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Tang Z, Xie J, Jin M, Wei G, Fu Z, Luo X, Li C, Jia X, Zheng H, Zhong L, Li X, Wang J, Chen G, Chen Y, Liao W, Liao Y, Bin J, Huang S. Sympathetic hyperinnervation drives abdominal aortic aneurysm development by promoting vascular smooth muscle cell phenotypic switching. J Adv Res 2024:S2090-1232(24)00218-2. [PMID: 38821358 DOI: 10.1016/j.jare.2024.05.028] [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: 03/26/2024] [Revised: 05/12/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024] Open
Abstract
INTRODUCTION Sympathetic hyperinnervation plays an important role in modulating the vascular smooth muscle cell (VSMC) phenotype and vascular diseases, but its role in abdominal aortic aneurysm (AAA) is still unknown. OBJECTIVES This study aimed to investigate the role of sympathetic hyperinnervation in promoting AAA development and the underlying mechanism involved. METHODS Western blotting and immunochemical staining were used to detect sympathetic hyperinnervation. We performed sympathetic denervation through coeliac ganglionectomy (CGX) and 6-OHDA administration to understand the role of sympathetic hyperinnervation in AAA and investigated the underlying mechanisms through transcriptome and functional studies. Sema4D knockout (Sema4D-/-) mice were utilized to determine the involvement of Sema4D in inducing sympathetic hyperinnervation and AAA development. RESULTS We observed sympathetic hyperinnervation, the most important form of sympathetic neural remodeling, in both mouse AAA models and AAA patients. Elimination of sympathetic hyperinnervation by CGX or 6-OHDA significantly inhibited AAA development and progression. We further revealed that sympathetic hyperinnervation promoted VSMC phenotypic switching in AAA by releasing extracellular ATP (eATP) and activating eATP-P2rx4-p38 signaling. Moreover, single-cell RNA sequencing revealed that Sema4D secreted by osteoclast-like cells induces sympathetic nerve diffusion and hyperinnervation through binding to Plxnb1. We consistently observed that AAA progression was significantly ameliorated in Sema4D-deficient mice. CONCLUSIONS Sympathetic hyperinnervation driven by osteoclast-like cell-derived Sema4D promotes VSMC phenotypic switching and accelerates pathological aneurysm progression by activating the eATP/P2rx4/p38 pathway. Inhibition of sympathetic hyperinnervation emerges as a potential novel therapeutic strategy for preventing and treating AAA.
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Affiliation(s)
- Zhenquan Tang
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Jingfang Xie
- Guangdong Provincial Geriatrics Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou 510080, China
| | - Ming Jin
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Guoquan Wei
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Ziwei Fu
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Xiajing Luo
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Chuling Li
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Xiaoqian Jia
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Hao Zheng
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Lintao Zhong
- Department of Cardiology, Zhuhai People's Hospital (Zhuhai Hospital Affiliated with Jinan University), Zhuhai 519000, China
| | - Xinzhong Li
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Junfen Wang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Guojun Chen
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Yanmei Chen
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Wangjun Liao
- Department of Oncology, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China
| | - Yulin Liao
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China
| | - Jianping Bin
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China.
| | - Senlin Huang
- Department of Cardiology, State Key Laboratory of Organ Failure Research, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China; Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, 510515 Guangzhou, China.
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Zou YT, Li JY, Chai JY, Hu YS, Zhang WJ, Zhang Q. The impact of the P2X7 receptor on the tumor immune microenvironment and its effects on tumor progression. Biochem Biophys Res Commun 2024; 707:149513. [PMID: 38508051 DOI: 10.1016/j.bbrc.2024.149513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 03/22/2024]
Abstract
Cancer is a significant global health concern, and finding effective methods to treat it has been a focus of scientific research. It has been discovered that the growth, invasion, and metastasis of tumors are closely related to the environment in which they exist, known as the tumor microenvironment (TME). The immune response interacting with the tumor occurring within the TME constitutes the tumor immune microenvironment, and the immune response can lead to anti-tumor and pro-tumor outcomes and has shown tremendous potential in immunotherapy. A channel called the P2X7 receptor (P2X7R) has been identified within the TME. It is an ion channel present in various immune cells and tumor cells, and its activation can lead to inflammation, immune responses, angiogenesis, immunogenic cell death, and promotion of tumor development. This article provides an overview of the structure, function, and pharmacological characteristics of P2X7R. We described the concept and components of tumor immune microenvironment and the influence immune components has on tumors. We also outlined the impact of P2X7R regulation and how it affects the development of tumors and summarized the effects of drugs targeting P2X7R on tumor progression, both past and current, assisting researchers in treating tumors using P2X7R as a target.
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Affiliation(s)
- Yu-Ting Zou
- The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Jin-Yuan Li
- The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Jun-Yi Chai
- The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Yu-Shan Hu
- The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Wen-Jun Zhang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China; The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China.
| | - Qiao Zhang
- Orthopedics Department, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
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Mut-Arbona P, Sperlágh B. P2 receptor-mediated signaling in the physiological and pathological brain: From development to aging and disease. Neuropharmacology 2023; 233:109541. [PMID: 37062423 DOI: 10.1016/j.neuropharm.2023.109541] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/25/2023] [Accepted: 04/06/2023] [Indexed: 04/18/2023]
Abstract
The purinergic pathway mediates both pro-inflammatory and anti-inflammatory responses, whereas the breakdown of adenosine triphosphate (ATP) is in a critical equilibrium. Under physiological conditions, extracellular ATP is maintained at a nanomolar concentration. Whether released into the medium following tissue damage, inflammation, or hypoxia, ATP is considered a clear indicator of cell damage and a marker of pathological conditions. In this overview, we provide an update on the participation of P2 receptor-mediated purinergic signaling in normal and pathological brain development, with special emphasis on neurodevelopmental psychiatric disorders. Since purinergic signaling is ubiquitous, it is not surprising that it plays a prominent role in developmental processes and pathological alterations. The main aim of this review is to conceptualize the time-dependent dynamic changes in the participation of different players in the purinome in shaping the normal and aberrant developmental patterns and diseases of the central nervous system over one's lifespan.
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Affiliation(s)
- Paula Mut-Arbona
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Budapest, Hungary; János Szentágothai Doctoral School, Semmelweis University, 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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Staruschenko A, Ma R, Palygin O, Dryer SE. Ion channels and channelopathies in glomeruli. Physiol Rev 2023; 103:787-854. [PMID: 36007181 PMCID: PMC9662803 DOI: 10.1152/physrev.00013.2022] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/15/2022] [Accepted: 08/21/2022] [Indexed: 11/22/2022] Open
Abstract
An essential step in renal function entails the formation of an ultrafiltrate that is delivered to the renal tubules for subsequent processing. This process, known as glomerular filtration, is controlled by intrinsic regulatory systems and by paracrine, neuronal, and endocrine signals that converge onto glomerular cells. In addition, the characteristics of glomerular fluid flow, such as the glomerular filtration rate and the glomerular filtration fraction, play an important role in determining blood flow to the rest of the kidney. Consequently, disease processes that initially affect glomeruli are the most likely to lead to end-stage kidney failure. The cells that comprise the glomerular filter, especially podocytes and mesangial cells, express many different types of ion channels that regulate intrinsic aspects of cell function and cellular responses to the local environment, such as changes in glomerular capillary pressure. Dysregulation of glomerular ion channels, such as changes in TRPC6, can lead to devastating glomerular diseases, and a number of channels, including TRPC6, TRPC5, and various ionotropic receptors, are promising targets for drug development. This review discusses glomerular structure and glomerular disease processes. It also describes the types of plasma membrane ion channels that have been identified in glomerular cells, the physiological and pathophysiological contexts in which they operate, and the pathways by which they are regulated and dysregulated. The contributions of these channels to glomerular disease processes, such as focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy, as well as the development of drugs that target these channels are also discussed.
