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Kiaie SH, Hatami Z, Nasr MS, Pazooki P, Hemmati S, Baradaran B, Valizadeh H. Pharmacological interaction and immune response of purinergic receptors in therapeutic modulation. Purinergic Signal 2024; 20:321-343. [PMID: 37843749 PMCID: PMC11303644 DOI: 10.1007/s11302-023-09966-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 09/10/2023] [Indexed: 10/17/2023] Open
Abstract
Nucleosides and purine nucleotides serve as transmitter and modulator agents that extend their functions beyond the cell. In this context, purinergic signaling plays a crucial role in regulating energy homeostasis and modulating metabolic alterations in tumor cells. Therefore, it is essential to consider the pharmacological targeting of purinergic receptors (PUR), which encompass the expression and inhibition of P1 receptors (metabotropic adenosine receptors) as well as P2 receptors (extracellular ATP/ADP) comprising P2X and P2Y receptors. Thus, the pharmacological interaction between inhibitors (such as RNA, monoclonal antibodies, and small molecules) and PUR represents a key aspect in facilitating the development of therapeutic interventions. Moreover, this review explores recent advancements in pharmacological inhibitors and the regulation of innate and adaptive immunity of PUR, specifically in relation to immunological and inflammatory responses. These responses encompass the release of pro-inflammatory cytokines (PIC), the production of reactive oxygen and nitrogen species (ROS and RNS), the regulation of T cells, and the activation of inflammasomes in all human leukocytes.
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Affiliation(s)
- Seyed Hossein Kiaie
- Drug Applied Research Center, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zahra Hatami
- Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Sadegh Nasr
- Department of Computer Science and Engineering Multi-Interprofessional Center for Health Informatics (MICHI), The University of Texas at Arlington, Arlington, TX, USA
| | - Pouya Pazooki
- Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Salar Hemmati
- Institute Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behzad Baradaran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Hadi Valizadeh
- Drug Applied Research Center, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
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2
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Migita K, Oyabu K, Terada K. Rectification of ATP-gated current of rat P2X2 and P2X7 receptors depends on the cytoplasmic N-terminus. Biochem Biophys Res Commun 2023; 688:149213. [PMID: 37976814 DOI: 10.1016/j.bbrc.2023.149213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 11/02/2023] [Indexed: 11/19/2023]
Abstract
The phenotypes of ATP-gated currents thought ionotropic P2X channels depend on the composition of the oligomeric receptor. We constructed chimeric P2X2/P2X7 receptors to study the effect of cytoplasmic domains on rectification of current flow through the open channel. We found that the identity of the N-terminus determines the pattern of rectification, with chimeric receptors containing the N-terminus of the P2X2 receptor displaying inward rectification, and chimeric receptors containing the N-terminus of the P2X7 receptor displaying slightly outward rectification. In contrast, rectification of current through chimeric receptors with swapped C-termini always mimicked the wild-type receptor. Thus, our findings suggest that the N-terminus of P2X receptors regulate ion flow through the channel pore and are responsible in part for determining current rectification.
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Affiliation(s)
- Keisuke Migita
- Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan.
| | - Kohei Oyabu
- Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Kazuki Terada
- Division of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, 670-8524, Japan
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3
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Cibelli A, Dohare P, Spray DC, Scemes E. Differential activation of mouse and human Panx1 channel variants. PLoS One 2023; 18:e0295710. [PMID: 38100403 PMCID: PMC10723736 DOI: 10.1371/journal.pone.0295710] [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: 09/06/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023] Open
Abstract
Pannexins are ubiquitously expressed in human and mouse tissues. Pannexin 1 (Panx1), the most thoroughly characterized member of this family, forms plasmalemmal membrane channels permeable to relatively large molecules, such as ATP. Although human and mouse Panx1 amino acid sequences are conserved in the presently known regulatory sites involved in trafficking and modulation of the channel, differences are reported in the N- and C-termini of the protein, and the mechanisms of channel activation by different stimuli remain controversial. Here we used a neuroblastoma cell line to study the activation properties of endogenous mPanx1 and exogenously expressed hPanx1. Dye uptake and electrophysiological recordings revealed that in contrast to mouse Panx1, the human ortholog is insensitive to stimulation with high extracellular [K+] but responds similarly to activation of the purinergic P2X7 receptor. The two most frequent Panx1 polymorphisms found in the human population, Q5H (rs1138800) and E390D (rs74549886), exogenously expressed in Panx1-null N2a cells revealed that regarding P2X7 receptor mediated Panx1 activation, the Q5H mutant is a gain of function whereas the E390D mutant is a loss of function variant. Collectively, we demonstrate differences in the activation between human and mouse Panx1 orthologs and suggest that these differences may have translational implications for studies where Panx1 has been shown to have significant impact.
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Affiliation(s)
- Antonio Cibelli
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Preeti Dohare
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - David C. Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Eliana Scemes
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States of America
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4
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Iring-Varga B, Baranyi M, Gölöncsér F, Tod P, Sperlágh B. The antidepressant effect of short- and long-term zinc exposition is partly mediated by P2X7 receptors in male mice. Front Pharmacol 2023; 14:1241406. [PMID: 37908978 PMCID: PMC10613712 DOI: 10.3389/fphar.2023.1241406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/28/2023] [Indexed: 11/02/2023] Open
Abstract
Background: As a member of the purinergic receptor family, divalent cation-regulated ionotropic P2X7 (P2rx7) plays a role in the pathophysiology of psychiatric disorders. This study aimed to investigate whether the effects of acute zinc administration and long-term zinc deprivation on depression-like behaviors in mice are mediated by P2X7 receptors. Methods: The antidepressant-like effect of elevated zinc level was studied using a single acute intraperitoneal injection in C57BL6/J wild-type and P2rx7 gene-deficient (P2rx7 -/-) young adult and elderly animals in the tail suspension test (TST) and the forced swim test (FST). In the long-term experiments, depression-like behavior caused by zinc deficiency was investigated with the continuous administration of zinc-reduced and control diets for 8 weeks, followed by the same behavioral tests. The actual change in zinc levels owing to the treatments was examined by assaying serum zinc levels. Changes in monoamine and brain-derived neurotrophic factor (BDNF) levels were measured from the hippocampus and prefrontal cortex brain areas by enzyme-linked immunosorbent assay and high-performance liquid chromatography, respectively. Results: A single acute zinc treatment increased the serum zinc level evoked antidepressant-like effect in both genotypes and age groups, except TST in elderly P2rx7 -/- animals, where no significant effect was detected. Likewise, the pro-depressant effect of zinc deprivation was observed in young adult mice in the FST and TST, which was alleviated in the case of the TST in the absence of functional P2X7 receptors. Among elderly mice, no pro-depressant effect was observed in P2rx7 -/- mice in either tests. Treatment and genotype changes in monoamine and BDNF levels were also detected in the hippocampi. Conclusion: Changes in zinc intake were associated with age-related changes in behavior in the TST and FST. The antidepressant-like effect of zinc is partially mediated by the P2X7 receptor.
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Affiliation(s)
- Bernadett Iring-Varga
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School, Semmelweis University, Budapest, Hungary
| | - Mária Baranyi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary
| | - Flóra Gölöncsér
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary
| | - Pál Tod
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary
| | - Beáta Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School, Semmelweis University, Budapest, Hungary
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5
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Fjærvoll HK, Fjærvoll KA, Yang M, Bair J, Utheim TP, Dartt DA. Purinergic 2X 4 (P2X4), but not P2X7, receptors increase cytosolic [Ca 2+] and stimulate mucin secretion in rat conjunctival goblet cells to maintain ocular surface health. Exp Eye Res 2023; 235:109614. [PMID: 37580003 DOI: 10.1016/j.exer.2023.109614] [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: 05/07/2023] [Revised: 07/14/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
Ionotropic purinergic receptors (P2XRs) are activated by ATP and ATP analogs. ATP can be released through ATP-permeable channels such as the pannexin hemichannels. Upon activation, the P2XRs become permeable to Ca2+, a potent stimulator of mucin secretion in conjunctival goblet cells (CGCs). The purpose of this study was to investigate the presence and function of P2XRs in CGCs. We also examined the presence of pannexin hemichannels. Rat first passage CGCs were stained with the goblet cell marker anti-cytokeratin 7 antibody and specific antibodies to P2X1-7 receptors and pannexin 1-3. mRNA expression was determined by RT-PCR using primers specific to P2XRs and pannexins. Proteins were identified with Western blotting (WB) using the same antibodies as for immunofluorescence (IF) microscopy. To study receptor function, CGCs were incubated with Fura 2-AM, exposed to agonists and antagonists, and intracellular [Ca2+] ([Ca2+]i) measured. [Ca2+]i was also measured after knock down of P2X4 and P2X7 receptor expression, and when exploiting P2XR specific characteristics. Lastly, mucin secretion was measured after the addition of several P2XR agonists. All P2XRs and pannexins were visualized with IF microscopy, and identified with RT-PCR and WB. [Ca2+]i was significantly increased when stimulated with ATP (10-7-10-4 M). Suramin, a non-selective P2XR antagonist at 10-4 M did not reduce ATP-induced peak [Ca2+]i. The potent P2X7 agonist, BzATP (10-7-10-4 M) increased the [Ca2+]i, although to a lesser extent than ATP. When measuring [Ca2+]i the effect of repeated applications of ATP at 10-5 or 10-6 M the response "desensitized" after 30-60 s. The P2X4 specific antagonist 5-BDBD decreased the P2X4 agonist, 2MeSATP,-induced [Ca2+]i increase. Furthermore, siRNA against the P2X4R, but not the P2X7R, decreased agonist-induced peak [Ca2+]i. ATP (10-5 M), BzATP (10-4 M) and 2MeSATP (10-5 M) induced mucin secretion. We conclude that all seven P2XRs are present in cultured rat CGCs. Of the P2XRs, only activation of the homotrimeric P2X4R appears to increase [Ca2+]i and induce mucin secretion. The P2X4R in CGCs offers a new therapeutic target for protective mucin secretion.
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Affiliation(s)
- Haakon K Fjærvoll
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States; Medical Student Research Program, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Ketil A Fjærvoll
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States; Medical Student Research Program, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Menglu Yang
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Jeffrey Bair
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Tor P Utheim
- Medical Student Research Program, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway; Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Darlene A Dartt
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
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Yin Y, Wei L, Caseley EA, Lopez‐Charcas O, Wei Y, Li D, Muench SP, Roger S, Wang L, Jiang L. Leveraging the ATP-P2X7 receptor signalling axis to alleviate traumatic CNS damage and related complications. Med Res Rev 2023; 43:1346-1373. [PMID: 36924449 PMCID: PMC10947395 DOI: 10.1002/med.21952] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 11/11/2022] [Accepted: 02/28/2023] [Indexed: 03/18/2023]
Abstract
The P2X7 receptor is an exceptional member of the P2X purinergic receptor family, with its activation requiring high concentrations of extracellular adenosine 5'-triphosphate (ATP) that are often associated with tissue damage and inflammation. In the central nervous system (CNS), it is highly expressed in glial cells, particularly in microglia. In this review, we discuss the role and mechanisms of the P2X7 receptor in mediating neuroinflammation and other pathogenic events in a variety of traumatic CNS damage conditions, which lead to loss of neurological and cognitive functions. We raise the perspective on the steady progress in developing CNS-penetrant P2X7 receptor-specific antagonists that leverage the ATP-P2X7 receptor signaling axis as a potential therapeutic strategy to alleviate traumatic CNS damage and related complications.
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Affiliation(s)
- Yaling Yin
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Linyu Wei
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Emily A. Caseley
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
| | - Osbaldo Lopez‐Charcas
- EA4245, Transplantation, Immunology and Inflammation, Faculty of MedicineUniversity of ToursToursFrance
| | - Yingjuan Wei
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Dongliang Li
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
- Sanquan College of Xinxiang Medical UniversityXinxiangChina
| | - Steve P. Muench
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
| | - Sebastian Roger
- EA4245, Transplantation, Immunology and Inflammation, Faculty of MedicineUniversity of ToursToursFrance
| | - Lu Wang
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Lin‐Hua Jiang
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
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7
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Zerbetto De Palma G, Recoulat Angelini AA, Vitali V, González Flecha FL, Alleva K. Cooperativity in regulation of membrane protein function: phenomenological analysis of the effects of pH and phospholipids. Biophys Rev 2023; 15:721-731. [PMID: 37681089 PMCID: PMC10480370 DOI: 10.1007/s12551-023-01095-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 07/01/2023] [Indexed: 09/09/2023] Open
Abstract
Interaction between membrane proteins and ligands plays a key role in governing a wide spectrum of cellular processes. These interactions can provide a cooperative-type regulation of protein function. A wide variety of proteins, including enzymes, channels, transporters, and receptors, displays cooperative behavior in their interactions with ligands. Moreover, the ligands involved encompass a vast diversity and include specific molecules or ions that bind to specific binding sites. In this review, our particular focus is on the interaction between integral membrane proteins and ligands that can present multiple "binding sites", such as protons or membrane phospholipids. The study of the interaction that protons or lipids have with membrane proteins often presents challenges for classical mechanistic modeling approaches. In this regard, we show that, like Hill's pioneering work on hemoglobin regulation, phenomenological modeling constitutes a powerful tool for capturing essential features of these systems.
