatory response, which corresponds with reduced disease severity. P2X7 antagonism blunts blood pressure elevation in hypertension and progression of atherosclerosis in animal models. IL-1β and IL-18 inhibition has shown efficacy in clinical trials reducing major adverse cardiac events, including myocardial infarction, and heart failure. With several P2X7 antagonists available with proven safety margins, P2X7 antagonism could represent an untapped potential for therapeutic intervention in cardiovascular disorders.
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Affiliation(s)
- Brandon G. Shokoples
- Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (B.G.S., P.P., E.L.S.), Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - Pierre Paradis
- Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (B.G.S., P.P., E.L.S.), Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - Ernesto L. Schiffrin
- Vascular and Hypertension Research Unit, Lady Davis Institute for Medical Research (B.G.S., P.P., E.L.S.), Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
- Department of Medicine (E.L.S.), Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
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20
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Bibič L, Stokes L. Revisiting the Idea That Amyloid-β Peptide Acts as an Agonist for P2X7. Front Mol Neurosci 2020; 13:166. [PMID: 33071753 PMCID: PMC7530339 DOI: 10.3389/fnmol.2020.00166] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 08/11/2020] [Indexed: 01/24/2023] Open
Abstract
The P2X7 receptor (P2X7) is a cell surface ligand-gated ion channel, activated by its physiological nucleotide agonist ATP and a synthetic analog (BzATP). However, it has also been suggested that there may be structurally unrelated, non-nucleotide agonists such as the amyloidogenic β peptide. Here we aimed to reassess the effect of amyloid β peptides in various in vitro cell models, namely HEK293 overexpressing human P2X7, the microglial BV-2 cell line, and BV-2 cells lacking P2X7. We measured YO-PRO-1 dye uptake in response to full-length amyloid β peptide (1-42) or the shorter amyloid β peptide (25-35) and there was a concentration-dependent increase in YO-PRO-1 dye uptake in HEK-hP2X7 cells. However, these amyloid β peptide-induced increases in YO-PRO-1 dye uptake were also identical in non-transfected HEK-293 cells. We could observe small transient increases in [Ca2+] i induced by amyloid β peptides in BV-2 cells, however these were identical in BV-2 cells lacking P2X7. Furthermore, our metabolic viability and LDH release experiments suggest no significant change in viability or cell membrane damage in HEK-hP2X7 cells. In the BV-2 cells we found that high concentrations of amyloid β peptides (1-42) and (25-35) could reduce cell viability by up to 35% but this was also seen in BV-2 cells lacking P2X7. We found no evidence of LDH release by amyloid β peptides. In summary, we found no evidence that amyloid β peptides act as agonists of P2X7 in our in vitro models. Our study raises the possibility that amyloid β peptides simply mimic features of P2X7 activation.
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Affiliation(s)
- Lučka Bibič
- School of Pharmacy, University of East Anglia, Norwich, United Kingdom
| | - Leanne Stokes
- School of Pharmacy, University of East Anglia, Norwich, United Kingdom
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21
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Sun Y, Lu Y, Saredy J, Wang X, Drummer Iv C, Shao Y, Saaoud F, Xu K, Liu M, Yang WY, Jiang X, Wang H, Yang X. ROS systems are a new integrated network for sensing homeostasis and alarming stresses in organelle metabolic processes. Redox Biol 2020; 37:101696. [PMID: 32950427 PMCID: PMC7767745 DOI: 10.1016/j.redox.2020.101696] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) are critical for the progression of cardiovascular diseases, inflammations and tumors. However, the mechanisms of how ROS sense metabolic stress, regulate metabolic pathways and initiate proliferation, inflammation and cell death responses remain poorly characterized. In this analytic review, we concluded that: 1) Based on different features and functions, eleven types of ROS can be classified into seven functional groups: metabolic stress-sensing, chemical connecting, organelle communication, stress branch-out, inflammasome-activating, dual functions and triple functions ROS. 2) Among the ROS generation systems, mitochondria consume the most amount of oxygen; and nine types of ROS are generated; thus, mitochondrial ROS systems serve as the central hub for connecting ROS with inflammasome activation, trained immunity and immunometabolic pathways. 3) Increased nuclear ROS production significantly promotes cell death in comparison to that in other organelles. Nuclear ROS systems serve as a convergent hub and decision-makers to connect unbearable and alarming metabolic stresses to inflammation and cell death. 4) Balanced ROS levels indicate physiological homeostasis of various metabolic processes in subcellular organelles and cytosol, while imbalanced ROS levels present alarms for pathological organelle stresses in metabolic processes. Based on these analyses, we propose a working model that ROS systems are a new integrated network for sensing homeostasis and alarming stress in metabolic processes in various subcellular organelles. Our model provides novel insights on the roles of the ROS systems in bridging metabolic stress to inflammation, cell death and tumorigenesis; and provide novel therapeutic targets for treating those diseases. (Word count: 246).
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Affiliation(s)
- Yu Sun
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Yifan Lu
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Jason Saredy
- Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Xianwei Wang
- Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Charles Drummer Iv
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Ying Shao
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Fatma Saaoud
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Keman Xu
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - Ming Liu
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA
| | - William Y Yang
- Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Xiaohua Jiang
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA; Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Hong Wang
- Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Xiaofeng Yang
- Centers for Cardiovascular Research and Inflammation, Translational and Clinical Lung Research, USA; Metabolic Disease Research and Cardiovascular Research and Thrombosis Research, Departments of Pharmacology, Microbiology and Immunology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
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22
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ATP-Nlrp3 Inflammasome-Complement Cascade Axis in Sterile Brain Inflammation in Psychiatric Patients and its Impact on Stem Cell Trafficking. Stem Cell Rev Rep 2020; 15:497-505. [PMID: 31020518 PMCID: PMC6647482 DOI: 10.1007/s12015-019-09888-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent evidence indicates that the occurrence of psychiatric disorders in patients is linked to a local “sterile” inflammation of brain or due to a systemic inflammation process that affects the central nervous system. This is supported by the observation that in peripheral blood of psychotic patients are detectable several mediators and markers of inflammation as well as clinical data on correlations between systemic chronic inflammatory processes and psychiatric disorders. This may explain why some reported anti-inflammatory treatment strategies have beneficial effects on ameliorating psychotic events. In this review we will present a concept that aberrant purinergic signaling and increases in extracellular level of adenosine triphosphate (ATP) in the brain parenchyma may lead to activation of Nlrp3 inflammasome in microglia cells and as a consequence microglia released danger associated molecular pattern (DAMP) proteins activate complement cascade (ComC) in mannan binding lectin (MBL) – dependent manner. Activation of ATP-Nlrp3 inflammasome-ComC axis may also orchestrate trafficking of stem cells released from bone marrow into peripheral blood observed in psychotic patients. Based on this, the ATP-Nlrp3 inflammasome-ComC axis may become a target for new therapeutic approaches, which justifies the development and clinical application of efficient anti-inflammatory treatment strategies targeting this axis in psychiatry.