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Affiliation(s)
- Alexander Staruschenko
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida
- Hypertension and Kidney Research Center, University of South Florida, Tampa, Florida
- James A. Haley Veterans Hospital, Tampa, Florida
| | - Rong Ma
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Oleg Palygin
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
- Department of Biomedical Sciences, Tilman J. Fertitta Family College of Medicine, University of Houston, Houston, Texas
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Immadisetty K, Alenciks J, Kekenes-Huskey PM. Modulation of P2X4 pore closure by magnesium, potassium, and ATP. Biophys J 2022; 121:1134-1142. [PMID: 35248546 PMCID: PMC9034312 DOI: 10.1016/j.bpj.2022.02.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/12/2021] [Accepted: 02/22/2022] [Indexed: 11/30/2022] Open
Abstract
The P2X4 receptor plays a prominent role in cellular responses to extracellular ATP. Through classical all-atom molecular dynamics (MD) simulations totaling 24 μs we have investigated how metal-complexed ATP stabilizes the channel's open state and prevents its closing. We have identified two metal-binding sites, Mg2+ and potassium K+, one at the intersection of the three subunits in the ectodomain (MBS1) and the second one near the ATP-binding site (MBS2), similar to those characterized in Gulf Coast P2X. Our data indicate that when Mg2+ and K+ ions are complexed with ATP, the channel is locked into an open state. Interestingly, irrespective of the number of bound ATP molecules, Mg2+ ions bound to the MBS2 impeded the collapse of the open-state protein to a closed state by stabilizing the ATP-protein interactions. However, when Mg2+ in the MBS2 was replaced with K+ ions, as might be expected when in equilibrium with an extracellular solution, the interactions between the subunits were weakened and the pore collapsed. This collapse was apparent when fewer than two ATPs were bound to MBS2 in the presence of K+. Therefore, the different capacities of common cations to stabilize the channel may underlie a mechanism governing P2X4 channel gating in physiological systems. This study therefore provides structural insights into the differential modulation of ATP activation of P2X4 by Mg2+ and K+.
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Rotondo JC, Mazziotta C, Lanzillotti C, Stefani C, Badiale G, Campione G, Martini F, Tognon M. The Role of Purinergic P2X7 Receptor in Inflammation and Cancer: Novel Molecular Insights and Clinical Applications. Cancers (Basel) 2022; 14:1116. [PMID: 35267424 PMCID: PMC8909580 DOI: 10.3390/cancers14051116] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/09/2022] [Accepted: 02/17/2022] [Indexed: 12/11/2022] Open
Abstract
The purinergic P2X7 receptor (P2X7R) is a transmembrane protein whose expression has been related to a variety of cellular processes, while its dysregulation has been linked to inflammation and cancer. P2X7R is expressed in cancer and immune system cell surfaces. ATP plays a key role in numerous metabolic processes due to its abundance in the tumour microenvironment. P2X7R plays an important role in cancer by interacting with ATP. The unusual property of P2X7R is that stimulation with low doses of ATP causes the opening of a permeable channel for sodium, potassium, and calcium ions, whereas sustained stimulation with high doses of ATP favours the formation of a non-selective pore. The latter effect induces a change in intracellular homeostasis that leads to cell death. This evidence suggests that P2X7R has both pro- and anti-tumour proprieties. P2X7R is increasingly recognised as a regulator of inflammation. In this review, we aimed to describe the most relevant characteristics of P2X7R function, activation, and its ligands, while also summarising the role of P2X7R activation in the context of inflammation and cancer. The currently used therapeutic approaches and clinical trials of P2X7R modulators are also described.
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Affiliation(s)
- John Charles Rotondo
- Laboratories of Cell Biology and Molecular Genetics, Section of Experimental Medicine, Department of Medical Sciences, School of Medicine, University of Ferrara, 44121 Ferrara, Italy; (J.C.R.); (C.M.); (C.L.); (C.S.); (G.B.); (G.C.); (F.M.)
- Centre for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Chiara Mazziotta
- Laboratories of Cell Biology and Molecular Genetics, Section of Experimental Medicine, Department of Medical Sciences, School of Medicine, University of Ferrara, 44121 Ferrara, Italy; (J.C.R.); (C.M.); (C.L.); (C.S.); (G.B.); (G.C.); (F.M.)
- Centre for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Carmen Lanzillotti
- Laboratories of Cell Biology and Molecular Genetics, Section of Experimental Medicine, Department of Medical Sciences, School of Medicine, University of Ferrara, 44121 Ferrara, Italy; (J.C.R.); (C.M.); (C.L.); (C.S.); (G.B.); (G.C.); (F.M.)
- Centre for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Chiara Stefani
- Laboratories of Cell Biology and Molecular Genetics, Section of Experimental Medicine, Department of Medical Sciences, School of Medicine, University of Ferrara, 44121 Ferrara, Italy; (J.C.R.); (C.M.); (C.L.); (C.S.); (G.B.); (G.C.); (F.M.)
| | - Giada Badiale
- Laboratories of Cell Biology and Molecular Genetics, Section of Experimental Medicine, Department of Medical Sciences, School of Medicine, University of Ferrara, 44121 Ferrara, Italy; (J.C.R.); (C.M.); (C.L.); (C.S.); (G.B.); (G.C.); (F.M.)
| | - Giulia Campione
- Laboratories of Cell Biology and Molecular Genetics, Section of Experimental Medicine, Department of Medical Sciences, School of Medicine, University of Ferrara, 44121 Ferrara, Italy; (J.C.R.); (C.M.); (C.L.); (C.S.); (G.B.); (G.C.); (F.M.)
| | - Fernanda Martini
- Laboratories of Cell Biology and Molecular Genetics, Section of Experimental Medicine, Department of Medical Sciences, School of Medicine, University of Ferrara, 44121 Ferrara, Italy; (J.C.R.); (C.M.); (C.L.); (C.S.); (G.B.); (G.C.); (F.M.)
- Centre for Studies on Gender Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
- Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, 44121 Ferrara, Italy
| | - Mauro Tognon
- Laboratories of Cell Biology and Molecular Genetics, Section of Experimental Medicine, Department of Medical Sciences, School of Medicine, University of Ferrara, 44121 Ferrara, Italy; (J.C.R.); (C.M.); (C.L.); (C.S.); (G.B.); (G.C.); (F.M.)
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Szrejder M, Rogacka D, Piwkowska A. Purinergic P2 receptors: Involvement and therapeutic implications in diabetes-related glomerular injury. Arch Biochem Biophys 2021; 714:109078. [PMID: 34742673 DOI: 10.1016/j.abb.2021.109078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/15/2021] [Accepted: 10/30/2021] [Indexed: 02/08/2023]
Abstract
The purinergic activation of P2 receptors initiates a powerful and rapid signaling cascade that contributes to the regulation of an array of physiological and pathophysiological processes in many organs, including the kidney. P2 receptors are broadly distributed in both epithelial and vascular renal cells. Disturbances of purinergic signaling can lead to impairments in renal function. A growing body of evidence indicates changes in P2 receptor expression and nucleotide metabolism in chronic renal injury and inflammatory diseases. Increasing attention has focused on purinergic P2X7 receptors, which are not normally expressed in healthy kidney tissue but are highly expressed at sites of tissue damage and inflammation. Under hyperglycemic conditions, several mechanisms that are linked to purinergic signaling and involve nucleotide release and degradation are disrupted, resulting in the accumulation of adenosine 5'-triphosphate in the bloodstream in diabetes. Dysfunction of the purinergic system might be associated with serious vascular complications in diabetes, including diabetic nephropathy. This review summarizes our current knowledge of the role of P2 receptors in diabetes-related glomerular injury and its implications for new therapeutics for diabetic nephropathy.