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Affiliation(s)
- Gerardo Zerbetto De Palma
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Biotecnología, Universidad Nacional de Hurlingham, Villa Tesei, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alvaro A. Recoulat Angelini
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Victoria Vitali
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - F. Luis. González Flecha
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Karina Alleva
- Facultad de Farmacia y Bioquímica, Departamento de Fisicomatemática, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
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8
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Ballout J, Claßen R, Richter K, Grau V, Diener M. Ionotropic P2X
4
and P2X
7
receptors in the regulation of ion transport across rat colon. Br J Pharmacol 2022; 179:4992-5011. [DOI: 10.1111/bph.15928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/18/2022] [Accepted: 07/09/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- Jasmin Ballout
- Institute for Veterinary Physiology and Biochemistry Justus Liebig University Giessen Germany
| | - Rebecca Claßen
- Institute for Veterinary Physiology and Biochemistry Justus Liebig University Giessen Germany
| | - Katrin Richter
- Laboratory of Experimental Surgery, Departement of General Surgery, German Centre for Lung Research (DZL) Justus Liebig University Giessen Germany
| | - Veronika Grau
- Laboratory of Experimental Surgery, Departement of General Surgery, German Centre for Lung Research (DZL) Justus Liebig University Giessen Germany
| | - Martin Diener
- Institute for Veterinary Physiology and Biochemistry Justus Liebig University Giessen Germany
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9
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Oken AC, Krishnamurthy I, Savage JC, Lisi NE, Godsey MH, Mansoor SE. Molecular Pharmacology of P2X Receptors: Exploring Druggable Domains Revealed by Structural Biology. Front Pharmacol 2022; 13:925880. [PMID: 35784697 PMCID: PMC9248971 DOI: 10.3389/fphar.2022.925880] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/10/2022] [Indexed: 11/18/2022] Open
Abstract
Extracellular ATP is a critical signaling molecule that is found in a wide range of concentrations across cellular environments. The family of nonselective cation channels that sense extracellular ATP, termed P2X receptors (P2XRs), is composed of seven subtypes (P2X1-P2X7) that assemble as functional homotrimeric and heterotrimeric ion channels. Each P2XR is activated by a distinct concentration of extracellular ATP, spanning from high nanomolar to low millimolar. P2XRs are implicated in a variety of physiological and pathophysiological processes in the cardiovascular, immune, and central nervous systems, corresponding to the spatiotemporal expression, regulation, and activation of each subtype. The therapeutic potential of P2XRs is an emerging area of research in which structural biology has seemingly exceeded medicinal chemistry, as there are several published P2XR structures but currently no FDA-approved drugs targeting these ion channels. Cryogenic electron microscopy is ideally suited to facilitate structure-based drug design for P2XRs by revealing and characterizing novel ligand-binding sites. This review covers structural elements in P2XRs including the extracellular orthosteric ATP-binding site, extracellular allosteric modulator sites, channel pore, and cytoplasmic substructures, with an emphasis on potential therapeutic ligand development.
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Affiliation(s)
- Adam C. Oken
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Ipsita Krishnamurthy
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Jonathan C. Savage
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Nicolas E. Lisi
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Michael H. Godsey
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Steven E. Mansoor
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
- *Correspondence: Steven E. Mansoor,
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10
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Microglia Modulate Cortical Spreading Depolarizations After Ischemic Stroke: A Narrative Review. Neurocrit Care 2022; 37:133-138. [PMID: 35288861 PMCID: PMC9259539 DOI: 10.1007/s12028-022-01469-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 02/08/2022] [Indexed: 01/06/2023]
Abstract
Cortical spreading depolarizations (CSDs) are characterized by waves of diminished electroencephalography activity that propagate across the cortex with subsequent loss of ionic homeostasis. CSDs have been found in many pathological conditions, including migraine, traumatic brain injury, and ischemic stroke. Because of CSD-associated ionic and metabolic disturbances at the peri-infarct area after ischemic stroke, it is thought that CSDs exacerbate tissue infarction and worsen clinical outcomes. Microglia, the main innate immune cells in the brain, are among the first responders to brain tissue damage. Recent studies demonstrated that microglia play a critical role in CSD initiation and propagation. In this article, we discuss the significance of CSD in the setting of ischemic stroke and how microglia may modulate peri-infarct CSDs, also known as iso-electric depolarizations. Finally, we discuss the significance of microglial Ca2+ and how it might be used as a potential therapeutic target for patients with ischemic stroke.
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11
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Abstract
The P2X7 receptor has been proposed as a novel drug target for different types of diseases associated with inflammation, including brain diseases, peripheral inflammation, and cancers. Structurally diverse P2X7 receptor antagonists, mainly negative allosteric modulators (NAMs), have been developed in recent years, and several P2X7 receptor antagonists are currently evaluated in clinical trials. The P2X7 receptor requires high micro- to even millimolar ATP concentrations to be activated. Selective agonists for the P2X7 receptor are not available. Positive allosteric modulators (PAMs) have been described, but PAMs with high potency and selectivity are still lacking. This chapter discusses medicinal chemistry approaches toward the development of P2X7 receptor modulators and presents a selection of recommended tool compounds for studying P2X7 receptors in humans and rodents.
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Affiliation(s)
- Christa E Müller
- Pharmaceutical & Medicinal Chemistry, PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Bonn, Germany.
| | - Vigneshwaran Namasivayam
- Pharmaceutical & Medicinal Chemistry, PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Bonn, Germany
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12
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Peralta FA, Huidobro-Toro JP, Mera-Adasme R. Hybrid QM/MM Simulations Confirm Zn(II) Coordination Sphere That Includes Four Cysteines from the P2 × 4R Head Domain. Int J Mol Sci 2021; 22:ijms22147288. [PMID: 34298909 PMCID: PMC8303255 DOI: 10.3390/ijms22147288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 11/21/2022] Open
Abstract
To ascertain the role of Zn(II) as an allosteric modulator on P2X4R, QM/MM molecular dynamic simulations were performed on the WT and two P2X4R mutants suggested by previous electrophysiological data to affect Zn(II) binding. The Gibbs free energy for the reduction of the putative P2X4R Zn(II) binding site by glutathione was estimated at −22 kcal/mol. Simulations of the WT P2X4R head domain revealed a flexible coordination sphere dominated by an octahedral geometry encompassing C126, N127, C132, C149, C159 and a water molecule. The C132A mutation disrupted the metal binding site, leading to a coordination sphere with a majority of water ligands, and a displacement of the metal ion towards the solvent. The C132A/C159A mutant exhibited a tendency towards WT-like stability by incorporating the R148 backbone to the coordination sphere. Thus, the computational findings agree with previous experimental data showing Zn(II) modulation for the WT and C132A/C159A variants, but not for the C132A mutant. The results provide molecular insights into the nature of the Zn(II) modulation in P2X4R, and the effect of the C132A and C132A/C159A mutations, accounting for an elusive modulation mechanism possibly occurring in other extracellular or membrane protein.
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Affiliation(s)
| | - J. Pablo Huidobro-Toro
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170124, Chile
- Centro Para el Desarrollo de Nanociencia y Nanotecnología, (CEDENNA), Universidad de Santiago de Chile (USACH), Santiago 9170124, Chile
- Correspondence: (J.P.H.-T.); (R.M.-A.)
| | - Raúl Mera-Adasme
- Departamento de Ciencias del Ambiente, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170124, Chile
- Correspondence: (J.P.H.-T.); (R.M.-A.)
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13
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P2X7 Receptors and TMEM16 Channels Are Functionally Coupled with Implications for Macropore Formation and Current Facilitation. Int J Mol Sci 2021; 22:ijms22126542. [PMID: 34207150 PMCID: PMC8234106 DOI: 10.3390/ijms22126542] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 02/03/2023] Open
Abstract
P2X7 receptors (P2X7) are cationic channels involved in many diseases. Following their activation by extracellular ATP, distinct signaling pathways are triggered, which lead to various physiological responses such as the secretion of pro-inflammatory cytokines or the modulation of cell death. P2X7 also exhibit unique behaviors, such as “macropore” formation, which corresponds to enhanced large molecule cell membrane permeability and current facilitation, which is caused by prolonged activation. These two phenomena have often been confounded but, thus far, no clear mechanisms have been resolved. Here, by combining different approaches including whole-cell and single-channel recordings, pharmacological and biochemical assays, CRISPR/Cas9 technology and cell imaging, we provide evidence that current facilitation and macropore formation involve functional complexes comprised of P2X7 and TMEM16, a family of Ca2+-activated ion channel/scramblases. We found that current facilitation results in an increase of functional complex-embedded P2X7 open probability, a result that is recapitulated by plasma membrane cholesterol depletion. We further show that macropore formation entails two distinct large molecule permeation components, one of which requires functional complexes featuring TMEM16F subtype, the other likely being direct permeation through the P2X7 pore itself. Such functional complexes can be considered to represent a regulatory hub that may orchestrate distinct P2X7 functionalities.
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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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Cell surface thermal proteome profiling tracks perturbations and drug targets on the plasma membrane. Nat Methods 2021; 18:84-91. [PMID: 33398190 DOI: 10.1038/s41592-020-01022-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 11/17/2020] [Indexed: 01/28/2023]
Abstract
Numerous drugs and endogenous ligands bind to cell surface receptors leading to modulation of downstream signaling cascades and frequently to adaptation of the plasma membrane proteome. In-depth analysis of dynamic processes at the cell surface is challenging due to biochemical properties and low abundances of plasma membrane proteins. Here we introduce cell surface thermal proteome profiling for the comprehensive characterization of ligand-induced changes in protein abundances and thermal stabilities at the plasma membrane. We demonstrate drug binding to extracellular receptors and transporters, discover stimulation-dependent remodeling of T cell receptor complexes and describe a competition-based approach to measure target engagement of G-protein-coupled receptor antagonists. Remodeling of the plasma membrane proteome in response to treatment with the TGFB receptor inhibitor SB431542 leads to partial internalization of the monocarboxylate transporters MCT1/3 explaining the antimetastatic effects of the drug.
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Shao X, Guha S, Lu W, Campagno KE, Beckel JM, Mills JA, Yang W, Mitchell CH. Polarized Cytokine Release Triggered by P2X7 Receptor from Retinal Pigmented Epithelial Cells Dependent on Calcium Influx. Cells 2020; 9:cells9122537. [PMID: 33255431 PMCID: PMC7760537 DOI: 10.3390/cells9122537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 12/20/2022] Open
Abstract
Cytokine release from non-inflammatory cells is a key step in innate immunity, and agonists triggering cytokine release are central in coordinating responses. P2X7 receptor (P2X7R) stimulation by extracellular ATP is best known to active the NLRP3 inflammasome and release IL-1β, but stimulation also leads to release of other cytokines. As cytokine signaling by retinal pigmented epithelial (RPE) cells is implicated in retinal neurodegeneration, the role of P2X7R in release of cytokine IL-6 from RPE cells was investigated. P2X7R stimulation triggered IL-6 release from primary mouse RPE, human iPS-RPE and human ARPE-19 cells. IL-6 release was polarized, with predominant rise across apical membranes. IL-6 release was inhibited by P2X7R antagonists A438079, A839977, and AZ10606120, but not the NRTI lamivudine (3TC), P2X1R antagonist NF279, or P2Y1R antagonist MRS2179. P2X7R-mediated IL-6 release required extracellular Ca2+ and was blocked by Ca2+ chelator BAPTA. IL-6 release and Ca2+ elevation occurred rapidly, consistent with vesicular IL-6 staining in unstimulated cells. P2X7R stimulation did not trigger IL-1β release in these unprimed cells. P2X7R-mediated IL-6 release was enhanced in RPE cells from the ABCA4−/− mouse model of retinal degeneration. In summary, P2X7R stimulation triggers rapid Ca2+-dependent IL-6 release across the apical membrane of RPE cells.