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23
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Cisneros-Mejorado AJ, Pérez-Samartín A, Domercq M, Arellano RO, Gottlieb M, Koch-Nolte F, Matute C. P2X7 Receptors as a Therapeutic Target in Cerebrovascular Diseases. Front Mol Neurosci 2020; 13:92. [PMID: 32714144 PMCID: PMC7340211 DOI: 10.3389/fnmol.2020.00092] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/05/2020] [Indexed: 12/20/2022] Open
Abstract
Shortage of oxygen and nutrients in the brain induces the release of glutamate and ATP that can cause excitotoxicity and contribute to neuronal and glial damage. Our understanding of the mechanisms of ATP release and toxicity in cerebrovascular diseases is incomplete. This review aims at summarizing current knowledge about the participation of key elements in the ATP-mediated deleterious effects in these pathologies. This includes pannexin-1 hemichannels, calcium homeostasis modulator-1 (CALHM1), purinergic P2X7 receptors, and other intermediaries of CNS injury downstream of ATP release. Available data together with recent pharmacological developments in purinergic signaling may constitute a new opportunity to translate preclinical findings into more effective therapies in cerebrovascular diseases.
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Affiliation(s)
| | - Alberto Pérez-Samartín
- Achucarro Basque Center for Neuroscience, Departamento de Neurociencias, Universidad del País Vasco, CIBERNED, Leioa, Spain
| | - María Domercq
- Achucarro Basque Center for Neuroscience, Departamento de Neurociencias, Universidad del País Vasco, CIBERNED, Leioa, Spain
| | - Rogelio O Arellano
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Mexico
| | - Miroslav Gottlieb
- Institute of Neurobiology, Slovak Academy of Sciences, Kosice, Slovakia
| | | | - Carlos Matute
- Achucarro Basque Center for Neuroscience, Departamento de Neurociencias, Universidad del País Vasco, CIBERNED, Leioa, Spain
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24
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Wilkaniec A, Cieślik M, Murawska E, Babiec L, Gąssowska-Dobrowolska M, Pałasz E, Jęśko H, Adamczyk A. P2X7 Receptor is Involved in Mitochondrial Dysfunction Induced by Extracellular Alpha Synuclein in Neuroblastoma SH-SY5Y Cells. Int J Mol Sci 2020; 21:ijms21113959. [PMID: 32486485 PMCID: PMC7312811 DOI: 10.3390/ijms21113959] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022] Open
Abstract
The purinergic P2X7 receptor (P2X7R) belongs to a family of trimeric ion channels that are gated by extracellular adenosine 5′-triphosphate (ATP). Several studies have pointed to a role of P2X7R-dependent signalling in Parkinson's disease (PD)-related neurodegeneration. The pathology of (PD) is characterized by the formation of insoluble alpha-synuclein (α-Syn) aggregates—Lewy bodies, but the mechanisms underlying α-Syn-induced dopaminergic cell death are still partially unclear. Our previous studies indicate that extracellular α-Syn directly interact with neuronal P2X7R and induces intracellular free calcium mobilization in neuronal cells. The main objective of this study was to examine the involvement of P2X7R receptor in α-Syn-induced mitochondrial dysfunction and cell death. We found that P2X7R stimulation is responsible for α-Syn-induced oxidative stress and activation of the molecular pathways of programmed cell death. Exogenous α-Syn treatment led to P2X7R-dependent decrease in mitochondrial membrane potential as well as elevation of mitochondrial ROS production resulting in breakdown of cellular energy production. Moreover, P2X7R-dependent deregulation of AMP-activated protein kinase as well as decrease in parkin protein level could be responsible for α-Syn-induced mitophagy impairment and accumulation of dysfunctional mitochondria. P2X7R might be putative pharmacological targets in molecular mechanism of extracellular α-Syn toxicity.
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Affiliation(s)
- Anna Wilkaniec
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
- Correspondence: ; Tel.: +48-22-608-66-00; Fax: +48-22-608-64-13
| | - Magdalena Cieślik
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Emilia Murawska
- Department of Applied Microbiology, Institute of Microbiology, Warsaw University, Miecznikowa 1 Street, 02-096 Warsaw, Poland;
| | - Lidia Babiec
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Magdalena Gąssowska-Dobrowolska
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Ewelina Pałasz
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Henryk Jęśko
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Agata Adamczyk
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
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25
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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: 32] [Impact Index Per Article: 8.0] [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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26
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Xu M, Zhang L, Liu G, Jiang N, Zhou W, Zhang Y. Pathological Changes in Alzheimer's Disease Analyzed Using Induced Pluripotent Stem Cell-Derived Human Microglia-Like Cells. J Alzheimers Dis 2020; 67:357-368. [PMID: 30562902 DOI: 10.3233/jad-180722] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microglia constitute the majority of innate immune cells in the brain, and their dysfunction is associated with various central nervous system diseases. Human microglia are extremely difficult to obtain experimentally, thereby limiting studies on their role in complex diseases. Microglia derived from human stem cells provide new tools to assess the pathogenesis of complex diseases and to develop effective treatment methods. This study aimed to develop a reliable method to derive human microglial-like cells (iMGLs) from induced pluripotent stem cells (iPSCs) expressing microglia-specific markers IBA1 and TMEM119 and respond to lipopolysaccharide (LPS) stimulation. Thereafter, we compared iMGL functions from Alzheimer's disease (AD) patients and cognitive normal controls (CNCs). AD-iMGLs displayed stronger phagocytic ability with or without stimulation. High LPS concentrations (>2μg/ml) caused death in CNC-iMGLs, while AD-iMGLs did not display significant cell death. Cytokine analysis revealed that TNF-α, IL-6, and IL-10 secreted by AD-iMGLs were significantly increased upon LPS stimulation compared to those in CNC-iMGLs. The present results indicate that AD-iMGLs exhibit significant inflammatory characteristics and can reflect some pathological changes in microglia in AD, thereby providing new valuable tools to screen candidate drugs for AD and to elucidate the mechanisms underlying AD pathogenesis.
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Affiliation(s)
- Mei Xu
- Beijing Institute of Pharmacology and Toxicology, Beijing, P.R. China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, P.R. China
| | - Lin Zhang
- Beijing Institute of Pharmacology and Toxicology, Beijing, P.R. China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, P.R. China
| | - Gang Liu
- Beijing Institute of Pharmacology and Toxicology, Beijing, P.R. China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, P.R. China
| | - Ning Jiang
- Beijing Institute of Pharmacology and Toxicology, Beijing, P.R. China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, P.R. China
| | - Wenxia Zhou
- Beijing Institute of Pharmacology and Toxicology, Beijing, P.R. China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, P.R. China
| | - Yongxiang Zhang
- Beijing Institute of Pharmacology and Toxicology, Beijing, P.R. China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, P.R. China
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27
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Neuroinflammation in CNS diseases: Molecular mechanisms and the therapeutic potential of plant derived bioactive molecules. PHARMANUTRITION 2020. [DOI: 10.1016/j.phanu.2020.100176] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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28
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Bidula S, Dhuna K, Helliwell R, Stokes L. Positive allosteric modulation of P2X7 promotes apoptotic cell death over lytic cell death responses in macrophages. Cell Death Dis 2019; 10:882. [PMID: 31767863 PMCID: PMC6877589 DOI: 10.1038/s41419-019-2110-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 10/15/2019] [Accepted: 10/25/2019] [Indexed: 12/30/2022]
Abstract
P2X7 is an ATP-gated ion channel that is highly expressed by leukocytes, such as macrophages. Here, P2X7 has been demonstrated to be involved in the regulation of various cell death pathways; including apoptosis, pyroptosis, necrosis, and autophagy. However, cell death induction via P2X7 is complex and is reliant upon the nature of the stimulus, the duration of the stimulus, and the cell type investigated. Previous reports state that high extracellular ATP concentrations promote osmotic lysis, but whether positive allosteric modulation of P2X7 in the presence of lower concentrations of ATP condemns cells to the same fate is unknown. In this study, we compared cell death induced by high ATP concentrations, to cell death induced by compound K, a recently identified and potent positive allosteric modulator of P2X7. Based on our observations, we propose that high ATP concentrations induce early cell swelling, loss of mitochondrial membrane potential, plasma membrane rupture, and LDH release. Conversely, positive allosteric modulation of P2X7 primarily promotes an intrinsic apoptosis pathway. This was characterised by an increase in mitochondrial Ca2+, accelerated production of mitochondrial ROS, loss of mitochondrial membrane permeability in a Bax-dependent manner, the potential involvement of caspase-1, and caspase-3, and significantly accelerated kinetics of caspase-3 activation. This study highlights the ability of positive allosteric modulators to calibrate P2X7-dependent cell death pathways and may have important implications in modulating the antimicrobial immune response and in the resolution of inflammation.