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Affiliation(s)
- Maria Szrejder
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland.
| | - Dorota Rogacka
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; Department of Molecular Biotechnology, University of Gdańsk, Faculty of Chemistry, Gdańsk, Poland
| | - Agnieszka Piwkowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdańsk, Poland; Department of Molecular Biotechnology, University of Gdańsk, Faculty of Chemistry, Gdańsk, Poland
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Poshtkohi A, Wade J, McDaid L, Liu J, Dallas M, Bithell A. Mathematical modelling of human P2X-mediated plasma membrane electrophysiology and calcium dynamics in microglia. PLoS Comput Biol 2021; 17:e1009520. [PMID: 34723961 PMCID: PMC8584768 DOI: 10.1371/journal.pcbi.1009520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 11/11/2021] [Accepted: 10/02/2021] [Indexed: 01/14/2023] Open
Abstract
Regulation of cytosolic calcium (Ca2+) dynamics is fundamental to microglial function. Temporal and spatial Ca2+ fluxes are induced from a complicated signal transduction pathway linked to brain ionic homeostasis. In this paper, we develop a novel biophysical model of Ca2+ and sodium (Na+) dynamics in human microglia and evaluate the contribution of purinergic receptors (P2XRs) to both intracellular Ca2+ and Na+ levels in response to agonist/ATP binding. This is the first comprehensive model that integrates P2XRs to predict intricate Ca2+ and Na+ transient responses in microglia. Specifically, a novel compact biophysical model is proposed for the capture of whole-cell patch-clamp currents associated with P2X4 and P2X7 receptors, which is composed of only four state variables. The entire model shows that intricate intracellular ion dynamics arise from the coupled interaction between P2X4 and P2X7 receptors, the Na+/Ca2+ exchanger (NCX), Ca2+ extrusion by the plasma membrane Ca2+ ATPase (PMCA), and Ca2+ and Na+ leak channels. Both P2XRs are modelled as two separate adenosine triphosphate (ATP) gated Ca2+ and Na+ conductance channels, where the stoichiometry is the removal of one Ca2+ for the hydrolysis of one ATP molecule. Two unique sets of model parameters were determined using an evolutionary algorithm to optimise fitting to experimental data for each of the receptors. This allows the proposed model to capture both human P2X7 and P2X4 data (hP2X7 and hP2X4). The model architecture enables a high degree of simplicity, accuracy and predictability of Ca2+ and Na+ dynamics thus providing quantitative insights into different behaviours of intracellular Na+ and Ca2+ which will guide future experimental research. Understanding the interactions between these receptors and other membrane-bound transporters provides a step forward in resolving the qualitative link between purinergic receptors and microglial physiology and their contribution to brain pathology. Mathematical modelling and computer simulation are powerful tools by which we can analyse complex biological systems, particularly, neural phenomena involved in brain dysfunction. In this research, we develop a theoretical foundation for studying P2X-mediated calcium and sodium signalling in human microglial cells. Microglia, which are brain-resident macrophages, restructure their intracellular actin cytoskeleton to enable motility; this restructuring requires a complex molecular cascade involving a set of ionic channels, membrane-coupled receptors and cytosolic components. Recent studies highlight the importance for increasing our understanding of microglia physiology, since their functions play critical roles in both normal physiological and pathological dynamics of the brain. There is a need to develop reliable human cellular models to investigate the biology of microglia aimed at understanding the influence of purinergic signalling in brain dysfunction to provide novel drug discovery targets. In this work, a detailed mathematical model is built for the dynamics of human P2XRs in microglia. Subsequently, experimental whole-cell currents are used to derive P2X-mediated electrophysiology of human microglia (i.e. sodium and calcium dynamics, and membrane potential). Our predictions reveal new quantitative insights into P2XRs on how they regulate ionic concentrations in terms of physiological interactions and transient responses.
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Affiliation(s)
- Alireza Poshtkohi
- School of Computing, Engineering and Intelligent Systems, Ulster University, Londonderry, United Kingdom
- * E-mail:
| | - John Wade
- School of Computing, Engineering and Intelligent Systems, Ulster University, Londonderry, United Kingdom
| | - Liam McDaid
- School of Computing, Engineering and Intelligent Systems, Ulster University, Londonderry, United Kingdom
| | - Junxiu Liu
- School of Computing, Engineering and Intelligent Systems, Ulster University, Londonderry, United Kingdom
| | - Mark Dallas
- School of Pharmacy, University of Reading, Reading, United Kingdom
| | - Angela Bithell
- School of Pharmacy, University of Reading, Reading, United Kingdom
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Huang Z, Xie N, Illes P, Di Virgilio F, Ulrich H, Semyanov A, Verkhratsky A, Sperlagh B, Yu SG, Huang C, Tang Y. From purines to purinergic signalling: molecular functions and human diseases. Signal Transduct Target Ther 2021; 6:162. [PMID: 33907179 PMCID: PMC8079716 DOI: 10.1038/s41392-021-00553-z] [Citation(s) in RCA: 172] [Impact Index Per Article: 57.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/24/2021] [Accepted: 02/24/2021] [Indexed: 02/06/2023] Open
Abstract
Purines and their derivatives, most notably adenosine and ATP, are the key molecules controlling intracellular energy homoeostasis and nucleotide synthesis. Besides, these purines support, as chemical messengers, purinergic transmission throughout tissues and species. Purines act as endogenous ligands that bind to and activate plasmalemmal purinoceptors, which mediate extracellular communication referred to as "purinergic signalling". Purinergic signalling is cross-linked with other transmitter networks to coordinate numerous aspects of cell behaviour such as proliferation, differentiation, migration, apoptosis and other physiological processes critical for the proper function of organisms. Pathological deregulation of purinergic signalling contributes to various diseases including neurodegeneration, rheumatic immune diseases, inflammation, and cancer. Particularly, gout is one of the most prevalent purine-related disease caused by purine metabolism disorder and consequent hyperuricemia. Compelling evidence indicates that purinoceptors are potential therapeutic targets, with specific purinergic agonists and antagonists demonstrating prominent therapeutic potential. Furthermore, dietary and herbal interventions help to restore and balance purine metabolism, thus addressing the importance of a healthy lifestyle in the prevention and relief of human disorders. Profound understanding of molecular mechanisms of purinergic signalling provides new and exciting insights into the treatment of human diseases.
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Grants
- National Key R&D Program of China (2019YFC1709101,2020YFA0509400, 2020YFC2002705), the National Natural Science Foundation of China (81821002, 81790251, 81373735, 81972665), Guangdong Basic and Applied Basic Research Foundation (2019B030302012), the Project First-Class Disciplines Development of Chengdu University of Traditional Chinese Medicine (CZYHW1901), São Paulo Research Foundation (FAPESP 2018/07366-4), Russian Science Foundation grant 20-14-00241, NSFC-BFBR;and Science and Technology Program of Sichuan Province, China (2019YFH0108)
- National Key R&D Program of China (2020YFA0509400, 2020YFC2002705), the National Natural Science Foundation of China (81821002, 81790251).