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Affiliation(s)
- Xiaolei Shao
- Shenzhen Eye Hospital, School of Optometry, Shenzhen University, Shenzhen 518060, China;
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.G.); (J.M.B.)
| | - Sonia Guha
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.G.); (J.M.B.)
- Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Wennan Lu
- Department of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA 19104, USA; (W.L.); (K.E.C.)
| | - Keith E. Campagno
- Department of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA 19104, USA; (W.L.); (K.E.C.)
| | - Jonathan M. Beckel
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.G.); (J.M.B.)
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jason A. Mills
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA;
- Kirby Center for Molecular Ophthalmology and Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Wenli Yang
- Department of Medicine and Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA;
| | - Claire H. Mitchell
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA 19104, USA; (S.G.); (J.M.B.)
- Department of Basic and Translational Science, University of Pennsylvania, Philadelphia, PA 19104, USA; (W.L.); (K.E.C.)
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA;
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Correspondence: ; Tel.: +1-215-573-2176
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Martínez-Cuesta MÁ, Blanch-Ruiz MA, Ortega-Luna R, Sánchez-López A, Álvarez Á. Structural and Functional Basis for Understanding the Biological Significance of P2X7 Receptor. Int J Mol Sci 2020; 21:ijms21228454. [PMID: 33182829 PMCID: PMC7696479 DOI: 10.3390/ijms21228454] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/04/2020] [Accepted: 11/06/2020] [Indexed: 12/11/2022] Open
Abstract
The P2X7 receptor (P2X7R) possesses a unique structure associated to an as yet not fully understood mechanism of action that facilitates cell permeability to large ionic molecules through the receptor itself and/or nearby membrane proteins. High extracellular adenosine triphosphate (ATP) levels—inexistent in physiological conditions—are required for the receptor to be triggered and contribute to its role in cell damage signaling. The inconsistent data on its activation pathways and the few studies performed in natively expressed human P2X7R have led us to review the structure, activation pathways, and specific cellular location of P2X7R in order to analyze its biological relevance. The ATP-gated P2X7R is a homo-trimeric receptor channel that is occasionally hetero-trimeric and highly polymorphic, with at least nine human splice variants. It is localized predominantly in the cellular membrane and has a characteristic plasticity due to an extended C-termini, which confers it the capacity of interacting with membrane structural compounds and/or intracellular signaling messengers to mediate flexible transduction pathways. Diverse drugs and a few endogenous molecules have been highlighted as extracellular allosteric modulators of P2X7R. Therefore, studies in human cells that constitutively express P2X7R need to investigate the precise endogenous mediator located nearby the activation/modulation domains of the receptor. Such research could help us understand the possible physiological ATP-mediated P2X7R homeostasis signaling.
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Affiliation(s)
- María Ángeles Martínez-Cuesta
- Departamento de Farmacología, Facultad de Medicina y Odontología, Universidad de Valencia, 46010 Valencia, Spain; (M.A.B.-R.); (R.O.-L.); (A.S.-L.)
- CIBERehd, Valencia, Spain
- Correspondence: (M.Á.M.-C.); (Á.Á.); Tel.: +34-963983716 (M.Á.M.-C.); +34-963864898 (Á.Á.)
| | - María Amparo Blanch-Ruiz
- Departamento de Farmacología, Facultad de Medicina y Odontología, Universidad de Valencia, 46010 Valencia, Spain; (M.A.B.-R.); (R.O.-L.); (A.S.-L.)
| | - Raquel Ortega-Luna
- Departamento de Farmacología, Facultad de Medicina y Odontología, Universidad de Valencia, 46010 Valencia, Spain; (M.A.B.-R.); (R.O.-L.); (A.S.-L.)
| | - Ainhoa Sánchez-López
- Departamento de Farmacología, Facultad de Medicina y Odontología, Universidad de Valencia, 46010 Valencia, Spain; (M.A.B.-R.); (R.O.-L.); (A.S.-L.)
| | - Ángeles Álvarez
- Departamento de Farmacología, Facultad de Medicina y Odontología, Universidad de Valencia, 46010 Valencia, Spain; (M.A.B.-R.); (R.O.-L.); (A.S.-L.)
- CIBERehd, Valencia, Spain
- Correspondence: (M.Á.M.-C.); (Á.Á.); Tel.: +34-963983716 (M.Á.M.-C.); +34-963864898 (Á.Á.)
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Glaser T, Andrejew R, Oliveira-Giacomelli Á, Ribeiro DE, Bonfim Marques L, Ye Q, Ren WJ, Semyanov A, Illes P, Tang Y, Ulrich H. Purinergic Receptors in Basal Ganglia Diseases: Shared Molecular Mechanisms between Huntington's and Parkinson's Disease. Neurosci Bull 2020; 36:1299-1314. [PMID: 33026587 PMCID: PMC7674528 DOI: 10.1007/s12264-020-00582-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/30/2020] [Indexed: 12/22/2022] Open
Abstract
Huntington's (HD) and Parkinson's diseases (PD) are neurodegenerative disorders caused by the death of GABAergic and dopaminergic neurons in the basal ganglia leading to hyperkinetic and hypokinetic symptoms, respectively. We review here the participation of purinergic receptors through intracellular Ca2+ signaling in these neurodegenerative diseases. The adenosine A2A receptor stimulates striatopallidal GABAergic neurons, resulting in inhibitory actions on GABAergic neurons of the globus pallidus. A2A and dopamine D2 receptors form functional heteromeric complexes inducing allosteric inhibition, and A2A receptor activation results in motor inhibition. Furthermore, the A2A receptor physically and functionally interacts with glutamate receptors, mainly with the mGlu5 receptor subtype. This interaction facilitates glutamate release, resulting in NMDA glutamate receptor activation and an increase of Ca2+ influx. P2X7 receptor activation also promotes glutamate release and neuronal damage. Thus, modulation of purinergic receptor activity, such as A2A and P2X7 receptors, and subsequent aberrant Ca2+ signaling, might present interesting therapeutic potential for HD and PD.
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Affiliation(s)
- Talita Glaser
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP, 05508-000, Brazil
| | - Roberta Andrejew
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP, 05508-000, Brazil
| | - Ágatha Oliveira-Giacomelli
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP, 05508-000, Brazil
| | - Deidiane Elisa Ribeiro
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP, 05508-000, Brazil
| | - Lucas Bonfim Marques
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP, 05508-000, Brazil
| | - Qing Ye
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP, 05508-000, Brazil
- Key Laboratory of Sichuan Province for Acupuncture and Chronobiology, Chengdu, 610075, China
| | - Wen-Jing Ren
- Key Laboratory of Sichuan Province for Acupuncture and Chronobiology, Chengdu, 610075, China
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, 04107, Germany
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
- Sechenov First Moscow State Medical University, Moscow, 119992, Russia
| | - Peter Illes
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, 04107, Germany
- International Collaborative Centre on Big Science Plan for Purine Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
| | - Yong Tang
- Key Laboratory of Sichuan Province for Acupuncture and Chronobiology, Chengdu, 610075, China
- International Collaborative Centre on Big Science Plan for Purine Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
| | - Henning Ulrich
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes 748, São Paulo, SP, 05508-000, Brazil.
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Rivas-Yáñez E, Barrera-Avalos C, Parra-Tello B, Briceño P, Rosemblatt MV, Saavedra-Almarza J, Rosemblatt M, Acuña-Castillo C, Bono MR, Sauma D. P2X7 Receptor at the Crossroads of T Cell Fate. Int J Mol Sci 2020; 21:E4937. [PMID: 32668623 PMCID: PMC7404255 DOI: 10.3390/ijms21144937] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/26/2020] [Accepted: 07/07/2020] [Indexed: 02/06/2023] Open
Abstract
The P2X7 receptor is a ligand-gated, cation-selective channel whose main physiological ligand is ATP. P2X7 receptor activation may also be triggered by ARTC2.2-dependent ADP ribosylation in the presence of extracellular NAD. Upon activation, this receptor induces several responses, including the influx of calcium and sodium ions, phosphatidylserine externalization, the formation of a non-selective membrane pore, and ultimately cell death. P2X7 receptor activation depends on the availability of extracellular nucleotides, whose concentrations are regulated by the action of extracellular nucleotidases such as CD39 and CD38. The P2X7 receptor has been extensively studied in the context of the immune response, and it has been reported to be involved in inflammasome activation, cytokine production, and the migration of different innate immune cells in response to ATP. In adaptive immune responses, the P2X7 receptor has been linked to T cell activation, differentiation, and apoptosis induction. In this review, we will discuss the evidence of the role of the P2X7 receptor on T cell differentiation and in the control of T cell responses in inflammatory conditions.
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Affiliation(s)
- Elizabeth Rivas-Yáñez
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile; (E.R.-Y.); (B.P.-T.); (P.B.); (M.V.R.); (J.S.-A.); (M.R.)
| | - Carlos Barrera-Avalos
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile;
| | - Brian Parra-Tello
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile; (E.R.-Y.); (B.P.-T.); (P.B.); (M.V.R.); (J.S.-A.); (M.R.)
| | - Pedro Briceño
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile; (E.R.-Y.); (B.P.-T.); (P.B.); (M.V.R.); (J.S.-A.); (M.R.)
| | - Mariana V. Rosemblatt
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile; (E.R.-Y.); (B.P.-T.); (P.B.); (M.V.R.); (J.S.-A.); (M.R.)
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago 7510157, Chile
| | - Juan Saavedra-Almarza
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile; (E.R.-Y.); (B.P.-T.); (P.B.); (M.V.R.); (J.S.-A.); (M.R.)
| | - Mario Rosemblatt
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile; (E.R.-Y.); (B.P.-T.); (P.B.); (M.V.R.); (J.S.-A.); (M.R.)
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago 7510157, Chile
- Fundación Ciencia & Vida, Santiago 7780272, Chile
| | - Claudio Acuña-Castillo
- Centro de Biotecnología Acuícola, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - María Rosa Bono
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile; (E.R.-Y.); (B.P.-T.); (P.B.); (M.V.R.); (J.S.-A.); (M.R.)
| | - Daniela Sauma
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile; (E.R.-Y.); (B.P.-T.); (P.B.); (M.V.R.); (J.S.-A.); (M.R.)
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Currò D, Navarra P, Samengo I, Martire M. P2X7 receptors exert a permissive effect on the activation of presynaptic AMPA receptors in rat trigeminal caudal nucleus glutamatergic nerve terminals. J Headache Pain 2020; 21:83. [PMID: 32615921 PMCID: PMC7330953 DOI: 10.1186/s10194-020-01153-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 06/29/2020] [Indexed: 12/12/2022] Open
Abstract
Background Purine receptors play roles in peripheral and central sensitization and are associated with migraine headache. We investigated the possibility that ATP plays a permissive role in the activation of AMPA receptors thus inducing Glu release from nerve terminals isolated from the rat trigeminal caudal nucleus (TCN). Methods Nerve endings isolated from the rat TCN were loaded with [3H]D-aspartic acid ([3H]D-ASP), layered into thermostated superfusion chambers, and perfused continuously with physiological medium, alone or with various test drugs. Radioactivity was measured to assess [3H]D-ASP release under different experimental conditions. Results Synaptosomal [3H]D-ASP spontaneous release was stimulated by ATP and to an even greater extent by the ATP analogue benzoylbenzoylATP (BzATP). The stimulation of [3H]D-ASP basal release by the purinergic agonists was prevented by the selective P2X7 receptor antagonist A438079. AMPA had no effect on basal [3H]D-ASP release, but the release observed when synaptosomes were exposed to AMPA plus a purinoceptor agonist exceeded that observed with ATP or BzATP alone. The selective AMPA receptor antagonist NBQX blocked this “excess” release. Co-exposure to AMPA and BzATP, each at a concentration with no release-stimulating effects, evoked a significant increase in [3H]D-ASP basal release, which was prevented by exposure to a selective AMPA antagonist. Conclusions P2X7 receptors expressed on glutamatergic nerve terminals in the rat TCN can mediate Glu release directly and indirectly by facilitating the activation of presynaptic AMPA receptors. The high level of glial ATP that occurs during chronic pain states can promote widespread release of Glu as well as can increase the function of AMPA receptors. In this manner, ATP contributes to the AMPA receptor activation involved in the onset and maintenance of the central sensitization associated with chronic pain.