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Affiliation(s)
- Stefan Bidula
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Kshitija Dhuna
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, 3083, Australia
| | - Ray Helliwell
- School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, 3083, Australia
| | - Leanne Stokes
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, United Kingdom.
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29
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Neurodegeneration and Neuro-Regeneration-Alzheimer's Disease and Stem Cell Therapy. Int J Mol Sci 2019; 20:ijms20174272. [PMID: 31480448 PMCID: PMC6747457 DOI: 10.3390/ijms20174272] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 12/17/2022] Open
Abstract
Aging causes many changes in the human body, and is a high risk for various diseases. Dementia, a common age-related disease, is a clinical disorder triggered by neurodegeneration. Brain damage caused by neuronal death leads to cognitive decline, memory loss, learning inabilities and mood changes. Numerous disease conditions may cause dementia; however, the most common one is Alzheimer’s disease (AD), a futile and yet untreatable illness. Adult neurogenesis carries the potential of brain self-repair by an endogenous formation of newly-born neurons in the adult brain; however it also declines with age. Strategies to improve the symptoms of aging and age-related diseases have included different means to stimulate neurogenesis, both pharmacologically and naturally. Finally, the regulatory mechanisms of stem cells neurogenesis or a functional integration of newborn neurons have been explored to provide the basis for grafted stem cell therapy. This review aims to provide an overview of AD pathology of different neural and glial cell types and summarizes current strategies of experimental stem cell treatments and their putative future use in clinical settings.
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30
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Zhong S, Zhou Z, Liang Y, Cheng X, Li Y, Teng W, Zhao M, Liu C, Guan M, Zhao C. Targeting strategies for chemotherapy-induced peripheral neuropathy: does gut microbiota play a role? Crit Rev Microbiol 2019; 45:369-393. [PMID: 31106639 DOI: 10.1080/1040841x.2019.1608905] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a progressive, often irreversible condition that produces severe neurological deficits. Emerging data suggest that chemotherapy also exerts detrimental effects on gut microbiota composition and intestinal permeability, contributing to dysbiosis and inflammation. Compared with other complications associated with chemotherapy, such as diarrhoea and mucositis, CIPN is of particular concern because it is the most common reason for terminating or suspending treatment. However, specific and effective curative treatment strategies are lacking. In this review, we provide an update on current preclinical and clinical understandings about the role of gut microbiota in CIPN. The gut microbiota serves as an intersection between the microbiome-gut-brain and the neuroimmune-endocrine axis, forming a complex network that can directly or indirectly affect key components involved in the manifestations of CIPN. Herein, we discuss several potential mechanisms within the context of the networks and summarize alterations in gut microbiome induced by chemotherapeutic drugs, providing great potential for researchers to target pathways associated with the gut microbiome and overcome CIPN.
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Affiliation(s)
- Shanshan Zhong
- Department of Neurology and Stroke Center, The First Hospital of China Medical University , Shenyang , PR China
| | - Zhike Zhou
- Department of Geriatrics, The First Hospital of China Medical University , Shenyang , PR China
| | - Yifan Liang
- Department of Neurology and Stroke Center, The First Hospital of China Medical University , Shenyang , PR China
| | - Xi Cheng
- Department of Neurology and Stroke Center, The First Hospital of China Medical University , Shenyang , PR China
| | - Yong Li
- Department of Biochemistry and Molecular Cell Biology, Shanghai Jiao Tong University , Shenyang , PR China
| | - Weiyu Teng
- Department of Neurology and Stroke Center, The First Hospital of China Medical University , Shenyang , PR China
| | - Mei Zhao
- Department of Cardiology, Shengjing Hospital of China Medical University , Shenyang , PR China
| | - Chang Liu
- Department of Neurology and Stroke Center, The First Hospital of China Medical University , Shenyang , PR China
| | - Meiting Guan
- Department of Neurology and Stroke Center, The First Hospital of China Medical University , Shenyang , PR China
| | - Chuansheng Zhao
- Department of Neurology and Stroke Center, The First Hospital of China Medical University , Shenyang , PR China
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31
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Development of brain PET imaging agents: Strategies for imaging neuroinflammation in Alzheimer's disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 165:371-399. [DOI: 10.1016/bs.pmbts.2019.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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32
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Janks L, Sharma CVR, Egan TM. A central role for P2X7 receptors in human microglia. J Neuroinflammation 2018; 15:325. [PMID: 30463629 PMCID: PMC6247771 DOI: 10.1186/s12974-018-1353-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 10/30/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The ATP-gated ionotropic P2X7 receptor (P2X7R) has the unusual ability to function as a small cation channel and a trigger for permeabilization of plasmalemmal membranes. In murine microglia, P2X7R-mediated permeabilization is fundamental to microglial activation, proliferation, and IL-1β release. However, the role of the P2X7R in primary adult human microglia is poorly understood. METHODS We used patch-clamp electrophysiology to record ATP-gated current in cultured primary human microglia; confocal microscopy to measure membrane blebbing; fluorescence microscopy to demonstrate membrane permeabilization, caspase-1 activation, phosphatidylserine translocation, and phagocytosis; and kit-based assays to measure cytokine levels. RESULTS We found that ATP-gated inward currents facilitated with repetitive applications of ATP as expected for current through P2X7Rs and that P2X7R antagonists inhibited these currents. P2X7R antagonists also prevented the ATP-induced uptake of large cationic fluorescent dyes whereas drugs that target pannexin-1 channels had no effect. In contrast, ATP did not induce uptake of anionic dyes. The uptake of cationic dyes was blocked by drugs that target Cl- channels. Finally, we found that ATP activates caspase-1 and inhibits phagocytosis, and these effects are blocked by both P2X7R and Cl- channel antagonists. CONCLUSIONS Our results demonstrate that primary human microglia in culture express functional P2X7Rs that stimulate both ATP-gated cationic currents and uptake of large molecular weight cationic dyes. Importantly, our data demonstrate that hypotheses drawn from work on murine immune cells accurately predict the essential role of P2X7Rs in a number of human innate immune functions such as phagocytosis and caspase-1 activation. Therefore, the P2X7R represents an attractive target for therapeutic intervention in human neuroinflammatory disorders.