- National Key R&D Program of China (2020YFA0509400, 2020YFC2002705), the National Natural Science Foundation of China (81821002, 81790251), Guangdong Basic and Applied Basic Research Foundation (2019B030302012).
- the Project First-Class Disciplines Development of Chengdu University of Traditional Chinese Medicine (CZYHW1901) and Science and Technology Program of Sichuan Province, China (2019YFH0108).
- the Project First-Class Disciplines Development of Chengdu University of Traditional Chinese Medicine (CZYHW1901), and Science and Technology Program of Sichuan Province, China (2019YFH0108).
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Affiliation(s)
- Zhao Huang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Na Xie
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Peter Illes
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universitaet Leipzig, Leipzig, Germany
| | | | - Henning Ulrich
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Sechenov First Moscow State Medical University, Moscow, Russia
| | - Alexei Verkhratsky
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Sechenov First Moscow State Medical University, Moscow, Russia
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Beata Sperlagh
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Shu-Guang Yu
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Acupuncture and Chronobiology Key Laboratory of Sichuan Province, Chengdu, China
| | - Canhua Huang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, China.
- School of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
| | - Yong Tang
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
- Acupuncture and Chronobiology Key Laboratory of Sichuan Province, Chengdu, China.
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10
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Mechanisms of Synergistic Interactions of Diabetes and Hypertension in Chronic Kidney Disease: Role of Mitochondrial Dysfunction and ER Stress. Curr Hypertens Rep 2020; 22:15. [PMID: 32016622 DOI: 10.1007/s11906-020-1016-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW To discuss the importance of synergistic interactions of diabetes mellitus (DM) and hypertension (HT) in causing chronic kidney disease and the potential molecular mechanisms involved. RECENT FINDINGS DM and HT are the two most important risk factors for chronic kidney disease (CKD) and development of end-stage renal disease (ESRD). The combination of HT and DM may synergistically promote the progression of renal injury through mechanisms that have not been fully elucidated. Hyperglycemia and other metabolic changes in DM initiate endoplasmic reticulum (ER) stress and mitochondrial (MT) adaptation in different types of glomerular cells. These adaptations appear to make the cells more vulnerable to HT-induced mechanical stress. Excessive activation of mechanosensors, possibly via transient receptor potential cation channel subfamily C member 6 (TRPC6), may lead to impaired calcium (Ca2+) homeostasis and further exacerbate ER stress and MT dysfunction promoting cellular apoptosis and glomerular injury. The synergistic effects of HT and DM to promote kidney injury may be mediated by increased intraglomerular pressure. Chronic activation of mechanotransduction signaling may amplify metabolic effects of DM causing cellular injury through a vicious cycle of impaired Ca2+ homeostasis, mitochondrial dysfunction, and ER stress.
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11
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Vallon V, Unwin R, Inscho EW, Leipziger J, Kishore BK. Extracellular Nucleotides and P2 Receptors in Renal Function. Physiol Rev 2019; 100:211-269. [PMID: 31437091 DOI: 10.1152/physrev.00038.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The understanding of the nucleotide/P2 receptor system in the regulation of renal hemodynamics and transport function has grown exponentially over the last 20 yr. This review attempts to integrate the available data while also identifying areas of missing information. First, the determinants of nucleotide concentrations in the interstitial and tubular fluids of the kidney are described, including mechanisms of cellular release of nucleotides and their extracellular breakdown. Then the renal cell membrane expression of P2X and P2Y receptors is discussed in the context of their effects on renal vascular and tubular functions. Attention is paid to effects on the cortical vasculature and intraglomerular structures, autoregulation of renal blood flow, tubuloglomerular feedback, and the control of medullary blood flow. The role of the nucleotide/P2 receptor system in the autocrine/paracrine regulation of sodium and fluid transport in the tubular and collecting duct system is outlined together with its role in integrative sodium and fluid homeostasis and blood pressure control. The final section summarizes the rapidly growing evidence indicating a prominent role of the extracellular nucleotide/P2 receptor system in the pathophysiology of the kidney and aims to identify potential therapeutic opportunities, including hypertension, lithium-induced nephropathy, polycystic kidney disease, and kidney inflammation. We are only beginning to unravel the distinct physiological and pathophysiological influences of the extracellular nucleotide/P2 receptor system and the associated therapeutic perspectives.
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Affiliation(s)
- Volker Vallon
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
| | - Robert Unwin
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
| | - Edward W Inscho
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
| | - Jens Leipziger
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
| | - Bellamkonda K Kishore
- Departments of Medicine and Pharmacology, University of California San Diego & VA San Diego Healthcare System, San Diego, California; Centre for Nephrology, Division of Medicine, University College London, London, United Kingdom; IMED ECD CVRM R&D, AstraZeneca, Gothenburg, Sweden; Department of Medicine, Division of Nephrology, The University of Alabama at Birmingham, Birmingham, Alabama; Department of Biomedicine/Physiology, Aarhus University, Aarhus, Denmark; Departments of Internal Medicine and Nutrition and Integrative Physiology, and Center on Aging, University of Utah Health & Nephrology Research, VA Salt Lake City Healthcare System, Salt Lake City, Utah
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12
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Furuta Y, Tsai SH, Kinoshita M, Fujimoto K, Okumura R, Umemoto E, Kurashima Y, Kiyono H, Kayama H, Takeda K. E-NPP3 controls plasmacytoid dendritic cell numbers in the small intestine. PLoS One 2017; 12:e0172509. [PMID: 28225814 PMCID: PMC5321438 DOI: 10.1371/journal.pone.0172509] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 02/05/2017] [Indexed: 01/17/2023] Open
Abstract
Extracellular adenosine 5'-triphosphate (ATP) performs multiple functions including activation and induction of apoptosis of many cell types. The ATP-hydrolyzing ectoenzyme ecto-nucleotide pyrophosphatase/phosphodiesterase 3 (E-NPP3) regulates ATP-dependent chronic allergic responses by mast cells and basophils. However, E-NPP3 is also highly expressed on epithelial cells of the small intestine. In this study, we showed that E-NPP3 controls plasmacytoid dendritic cell (pDC) numbers in the intestine through regulation of intestinal extracellular ATP. In Enpp3-/- mice, ATP concentrations were increased in the intestinal lumen. pDC numbers were remarkably decreased in the small intestinal lamina propria and Peyer's patches. Intestinal pDCs of Enpp3-/- mice showed enhanced cell death as characterized by increases in annexin V binding and expression of cleaved caspase-3. pDCs were highly sensitive to ATP-induced cell death compared with conventional DCs. ATP-induced cell death was abrogated in P2rx7-/- pDCs. Accordingly, the number of intestinal pDCs was restored in Enpp3-/- P2rx7-/- mice. These findings demonstrate that E-NPP3 regulates ATP concentration and thereby prevents the decrease of pDCs in the small intestine.