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Affiliation(s)
- Diego Currò
- Institute of Pharmacology, School of Medicine, Università Cattolica del Sacro Cuore, Largo Francesco Vito, 1, 00168, Rome, Italy
| | - Pierluigi Navarra
- Institute of Pharmacology, School of Medicine, Università Cattolica del Sacro Cuore, Largo Francesco Vito, 1, 00168, Rome, Italy
| | - Irene Samengo
- Institute of Pharmacology, School of Medicine, Università Cattolica del Sacro Cuore, Largo Francesco Vito, 1, 00168, Rome, Italy
| | - Maria Martire
- Institute of Pharmacology, School of Medicine, Università Cattolica del Sacro Cuore, Largo Francesco Vito, 1, 00168, Rome, Italy.
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Ozen M, Xie H, Shin N, Al Yousif G, Clemens J, McLane MW, Lei J, Burd I. Magnesium sulfate inhibits inflammation through P2X7 receptors in human umbilical vein endothelial cells. Pediatr Res 2020; 87:463-471. [PMID: 31493768 PMCID: PMC7035964 DOI: 10.1038/s41390-019-0557-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/09/2019] [Accepted: 08/23/2019] [Indexed: 01/02/2023]
Abstract
BACKGROUND Magnesium sulfate (MgSO4) is utilized for fetal neuroprotection in preterm birth but its mechanism of action is still poorly understood. P2X7 receptor (P2X7R) is required for secretion of IL-1β, and can be blocked by divalent cations such as magnesium (Mg) and its own antagonist, Brilliant Blue G (BBG). We sought to determine whether during inflammation MgSO4 can block endothelial IL-1β secretion, using an in-vitro model. METHODS Human umbilical vein endothelial cell (HUVEC) cultures were treated with varying doses of LPS, 2'(3)-Ο-(4-Benzoylbenzoyl) adenosine-5'-triphosphate (BzATP), BBG and MgSO4 for 3- or 24 h. We determined cell cytotoxicity, apoptosis, IL-1β mRNA expression, IL-1β production and secretion and P2X7R expression on HUVECs. RESULTS We demonstrated that MgSO4 is efficacious in blocking IL-1β-mediated-inflammation in HUVECs, at both the initiation and propagation phases of inflammation. MgSO4 exerts these anti-inflammatory effects via downregulation of P2X7Rs on HUVECs. CONCLUSION LPS-exposure increases IL-1β production and secretion in HUVECs, which is further intensified by P2X7R agonist, BzATP while MgSO4 inhibits IL-1β in both presence and absence of BzATP. This effect is similar to the results of P2X7R antagonist, BBG, suggesting that the anti-inflammatory effects of MgSO4 is through P2X7R.
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Affiliation(s)
- Maide Ozen
- Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Pediatrics, Neonatal-Perinatal Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
| | - Han Xie
- Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Na Shin
- Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Ghada Al Yousif
- Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Julia Clemens
- Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Michael W McLane
- Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Jun Lei
- Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Irina Burd
- Integrated Research Center for Fetal Medicine, Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
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Zhang Y, Huang L, Kozlov SA, Rubini P, Tang Y, Illes P. Acupuncture alleviates acid- and purine-induced pain in rodents. Br J Pharmacol 2019; 177:77-92. [PMID: 31444978 DOI: 10.1111/bph.14847] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 08/12/2019] [Accepted: 08/14/2019] [Indexed: 12/14/2022] Open
Affiliation(s)
- Ying Zhang
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China
| | - Lumei Huang
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China
| | - Sergey A Kozlov
- Shemyakin-Ovchinikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Patrizia Rubini
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China
| | - Peter Illes
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, China.,Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, Germany
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23
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Liang X, Samways DSK, Cox J, Egan TM. Ca 2+ flux through splice variants of the ATP-gated ionotropic receptor P2X7 is regulated by its cytoplasmic N terminus. J Biol Chem 2019; 294:12521-12533. [PMID: 31248985 DOI: 10.1074/jbc.ra119.009666] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 06/26/2019] [Indexed: 01/12/2023] Open
Abstract
Activation of ionotropic P2X receptors increases free intracellular Ca2+ ([Ca2+] i ) by initiating a transmembrane cation flux. We studied the "a" and "k" splice variants of the rat purinergic P2X7 receptor (rP2X7aR and rP2X7kR) to exhibit a significant difference in Ca2+ flux through this channel. This difference is surprising because the variants share absolute sequence identity in the area of the pore that defines ionic selectivity. Here, we used patch-clamp fluorometry and chimeric receptors to show that the fraction of the total current carried by Ca2+ is a function of the primary sequence of the cytoplasmic N terminus. Using scanning mutagenesis, we identified five sites within the N terminus that respond to mutagenesis with a decrease in fractional calcium current and an increase in permeability to the polyatomic cation, N-methyl-d-glucamine (NMDG+), relative to Na+ (P NMDG/P Na). We tested the hypothesis that these sites line the permeation pathway by measuring the ability of thiol-reactive MTSET+ to alter the current of cysteine-substituted variants, but we detected no effect. Finally, we studied the homologous sites of the rat P2X2 receptor (rP2X2R) and observed that substitutions at Glu17 significantly reduced the fractional calcium current. Taken together, our results suggest that a change in the structure of the N terminus alters the ability of an intra-pore Ca2+ selectivity filter to discriminate among permeating cations. These results are noteworthy for two reasons: they identify a previously unknown outcome of mutagenesis of the N-terminal domain, and they suggest caution when assigning structure to function for truncated P2X receptors that lack a part of the N terminus.
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Affiliation(s)
- Xin Liang
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-Sen University, Guangzhou 510275, China
| | | | - Jane Cox
- Department of Pharmacology and Physiology and The Henry and Amelia Nasrallah Center for Neuroscience, Saint Louis University School of Medicine, St. Louis, Missouri 63104
| | - Terrance M Egan
- Department of Pharmacology and Physiology and The Henry and Amelia Nasrallah Center for Neuroscience, Saint Louis University School of Medicine, St. Louis, Missouri 63104.
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Magnesium protects against sepsis by blocking gasdermin D N-terminal-induced pyroptosis. Cell Death Differ 2019; 27:466-481. [PMID: 31209359 DOI: 10.1038/s41418-019-0366-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 04/24/2019] [Accepted: 05/30/2019] [Indexed: 12/24/2022] Open
Abstract
Hypomagnesemia is a significant risk factor for critically ill patients to develop sepsis, a life-threatening disease with a mortality rate over 25%. Our clinic data analysis showed that hypomagnesemia is associated with a decreased monocyte count in septic patients. At the cellular level, we found that Mg2+ inhibits pyroptosis. Specifically, Mg2+ limits the oligomerization and membrane localization of gasdermin D N-terminal (GSDMD-NT) upon the activation of either the canonical or noncanonical pyroptotic pathway. Mechanistically, we demonstrated that Ca2+ influx is a prerequisite for the function of GSDMD-NT. Mg2+ blocks Ca2+ influx by inhibiting the ATP-gated Ca2+ channel P2X7, thereby impeding the function of GSDMD-NT and inhibiting lipopolysaccharide (LPS)-induced noncanonical pyroptosis. Furthermore, Mg2+ administration protects mice from LPS-induced lethal septic shock. Together, our data reveal the underlying mechanism of how Mg2+ inhibits pyroptosis and suggest potential clinic applications of magnesium supplementation for sepsis prevention and treatment.
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25
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Colley CS, England E, Linley JE, Wilkinson TCI. Screening Strategies for the Discovery of Ion Channel Monoclonal Antibodies. ACTA ACUST UNITED AC 2018; 82:e44. [DOI: 10.1002/cpph.44] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Caroline S. Colley
- Antibody Discovery and Protein Engineering, MedImmune; Cambridge United Kingdom
| | - Elizabeth England
- Antibody Discovery and Protein Engineering, MedImmune; Cambridge United Kingdom
| | - John E. Linley
- Neuroscience, IMED Biotech Unit, AstraZeneca; Cambridge United Kingdom
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26
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Méndez-Barredo LH, Rodríguez-Meléndez JG, Gómez-Coronado KS, Guerrero-Alba R, Valdez-Morales EE, Espinosa-Luna R, Barajas-Espinosa A, Barajas-López C. Physiological Concentrations of Zinc Have Dual Effects on P2X Myenteric Receptors of Guinea Pig. Cell Mol Neurobiol 2018; 38:1439-1449. [PMID: 30109516 DOI: 10.1007/s10571-018-0612-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/09/2018] [Indexed: 10/28/2022]
Abstract
We, hereby, characterize the pharmacological effects of physiological concentrations of Zinc on native myenteric P2X receptors from guinea-pig small intestine and on P2X2 isoforms present in most myenteric neurons. This is the first study describing opposite effects of Zinc on these P2X receptors. It was not possible to determine whether both effects were concentration dependent, yet the inhibitory effect was mediated by competitive antagonism and was concentration dependent. The potentiating effect appears to be mediated by allosteric changes induced by Zinc on P2X myenteric channels, which is more frequently observed in myenteric neurons with low zinc concentrations. In P2X2-1 and P2X2-2 variants, the inhibitory effect is more common than in P2X myenteric channels. However, in the variants, the potentiatory effect is of equal magnitude as the inhibitory effect. Inhibitory and potentiatory effects are likely mediated by different binding sites that appear to be present on both P2X2 variants. In conclusion, in myenteric native P2X receptors, Zinc has quantitatively different pharmacological effects compared to those observed on homomeric channels: P2X2-1 and P2X2-2. Potentiatory and inhibitory Zinc effects upon these receptors are mediated by two different binding sites. All our data suggest that myenteric P2X receptors have a more complex pharmacology than those of the recombinant P2X2 receptors, which is likely related to other subunits known to be expressed in myenteric neurons. Because these dual effects occur at Zinc physiological concentrations, we suggest that they could be involved in physiological and pathological processes.
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Affiliation(s)
- Liliana H Méndez-Barredo
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Col. Lomas 4a Sección, CP78216, San Luis Potosí, SLP, Mexico
| | - Jessica G Rodríguez-Meléndez
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Col. Lomas 4a Sección, CP78216, San Luis Potosí, SLP, Mexico
| | - Karen S Gómez-Coronado
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Col. Lomas 4a Sección, CP78216, San Luis Potosí, SLP, Mexico
| | - Raquel Guerrero-Alba
- Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags, Mexico
| | - Eduardo E Valdez-Morales
- Cátedra CONACyT, Departamento de Cirugía, Centro de Ciencias de la Salud, Universidad Autónoma de Aguascalientes, Aguascalientes, Ags, Mexico
| | - Rosa Espinosa-Luna
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Col. Lomas 4a Sección, CP78216, San Luis Potosí, SLP, Mexico
| | - Alma Barajas-Espinosa
- Cátedra CONACyT, Departamento de Fisiología y Biofísica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, SLP, Mexico
| | - Carlos Barajas-López
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, Col. Lomas 4a Sección, CP78216, San Luis Potosí, SLP, Mexico.
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27
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Khan MT, Deussing J, Tang Y, Illes P. Astrocytic rather than neuronal P2X7 receptors modulate the function of the tri-synaptic network in the rodent hippocampus. Brain Res Bull 2018; 151:164-173. [PMID: 30098388 DOI: 10.1016/j.brainresbull.2018.07.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/21/2018] [Accepted: 07/25/2018] [Indexed: 12/12/2022]
Abstract
Whole-cell patch clamp recordings demonstrated that in the dentate gyrus (DG) as well as in the CA3 area of mouse hippocampal slices the prototypic P2X7 receptor (R) agonist dibenzoyl-ATP (Bz-ATP) induced inward current responses both in neurons and astrocytes. Whereas the selective P2X7R antagonist A438079 strongly inhibited both neuronal and astrocytic currents, a combination of ionotropic glutamate receptor (CNQX, AP-5) and GABAA-R (gabazine) antagonists depressed the Bz-ATP-induced current responses in the DG (granule cells) and CA3 neurons only. It was concluded that Bz-ATP activated astrocytic P2X7Rs and thereby released glutamate and GABA to stimulate nearby neurons. The residual A438079-resistant current response of astrocytes was suggested to be due to the stimulation of P2XRs of the non-P2X7-type. Further, we searched for presynaptic P2X7Rs at the axon terminals of DG and CA3 pyramidal neurons innervating CA3 and CA1 cells, respectively. Bz-ATP potentiated the frequency of spontaneous postsynaptic currents (sPSCs) in CA1 but not CA3 pyramidal cells. However, the Bz-ATP effect in CA1 cells was inhibited by gabazine or the astrocytic toxin fluorocitrate suggesting stimulation of P2X7Rs at stratum radiatum astrocytes located near to interneurons and synapsing onto CA1 neurons. Our data suggest that functional P2X7Rs are missing at neurons in the tri-synaptic network of the rodent hippocampus, but are present at nearby astrocytes indirectly regulating network activity.