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Affiliation(s)
- Laura Janks
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 South Grand Boulevard, St. Louis, MO, 63104, USA
| | | | - Terrance M Egan
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 South Grand Boulevard, St. Louis, MO, 63104, USA.
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Sekar P, Huang DY, Hsieh SL, Chang SF, Lin WW. AMPK-dependent and independent actions of P2X7 in regulation of mitochondrial and lysosomal functions in microglia. Cell Commun Signal 2018; 16:83. [PMID: 30458799 PMCID: PMC6245559 DOI: 10.1186/s12964-018-0293-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/01/2018] [Indexed: 12/24/2022] Open
Abstract
Background P2X7 is ubiquitously expressed in myeloid cells and regulates the pathophysiology of inflammatory diseases. Since mitochondrial function in microglia is highly associated with microglial functions in controlling neuronal plasticity and brain homeostasis, we interested to explore the roles of P2X7 in mitochondrial and lysosomal functions as well as mitophagy in microglia. Methods P2X7−/− bone marrow-derived macrophages (BMDM), primary microglia and BV-2 immortalized microglial cells were used to detect the particular protein expression by immunoblotting. Mitochondrial reactive oxygen species (mitoROS), intracellular calcium, mitochondrial mass and lysosomal integrity were examined by flow cytometry. Mitochondrial oxygen consumption rate (OCR) was recorded using Seahorse XF flux analyzer. Confocal microscopic images were performed to indicate the mitochondrial dynamics and mitophagy after P2X7 activation. Results In primary microglia, BV-2 microglial cells and BMDM, P2X7 agonist BzATP triggered AMPK activation and LC3II accumulation through reactive oxygen species (ROS) and CaMKKII pathways, and these effects were abolished by P2X7 antagonist A438079 and P2X7 deficiency. Moreover, we detected the dramatic decreases of mitochondrial OCR and mass following P2X7 activation. AMPK inhibition by compound C or AMPK silencing reversed the P2X7 actions in reduction of mitochondrial mass, induction of mitochondrial fission and mitophagy, but not in uncoupling of mitochondrial respiration. Interestingly, we found that P2X7 activation induced nuclear translocation of TFEB via an AMPK-dependent pathway and led to lysosomal biogenesis. Mimicking the actions of BzATP, nigericin also induced ROS-dependent AMPK activation, mitophagy, mitochondrial fission and respiratory inhibition. Longer exposure of BzATP induced cell death, and this effect was accompanied by the lysosomal instability and was inhibited by autophagy and cathepsin B inhibitors. Conclusion Altogether ROS- and CaMKK-dependent AMPK activation is involved in P2X7-mediated mitophagy, mitochondrial dynamics and lysosomal biogenesis in microglial cells, which is followed by cytotoxicity partially resulting from mitophagy and cathepsin B activation. Electronic supplementary material The online version of this article (10.1186/s12964-018-0293-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ponarulselvam Sekar
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan
| | - Duen-Yi Huang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | | | - Shwu-Fen Chang
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan
| | - Wan-Wan Lin
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan. .,Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
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34
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Diezmos EF, Markus I, Perera DS, Gan S, Zhang L, Sandow SL, Bertrand PP, Liu L. Blockade of Pannexin-1 Channels and Purinergic P2X7 Receptors Shows Protective Effects Against Cytokines-Induced Colitis of Human Colonic Mucosa. Front Pharmacol 2018; 9:865. [PMID: 30127744 PMCID: PMC6087744 DOI: 10.3389/fphar.2018.00865] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 07/17/2018] [Indexed: 12/31/2022] Open
Abstract
Introduction: The pannexin-1 (Panx1) channels are found in many cell types, and ATP released from these channels can act on nearby cells activating purinergic P2X7 receptors (P2X7R) which lead to inflammation. Although Panx1 and P2X7R are implicated in the process of inflammation and cell death, few studies have looked at the role they play in inflammatory bowel disease in human. Hence, the aim of the present study was to investigate the function of Panx1 and P2X7R in an ex vivo colitis model developed from human colonic mucosal explants. Materials and Methods: Healthy human colonic mucosal strips (4 × 10 mm) were incubated in carbogenated culture medium at 37°C for 16 h. Proinflammatory cytokines TNFα and IL-1β (each 10 ng/mL) were used to induce colitis in mucosal strips, and the effects of Panx1 and P2X7R on cytokines-induced tissue damage were determined in the presence of the Panx1 channel blocker 10Panx1 (100 μM) and P2X7R antagonist A438079 (100 μM). The effects of 10Panx1 and A438079 on cytokines-enhanced epithelial permeability were also studied using Caco-2 cells. Results: Histological staining showed that the mucosal strips had severe structural damage in the cytokines-only group but not in the incubation-control group (P < 0.01). Compared to the cytokines-only group, crypt damage was significantly decreased in groups receiving cytokines with inhibitors (10Panx1, A438079, or 10Panx1 + A438079, P < 0.05). The immunoreactive signals of tight junction protein zonula occludens-1 (ZO-1) were abundant in all control tissues but were significantly disrupted and lost in the cytokines-only group (P < 0.01). The diminished ZO-1 immunoreactivity induced by cytokines was prevented in the presence of 10Panx1 (P = 0.04). Likewise, 10Panx1 significantly attenuated the cytokines-evoked increase in paracellular permeability of Caco-2 cells. Although the inhibition of P2X7R activity by A438079 diminished cytokines-induced crypt damage, its effect on the maintenance of ZO-1 immunoreactivity and Caco-2 epithelial cell integrity was less evident. Conclusion: The blockade of Panx1 and P2X7R reduced the inflammatory cytokines-induced crypt damage, loss of tight junctions and increase in cell permeability. Thus, Panx1 and P2X7R may have roles in causing mucosal damage, a common clinical feature of inflammatory bowel disease.