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Affiliation(s)
- Yoki Furuta
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
- Department of Gastroenterology and Hepatology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Shih-Han Tsai
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Makoto Kinoshita
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Kosuke Fujimoto
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Ryu Okumura
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Eiji Umemoto
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Yosuke Kurashima
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
- Division of Mucosal Immunology, Department of Microbiology and Immunology, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Kiyono
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
- Division of Mucosal Immunology, Department of Microbiology and Immunology, Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Hisako Kayama
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Kiyoshi Takeda
- Laboratory of Immune Regulation, Department of Microbiology and Immunology, Graduate School of Medicine, WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo, Japan
- * E-mail:
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13
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Mittal R, Chan B, Grati M, Mittal J, Patel K, Debs LH, Patel AP, Yan D, Chapagain P, Liu XZ. Molecular Structure and Regulation of P2X Receptors With a Special Emphasis on the Role of P2X2 in the Auditory System. J Cell Physiol 2015; 231:1656-70. [PMID: 26627116 DOI: 10.1002/jcp.25274] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 12/01/2015] [Indexed: 12/23/2022]
Abstract
The P2X purinergic receptors are cation-selective channels gated by extracellular adenosine 5'-triphosphate (ATP). These purinergic receptors are found in virtually all mammalian cell types and facilitate a number of important physiological processes. Within the past few years, the characterization of crystal structures of the zebrafish P2X4 receptor in its closed and open states has provided critical insights into the mechanisms of ligand binding and channel activation. Understanding of this gating mechanism has facilitated to design and interpret new modeling and structure-function experiments to better elucidate how different agonists and antagonists can affect the receptor with differing levels of potency. This review summarizes the current knowledge on the structure, activation, allosteric modulators, function, and location of the different P2X receptors. Moreover, an emphasis on the P2X2 receptors has been placed in respect to its role in the auditory system. In particular, the discovery of three missense mutations in P2X2 receptors could become important areas of study in the field of gene therapy to treat progressive and noise-induced hearing loss. J. Cell. Physiol. 231: 1656-1670, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Rahul Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Brandon Chan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - M'hamed Grati
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Jeenu Mittal
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Kunal Patel
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Luca H Debs
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Amit P Patel
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Denise Yan
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida
| | - Prem Chapagain
- Department of Physics, Florida International University, Miami, Florida.,Biomolecular Science Institute, Florida International University, Miami, Florida
| | - Xue Zhong Liu
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, Florida.,Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida.,Department of Biochemistry, University of Miami Miller School of Medicine, Miami, Florida
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14
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Burnstock G, Evans LC, Bailey MA. Purinergic signalling in the kidney in health and disease. Purinergic Signal 2014; 10:71-101. [PMID: 24265071 PMCID: PMC3944043 DOI: 10.1007/s11302-013-9400-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/24/2013] [Indexed: 12/21/2022] Open
Abstract
The involvement of purinergic signalling in kidney physiology and pathophysiology is rapidly gaining recognition and this is a comprehensive review of early and recent publications in the field. Purinergic signalling involvement is described in several important intrarenal regulatory mechanisms, including tuboglomerular feedback, the autoregulatory response of the glomerular and extraglomerular microcirculation and the control of renin release. Furthermore, purinergic signalling influences water and electrolyte transport in all segments of the renal tubule. Reports about purine- and pyrimidine-mediated actions in diseases of the kidney, including polycystic kidney disease, nephritis, diabetes, hypertension and nephrotoxicant injury are covered and possible purinergic therapeutic strategies discussed.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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15
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Kim MJ, Turner CM, Hewitt R, Smith J, Bhangal G, Pusey CD, Unwin RJ, Tam FWK. Exaggerated renal fibrosis in P2X4 receptor-deficient mice following unilateral ureteric obstruction. Nephrol Dial Transplant 2014; 29:1350-61. [PMID: 24574541 PMCID: PMC4071051 DOI: 10.1093/ndt/gfu019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background The ATP-sensitive P2X7 receptor (P2X7R) has been shown to contribute to renal injury in nephrotoxic nephritis, a rodent model of acute glomerulonephritis, and in unilateral ureteric obstruction (UUO), a rodent model of chronic interstitial inflammation and fibrosis. Renal tubular cells, endothelial cells and macrophages also express the closely related P2X4 receptor (P2X4R), which is chromosomally co-located with P2X7R and has 40% homology; it is also pro-inflammatory and has been shown to interact with P2X7R to modulate its pro-apoptotic and pro-inflammatory effects. Therefore, we chose to explore the function of P2X4R in the UUO model of renal injury using knockout mice. We hypothesized that UUO-induced tubulointerstitial damage and fibrosis would also be attenuated in P2X4R−/− mice. Method P2X4R−/− and wild-type (WT) mice were subjected to either UUO or sham operation. Kidney samples taken on Days 7 and 14 were evaluated for renal inflammation and fibrosis, and expression of pro-fibrotic factors. Results To our surprise, the obstructed kidney in P2X4R−/− mice showed more severe renal injury, more collagen deposition (picrosirius red staining, increase of 53%; P < 0.05) and more type I collagen staining (increase of 107%; P < 0.01), as well as increased mRNA for TGF-β (increase of 102%, P < 0.0005) and CTGF (increase of 157%; P < 0.05) by Day 14, compared with the UUO WT mice. Conclusion These findings showed that lack of P2X4R expression leads to increased renal fibrosis, and increased expression of TGF-β and CTGF in the UUO model.
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Affiliation(s)
- Min Jeong Kim
- Imperial College Renal and Transplant Centre, Hammersmith Hospital, Imperial College London, London, UK Clinic for Transplantations immunology and Nephrology, University Hospital Basel, Basel, Switzerland Department of Biomedicine, Molecular Nephrology, University Hospital Basel, Basel, Switzerland
| | - Clare M Turner
- Imperial College Renal and Transplant Centre, Hammersmith Hospital, Imperial College London, London, UK
| | - Reiko Hewitt
- Imperial College Renal and Transplant Centre, Hammersmith Hospital, Imperial College London, London, UK
| | - Jennifer Smith
- Imperial College Renal and Transplant Centre, Hammersmith Hospital, Imperial College London, London, UK
| | - Gurjeet Bhangal
- Imperial College Renal and Transplant Centre, Hammersmith Hospital, Imperial College London, London, UK
| | - Charles D Pusey
- Imperial College Renal and Transplant Centre, Hammersmith Hospital, Imperial College London, London, UK
| | - Robert J Unwin
- UCL Centre for Nephrology, University College London, London, UK
| | - Frederick W K Tam
- Imperial College Renal and Transplant Centre, Hammersmith Hospital, Imperial College London, London, UK
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16
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Sorrell ME, Hauser KF. Ligand-gated purinergic receptors regulate HIV-1 Tat and morphine related neurotoxicity in primary mouse striatal neuron-glia co-cultures. J Neuroimmune Pharmacol 2013; 9:233-44. [PMID: 24158495 DOI: 10.1007/s11481-013-9507-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 10/04/2013] [Indexed: 12/20/2022]
Abstract
Emerging evidence suggests that opioid drugs, such as morphine and heroin, can exacerbate neuroAIDS. Microglia are the principal neuroimmune effectors thought to be responsible for neuron damage in HIV-infected individuals, and evidence suggests that opioid drugs acting via μ opioid receptors in microglia aggravate the neuropathophysiological effects of HIV. Key aspects of microglial function are regulated by the P2X family of ATP activated ligand-gated ion channels. In addition, opioid-dependent microglial activation has been reported to be mediated through P2X4 signaling, which prompted us to investigate whether the cation-permeable P2X receptors contribute to the neurotoxic effects of HIV and morphine. To address this question, neuron survival, as well as other endpoints including changes in dendritic length, extracellular ATP levels, and intracellular calcium levels, were assayed in primary neuron-glia co-cultures from mouse striatum. Treatment with TNP-ATP, a non-selective P2X antagonist, prevented the neurotoxic effects of exposure to morphine and/or HIV Tat, or ATP alone, suggesting P2X receptors mediate the neurotoxic effects of these insults in striatal neurons. Although P2X7, and perhaps P2X1, receptor activation decreases neuron survival, neither P2X1, P2X3, nor P2X7 selective receptor antagonists prevented Tat and/or morphine-induced neurotoxicity. These and other experiments indicate the P2X receptor family contributes to Tat- and morphine- related neuronal injury, and provide circumstantial evidence implicating P2X4 receptors in particular. Our findings reveal that members of the P2X receptor family, especially P2X4, may be novel therapeutic targets for restricting the synaptodendritic injury and neurodegeneration that accompanies neuroAIDS and opiate abuse.