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Affiliation(s)
- Muhammad Tahir Khan
- Rudolf-Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany
| | - Jan Deussing
- Department of Molecular Neurogenetics, Max-Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Peter Illes
- Rudolf-Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany; Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China.
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Kovács G, Környei Z, Tóth K, Baranyi M, Brunner J, Neubrandt M, Dénes Á, Sperlágh B. Modulation of P2X7 purinergic receptor activity by extracellular Zn 2+ in cultured mouse hippocampal astroglia. Cell Calcium 2018; 75:1-13. [PMID: 30098501 DOI: 10.1016/j.ceca.2018.07.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 07/05/2018] [Accepted: 07/28/2018] [Indexed: 02/06/2023]
Abstract
The P2X7R protein, a P2 type purinergic receptor functioning as a non-selective cation channel, is expressed in different cell types of the central nervous system in several regions of the brain. The activation of the P2X7R protein by ATP modulates excitatory neurotransmission and contributes to microglial activation, apoptosis and neuron-glia communication. Zinc is an essential micronutrient that is highly concentrated in the synaptic vesicles of glutamatergic hippocampal neurons where free zinc ions released into the synaptic cleft alter glutamatergic signal transmission. Changes in both P2X7R-mediated signaling and brain zinc homeostasis have been implicated in the pathogenesis of mood disorders. Here, we tested the hypothesis that extracellular zinc regulates P2X7R activity in the hippocampus. We observed that P2X7R is expressed in both neurons and glial cells in primary mouse hippocampal neuron-glia culture. Propidium iodide (PI) uptake through large pores formed by pannexins and P2X7R was dose-dependently inhibited by extracellular zinc ions. Calcium influx mediated by P2X7R in glial cells was also reduced by free zinc ions. Interestingly, no calcium influx was detected in response to ATP or 3'-O-(4-Benzoyl) benzoyl ATP (BzATP) in neurons despite the expression of P2X7R at the plasma membrane. Our results show that free zinc ions can modulate hippocampal glial purinergic signaling, and changes in the activity of P2X7R may contribute to the development of depression-like behaviors associated with zinc deficiency.
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Affiliation(s)
- Gergely Kovács
- Department of Pharmacology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Szigony utca 43, HU-1083 Budapest, Hungary; Szentágothai Research Centre, Institute of Physiology, Medical School, University of Pécs, 7624 Ifjúság útja 20, Pécs, Hungary.
| | - Zsuzsanna Környei
- Laboratory of Neuroimmunology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Szigony utca 43, Budapest, HU-1083 Hungary
| | - Krisztina Tóth
- Laboratory of Neuroimmunology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Szigony utca 43, Budapest, HU-1083 Hungary
| | - Mária Baranyi
- Department of Pharmacology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Szigony utca 43, HU-1083 Budapest, Hungary
| | - János Brunner
- Laboratory of Cellular Neuropharmacology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Szigony utca 43, HU-1083 Budapest, Hungary
| | - Máté Neubrandt
- Laboratory of Cellular Neuropharmacology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Szigony utca 43, HU-1083 Budapest, Hungary
| | - Ádám Dénes
- Laboratory of Neuroimmunology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Szigony utca 43, Budapest, HU-1083 Hungary
| | - Beáta Sperlágh
- Department of Pharmacology, Institute of Experimental Medicine of the Hungarian Academy of Sciences, Szigony utca 43, HU-1083 Budapest, Hungary
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29
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Young CNJ, Górecki DC. P2RX7 Purinoceptor as a Therapeutic Target-The Second Coming? Front Chem 2018; 6:248. [PMID: 30003075 PMCID: PMC6032550 DOI: 10.3389/fchem.2018.00248] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 06/08/2018] [Indexed: 12/22/2022] Open
Abstract
The P2RX7 receptor is a unique member of a family of extracellular ATP (eATP)-gated ion channels expressed in immune cells, where its activation triggers the inflammatory cascade. Therefore, P2RX7 has been long investigated as a target in the treatment of infectious and inflammatory diseases. Subsequently, P2RX7 signaling has been documented in other physiological and pathological processes including pain, CNS and psychiatric disorders and cancer. As a result, a range of P2RX7 antagonists have been developed and trialed. Interestingly, the recent crystallization of mammalian and chicken receptors revealed that most widely-used antagonists may bind a unique allosteric site. The availability of crystal structures allows rational design of improved antagonists and modeling of binding sites of the known or presumed inhibitors. However, several unanswered questions limit the cogent development of P2RX7 therapies. Firstly, this receptor functions as an ion channel, but its chronic stimulation by high eATP causes opening of the non-selective large pore (LP), which can trigger cell death. Not only the molecular mechanism of LP opening is still not fully understood but its function(s) are also unclear. Furthermore, how can tumor cells take advantage of P2RX7 for growth and spread and yet survive overexpression of potentially cytotoxic LP in the eATP-rich environment? The recent discovery of the feedback loop, wherein the LP-evoked release of active MMP-2 triggers the receptor cleavage, provided one explanation. Another mechanism might be that of cancer cells expressing a structurally altered P2RX7 receptor, devoid of the LP function. Exploiting such mechanisms should lead to the development of new, less toxic anticancer treatments. Notably, targeted inhibition of P2RX7 is crucial as its global blockade reduces the immune and inflammatory responses, which have important anti-tumor effects in some types of malignancies. Therefore, another novel approach is the synthesis of tissue/cell specific P2RX7 antagonists. Progress has been aided by the development of p2rx7 knockout mice and new conditional knock-in and knock-out models are being created. In this review, we seek to summarize the recent advances in our understanding of molecular mechanisms of receptor activation and inhibition, which cause its re-emergence as an important therapeutic target. We also highlight the key difficulties affecting this development.
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Affiliation(s)
- Chris N. J. Young
- Molecular Medicine Laboratory, Institute of Biomedical and Biomolecular Sciences, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
- Faculty of Health and Life Sciences, The School of Allied Health Sciences, De Montfort University, Leicester, United Kingdom
| | - Dariusz C. Górecki
- Molecular Medicine Laboratory, Institute of Biomedical and Biomolecular Sciences, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, United Kingdom
- The General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Warsaw, Poland
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30
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P2X7 ionotropic receptor is functionally expressed in rabbit articular chondrocytes and mediates extracellular ATP cytotoxicity. Purinergic Signal 2018; 14:245-258. [PMID: 29845461 DOI: 10.1007/s11302-018-9611-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 05/14/2018] [Indexed: 02/06/2023] Open
Abstract
Extracellular ATP regulates various cellular functions by engaging multiple subtypes of P2 purinergic receptors. In many cell types, the ionotropic P2X7 receptor mediates pathological events such as inflammation and cell death. However, the importance of this receptor in chondrocytes remains largely unexplored. Here, we report the functional identification of P2X7 receptor in articular chondrocytes and investigate the involvement of P2X7 receptors in ATP-induced cytotoxicity. Chondrocytes were isolated from rabbit articular cartilage, and P2X7 receptor currents were examined using the whole-cell patch-clamp technique. ATP-induced cytotoxicity was evaluated by measuring caspase-3/7 activity, lactate dehydrogenase (LDH) leakage, and prostagrandin E2 (PGE2) release using microscopic and fluorimetric/colorimetric evaluation. Extracellular ATP readily evoked a cationic current without obvious desensitization. This ATP-activated current was dose related, but required millimolar concentrations. A more potent P2X7 receptor agonist, BzATP, also activated this current but at 100-fold lower concentrations. ATP-induced currents were largely abolished by selective P2X7 antagonists, suggesting a predominant role for the P2X7 receptor. RT-PCR confirmed the presence of P2X7 in chondrocytes. Heterologous expression of a rabbit P2X7 clone successfully reproduced the ATP-induced current. Exposure of chondrocytes to ATP increased caspase-3/7 activities, an effect that was totally abrogated by P2X7 receptor antagonists. Extracellular ATP also enhanced LDH release, which was partially attenuated by the P2X7 inhibitor. The P2X7 receptor-mediated elevation in apoptotic caspase signaling was accompanied by increased PGE2 release and was attenuated by inhibition of either phospholipase A2 or cyclooxygenase-2. This study provides direct evidence for the presence of functional P2X7 receptors in articular chondrocytes. Our results suggest that the P2X7 receptor is a potential therapeutic target in chondrocyte death associated with cartilage injury and disorders including osteoarthritis.
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31
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Rokic MB, Castro P, Leiva-Salcedo E, Tomic M, Stojilkovic SS, Coddou C. Opposing Roles of Calcium and Intracellular ATP on Gating of the Purinergic P2X2 Receptor Channel. Int J Mol Sci 2018; 19:ijms19041161. [PMID: 29641486 PMCID: PMC5979340 DOI: 10.3390/ijms19041161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 03/30/2018] [Accepted: 04/03/2018] [Indexed: 11/16/2022] Open
Abstract
P2X2 receptors (P2X2R) exhibit a slow desensitization during the initial ATP application and a progressive, calcium-dependent increase in rates of desensitization during repetitive stimulation. This pattern is observed in whole-cell recordings from cells expressing recombinant and native P2X2R. However, desensitization is not observed in perforated-patched cells and in two-electrode voltage clamped oocytes. Addition of ATP, but not ATPγS or GTP, in the pipette solution also abolishes progressive desensitization, whereas intracellular injection of apyrase facilitates receptor desensitization. Experiments with injection of alkaline phosphatase or addition of staurosporine and ATP in the intracellular solution suggest a role for a phosphorylation-dephosphorylation in receptor desensitization. Mutation of residues that are potential phosphorylation sites identified a critical role of the S363 residue in the intracellular ATP action. These findings indicate that intracellular calcium and ATP have opposing effects on P2X2R gating: calcium allosterically facilitates receptor desensitization and ATP covalently prevents the action of calcium. Single cell measurements further revealed that intracellular calcium stays elevated after washout in P2X2R-expressing cells and the blockade of mitochondrial sodium/calcium exchanger lowers calcium concentrations during washout periods to basal levels, suggesting a role of mitochondria in this process. Therefore, the metabolic state of the cell can influence P2X2R gating.
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Affiliation(s)
- Milos B Rokic
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
| | - Patricio Castro
- Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo 1781421, Chile.
- Laboratory of Developmental Physiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Concepción 4030000, Chile.
| | - Elias Leiva-Salcedo
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170022, Chile.
- Centro para el Desarrollo de Nanociencias y Nanotecnología (CEDENNA), Santiago 9170022, Chile.
| | - Melanija Tomic
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
| | - Stanko S Stojilkovic
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
| | - Claudio Coddou
- Section on Cellular Signaling, National Institutes of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
- Departamento de Ciencias Biomédicas, Facultad de Medicina, Universidad Católica del Norte, Coquimbo 1781421, Chile.
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32
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Chen Z, He L, Li L, Chen L. The P2X7 purinergic receptor: An emerging therapeutic target in cardiovascular diseases. Clin Chim Acta 2018; 479:196-207. [PMID: 29366837 DOI: 10.1016/j.cca.2018.01.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 10/24/2022]
Abstract
The P2X7 purinergic receptor, a calcium permeable cationic channel, is activated by extracellular ATP. Most studies show that P2X7 receptor plays an important role in the nervous system diseases, immune response, osteoporosis and cancer. Mounting evidence indicates that P2X7 receptor is also associated with cardiovascular disease. For example, the P2X7 receptor activated by ATP can attenuate myocardial ischemia-reperfusion injury. By contrast, inhibition of P2X7 receptor decreases arrhythmia after myocardial infarction, prolongs cardiac survival after a long term heart transplant, alleviates the dilated cardiomyopathy and the autoimmune myocarditis process. The P2X7 receptor also mitigates vascular diseases including atherosclerosis, hypertension, thrombosis and diabetic retinopathy. This review focuses on the latest research on the role and therapeutic potential of P2X7 receptor in cardiovascular diseases.