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Affiliation(s)
- Erica F Diezmos
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Irit Markus
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - D S Perera
- Sydney Colorectal Associates, Hurstville, NSW, Australia
| | - Steven Gan
- Sydney Colorectal Associates, Hurstville, NSW, Australia
| | - Li Zhang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Shaun L Sandow
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Inflammation and Healing Cluster, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sunshine Coast, QLD, Australia
| | - Paul P Bertrand
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,School of Health and Biomedical Sciences, RMIT University, Bundoora, Melbourne, VIC, Australia
| | - Lu Liu
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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35
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Alves LA, Ferreira LB, Pacheco PF, Mendivelso EAC, Teixeira PCN, Faria RX. Pore forming channels as a drug delivery system for photodynamic therapy in cancer associated with nanoscintillators. Oncotarget 2018; 9:25342-25354. [PMID: 29861876 PMCID: PMC5982756 DOI: 10.18632/oncotarget.25150] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 03/27/2018] [Indexed: 01/05/2023] Open
Abstract
According to the World Health Organization (WHO), cancer is one of main causes of death worldwide, with 8.2 million people dying from this disease in 2012. Because of this, new forms of treatments or improvement of current treatments are crucial. In this regard, Photodynamic therapy (PDT) has been used to successfully treat cancers that can be easily accessed externally or by fibre-optic endoscopes, such as skin, bladder and esophagus cancers. In addition, this therapy can used alongside radiotherapy and chemotherapy in order to kill cancer cells. The main problem in implementing PDT is penetration of visible light deeper than 10 mm in tissues, due to scattering and absorption by tissue chromophores. Unfortunately, this excludes several internal organs affected by cancer. Another issue in this regard is the use of a selective cancer cell-photosensitizing compound. Nevertheless, several groups have recently developed scintillation nanoparticles, which can be stimulated by X-rays, thereby making this a possible solution for light production in deeper tissues. Alternative approaches have also been developed, such as photosensitizer structure modifications and cell membrane permeabilizing agents. In this context, certain channels lead to transitory plasma membrane permeability changes, such as pannexin, connexin hemmichannels, TRPV1-4 and P2×7, which allow for the non-selective passage of molecules up to 1,000 Da. Herein, we discuss the particular case of the P2×7 receptor-associated pore as a drug delivery system for hydrophilic substances to be applied in PDT, which could also be carried out with other channels. Methylene blue (MB) is a low cost dye used as a prototype photosensitizer, approved for clinical use in several other clinical conditions, as well as photodynamic therapy for fungi infections.
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Affiliation(s)
- Luiz Anastacio Alves
- Laboratório de Comunicação Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz-FIOCRUZ, 21045-900, Rio de Janeiro, RJ, Brasil
| | - Leonardo Braga Ferreira
- Laboratório de Inflamação e Instituto Oswaldo Cruz, Fundação Oswaldo Cruz-FIOCRUZ, 21045-900, Rio de Janeiro, RJ, Brasil
| | - Paulo Furtado Pacheco
- Laboratório de Toxoplasmose Instituto Oswaldo Cruz, Fundação Oswaldo Cruz-FIOCRUZ, 21045-900, Rio de Janeiro, RJ, Brasil
| | | | - Pedro Celso Nogueira Teixeira
- Laboratório de Comunicação Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz-FIOCRUZ, 21045-900, Rio de Janeiro, RJ, Brasil
| | - Robson Xavier Faria
- Laboratório de Toxoplasmose Instituto Oswaldo Cruz, Fundação Oswaldo Cruz-FIOCRUZ, 21045-900, Rio de Janeiro, RJ, Brasil
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Lee SH, Suk K. Identification of glia phenotype modulators based on select glial function regulatory signaling pathways. Expert Opin Drug Discov 2018; 13:627-641. [DOI: 10.1080/17460441.2018.1465925] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Sun-Hwa Lee
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Republic of Korea
| | - Kyoungho Suk
- Department of Pharmacology, Brain Science & Engineering Institute, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
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Abstract
Neuroinflammation, which involves microglial activation, is thought to play a key role in the development and progression of neurodegenerative diseases and other brain pathologies. Positron emission tomography is an ideal imaging technique for studying biochemical processes in vivo, and particularly for studying the living brain. Neuroinflammation has been traditionally studied using radiotracers targeting the translocator protein 18 kDa, but this comes with certain limitations. The current review describes alternative biological targets that have gained interest for the imaging of microglial activation over recent years, such as the cannabinoid receptor type 2, cyclooxygenase-2, the P2X₇ receptor and reactive oxygen species, and some promising radiotracers for these targets. Although many advances have been made in the field of neuroinflammation imaging, current radiotracers all target the pro-inflammatory (M1) phenotype of activated microglia, since the number of known biological targets specific for the anti-inflammatory (M2) phenotype that are also suited as a target for radiotracer development is still limited. Next to proceeding the currently available tracers for M1 microglia into the clinic, the development of a suitable radiotracer for M2 microglia would mean a great advance in the field, as this would allow for imaging of the dynamics of microglial activation in different diseases.
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Affiliation(s)
- Bieneke Janssen
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Danielle J Vugts
- Department of Radiology & Nuclear Medicine, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
| | - Robert H Mach
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Coordinate effects of P2X7 and extracellular acidification in microglial cells. Oncotarget 2018; 9:12718-12731. [PMID: 29560104 PMCID: PMC5849168 DOI: 10.18632/oncotarget.24331] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 01/24/2018] [Indexed: 12/26/2022] Open
Abstract
Extracellular adenosine 5′-triphosphate (ATP) is a damage-associated molecular pattern and contributes to inflammation associated diseases including cancer. Extracellular acidosis is a novel danger signal in the inflammatory sites, where it can modulate inflammation, immunity and tumor growth. Extracellular acidification was shown to inhibit P2X7-mediated channel currents, while it remains unknown how acidification and P2X7 together affect cellular responses. Here, we treated BV-2 microglial cells with ATP in a short period (<15 min) or a sustained acidified condition. For short acidification we compared the actions of neutralized ATP and acidic ATP in a condition with pH buffering. For sustained acidification, we treated cells with neutralized ATP in acidic medium or acidic ATP in medium without pH buffering. In the short acidified condition, neutralized ATP induced higher responses than acidic ATP to increase intracellular calcium and reactive oxygen species, decrease intracellular potassium and induce cell death. In contrast, these cellular responses and mitochondrial fission caused by neutralized ATP were enhanced by pH 6.0 and pH 4.5 media. P2X7 activation can also rapidly block mitochondrial ATP turnover and respiration capacity, both of which were mimicked by nigericin and enhanced by acidity. Taken together P2X7-mediated ionic fluxes and reactive oxygen species production are attenuated under short acidification, while sustained acidification itself can induce mitochondrial toxicity which deteriorates the mitochondrial function under P2X7 activation.
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Geraghty NJ, Mansfield KJ, Fuller SJ, Watson D, Sluyter R. The P2X7 receptor is not essential for development of imiquimod-induced psoriasis-like inflammation in mice. Purinergic Signal 2017; 13:405-415. [PMID: 28597172 PMCID: PMC5714832 DOI: 10.1007/s11302-017-9569-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 04/13/2017] [Indexed: 02/06/2023] Open
Abstract
Psoriasis is a chronic inflammatory skin disorder, characterised by epidermal hyperplasia (acanthosis) and leukocyte infiltration of the skin. Current therapies are inadequate, highlighting the need for new therapeutic targets. The P2X7 receptor is implicated in the pathogenesis of psoriasis. This study investigated the role of P2X7 in imiquimod (IMQ)-induced psoriasis-like inflammation. Topically applied IMQ caused twofold greater ear swelling in BALB/c mice compared to C57BL/6 mice, which encode a partial loss-of-function missense mutation in the P2RX7 gene. However, there was no difference in histological skin pathology (acanthosis and leukocyte infiltration) between the two strains. IMQ treatment up-regulated P2X7 expression in skin from both mouse strains. Additionally, IMQ induced ATP release from cultured human keratinocytes, a process independent of cell death. Injection of the P2X7 antagonist Brilliant Blue G (BBG) but not A-804598 partly reduced ear swelling compared to vehicle-injected control mice. Neither antagonist altered skin pathology. Moreover, no difference in ear swelling or skin pathology was observed between C57BL/6 and P2X7 knock-out (KO) mice. Flow cytometric analysis of IMQ-treated skin from C57BL/6 and P2X7 KO mice demonstrated similar leukocyte infiltration, including neutrophils, macrophages and T cells. In conclusion, this study demonstrates that P2X7 is not essential for development of IMQ-induced psoriasis-like inflammation but does not exclude a role for this receptor in psoriasis development in humans or other mouse models of this disease.