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Affiliation(s)
- Mary E Sorrell
- Department of Pharmacology & Toxicology, Virginia Commonwealth University School of Medicine, 1217 East Marshall Street, Richmond, VA, 23298-0613, USA
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17
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Solini A, Menini S, Rossi C, Ricci C, Santini E, Blasetti Fantauzzi C, Iacobini C, Pugliese G. The purinergic 2X7 receptor participates in renal inflammation and injury induced by high-fat diet: possible role of NLRP3 inflammasome activation. J Pathol 2013; 231:342-53. [PMID: 23843215 DOI: 10.1002/path.4237] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 07/04/2013] [Accepted: 07/05/2013] [Indexed: 01/05/2023]
Abstract
Renal disease associated with type 2 diabetes and the metabolic syndrome is characterized by a distinct inflammatory phenotype. The purinergic 2X7 receptor (P2X7 R) and the nucleotide-binding and oligomerization domain-like receptor containing a pyrin domain 3 (NLRP3) inflammasome have been separately shown to play a role in two models of non-metabolic chronic kidney disease. Moreover, the NLRP3 inflammasome has been implicated in chronic low-grade sterile inflammation characterizing metabolic disorders, though the mechanism(s) involved in inflammasome activation under these conditions are still unknown. We investigated the role of P2X7 R (through activation of the NLRP3 inflammasome) in renal inflammation and injury induced by a high-fat diet, an established model of the metabolic syndrome. On a high-fat diet, mice lacking P2X7 R developed attenuated renal functional and structural alterations as well as reduced inflammation, fibrosis, and oxidative/carbonyl stress, as compared with wild-type animals, in the absence of significant differences in metabolic parameters. This was associated with blunted up-regulation of the NLRP3 inflammasome components NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), pro-caspase 1, pro-interleukin (IL)-1β, and pro-IL-18, as well as reduced inflammasome activation, as evidenced by decreased formation of mature caspase 1, whereas mature IL-1β and IL-18 were not detected. Up-regulated expression of NLRP3 and pro-caspase 1, post-translational processing of pro-caspase-1, and release of IL-18 in response to lipopolysaccharide + 2'(3')-O-(4-benzoylbenzoyl)ATP were attenuated by P2X7 R silencing in cultured mouse podocytes. Protein and mRNA expression of P2X7 R, NLRP3, and ASC were also increased in kidneys from subjects with type 2 diabetes and the metabolic syndrome, showing histologically documented renal disease. These data provide evidence of a major role for the purinergic system, at least in part through activation of the NLRP3 inflammasome, in the process driving 'metabolic' renal inflammation and injury and identify P2X7 R and NLRP3 as novel therapeutic targets.
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Affiliation(s)
- Anna Solini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
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Arulkumaran N, Turner CM, Sixma ML, Singer M, Unwin R, Tam FWK. Purinergic signaling in inflammatory renal disease. Front Physiol 2013; 4:194. [PMID: 23908631 PMCID: PMC3725473 DOI: 10.3389/fphys.2013.00194] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/05/2013] [Indexed: 11/21/2022] Open
Abstract
Extracellular purines have a role in renal physiology and adaption to inflammation. However, inflammatory renal disease may be mediated by extracellular purines, resulting in renal injury. The role of purinergic signaling is dependent on the concentrations of extracellular purines. Low basal levels of purines are important in normal homeostasis and growth. Concentrations of extracellular purines are significantly elevated during inflammation and mediate either an adaptive role or propagate local inflammation. Adenosine signaling mediates alterations in regional renal blood flow by regulation of the renal microcirculation, tubulo-glomerular feedback, and tubular transport of sodium and water. Increased extracellular ATP and renal P2 receptor-mediated inflammation are associated with various renal diseases, including hypertension, diabetic nephropathy, and glomerulonephritis. Experimental data suggests P2 receptor deficiency or receptor antagonism is associated with amelioration of antibody-mediated nephritis, suggesting a pathogenic (rather than adaptive) role of purinergic signaling. We discuss the role of extracellular nucleotides in adaptation to ischemic renal injury and in the pathogenesis of inflammatory renal disease.
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Affiliation(s)
- Nishkantha Arulkumaran
- Imperial College Kidney and Transplant Institute, Imperial College London, Hammersmith Hospital London, UK ; Division of Medicine, Bloomsbury Institute of Intensive Care Medicine, University College London London, UK
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Trabanelli S, Ocadlíková D, Gulinelli S, Curti A, Salvestrini V, Vieira RDP, Idzko M, Di Virgilio F, Ferrari D, Lemoli RM. Extracellular ATP exerts opposite effects on activated and regulatory CD4+ T cells via purinergic P2 receptor activation. THE JOURNAL OF IMMUNOLOGY 2012; 189:1303-10. [PMID: 22753942 DOI: 10.4049/jimmunol.1103800] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It has been reported that ATP inhibits or stimulates lymphoid cell proliferation depending on the cellular subset analyzed. In this study, we show that ATP exerts strikingly opposite effects on anti-CD3/CD28-activated and regulatory CD4(+) T cells (T(regs)), based on nucleotide concentration. We demonstrate that physiological concentrations of extracellular ATP (1-50 nM) do not affect activated CD4(+) T cells and T(regs). Conversely, higher ATP concentrations have a bimodal effect on activated CD4(+) T cells. Whereas 250 nM ATP stimulates proliferation, cytokine release, expression of adhesion molecules, and adhesion, 1 mM ATP induces apoptosis and inhibits activated CD4(+) T cell functions. The expression analysis and pharmacological profile of purinergic P2 receptors for extracellular nucleotides suggest that activated CD4(+) T cells are induced to apoptosis via the upregulation and engagement of P2X7R and P2X4R. On the contrary, 1 mM ATP enhances proliferation, adhesion, migration, via P2Y2R activation, and immunosuppressive ability of T(regs). Similar results were obtained when activated CD4(+) T cells and T(regs) were exposed to ATP released by necrotized leukemic cells. Taken together, our results show that different concentrations of extracellular ATP modulate CD4(+) T cells according to their activated/regulatory status. Because extracellular ATP concentration highly increases in fast-growing tumors or hyperinflamed tissues, the manipulation of purinergic signaling might represent a new therapeutic target to shift the balance between activated CD4(+) T cells and T(regs).
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Affiliation(s)
- Sara Trabanelli
- Department of Hematology and Oncological Sciences L. & A. Seràgnoli, University of Bologna, 9-40138 Bologna, Italy.