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Affiliation(s)
- Zhe Chen
- Institute of Pharmacy and Pharmacology, University of South China, Hengyang 421001, China
| | - Lu He
- Institute of Pharmacy and Pharmacology, University of South China, Hengyang 421001, China
| | - Lanfang Li
- Institute of Pharmacy and Pharmacology, University of South China, Hengyang 421001, China.
| | - Linxi Chen
- Institute of Pharmacy and Pharmacology, University of South China, Hengyang 421001, China.
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33
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Paredes C, Li S, Chen X, Coddou C. Divalent metal modulation of Japanese flounder ( Paralichthys olivaceus) purinergic P2X7 receptor. FEBS Open Bio 2018; 8:383-389. [PMID: 29511615 PMCID: PMC5832984 DOI: 10.1002/2211-5463.12375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/19/2017] [Accepted: 12/21/2017] [Indexed: 01/09/2023] Open
Abstract
Paralichthys olivaceus P2X7 receptor (poP2X7R) is a recently identified as a P2X7 purinergic receptor involved in innate immunity of the Japanese flounder Paralichthys olivaceus. Divalent metals are allosteric modulators of mammalian P2XRs, but there is no information for fish P2XRs. Here, we characterized the effects of divalent metals on poP2X7R channel activity by electrophysiology and molecular biology techniques. Copper, zinc and mercury inhibited poP2X7R‐mediated currents with different maximal inhibition potency, while cadmium had no effect on poP2X7R activity. Mercury‐induced inhibition was irreversible, but the inhibitory effects of copper and zinc were reversed after washout. Cooper and zinc also reduced poP2X7R‐mediated interleukin‐1 mRNA production. These findings suggest that divalent metals have potential effects on the Japanese flounder innate immune response through modulation of poP2X7R activity.
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Affiliation(s)
- Carolina Paredes
- Department of Biomedical Sciences Faculty of Medicine Universidad Católica del Norte Coquimbo Chile
| | - Shuo Li
- Tianjin Key Laboratory of Animal and Plant Resistance College of Life Sciences Tianjin Normal University China
| | - Xiaoli Chen
- Tianjin Key Laboratory of Animal and Plant Resistance College of Life Sciences Tianjin Normal University China
| | - Claudio Coddou
- Department of Biomedical Sciences Faculty of Medicine Universidad Católica del Norte Coquimbo Chile
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34
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Barros-Barbosa AR, Oliveira Â, Lobo MG, Cordeiro JM, Correia-de-Sá P. Under stressful conditions activation of the ionotropic P2X7 receptor differentially regulates GABA and glutamate release from nerve terminals of the rat cerebral cortex. Neurochem Int 2017; 112:81-95. [PMID: 29154812 DOI: 10.1016/j.neuint.2017.11.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 11/08/2017] [Accepted: 11/10/2017] [Indexed: 01/08/2023]
Abstract
γ-Aminobutyric acid (GABA) and glutamate (Glu) are the main inhibitory and excitatory neurotransmitters in the central nervous system (CNS), respectively. Fine tuning regulation of extracellular levels of these amino acids is essential for normal brain activity. Recently, we showed that neocortical nerve terminals from patients with epilepsy express higher amounts of the non-desensitizing ionotropic P2X7 receptor. Once activated by ATP released from neuronal cells, the P2X7 receptor unbalances GABAergic vs. glutamatergic neurotransmission by differentially interfering with GABA and Glu uptake. Here, we investigated if activation of the P2X7 receptor also affects [3H]GABA and [14C]Glu release measured synchronously from isolated nerve terminals (synaptosomes) of the rat cerebral cortex. Data show that activation of the P2X7 receptor consistently increases [14C]Glu over [3H]GABA release from cortical nerve terminals, but the GABA/Glu ratio depends on extracellular Ca2+ concentrations. While the P2X7-induced [3H]GABA release is operated by a Ca2+-dependent pathway when external Ca2+ is available, this mechanism shifts towards the reversal of the GAT1 transporter in low Ca2+ conditions. A different scenario is verified regarding [14C]Glu outflow triggered by the P2X7 receptor, since the amino acid seems to be consistently released through the recruitment of connexin-containing hemichannels upon P2X7 activation, both in the absence and in the presence of external Ca2+. Data from this study add valuable information suggesting that ATP, via P2X7 activation, not only interferes with the high-affinity uptake of GABA and Glu but actually favors the release of these amino acids through distinct molecular mechanisms amenable to differential therapeutic control.
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Affiliation(s)
- Aurora R Barros-Barbosa
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - Ângela Oliveira
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - M Graça Lobo
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - J Miguel Cordeiro
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal.
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35
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Gonzaga DTG, Ferreira LBG, Moreira Maramaldo Costa TE, von Ranke NL, Anastácio Furtado Pacheco P, Sposito Simões AP, Arruda JC, Dantas LP, de Freitas HR, de Melo Reis RA, Penido C, Bello ML, Castro HC, Rodrigues CR, Ferreira VF, Faria RX, da Silva FDC. 1-Aryl-1 H - and 2-aryl-2 H -1,2,3-triazole derivatives blockade P2X7 receptor in vitro and inflammatory response in vivo. Eur J Med Chem 2017; 139:698-717. [DOI: 10.1016/j.ejmech.2017.08.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/02/2017] [Accepted: 08/15/2017] [Indexed: 01/09/2023]
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Karasawa A, Michalski K, Mikhelzon P, Kawate T. The P2X7 receptor forms a dye-permeable pore independent of its intracellular domain but dependent on membrane lipid composition. eLife 2017; 6:31186. [PMID: 28920575 PMCID: PMC5624784 DOI: 10.7554/elife.31186] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 09/15/2017] [Indexed: 12/15/2022] Open
Abstract
The P2X7 receptor mediates extracellular ATP signaling implicated in the development of devastating diseases such as chronic pain and cancer. Activation of the P2X7 receptor leads to opening of the characteristic dye-permeable membrane pore for molecules up to ~900 Da. However, it remains controversial what constitutes this peculiar pore and how it opens. Here we show that the panda receptor, when purified and reconstituted into liposomes, forms an intrinsic dye-permeable pore in the absence of other cellular components. Unexpectedly, we found that this pore opens independent of its unique C-terminal domain. We also found that P2X7 channel activity is facilitated by phosphatidylglycerol and sphingomyelin, but dominantly inhibited by cholesterol through direct interactions with the transmembrane domain. In combination with cell-based functional studies, our data suggest that the P2X7 receptor itself constitutes a lipid-composition dependent dye-permeable pore, whose opening is facilitated by palmitoylated cysteines near the pore-lining helix.
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Affiliation(s)
- Akira Karasawa
- Department of Molecular Medicine, Cornell University, Ithaca, United States
| | - Kevin Michalski
- Department of Molecular Medicine, Cornell University, Ithaca, United States
| | - Polina Mikhelzon
- Department of Molecular Medicine, Cornell University, Ithaca, United States
| | - Toshimitsu Kawate
- Department of Molecular Medicine, Cornell University, Ithaca, United States
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37
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Chen SP, Qin T, Seidel JL, Zheng Y, Eikermann M, Ferrari MD, van den Maagdenberg AMJM, Moskowitz MA, Ayata C, Eikermann-Haerter K. Inhibition of the P2X7-PANX1 complex suppresses spreading depolarization and neuroinflammation. Brain 2017; 140:1643-1656. [PMID: 28430869 DOI: 10.1093/brain/awx085] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 02/12/2017] [Indexed: 01/09/2023] Open
Abstract
Spreading depolarization is a wave of neuronal and glial depolarization. Within minutes after spreading depolarization, the neuronal hemichannel pannexin 1 (PANX1) opens and forms a pore complex with the ligand-gated cation channel P2X7, allowing the release of excitatory neurotransmitters to sustain spreading depolarization and activate neuroinflammation. Here, we explore the hypothesis that the P2X7-PANX1 pore complex is a critical determinant of spreading depolarization susceptibility with important consequences for neuroinflammation and trigeminovascular activation. We found that genetic loss of function or ablation of the P2x7 gene inhibits spreading depolarization. Moreover, pharmacological suppression of the P2X7-PANX1 pore complex inhibits spreading depolarization in mice carrying the human familial hemiplegic migraine type 1 R192Q missense mutation as well as in wild-type mice and rats. Pore inhibitors elevate the electrical threshold for spreading depolarization, and reduce spreading depolarization frequency and amplitude. Pore inhibitors also suppress downstream consequences of spreading depolarization such as upregulation of interleukin-1 beta, inducible nitric oxide synthase and cyclooxygenase-2 in the cortex after spreading depolarization. In addition, they inhibit surrogates for trigeminovascular activation, including expression of calcitonin gene-related peptide in the trigeminal ganglion and c-Fos in the trigeminal nucleus caudalis. Our results are consistent with the hypothesis that the P2X7-PANX1 pore complex is a critical determinant of spreading depolarization susceptibility and its downstream consequences, of potential relevance to its signature disorders such as migraine.
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Affiliation(s)
- Shih-Pin Chen
- Neurovascular Research Lab, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Tao Qin
- Neurovascular Research Lab, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jessica L Seidel
- Neurovascular Research Lab, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Yi Zheng
- Neurovascular Research Lab, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Matthias Eikermann
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA and Universitaet Duisburg Essen, Essen, Germany
| | - Michel D Ferrari
- Department of Neurology, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands
| | - Arn M J M van den Maagdenberg
- Department of Neurology, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands.,Department of Human Genetics, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands
| | - Michael A Moskowitz
- Stroke and Neurovascular Regulation Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Cenk Ayata
- Neurovascular Research Lab, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Katharina Eikermann-Haerter
- Neurovascular Research Lab, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
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38
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P2X7 receptor large pore signaling in avian Müller glial cells. J Bioenerg Biomembr 2017; 49:215-229. [PMID: 28573491 DOI: 10.1007/s10863-017-9717-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 05/11/2017] [Indexed: 01/15/2023]
Abstract
ATP is a pleiotropic molecule that promotes extra- and intracellular signaling to regulate numerous functions. This nucleotide activates purine and pyrimidine receptors at the plasma membrane, categorized as ionotropic P2X or G-protein-coupled receptor (GPCR) P2Y receptors. P2X are ligand-gated ion channel receptors, expressed in both retinal neurons and Müller cells leading to neuron-glia communication, calcium waves and neurovascular coupling. However, how P2X pore is formed upon ATP activation and how signaling pathways regulates the complex is still a matter of controversy. Here we studied the properties of the P2X7 receptor (P2X7R) using electrophysiology, single cell Ca2+ imaging, and dye uptake assay in purified avian Müller glia in culture. Our data show that ATP (or benzoyl-benzoyl ATP, BzATP) evoked large inward currents in patch-clamp studies while addition of P2X7R antagonist such as brilliant Blue G (BBG), abolished these currents. Ruthenium red (RU-2), a general transient receptor potential (TRP) inhibitor, reduced currents induced by ATP. Our data also point to the involvement of mitogen activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K), Ca2+-calmodulin kinase II (CAMKII), microtubules or protein kinase C (PKC) modulating ATP-induced ionic current in Müller cells. We show that ATP induced Ca2+ influx, partially inhibited by P2X7R antagonists (oxidized ATP or BBG), and totally inhibited by blockers of other pores such as transient receptor potential (TRPs) or connexin hemichannel. Additionally, MAPK, PKC, PI3K or CAMKII inhibitors also are involved in the modulation of intracellular calcium signaling. Finally, ATP induced 80-90% of dye uptake in Muller glia cells, while oxidized ATP (oATP), BBG or A740003 inhibited this effect. We conclude that large conductance channel and other P2XRs are not involved in the ATP-induced dye uptake, but signaling pathways such as MAPK, PI3-K, microtubules or PKC are involved in pore formation.
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39
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The Role of the P2X7 Receptor in Ocular Stresses: A Potential Therapeutic Target. Vision (Basel) 2017; 1:vision1020014. [PMID: 31740640 PMCID: PMC6835678 DOI: 10.3390/vision1020014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/10/2017] [Accepted: 05/14/2017] [Indexed: 01/30/2023] Open
Abstract
The P2X7 receptor is expressed in both anterior and posterior segments of the eyeball. In the ocular surface, the P2X7 receptor is activated in case of external aggressions: preservatives and surfactants induce the activation of P2X7 receptors, leading to either apoptosis, inflammation, or cell proliferation. In the retina, the key endogenous actors of age-related macular degeneration, diabetic retinopathy, and glaucoma act through P2X7 receptors’ activation and/or upregulation of P2X7 receptors’ expression. Different therapeutic strategies aimed at the P2X7 receptor exist. P2X7 receptor antagonists, such as divalent cations and Brilliant Blue G (BBG) could be used to target either the ocular surface or the retina, as long as polyunsaturated fatty acids may exert their effects through the disruption of plasma membrane lipid rafts or saffron that reduces the response evoked by P2X7 receptor stimulation. Treatments against P2X7 receptor activation are proposed by using either eye drops or food supplements.