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Affiliation(s)
- Nicholas J Geraghty
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Kylie J Mansfield
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Stephen J Fuller
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Debbie Watson
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Ronald Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.
- Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.
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40
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Chen Q, Wu H, Tao J, Liu C, Deng Z, Liu Y, Chen G, Liu B, Xu C. Effect of naringin on gp120-induced injury mediated by P2X7 receptors in rat primary cultured microglia. PLoS One 2017; 12:e0183688. [PMID: 28832643 PMCID: PMC5568276 DOI: 10.1371/journal.pone.0183688] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/09/2017] [Indexed: 12/16/2022] Open
Abstract
Human immunodeficiency virus type-1 (HIV-1) envelope glycoprotein 120 has been shown to activate microglia, causing release of inflammatory and toxic factors. The P2X7 receptor, primarily expressed on microglia, is closely associated with inflammation. Naringin, a plant bioflavonoid, has anti-inflammatory and anti-oxidative properties. We hypothesized that P2X7 receptor mediated gp120-induced injury in primary cultured microglia, and that naringin would have a protective effect. We showed that HIV-1 gp120 peptide (V3 loop, fragment 308–331) appeared to induce apoptosis of primary cultured microglia. However, there was a decrease of microglia apoptosis in gp120+naringin group compared with gp120 group. Using qPCR, Western blot, and immunofluorescence, we showed that gp120 stimulated expression of P2X7 mRNA and receptor protein, and this stimulation was inhibited by naringin. Treatment with gp120 increased concentrations of eATP, TNFα and IL-1β, and these effects were inhibited by naringin. Taken together, these results suggested that gp120 contributed to microglial cell injury and neurotoxic activity by up-regulating expression of P2X7, in a naringin-protective manner.
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Affiliation(s)
- Qiang Chen
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, P.R. China
| | - Hui Wu
- The Second Clinical Medical College of Nanchang University, Nanchang, P.R. China
| | - Jia Tao
- The Second Clinical Medical College of Nanchang University, Nanchang, P.R. China
| | - Chenglong Liu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, P.R. China
| | - Zeyu Deng
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, P.R. China
| | - Yang Liu
- The First Clinical Medical College of Nanchang University, Nanchang, P.R. China
| | - Guoqiao Chen
- The First Clinical Medical College of Nanchang University, Nanchang, P.R. China
| | - Baoyun Liu
- The First Clinical Medical College of Nanchang University, Nanchang, P.R. China
| | - Changshui Xu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, P.R. China
- * E-mail:
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41
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Geraghty NJ, Belfiore L, Ly D, Adhikary SR, Fuller SJ, Varikatt W, Sanderson-Smith ML, Sluyter V, Alexander SI, Sluyter R, Watson D. The P2X7 receptor antagonist Brilliant Blue G reduces serum human interferon-γ in a humanized mouse model of graft-versus-host disease. Clin Exp Immunol 2017; 190:79-95. [PMID: 28665482 DOI: 10.1111/cei.13005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2017] [Indexed: 01/31/2023] Open
Abstract
Graft-versus-host disease (GVHD) remains a major problem after allogeneic haematopoietic stem cell transplantation, a curative therapy for haematological malignancies. Previous studies have demonstrated a role for the adenosine triphosphate (ATP)-gated P2X7 receptor channel in allogeneic mouse models of GVHD. In this study, injection of human peripheral blood mononuclear cells (PBMCs) into immunodeficient non-obese diabetic-severe combined immunodeficiency-interleukin (NOD-SCID-IL)-2Rγnull (NSG) mice established a humanized mouse model of GVHD. This model was used to study the effect of P2X7 blockade in this disease. From five weeks post-PBMC injection, humanized mice exhibited clinical signs and histopathology characteristic of GVHD. The P2X7 antagonist, Brilliant Blue G (BBG), blocked ATP-induced cation uptake into both murine and human cells in vitro. Injection of BBG (50 mg/kg) into NSG mice did not affect engraftment of human leucocytes (predominantly T cells), or the clinical score and survival of mice. In contrast, BBG injection reduced circulating human interferon (IFN)-γ significantly, which was produced by human CD4+ and CD8+ T cells. BBG also reduced human T cell infiltration and apoptosis in target organs of GVHD. In conclusion, the P2X7 antagonist BBG reduced circulating IFN-γ in a humanized mouse model of GVHD supporting a potential role for P2X7 to alter the pathology of this disease in humans.
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Affiliation(s)
- N J Geraghty
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - L Belfiore
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - D Ly
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - S R Adhikary
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - S J Fuller
- Sydney Medical School Nepean, University of Sydney, Nepean Hospital, Penrith, NSW, Australia
| | - W Varikatt
- Sydney Medical School Westmead, University of Sydney, Westmead Hospital, NSW, Australia.,Institute for Clinical Pathology and Medical Research, Westmead, NSW Health Pathology, Australia
| | - M L Sanderson-Smith
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - V Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - S I Alexander
- Children's Hospital at Westmead, Westmead, NSW, Australia
| | - R Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - D Watson
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
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42
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The impact of oxidative stress and inflammation on RPE degeneration in non-neovascular AMD. Prog Retin Eye Res 2017; 60:201-218. [PMID: 28336424 DOI: 10.1016/j.preteyeres.2017.03.002] [Citation(s) in RCA: 478] [Impact Index Per Article: 68.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
Abstract
The retinal pigment epithelium (RPE) is a highly specialized, unique epithelial cell that interacts with photoreceptors on its apical side and with Bruch's membrane and the choriocapillaris on its basal side. Due to vital functions that keep photoreceptors healthy, the RPE is essential for maintaining vision. With aging and the accumulated effects of environmental stresses, the RPE can become dysfunctional and die. This degeneration plays a central role in age-related macular degeneration (AMD) pathobiology, the leading cause of blindness among the elderly in western societies. Oxidative stress and inflammation have both physiological and potentially pathological roles in RPE degeneration. Given the central role of the RPE, this review will focus on the impact of oxidative stress and inflammation on the RPE with AMD pathobiology. Physiological sources of oxidative stress as well as unique sources from photo-oxidative stress, the phagocytosis of photoreceptor outer segments, and modifiable factors such as cigarette smoking and high fat diet ingestion that can convert oxidative stress into a pathological role, and the negative impact of impairing the cytoprotective roles of mitochondrial dynamics and the Nrf2 signaling system on RPE health in AMD will be discussed. Likewise, the response by the innate immune system to an inciting trigger, and the potential role of local RPE production of inflammation, as well as a potential role for damage by inflammation with chronicity if the inciting trigger is not neutralized, will be debated.