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Involvement of P2X4 receptor in P2X7 receptor-dependent cell death of mouse macrophages. Biochem Biophys Res Commun 2012; 419:374-80. [PMID: 22349510 DOI: 10.1016/j.bbrc.2012.01.156] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 01/28/2012] [Indexed: 12/11/2022]
Abstract
Interaction of P2X7 receptor with P2X4 receptor has recently been suggested, but it remains unclear whether P2X4 receptor is involved in P2X7 receptor-mediated events, such as cell death of macrophages induced by high concentrations of extracellular ATP. Here, we present evidence that P2X4 receptor does play a role in P2X7 receptor-dependent cell death. Treatment of mouse macrophage RAW264.7 cells with 1mM ATP induced Ca(2+) influx, non-selective large pore formation, activation of extracellular signal-regulated protein kinase (ERK) 1/2 and p38 mitogen-activated protein kinase (MAPK), and cell death via activation of P2X7 receptor. P2X4-knockdown cells, established by transfecting RAW264.7 cells with two short hairpin RNAs (shRNAs) targeting P2X4 receptor, showed a decrease of the initial peak of intracellular Ca(2+) after treatment with ATP, though pore formation and the P2X7-mediated activation of ERK1/2 and p38 MAPK were not affected. Intriguingly, P2X4 knockdown resulted in significant suppression of cell death induced by ATP or P2X7 agonist BzATP. In conclusion, our results suggest that P2X4 receptor is involved in P2X7 receptor-mediated cell death, but not pore formation or MAPK signaling.
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Apicella L, Fabbretti E. P2X3 receptor expression by HEK cells conditions their survival. Purinergic Signal 2011; 8:295-300. [PMID: 22160848 DOI: 10.1007/s11302-011-9285-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 11/21/2011] [Indexed: 11/26/2022] Open
Abstract
On nociceptive neurons, one important mechanism to generate pain signals is the activation of P2X3 receptors, which are membrane proteins gated by extracellular ATP. In this work, we have studied the recovery of recombinant P2X3 receptor expression in human embryonic kidney (HEK) cells. Our data demonstrated that HEK cells were not permissive for stable P2X3 expression, since the significant time-dependent cell loss. In vivo treatment with P2X3 receptor antagonist limited the effect. The expression of a single P2X3 point mutant Y393A, also largely accelerated cell death. We suggest the requirements of a permissive intracellular molecular machinery for appropriate receptor expression. The present report suggests that despite HEK cells are often used as recombinant expression system for the study a variety of receptors function, they represent a limiting permissive environment for P2X3 receptors.
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Affiliation(s)
- Lucio Apicella
- Neurobiology Sector and Italian Institute of Technology Unit, International School for Advanced Studies (SISSA), Trieste, Italy
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22
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Montreekachon P, Chotjumlong P, Bolscher JGM, Nazmi K, Reutrakul V, Krisanaprakornkit S. Involvement of P2X(7) purinergic receptor and MEK1/2 in interleukin-8 up-regulation by LL-37 in human gingival fibroblasts. J Periodontal Res 2011; 46:327-37. [PMID: 21338358 DOI: 10.1111/j.1600-0765.2011.01346.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND OBJECTIVE The antimicrobial peptide LL-37, derived from human neutrophils, can directly chemoattract leukocytes and up-regulate the expression of several immune-related genes in various cell types. In this study, we wanted to determine the immunoregulatory effect of LL-37 on interleukin-8 (IL-8) expression in human gingival fibroblasts (HGFs) and to characterize intracellular signaling pathway(s) and receptor(s) involved in IL-8 induction. MATERIAL AND METHODS Cultured fibroblasts were treated with different concentrations of LL-37 or interleukin-1β (IL-1β), as a positive control, for specific periods of time in the presence or absence of various inhibitors. RT-PCR and real-time PCR were conducted to analyze the expression of IL-8 mRNA, and the IL-8 levels in cell-free culture media were measured using ELISAs. The MTT assay was performed to determine the cytotoxicity of LL-37. RESULTS Nontoxic concentrations of LL-37 (up to 10 μm) and IL-1β significantly up-regulated the expression of IL-8 mRNA in a dose-dependent manner (p < 0.05). The IL-8 protein levels were consistently significantly elevated in conditioned media of LL-37-treated HGFs (p < 0.05). IL-8 up-regulation by LL-37 was completely abrogated by 20 μm U0126, consistent with transient phosphorylation of p44/42 MAP kinases. Moreover, pretreatment with Brilliant Blue G (a selective antagonist of the P2X(7) receptor) and the neutralizing antibody against P2X(7) blocked IL-8 up-regulation in a dose-dependent manner, consistent with expression of the P2X(7) receptor in HGFs. CONCLUSION These findings indicate that LL-37 induces IL-8 expression via the P2X(7) receptor and the MEK1/2-dependent p44/42 MAP kinases in HGFs, suggesting both direct and indirect involvement of LL-37 in neutrophil recruitment into an inflammatory site within diseased periodontal tissues.
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Affiliation(s)
- P Montreekachon
- Center of Excellence for Innovation in Chemistry, Department of Oral Biology and Diagnostic Sciences, Chiang Mai University, Thailand
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23
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Lorca RA, Rozas C, Loyola S, Moreira-Ramos S, Zeise ML, Kirkwood A, Huidobro-Toro JP, Morales B. Zinc enhances long-term potentiation through P2X receptor modulation in the hippocampal CA1 region. Eur J Neurosci 2011; 33:1175-1185. [PMID: 21324005 DOI: 10.1111/j.1460-9568.2010.07589.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Zn²(+) is an essential ion that is stored in and co-released from glutamatergic synapses and it modulates neurotransmitter receptors involved in long-term potentiation (LTP). However, the mechanism(s) underlying Zn²(+) -induced modulation of LTP remain(s) unclear. As the purinergic P2X receptors are relevant targets for Zn²(+) action, we have studied their role in LTP modulation by Zn²(+) in the CA1 region of rat hippocampal slices. Induction of LTP in the presence of Zn²(+) revealed a biphasic effect - 5-50 μm enhanced LTP induction, whereas 100-300 μm Zn²(+) inhibited LTP. The involvement of a purinergic mechanism is supported by the fact that application of the P2X receptor antagonists 2',3'-O-(2,4,6-trinitrophenyl) ATP (TNP-ATP) and periodate-oxidized ATP fully abolished the facilitatory effect of Zn²(+) . Notably, application of the P2X₇ receptor-specific antagonist Brilliant Blue G did not modify the Zn²(+) -dependent facilitation of LTP. Exogenous ATP also produced a biphasic effect - 0.1-1 μm ATP facilitated LTP, whereas 5-10 μm inhibited LTP. The facilitatory effect of ATP was abolished by the application of TNP-ATP and was modified in the presence of 5 μm Zn²(+) , suggesting that P2X receptors are involved in LTP induction and that Zn²(+) leads to an increase in the affinity of P2X receptors for ATP. The latter confirms our previous results from heterologous expression systems. Collectively, our results indicate that Zn²(+) at low concentrations enhances LTP by modulating P2X receptors. Although it is not yet clear which purinergic receptor subtype(s) is responsible for these effects on LTP, the data presented here suggest that P2X₄ but not P2X₇ is involved.
