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Al-Aqtash R, Collier DM. Ionotropic purinergic receptor 7 (P2X7) channel structure and pharmacology provides insight regarding non-nucleotide agonism. Channels (Austin) 2024; 18:2355150. [PMID: 38762911 PMCID: PMC11110710 DOI: 10.1080/19336950.2024.2355150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 05/10/2024] [Indexed: 05/21/2024] Open
Abstract
P2X7 is a member of the Ionotropic Purinergic Receptor (P2X) family. The P2X family of receptors is composed of seven (P2X1-7), ligand-gated, nonselective cation channels. Changes in P2X expression have been reported in multiple disease models. P2Xs have large complex extracellular domains that function as receptors for a variety of ligands, including endogenous and synthetic agonists and antagonists. ATP is the canonical agonist. ATP affinity ranges from nanomolar to micromolar for most P2XRs, but P2X7 has uniquely poor ATP affinity. In many physiological settings, it may be difficult to achieve the millimolar extracellular ATP concentrations needed for P2X7 channel activation; however, channel function is implicated in pain sensation, immune cell function, cardiovascular disease, cancer, and osteoporosis. Multiple high-resolution P2X7 structures have been solved in apo-, ATP-, and antagonist-bound states. P2X7 structural data reveal distinct allosteric and orthosteric antagonist-binding sites. Both allosteric and orthosteric P2X7 antagonists are well documented to inhibit ATP-evoked channel current. However, a growing body of evidence supports P2X7 activation by non-nucleotide agonists, including extracellular histone proteins and human cathelicidin-derived peptides (LL-37). Interestingly, P2X7 non-nucleotide agonism is not inhibited by allosteric antagonists, but is inhibited by orthosteric antagonists. Herein, we review P2X7 function with a focus on the efficacy of available pharmacology on P2X7 channel current activation by non-nucleotide agonists in effort to understand agonist/antagonist efficacy, and consider the impact of these data on the current understanding of P2X7 in physiology and disease given these limitations of P2X7-selective antagonists and incomplete knockout mouse models.
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Affiliation(s)
- Rua’a Al-Aqtash
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Daniel M. Collier
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
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2
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Leite-Aguiar R, Bello-Santos VG, Castro NG, Coutinho-Silva R, Savio LEB. Techniques for evaluating the ATP-gated ion channel P2X7 receptor function in macrophages and microglial cells. J Immunol Methods 2024; 532:113727. [PMID: 38997100 DOI: 10.1016/j.jim.2024.113727] [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: 02/19/2024] [Revised: 05/31/2024] [Accepted: 07/08/2024] [Indexed: 07/14/2024]
Abstract
Resident macrophages are tissue-specific innate immune cells acting as sentinels, constantly patrolling their assigned tissue to maintain homeostasis, and quickly responding to pathogenic invaders or molecular danger signals molecules when necessary. Adenosine triphosphate (ATP), when released to the extracellular medium, acts as a danger signal through specific purinergic receptors. Interaction of ATP with the purinergic receptor P2X7 activates macrophages and microglial cells in different pathological conditions, triggering inflammation. The highly expressed P2X7 receptor in these cells induces cell membrane permeabilization, inflammasome activation, cell death, and the production of inflammatory mediators, including cytokines and nitrogen and oxygen-reactive species. This review explores the techniques to evaluate the functional and molecular aspects of the P2X7 receptor, particularly in macrophages and microglial cells. Polymerase chain reaction (PCR), Western blotting, and immunocytochemistry or immunohistochemistry are essential for assessing gene and protein expression in these cell types. Evaluation of P2X7 receptor function involves the use of ATP and selective agonists and antagonists and diverse techniques, including electrophysiology, intracellular calcium measurements, ethidium bromide uptake, and propidium iodide cell viability assays. These techniques are crucial for studying the role of P2X7 receptors in immune responses, neuroinflammation, and various pathological conditions. Therefore, a comprehensive understanding of the functional and molecular aspects of the P2X7 receptor in macrophages and microglia is vital for unraveling its involvement in immune modulation and its potential as a therapeutic target. The methodologies presented and discussed herein offer valuable tools for researchers investigating the complexities of P2X7 receptor signaling in innate immune cells in health and disease.
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Affiliation(s)
- Raíssa Leite-Aguiar
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Robson Coutinho-Silva
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiz Eduardo Baggio Savio
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil..
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3
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Munaron L, Chinigò G, Scarpellino G, Ruffinatti FA. The fallacy of functional nomenclature in the kingdom of biological multifunctionality: physiological and evolutionary considerations on ion channels. J Physiol 2024; 602:2367-2381. [PMID: 37635695 DOI: 10.1113/jp284422] [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: 05/11/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023] Open
Abstract
Living organisms are multiscale complex systems that have evolved high degrees of multifunctionality and redundancy in the structure-function relationship. A number of factors, only in part determined genetically, affect the jobs of proteins. The overall structural organization confers unique molecular properties that provide the potential to perform a pattern of activities, some of which are co-opted by specific environments. The variety of multifunctional proteins is expanding, but most cases are handled individually and according to the still dominant 'one structure-one function' approach, which relies on the attribution of canonical names typically referring to the first task identified for a given protein. The present topical review focuses on the multifunctionality of ion channels as a paradigmatic example. Mounting evidence reports the ability of many ion channels (including members of voltage-dependent, ligand-gated and transient receptor potential families) to exert biological effects independently of their ion conductivity. 'Functionally based' nomenclature (the practice of naming a protein or family of proteins based on a single purpose) is a conceptual bias for three main reasons: (i) it increases the amount of ambiguity, deceiving our understanding of the multiple contributions of biomolecules that is the heart of the complexity; (ii) it is in stark contrast to protein evolution dynamics, largely based on multidomain arrangement; and (iii) it overlooks the crucial role played by the microenvironment in adjusting the actions of cell structures and in tuning protein isoform diversity to accomplish adaptational requirements. Biological information in protein physiology is distributed among different entwined layers working as the primary 'locus' of natural selection and of evolutionary constraints.