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43
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Bartlett R, Sluyter V, Watson D, Sluyter R, Yerbury JJ. P2X7 antagonism using Brilliant Blue G reduces body weight loss and prolongs survival in female SOD1 G93A amyotrophic lateral sclerosis mice. PeerJ 2017; 5:e3064. [PMID: 28265522 PMCID: PMC5335685 DOI: 10.7717/peerj.3064] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 02/04/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease characterised by the accumulation of aggregated proteins, microglia activation and motor neuron loss. The mechanisms underlying neurodegeneration and disease progression in ALS are unknown, but the ATP-gated P2X7 receptor channel is implicated in this disease. Therefore, the current study aimed to examine P2X7 in the context of neurodegeneration, and investigate whether the P2X7 antagonist, Brilliant Blue G (BBG), could alter disease progression in a murine model of ALS. METHODS Human SOD1G93A transgenic mice, which normally develop ALS, were injected with BBG or saline, three times per week, from pre-onset of clinical disease (62-64 days of age) until end-stage. During the course of treatment mice were assessed for weight, clinical score and survival, and motor coordination, which was assessed by rotarod performance. Various parameters from end-stage mice were assessed as follows. Motor neuron loss and microgliosis were assessed by immunohistochemistry. Relative amounts of lumbar spinal cord SOD1 and P2X7 were quantified by immunoblotting. Serum monocyte chemoattractant protein-1 was measured by ELISA. Splenic leukocyte populations were assessed by flow cytometry. Relative expression of splenic and hepatic P2X7 mRNA was measured by quantitative real-time PCR. Lumbar spinal cord SOD1 and P2X7 were also quantified by immunoblotting in untreated female SOD1G93A mice during the course of disease. RESULTS BBG treatment reduced body weight loss in SOD1G93A mice of combined sex, but had no effect on clinical score, survival or motor coordination. BBG treatment reduced body weight loss in female, but not male, SOD1G93A mice. BBG treatment also prolonged survival in female, but not male, SOD1G93A mice, extending the mean survival time by 4.3% in female mice compared to female mice treated with saline. BBG treatment had no effect on clinical score or motor coordination in either sex. BBG treatment had no major effect on any end-stage parameters. Total amounts of lumbar spinal cord SOD1 and P2X7 in untreated female SOD1G93A mice did not change over time. DISCUSSION Collectively, this data suggests P2X7 may have a partial role in ALS progression in mice, but additional research is required to fully elucidate the contribution of this receptor in this disease.
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Affiliation(s)
- Rachael Bartlett
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
| | - Vanessa Sluyter
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
| | - Debbie Watson
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
| | - Ronald Sluyter
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
| | - Justin J. Yerbury
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Biosciences, Wollongong, NSW, Australia
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44
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Sluyter R, Bartlett R, Ly D, Yerbury JJ. P2X7 receptor antagonism in amyotrophic lateral sclerosis. Neural Regen Res 2017; 12:749-750. [PMID: 28616029 PMCID: PMC5461610 DOI: 10.4103/1673-5374.206643] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Ronald Sluyter
- School of Biological Sciences and Center for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute, NSW, Wollongong, Australia
| | - Rachael Bartlett
- School of Biological Sciences and Center for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute, NSW, Wollongong, Australia
| | - Diane Ly
- School of Biological Sciences and Center for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute, NSW, Wollongong, Australia
| | - Justin J Yerbury
- School of Biological Sciences and Center for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia; Illawarra Health and Medical Research Institute, NSW, Wollongong, Australia
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45
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James LRA, Sluyter R, Dillon CT, Ralph SF. Effects of Gold Nanoparticles and Gold Anti-Arthritic Compounds on Inflammation Marker Expression in Macrophages. Aust J Chem 2017. [DOI: 10.1071/ch17062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The ability of aurothiomalate and auranofin to alter the production of several cellular mediators of inflammation by RAW264.7 macrophages, was compared with each other and that of gold nanoparticles (Au NPs). Addition of auranofin was found to have a pronounced ability to lower the production of reactive nitrogen and oxygen species (RNS and ROS respectively), as well as interleukin-10 (IL-10) and tumour necrosis factor (TNF), by macrophages that were subsequently treated with lipopolysaccharide (LPS) to stimulate production of the mediators. In contrast, prior treatment of the cells with either aurothiomalate or Au NPs had either little or no significant effect on production of RNS and ROS. Treatment of the macrophages with Au NPs had a small effect on production of TNF by cells that were subsequently stimulated with LPS; however, the effect was much smaller than that elicited by auranofin. Similarly, aurothiomalate had a small but significant effect on production of IL-10. Varying the size of the Au NPs or the identity of the protective sheath surrounding the nanoparticles did not have a significant effect on the production of RNS or ROS by LPS-stimulated macrophages. The results of some of these investigations are discussed in the light of other studies reported in the literature. In addition, results obtained by scanning electron microscopy and energy-dispersive X-ray spectroscopy are presented that provide evidence for the accumulation of gold within macrophages exposed to Au NPs.
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46
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Wang XH, Xie X, Luo XG, Shang H, He ZY. Inhibiting purinergic P2X7 receptors with the antagonist brilliant blue G is neuroprotective in an intranigral lipopolysaccharide animal model of Parkinson's disease. Mol Med Rep 2016; 15:768-776. [PMID: 28035410 PMCID: PMC5364844 DOI: 10.3892/mmr.2016.6070] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 11/21/2016] [Indexed: 11/23/2022] Open
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder, which is characterized by the selective and progressive death of dopaminergic (DA) neurons in the substantia nigra. Increasing evidence suggests that inflammation is important in the degeneration of DA neurons. The purinergic receptor subtype P2X7 receptor (P2X7R) is key in the activation and proliferation of microglia. The present study aimed to examine whether inhibiting purinergic P2X7 receptors is neuroprotective in a rat model of PD, specifically via inhibiting p38 mitogen-activated protein kinase (MAPK). In an intranigral lipopolysaccharide (LPS) rat model of PD, immunohistochemical analysis revealed enhanced expression of P2X7R was observed in microglia. The administration of the P2X7R antagonist, brilliant blue G (BBG), reduced activation of the microglia and the loss of nigral DA neurons. In addition, immunohistochemistry and western blot analysis revealed the phosphorylation level of p38 MAPK increased in the microglia of the LPS-injected rats, which was inhibited by BBG treatment. The p38 MAPK inhibitor, SB203580, reduced microglial activation and the loss of DA neurons. Thus, these findings suggested that inhibition of P2X7R by BBG attenuated microglial activation and the loss of substantia nigra DA neurons via p38 MAPK in the rat LPS model of PD.
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Affiliation(s)
- Xin-Hong Wang
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Xin Xie
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Xiao-Guang Luo
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Hong Shang
- Department of Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Zhi-Yi He
- Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
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Carver KA, Lin CM, Bowes Rickman C, Yang D. Lack of the P2X 7 receptor protects against AMD-like defects and microparticle accumulation in a chronic oxidative stress-induced mouse model of AMD. Biochem Biophys Res Commun 2016; 482:81-86. [PMID: 27810364 DOI: 10.1016/j.bbrc.2016.10.140] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 10/29/2016] [Indexed: 12/17/2022]
Abstract
The P2X7 receptor (P2X7R) is an ATP-gated ion channel that is a key player in oxidative stress under pathological conditions. The P2X7R is expressed in the retinal pigmented epithelium (RPE) and neural retina. Chronic oxidative stress contributes to the pathogenesis of age-related macular degeneration (AMD). Mice lacking Cu, Zn superoxide dismutase (Sod1) developed chronic oxidative stress as well as AMD-like features, but whether the P2X7R plays a causative role in oxidative stress-induced AMD is unknown. Thus, the main purpose of this study was to test if concurrent knockout (KO) of P2X7R could block AMD-like defects seen in Sod1 KO mice. Using multiple approaches, we demonstrate that Sod1 KO causes AMD-like defects, including positive staining for oxidative stress markers, 3-nitrotyrosine and carboxymethyl lysine, thinning of the RPE and retina, thickening of Bruch's membrane, presence of basal laminar and linear deposits, RPE barrier disruption and accumulation of microglia/macrophages. Moreover, we find that Sod1 KO mice accumulate more microparticles (MPs) within RPE/choroid tissues. Concurrent KO of the P2X7R protects against AMD-like defects and MP accumulation in Sod1 KO mice. Together, we show for the first time, that deficiency of P2X7R prevents in vivo oxidative stress-induced accumulation of MPs and AMD-like defects. This work could potentially lead to novel therapies for AMD and other oxidative stress-driven diseases.