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40
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Rat P, Olivier E, Tanter C, Wakx A, Dutot M. A fast and reproducible cell- and 96-well plate-based method for the evaluation of P2X7 receptor activation using YO-PRO-1 fluorescent dye. J Biol Methods 2017; 4:e64. [PMID: 31453224 PMCID: PMC6708926 DOI: 10.14440/jbm.2017.136] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 12/14/2016] [Accepted: 12/14/2016] [Indexed: 02/06/2023] Open
Abstract
The YO-PRO-1 assay provides a quantitative estimation of P2X7 receptor activation. P2X7 receptor is associated to pathological conditions including infectious, inflammatory, neurological, musculoskeletal disorders, pain and cancer. Most primary cells and cell lines from diverse origin may be used thanks to the ubiquitous distribution of P2X7 receptor. To study the activation of P2X7 receptor by chemicals or biological agents, we established a microplate-based cytometry protocol to accurately and rapidly quantify the activation of P2X7 receptor that leads to the formation of large pores in cell membranes. The YO-PRO-1 assay is based on the ability of cells to incorporate and bind YO-PRO-1 dye to DNA after activation of P2X7 receptor through pore formation. Cells are seeded in 96-well plates and incubated with the compound being tested for the appropriate time. The microplate is then incubated for 10 min with YO-PRO-1 staining solution. After the 10 min staining time, fluorescence signal is read using a microplate reader in 1 min. This procedure is easier and requires less handling steps than flow cytometry. 96-well plate based YO-PRO-1 assay is a reproducible and fast method to study both P2X7 receptor activation by toxic agents at subnecrotic concentrations and P2X7 receptor inhibition by antagonists.
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Affiliation(s)
- Patrice Rat
- UMR 8638 CNRS COMETE, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Elodie Olivier
- UMR 8638 CNRS COMETE, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, 4 avenue de l'Observatoire, 75006 Paris, France.,Soliance-Givaudan, Route de Bazancourt, 51110 Pomacle, France
| | - Caroline Tanter
- Recherche et Développement, Laboratoire d'Evaluation Physiologique, Yslab, 2 rue Félix Le Dantec, 29000 Quimper, France
| | - Anaïs Wakx
- UMR 8638 CNRS COMETE, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Mélody Dutot
- UMR 8638 CNRS COMETE, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, 4 avenue de l'Observatoire, 75006 Paris, France.,Recherche et Développement, Laboratoire d'Evaluation Physiologique, Yslab, 2 rue Félix Le Dantec, 29000 Quimper, France
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41
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Fujiwara M, Ohbori K, Ohishi A, Nishida K, Uozumi Y, Nagasawa K. Species Difference in Sensitivity of Human and Mouse P2X7 Receptors to Inhibitory Effects of Divalent Metal Cations. Biol Pharm Bull 2017; 40:375-380. [DOI: 10.1248/bpb.b16-00887] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Makiko Fujiwara
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | - Kenshi Ohbori
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | - Akihiro Ohishi
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | - Kentaro Nishida
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | | | - Kazuki Nagasawa
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
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42
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Ohbori K, Fujiwara M, Ohishi A, Nishida K, Uozumi Y, Nagasawa K. Prophylactic Oral Administration of Magnesium Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice through a Decrease of Colonic Accumulation of P2X7 Receptor-Expressing Mast Cells. Biol Pharm Bull 2017; 40:1071-1077. [DOI: 10.1248/bpb.b17-00143] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kenshi Ohbori
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | - Makiko Fujiwara
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | - Akihiro Ohishi
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | - Kentaro Nishida
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
| | | | - Kazuki Nagasawa
- Department of Environmental Biochemistry, Kyoto Pharmaceutical University
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43
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Cui X, Wan B, Guo LH, Yang Y, Ren X. Insight into the Mechanisms of Combined Toxicity of Single-Walled Carbon Nanotubes and Nickel Ions in Macrophages: Role of P2X 7 Receptor. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:12473-12483. [PMID: 27750000 DOI: 10.1021/acs.est.6b03842] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Coexistence of nanomaterials and environmental pollutants requires in-depth understanding of combined toxicity and underlying mechanism. In this work, we found that coexposure to the mixture of noncytotoxic level of single-walled carbon nanotubes (SWCNTs) (10 μg/mL) and Ni2+ (20 μM) induced significant cytotoxicity in macrophages. However, almost equal amount of intracellular Ni2+ was detected after Ni2+/SWCNT coexposure or Ni2+ single exposure, indicating no enhanced cellular uptake of Ni2+ occurred. SDS-PAGE analysis revealed 50% more SWCNTs retained in Ni2+/SWCNT exposed cells than that with SWCNT exposure alone, regardless of the exposure sequence (coexposure, Ni2+ pre- or post-treatment), suggesting inhibited SWCNT exocytosis by Ni2+. The increased cellular dose of SWCNTs could quantitatively account for the elevated toxicity of Ni2+/SWCNT mixture to cells. It was then found that agonist (ATP) and antagonist (o-ATP) of P2X7R could regulate intracellular SWCNT amount and the cytotoxicity accordingly. In addition, inhibition of P2X7R by P2X7-targeting siRNA diminished the inhibitory effect of Ni2+. It was therefore concluded that Ni2+ impeded SWCNT exocytosis by inhibiting P2X7R, leading to higher intracellular retention of SWCNTs and elevated cytotoxicity. Our work identified exocytosis inhibition as an important mechanism for SWCNT/Ni2+ toxicity, and revealed the crucial role of P2X7R in mediating such inhibitory effect.
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Affiliation(s)
- Xuejing Cui
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Bin Wan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Liang-Hong Guo
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
- Institute of Environment and Health, Jianghan University , Wuhan, Hubei 430056, China
| | - Yu Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
| | - Xiaomin Ren
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
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44
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Yue J, Jin S, Li Y, Zhang L, Jiang W, Yang C, Du J. Magnesium inhibits the calcification of the extracellular matrix in tendon-derived stem cells via the ATP-P2R and mitochondrial pathways. Biochem Biophys Res Commun 2016; 478:314-322. [PMID: 27402270 DOI: 10.1016/j.bbrc.2016.06.108] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 06/22/2016] [Indexed: 01/14/2023]
Abstract
Tendon calcification has been widely regarded by researchers to result from the osteogenic differentiation of Tendon-Derived Stem Cells (TDSCs) and ectopic mineralization caused by the calcification of cellular matrix. Recent studies have revealed a correlation between the Mg(2+)/Ca(2+) balance and the degeneration or calcification of tendon tissues. Furthermore, the ATP-P2X/P2Y receptor pathway has been shown to play a decisive role in the process of calcification, with calcium exportation from mitochondria and calcium oscillations potentially representing the cohesive signal produced by this pathway. Our previous study demonstrated that matrix calcification is inhibited by magnesium. In this study, we examined the effects of extracellular Mg(2+) on the deposition of calcium phosphate matrix and cellular pathways in TDSCs. The suppression of the export of calcium from mitochondria has also been detected. We found that a high concentration of extracellular Mg(2+) ([Mg(2+)]e) inhibited the mineralization of the extracellular matrix in TDSCs and that 100 μM ATP reversed this inhibitory effect in vitro. In addition, the spontaneous release of ATP was inhibited by high [Mg(2+)]e levels. A high [Mg(2+)]e suppressed the expression of P2X4, P2X5 and P2X7 and activated the expression of P2Y1, P2Y2, P2Y4 and P2Y14. The interaction between Mg(2+) and Ca(2+) is therefore contradictory, Mg(2+) inhibits mitochondrial calcium concentrations, meanwhile it reverses the opening of mPTP that is induced by Ca(2+). JC-1 staining verified the protective effect of Mg(2+) on mitochondrial membrane potential and the decrease induced by Ca(2+). Taken together, these results indicate that high [Mg(2+)]e interferes with the expression of P2 receptors, resulting in decreased extracellular mineralization. The balance between Mg(2+) and Ca(2+) influences mitochondrial calcium exportation and provides another explanation for the mechanism underlying matrix calcification in TDSCs.
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Affiliation(s)
- Jiaji Yue
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, 301 Middle Yanchang Road, Shanghai 200072, People's Republic of China; Tongji University School of Medicine, 1239 Siping Road, Shanghai 200092, People's Republic of China
| | - Shanzi Jin
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, 301 Middle Yanchang Road, Shanghai 200072, People's Republic of China; Tongji University School of Medicine, 1239 Siping Road, Shanghai 200092, People's Republic of China
| | - Yaqiang Li
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, 301 Middle Yanchang Road, Shanghai 200072, People's Republic of China; Tongji University School of Medicine, 1239 Siping Road, Shanghai 200092, People's Republic of China
| | - Li Zhang
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, 301 Middle Yanchang Road, Shanghai 200072, People's Republic of China; Department of Trauma Surgery, Klinikum rechts der lsar, Technical University of Munich, Ismaningerstrasse 22, 81675 Munich, Germany
| | - Wenwei Jiang
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, 301 Middle Yanchang Road, Shanghai 200072, People's Republic of China; The First Clinical Medical College, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, People's Republic of China
| | - Chunxi Yang
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tenth People's Hospital of Tongji University, 301 Middle Yanchang Road, Shanghai 200072, People's Republic of China.
| | - Jiang Du
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
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45
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Chavda S, Luthert PJ, Salt TE. P2X 7R modulation of visually evoked synaptic responses in the retina. Purinergic Signal 2016; 12:611-625. [PMID: 27393519 PMCID: PMC5123999 DOI: 10.1007/s11302-016-9522-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 06/24/2016] [Indexed: 10/29/2022] Open
Abstract
P2X7Rs are distributed throughout all layers of the retina, and thus, their localisation on various cell types puts into question their specific site(s) of action. Using a dark-adapted, ex vivo mouse retinal whole mount preparation, the present study aimed to characterise the effect of P2X7R activation on light-evoked, excitatory RGC ON-field excitatory post-synaptic potentials (fEPSPs) and on outer retinal electroretinogram (ERG) responses under comparable conditions. The pharmacologically isolated NMDA receptor-mediated RGC ON-fEPSP was reduced in the presence of BzATP, an effect which was significantly attenuated by A438079 and other selective P2X7R antagonists A804598 or AF27139. In physiological Krebs medium, BzATP induced a significant potentiation of the ERG a-wave, with a concomitant reduction in the b-wave and the power of the oscillatory potentials. Conversely, in the pharmacologically modified Mg2+-free perfusate, BzATP reduced both the a-wave and b-wave. The effects of BzATP on the ERG components were suppressed by A438079. A role for P2X7R function in visual processing in both the inner and outer retina under physiological conditions remains controversial. The ON-fEPSP was significantly reduced in the presence of A804598 but not by A438079 or AF27139. Furthermore, A438079 did not have any effect on the ERG components in physiological Krebs but potentiated and reduced the a-wave and b-wave, respectively, when applied to the pharmacologically modified medium. Therefore, activation of P2X7Rs affects the function in the retinal ON pathway. The presence of a high concentration of extracellular ATP would most likely contribute to the modulation of visual transmission in the retina in the pathophysiological microenvironment.
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Affiliation(s)
- Seetal Chavda
- Visual Neuroscience, UCL Institute of Ophthalmology, London, EC1V 9EL, UK
| | - Philip J Luthert
- Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, EC1V 9EL, UK.,NIHR Biomedical Research Centre in Ophthalmology, London, EC1V 9EL, UK
| | - Thomas E Salt
- Visual Neuroscience, UCL Institute of Ophthalmology, London, EC1V 9EL, UK.