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Affiliation(s)
- Ramón A Lorca
- Laboratorio de Neurociencias, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170022, Chile.,Laboratorio de Nucleótidos, Centro de Regulación Celular y Patología, J.V. Luco, Instituto MIFAB, Departamento de Fisiología, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Carlos Rozas
- Laboratorio de Neurociencias, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170022, Chile
| | - Sebastian Loyola
- Laboratorio de Neurociencias, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170022, Chile
| | - Sandra Moreira-Ramos
- Laboratorio de Neurociencias, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170022, Chile
| | - Marc L Zeise
- Escuela de Psicología, Universidad de Santiago de Chile, Santiago, Chile
| | - Alfredo Kirkwood
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, Baltimore, MD, USA
| | - J Pablo Huidobro-Toro
- Laboratorio de Nucleótidos, Centro de Regulación Celular y Patología, J.V. Luco, Instituto MIFAB, Departamento de Fisiología, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Bernardo Morales
- Laboratorio de Neurociencias, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170022, Chile
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Davies JP, Robson L. Pharmacological properties and physiological function of a P2X-like current in single proximal tubule cells isolated from frog kidney. J Membr Biol 2010; 237:79-91. [PMID: 20972559 PMCID: PMC2990016 DOI: 10.1007/s00232-010-9308-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 09/22/2010] [Indexed: 11/06/2022]
Abstract
Although previous studies have provided evidence for the expression of P2X receptors in renal proximal tubule, only one cell line study has provided functional evidence. The current study investigated the pharmacological properties and physiological role of native P2X-like currents in single frog proximal tubule cells using the whole-cell patch-clamp technique. Extracellular ATP activated a cation conductance (P2Xf) that was also Ca2+-permeable. The agonist sequence for activation was ATP = αβ-MeATP > BzATP = 2-MeSATP, and P2Xf was inhibited by suramin, PPADS and TNP-ATP. Activation of P2Xf attenuated the rundown of a quinidine-sensitive K+ conductance, suggesting that P2Xf plays a role in K+ channel regulation. In addition, ATP/ADP apyrase and inhibitors of P2Xf inhibited regulatory volume decrease (RVD). These data are consistent with the presence of a P2X receptor that plays a role in the regulation of cell volume and K+ channels in frog renal proximal tubule cells.
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Affiliation(s)
- John P Davies
- Department of Biomedical Science, University of Sheffield, Sheffield S102TN, UK
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25
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Abstract
P2X receptors are membrane cation channels gated by extracellular ATP. Seven P2X receptor subunits (P2X(1-7)) are widely distributed in excitable and nonexcitable cells of vertebrates. They play key roles in inter alia afferent signaling (including pain), regulation of renal blood flow, vascular endothelium, and inflammatory responses. We summarize the evidence for these and other roles, emphasizing experimental work with selective receptor antagonists or with knockout mice. The receptors are trimeric membrane proteins: Studies of the biophysical properties of mutated subunits expressed in heterologous cells have indicated parts of the subunits involved in ATP binding, ion permeation (including calcium permeability), and membrane trafficking. We review our current understanding of the molecular properties of P2X receptors, including how this understanding is informed by the identification of distantly related P2X receptors in simple eukaryotes.
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Affiliation(s)
- Annmarie Surprenant
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom.
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26
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Puthussery T, Fletcher E. Extracellular ATP induces retinal photoreceptor apoptosis through activation of purinoceptors in rodents. J Comp Neurol 2009; 513:430-40. [PMID: 19180669 DOI: 10.1002/cne.21964] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We have previously demonstrated that photoreceptors express P2X(7) purinoceptors. These excitatory receptors are activated by extracellular adenosine 5'-triphosphate (ATP) and have been implicated in neurodegeneration in other parts of the central nervous system (CNS). In this study we examined whether extracellular ATP could contribute to photoreceptor degeneration in rodents through excessive activation of P2 purinoceptors. Intravitreal injection of high concentrations of extracellular ATP into normal rat eyes induced extensive and selective apoptosis of photoreceptors within 18 hours of injection. Five days after injection the outer nuclear layer was severely degenerated and electroretinographic responses were impaired. Preinjection of the purinergic antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS) protected against ATP-mediated apoptosis. The initial phase of ATP-induced photoreceptor death did not temporally coincide with retinal pigment epithelium degeneration or microglial activation, suggesting that cell death was due to direct activation of purinergic receptors on photoreceptors. Finally, we demonstrate that intravitreal injection of PPADS results in a 30% increase in photoreceptor survival in the rd1 mouse, a model of human recessive retinitis pigmentosa (RP). These findings highlight the importance of extracellular ATP in retinal neurodegeneration and provide a potential new avenue for therapeutic intervention in RP.
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Affiliation(s)
- Theresa Puthussery
- Department of Anatomy and Cell Biology, University of Melbourne, 3010, Victoria, Australia
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Fulgenzi A, Ticozzi P, Gabel CA, Dell'Antonio G, Quattrini A, Franzone JS, Ferrero ME. Periodate oxidized ATP (oATP) reduces hyperalgesia in mice: involvement of P2X7 receptors and implications for therapy. Int J Immunopathol Pharmacol 2008; 21:61-71. [PMID: 18336732 DOI: 10.1177/039463200802100108] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Some inflammatory mediators play an important role not only in the pathogenesis of the inflammatory pain, but also in that of neuropathic and visceral pain. We previously showed the antihyperalgesic effect of oATP, the inhibitor of the P2X7 receptors for the pro-nociceptive ATP, in experimental inflammation. Here we show the antihyperalgesic effect of oATP in mouse models of neuropathic and visceral pain, other than in a model of arthritic pain mimicking rheumatoid arthritis in humans. We also show that mice lacking P2X7 receptors (KO) are resistant to hyperalgesic thermal stimuli following the induction of arthritic, neuropathic and visceral pain. Local (injection into the right hind paw) pre-treatment with oATP is able to prevent the successive induction of ATP-dependent hyperalgesia in wild type mice. In addition, KO mice are not insensitive to intraplantar treatment with ATP. Our data suggest that, even if oATP is able to inhibit purinoceptors different from P2X7, the latter are the more important involved in pain transmission.
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Affiliation(s)
- A Fulgenzi
- Institute of General Pathology, University of Milan, Milan Italy
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28
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Yilmaz O, Yao L, Maeda K, Rose TM, Lewis EL, Duman M, Lamont RJ, Ojcius DM. ATP scavenging by the intracellular pathogen Porphyromonas gingivalis inhibits P2X7-mediated host-cell apoptosis. Cell Microbiol 2007; 10:863-75. [PMID: 18005240 DOI: 10.1111/j.1462-5822.2007.01089.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The purinergic receptor P2X(7) is involved in cell death, inhibition of intracellular infection and secretion of inflammatory cytokines. The role of the P2X(7) receptor in bacterial infection has been primarily established in macrophages. Here we show that primary gingival epithelial cells, an important component of the oral innate immune response, also express functional P2X(7) and are sensitive to ATP-induced apoptosis. Porphyromonas gingivalis, an intracellular bacterium and successful colonizer of oral tissues, can inhibit gingival epithelial cell apoptosis induced by ATP ligation of P2X(7) receptors. A P. gingivalis homologue of nucleoside diphosphate kinase (NDK), an ATP-consuming enzyme, is secreted extracellularly and is required for maximal suppression of apoptosis. An ndk-deficient mutant was unable to prevent ATP-induced host-cell death nor plasma membrane permeabilization in the epithelial cells. Treatment with purified recombinant NDK inhibited ATP-mediated host-cell plasma membrane permeabilization in a dose-dependent manner. Therefore, NDK promotes survival of host cells by hydrolysing extracellular ATP and preventing apoptosis-mediated through P2X(7).
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Affiliation(s)
- Ozlem Yilmaz
- Department of Periodontology, University of Florida, Gainesville, FL 32610, USA.
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