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Affiliation(s)
- Kyle A Carver
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - C M Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Catherine Bowes Rickman
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC 27710, USA; Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Dongli Yang
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA.
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N-Alkyl-Substituted Isatins Enhance P2X7 Receptor-Induced Interleukin-1β Release from Murine Macrophages. Mediators Inflamm 2016; 2016:2097219. [PMID: 27524862 PMCID: PMC4972911 DOI: 10.1155/2016/2097219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 06/23/2016] [Indexed: 11/17/2022] Open
Abstract
Extracellular adenosine 5'-triphosphate (ATP) activates the P2X7 receptor channel to induce the rapid release of the proinflammatory cytokine, interleukin- (IL-) 1β, from macrophages. Microtubule rearrangements are thought to be involved in this process. Some isatin derivatives alter microtubules and display anticancer activities. The current study investigated the effect of isatin and seven structurally diverse isatin derivatives on P2X7-mediated IL-1β release from murine J774 macrophages. ATP-induced IL-1β and lactate dehydrogenase (LDH) release were assessed by specific colorimetric assays. P2X7 activity was determined by flow cytometric measurements of ATP-induced cation dye uptake. Cytotoxicity of isatin derivatives was determined using a tetrazolium-based colorimetric assay. ATP caused rapid IL-1β release in a concentration-dependent manner, and this process was completely impaired by the P2X7 antagonist, AZ10606120. In contrast, 5,7-dibromo-N-(p-methoxybenzyl)isatin (NAI) and 3-{4-[5,7-dibromo-1-(4-methoxybenzyl)-2-oxoindolin-3-ylidenamino]phenyl}propanoic acid (NAI-imine) enhanced P2X7-induced IL-1β release by twofold compared to that of isatin and the parent molecule, 5,7-dibromoisatin. NAI and NAI-imine had minimal effect on P2X7-induced dye uptake and LDH release. In contrast, 24-hour incubation with NAI and NAI-imine (in the absence of exogenous ATP) induced macrophage death in a concentration-dependent manner. In conclusion, this study demonstrates that N-alkyl-substituted isatins enhance P2X7 receptor-induced IL-1β release from murine macrophages. Thus, in addition to direct anticancer effects, these compounds may also impact inflammatory and immune cells within the tumor microenvironment.
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Bhattacharya A, Biber K. The microglial ATP-gated ion channel P2X7 as a CNS drug target. Glia 2016; 64:1772-87. [PMID: 27219534 DOI: 10.1002/glia.23001] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 04/17/2016] [Accepted: 04/18/2016] [Indexed: 12/14/2022]
Abstract
Based on promising preclinical evidence, microglial P2X7 has increasingly being recognized as a target for therapeutic intervention in neurological and psychiatric diseases. However, despite this knowledge no P2X7-related drug has yet entered clinical trials with respect to CNS diseases. We here discuss the current literature on P2X7 being a drug target and identify unsolved issues and still open questions that have hampered the development of P2X7 dependent therapeutic approaches for CNS diseases. It is concluded here that the lack of brain penetrating P2X7 antagonists is a major obstacle in the field and that central P2X7 is a yet untested clinical drug target. In the CNS, microglial P2X7 activation causes neuroinflammation, which in turn plays a role in various CNS disorders. This has resulted in a surge of brain penetrant P2X7 antagonists. P2X7 is a viable, clinically untested CNS drug target. GLIA 2016;64:1772-1787.
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Affiliation(s)
- Anindya Bhattacharya
- LLC. Neuroscience Drug Discovery, Janssen Research & Development, 3210 Merryfield Row, San Diego, California
| | - Knut Biber
- Department of Psychiatry and Psychotherapy, University Hospital Freiburg, Hauptstrasse 5, Freiburg, Germany.,Department of Neuroscience, University Medical Center Groningen, University of Groningen, Ant. Deusinglaan 1, AV Groningen, The Netherlands
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Aprile-Garcia F, Metzger MW, Paez-Pereda M, Stadler H, Acuña M, Liberman AC, Senin SA, Gerez J, Hoijman E, Refojo D, Mitkovski M, Panhuysen M, Stühmer W, Holsboer F, Deussing JM, Arzt E. Co-Expression of Wild-Type P2X7R with Gln460Arg Variant Alters Receptor Function. PLoS One 2016; 11:e0151862. [PMID: 26986975 PMCID: PMC4795689 DOI: 10.1371/journal.pone.0151862] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/04/2016] [Indexed: 01/04/2023] Open
Abstract
The P2X7 receptor is a member of the P2X family of ligand-gated ion channels. A single-nucleotide polymorphism leading to a glutamine (Gln) by arginine (Arg) substitution at codon 460 of the purinergic P2X7 receptor (P2X7R) has been associated with mood disorders. No change in function (loss or gain) has been described for this SNP so far. Here we show that although the P2X7R-Gln460Arg variant per se is not compromised in its function, co-expression of wild-type P2X7R with P2X7R-Gln460Arg impairs receptor function with respect to calcium influx, channel currents and intracellular signaling in vitro. Moreover, co-immunoprecipitation and FRET studies show that the P2X7R-Gln460Arg variant physically interacts with P2X7R-WT. Specific silencing of either the normal or polymorphic variant rescues the heterozygous loss of function phenotype and restores normal function. The described loss of function due to co-expression, unique for mutations in the P2RX7 gene so far, explains the mechanism by which the P2X7R-Gln460Arg variant affects the normal function of the channel and may represent a mechanism of action for other mutations.
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Affiliation(s)
- Fernando Aprile-Garcia
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina
- Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | | | | | - Matías Acuña
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Ana C. Liberman
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Sergio A. Senin
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Juan Gerez
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Esteban Hoijman
- Centro de Microscopías Avanzadas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Damian Refojo
- Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Mišo Mitkovski
- Max Planck Institute of Experimental Medicine, 37075, Göttingen, Germany
| | | | - Walter Stühmer
- Max Planck Institute of Experimental Medicine, 37075, Göttingen, Germany
| | - Florian Holsboer
- Max Planck Institute of Psychiatry, 80804, Munich, Germany
- HMNC Brain Health, Munich, Germany
| | | | - Eduardo Arzt
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina
- Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Max Planck Institute of Psychiatry, 80804, Munich, Germany
- * E-mail:
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