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46
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Peralta FA, Huidobro-Toro JP. Zinc as Allosteric Ion Channel Modulator: Ionotropic Receptors as Metalloproteins. Int J Mol Sci 2016; 17:E1059. [PMID: 27384555 PMCID: PMC4964435 DOI: 10.3390/ijms17071059] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 06/20/2016] [Accepted: 06/22/2016] [Indexed: 12/20/2022] Open
Abstract
Zinc is an essential metal to life. This transition metal is a structural component of many proteins and is actively involved in the catalytic activity of cell enzymes. In either case, these zinc-containing proteins are metalloproteins. However, the amino acid residues that serve as ligands for metal coordination are not necessarily the same in structural proteins compared to enzymes. While crystals of structural proteins that bind zinc reveal a higher preference for cysteine sulfhydryls rather than histidine imidazole rings, catalytic enzymes reveal the opposite, i.e., a greater preference for the histidines over cysteines for catalysis, plus the influence of carboxylic acids. Based on this paradigm, we reviewed the putative ligands of zinc in ionotropic receptors, where zinc has been described as an allosteric modulator of channel receptors. Although these receptors do not strictly qualify as metalloproteins since they do not normally bind zinc in structural domains, they do transitorily bind zinc at allosteric sites, modifying transiently the receptor channel's ion permeability. The present contribution summarizes current information showing that zinc allosteric modulation of receptor channels occurs by the preferential metal coordination to imidazole rings as well as to the sulfhydryl groups of cysteine in addition to the carboxyl group of acid residues, as with enzymes and catalysis. It is remarkable that most channels, either voltage-sensitive or transmitter-gated receptor channels, are susceptible to zinc modulation either as positive or negative regulators.
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Affiliation(s)
- Francisco Andrés Peralta
- Laboratorio de Farmacología de Nucleótidos, Laboratorio de Farmacología, Departamento de Biología, Facultad de Química y Biología, y Centro para el Desarrollo de Nanociencias y Nanotecnología (CEDENNA), Universidad de Santiago de Chile, Alameda Libertador B. O'Higgins, 3363 Santiago, Chile.
| | - Juan Pablo Huidobro-Toro
- Laboratorio de Farmacología de Nucleótidos, Laboratorio de Farmacología, Departamento de Biología, Facultad de Química y Biología, y Centro para el Desarrollo de Nanociencias y Nanotecnología (CEDENNA), Universidad de Santiago de Chile, Alameda Libertador B. O'Higgins, 3363 Santiago, Chile.
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Barros-Barbosa AR, Fonseca AL, Guerra-Gomes S, Ferreirinha F, Santos A, Rangel R, Lobo MG, Correia-de-Sá P, Cordeiro JM. Up-regulation of P2X7 receptor-mediated inhibition of GABA uptake by nerve terminals of the human epileptic neocortex. Epilepsia 2015; 57:99-110. [PMID: 26714441 DOI: 10.1111/epi.13263] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2015] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Thirty percent of patients with epilepsy are refractory to medication. The majority of these patients have mesial temporal lobe epilepsy (MTLE). This prompts for new pharmacologic targets, like ATP-mediated signaling pathways, since the extracellular levels of the nucleotide dramatically increase during in vitro epileptic seizures. In this study, we investigated whether sodium-dependent high-affinity γ-aminobutyric acid (GABA) and glutamate uptake by isolated nerve terminals of the human neocortex could be modulated by ATP acting via slow-desensitizing P2X7 receptor (P2X7R). METHODS Modulation of [(3) H]GABA and [(14) C]glutamate uptake by ATP, through activation of P2X7R, was investigated in isolated nerve terminals of the neocortex of cadaveric controls and patients with drug-resistant epilepsy (non-MTLE or MTLE) submitted to surgery. Tissue density and distribution of P2X7R in the human neocortex was assessed by Western blot analysis and immunofluorescence confocal microscopy. RESULTS The P2X7R agonist, 2'(3')-O-(4-benzoylbenzoyl)ATP (BzATP, 3-100 μm) decreased [(3) H]GABA and [(14) C]glutamate uptake by nerve terminals of the neocortex of controls and patients with epilepsy. The inhibitory effect of BzATP (100 μm) was prevented by the selective P2X7R antagonist, A-438079 (3 μm). Down-modulation of [(14) C]glutamate uptake by BzATP (100 μm) was roughly similar in controls and patients with epilepsy, but the P2X7R agonist inhibited more effectively [(3) H]GABA uptake in the epileptic tissue. Neocortical nerve terminals of patients with epilepsy express higher amounts of the P2X7R protein than control samples. SIGNIFICANCE High-frequency cortical activity during epileptic seizures releases huge amounts of ATP, which by acting on low-affinity slowly desensitizing ionotropic P2X7R, leads to down-modulation of neuronal GABA and glutamate uptake. Increased P2X7R expression in neocortical nerve terminals of patients with epilepsy may, under high-frequency firing, endure GABA signaling and increase GABAergic rundown, thereby unbalancing glutamatergic neuroexcitation. This study highlights the relevance of the ATP-sensitive P2X7R as an important negative modulator of GABA and glutamate transport and prompts for novel antiepileptic therapeutic targets.
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Affiliation(s)
- Aurora R Barros-Barbosa
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Ana L Fonseca
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Sónia Guerra-Gomes
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Fátima Ferreirinha
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Agostinho Santos
- Serviço de Patologia Forense, Instituto Nacional de Medicina Legal e Ciências Forenses - Delegação do Norte (INMLCF-DN), Porto, Portugal
| | - Rui Rangel
- Serviço de Neurocirurgia, Centro Hospitalar do Porto - Hospital Geral de Santo António (CHP - HGSA), Porto, Portugal
| | - M Graça Lobo
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - J Miguel Cordeiro
- Laboratório de Farmacologia e Neurobiologia - Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
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Adamczyk M, Griffiths R, Dewitt S, Knäuper V, Aeschlimann D. P2X7 receptor activation regulates rapid unconventional export of transglutaminase-2. J Cell Sci 2015; 128:4615-28. [PMID: 26542019 PMCID: PMC4696497 DOI: 10.1242/jcs.175968] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/29/2015] [Indexed: 12/24/2022] Open
Abstract
Transglutaminases (denoted TG or TGM) are externalized from cells via an unknown unconventional secretory pathway. Here, we show for the first time that purinergic signaling regulates active secretion of TG2 (also known as TGM2), an enzyme with a pivotal role in stabilizing extracellular matrices and modulating cell–matrix interactions in tissue repair. Extracellular ATP promotes TG2 secretion by macrophages, and this can be blocked by a selective antagonist against the purinergic receptor P2X7 (P2X7R, also known as P2RX7). Introduction of functional P2X7R into HEK293 cells is sufficient to confer rapid, regulated TG2 export. By employing pharmacological agents, TG2 release could be separated from P2X7R-mediated microvesicle shedding. Neither Ca2+ signaling alone nor membrane depolarization triggered TG2 secretion, which occurred only upon receptor membrane pore formation and without pannexin channel involvement. A gain-of-function mutation in P2X7R associated with autoimmune disease caused enhanced TG2 externalization from cells, and this correlated with increased pore activity. These results provide a mechanistic explanation for a link between active TG2 secretion and inflammatory responses, and aberrant enhanced TG2 activity in certain autoimmune conditions. Summary: Purinergic signaling regulates unconventional secretion of transglutaminase-2 (TG2) and explains the link between aberrant protein modifications and inflammatory responses in TG2-dependent autoimmunity.
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Affiliation(s)
- Magdalena Adamczyk
- Matrix Biology & Tissue Repair Research Unit and Arthritis Research UK Biomechanics and Bioengineering Center of Excellence, College of Biomedical and Life Sciences, Cardiff University, Cardiff CF14 4XY, UK
| | - Rhiannon Griffiths
- Matrix Biology & Tissue Repair Research Unit and Arthritis Research UK Biomechanics and Bioengineering Center of Excellence, College of Biomedical and Life Sciences, Cardiff University, Cardiff CF14 4XY, UK
| | - Sharon Dewitt
- Matrix Biology & Tissue Repair Research Unit and Arthritis Research UK Biomechanics and Bioengineering Center of Excellence, College of Biomedical and Life Sciences, Cardiff University, Cardiff CF14 4XY, UK
| | - Vera Knäuper
- Matrix Biology & Tissue Repair Research Unit and Arthritis Research UK Biomechanics and Bioengineering Center of Excellence, College of Biomedical and Life Sciences, Cardiff University, Cardiff CF14 4XY, UK
| | - Daniel Aeschlimann
- Matrix Biology & Tissue Repair Research Unit and Arthritis Research UK Biomechanics and Bioengineering Center of Excellence, College of Biomedical and Life Sciences, Cardiff University, Cardiff CF14 4XY, UK
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Paroxetine suppresses recombinant human P2X7 responses. Purinergic Signal 2015; 11:481-90. [PMID: 26341077 DOI: 10.1007/s11302-015-9467-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/24/2015] [Indexed: 01/02/2023] Open
Abstract
P2X7 receptor (P2X7) activity may link inflammation to depressive disorders. Genetic variants of human P2X7 have been linked with major depression and bipolar disorders, and the P2X7 knockout mouse has been shown to exhibit anti-depressive-like behaviour. P2X7 is an ATP-gated ion channel and is a major regulator of the pro-inflammatory cytokine interleukin 1β (IL-1β) secretion from monocytes and microglia. We hypothesised that antidepressants may elicit their mood enhancing effects in part via modulating P2X7 activity and reducing inflammatory responses. In this study, we determined whether common psychoactive drugs could affect recombinant and native human P2X7 responses in vitro. Common antidepressants demonstrated opposing effects on human P2X7-mediated responses; paroxetine inhibited while fluoxetine and clomipramine mildly potentiated ATP-induced dye uptake in HEK-293 cells stably expressing recombinant human P2X7. Paroxetine inhibited dye uptake mediated by human P2X7 in a concentration-dependent manner with an IC(50) of 24 μM and significantly reduces ATP-induced inward currents. We confirmed that trifluoperazine hydrochloride suppressed human P2X7 responses (IC(50) of 6.4 μM). Both paroxetine and trifluoperazine did not inhibit rodent P2X7 responses, and mutation of a known residue (F 95L) did not alter the effect of either drug, suggesting neither drug binds at this site. Finally, we demonstrate that P2X7-induced IL-1β secretion from lipopolysaccharide (LPS)-primed human CD14(+) monocytes was suppressed with trifluoperazine and paroxetine.
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Barros-Barbosa AR, Lobo MG, Ferreirinha F, Correia-de-Sá P, Cordeiro JM. P2X7 receptor activation downmodulates Na(+)-dependent high-affinity GABA and glutamate transport into rat brain cortex synaptosomes. Neuroscience 2015; 306:74-90. [PMID: 26299340 DOI: 10.1016/j.neuroscience.2015.08.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/09/2015] [Accepted: 08/13/2015] [Indexed: 02/06/2023]
Abstract
Sodium-dependent high-affinity amino-acid transporters play crucial roles in terminating synaptic transmission in the central nervous system (CNS). However, there is lack of information about the mechanisms underlying the regulation of amino-acid transport by fast-acting neuromodulators, like ATP. Here, we investigated whether activation of the ATP-sensitive P2X7 receptor modulates Na(+)-dependent high-affinity γ-aminobutyric acid (GABA) and glutamate uptake into nerve terminals (synaptosomes) of the rat cerebral cortex. Radiolabeled neurotransmitter accumulation was evaluated by liquid scintillation spectrometry. The cell-permeant sodium-selective fluorescent indicator, SBFI-AM, was used to estimate Na(+) influx across plasma membrane. 2'(3')-O-(4-benzoylbenzoyl)ATP (BzATP, 3-300 μM), a prototypic P2X7 receptor agonist, concentration-dependently decreased [(3)H]GABA (14%) and [(14)C]glutamate (24%) uptake; BzATP decreased transport maximum velocity (Vmax) without affecting the Michaelis constant (Km) values. The selective P2X7 receptor antagonist, A-438079 (3 μM), prevented inhibition of [(3)H]GABA and [(14)C]glutamate uptake by BzATP (100 μM). The inhibitory effect of BzATP coincided with its ability to increase intracellular Na(+) and was mimicked by Na(+) ionophores, like gramicidin and monensin. Increases in intracellular Na(+) (with veratridine or ouabain) or substitution of extracellular Na(+) by N-methyl-D-glucamine (NMDG)(+) all decreased [(3)H]GABA and [(14)C]glutamate uptake and attenuated BzATP effects. Uptake inhibition by BzATP (100 μM) was also attenuated by calmidazolium, which selectively inhibits Na(+) currents through the P2X7 receptor pore. In conclusion, disruption of the Na(+) gradient by P2X7 receptor activation downmodulates high-affinity GABA and glutamate uptake into rat cortical synaptosomes. Interference with amino-acid transport efficacy may constitute a novel target for therapeutic management of cortical excitability.
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Affiliation(s)
- A R Barros-Barbosa
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - M G Lobo
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - F Ferreirinha
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal
| | - P Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal.
| | - J M Cordeiro
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal; Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Porto, Portugal.
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