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Affiliation(s)
- Luca Munaron
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Giorgia Chinigò
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Giorgia Scarpellino
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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4
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Magni L, Yu H, Christensen NM, Poulsen MH, Frueh A, Deshar G, Johansen AZ, Johansen JS, Pless SA, Jørgensen NR, Novak I. Human P2X7 receptor variants Gly150Arg and Arg276His polymorphisms have differential effects on risk association and cellular functions in pancreatic cancer. Cancer Cell Int 2024; 24:148. [PMID: 38664691 PMCID: PMC11044319 DOI: 10.1186/s12935-024-03339-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 04/18/2024] [Indexed: 04/29/2024] Open
Abstract
BACKGROUND The purinergic P2X7 receptor (P2X7R) plays an important role in the crosstalk between pancreatic stellate cells (PSCs) and cancer cells, thus promoting progression of pancreatic ductal adenocarcinoma (PDAC). Single nucleotide polymorphisms (SNPs) in the P2X7R have been reported for several cancers, but have not been explored in PDAC. MATERIALS AND METHODS Blood samples from PDAC patients and controls were genotyped for 11 non-synonymous SNPs in P2X7R and a risk analysis was performed. Relevant P2X7R-SNP GFP variants were expressed in PSCs and cancer cells and their function was assayed in the following tests. Responses in Ca2+ were studied with Fura-2 and dye uptake with YO-PRO-1. Cell migration was monitored by fluorescence microscopy. Released cytokines were measured with MSD assay. RESULTS Risk analysis showed that two SNPs 474G>A and 853G>A (rs28360447, rs7958316), that lead to the Gly150Arg and Arg276His variants, had a significant but opposite risk association with PDAC development, protecting against and predisposing to the disease, respectively. In vitro experiments performed on cancer cells and PSCs expressing the Gly150Arg variant showed reduced intracellular Ca2+ response, fluorescent dye uptake, and cell migration, while the Arg276His variant reduced dye uptake but displayed WT-like Ca2+ responses. As predicted, P2X7R was involved in cytokine release (IL-6, IL-1β, IL-8, TNF-α), but the P2X7R inhibitors displayed varied effects. CONCLUSION In conclusion, we provide evidence for the P2X7R SNPs association with PDAC and propose that they could be considered as potential biomarkers.
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Affiliation(s)
- Lara Magni
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen Ø, Denmark
| | - Haoran Yu
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen Ø, Denmark
| | - Nynne M Christensen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen Ø, Denmark
| | - Mette H Poulsen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Alexander Frueh
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen Ø, Denmark
| | - Ganga Deshar
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen Ø, Denmark
| | - Astrid Z Johansen
- Department of Oncology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Herlev, Denmark
| | - Julia S Johansen
- Department of Oncology, Copenhagen University Hospital - Herlev and Gentofte Hospital, Herlev, Denmark
- Department of Medicine, Copenhagen University Hospital - Herlev and Gentofte, Herlev, Denmark
| | - Stephan A Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Niklas R Jørgensen
- Department of Clinical Biochemistry, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ivana Novak
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen Ø, Denmark.
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Acuña-Castillo C, Escobar A, García-Gómez M, Bachelet VC, Huidobro-Toro JP, Sauma D, Barrera-Avalos C. P2X7 Receptor in Dendritic Cells and Macrophages: Implications in Antigen Presentation and T Lymphocyte Activation. Int J Mol Sci 2024; 25:2495. [PMID: 38473744 DOI: 10.3390/ijms25052495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/15/2024] [Accepted: 01/24/2024] [Indexed: 03/14/2024] Open
Abstract
The P2X7 receptor, a member of the P2X purinergic receptor family, is a non-selective ion channel. Over the years, it has been associated with various biological functions, from modulating to regulating inflammation. However, its emerging role in antigen presentation has captured the scientific community's attention. This function is essential for the immune system to identify and respond to external threats, such as pathogens and tumor cells, through T lymphocytes. New studies show that the P2X7 receptor is crucial for controlling how antigens are presented and how T cells are activated. These studies focus on antigen-presenting cells, like dendritic cells and macrophages. This review examines how the P2X7 receptor interferes with effective antigen presentation and activates T cells and discusses the fundamental mechanisms that can affect the immune response. Understanding these P2X7-mediated processes in great detail opens up exciting opportunities to create new immunological therapies.
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Affiliation(s)
- Claudio Acuña-Castillo
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Alejandro Escobar
- Laboratorio Biología Celular y Molecular, Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago 8380000, Chile
| | - Moira García-Gómez
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile
| | - Vivienne C Bachelet
- Escuela de Medicina, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Juan Pablo Huidobro-Toro
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile
| | - Daniela Sauma
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile
- Centro Ciencia & Vida, Av. Del Valle Norte 725, Huechuraba 8580000, Chile
| | - Carlos Barrera-Avalos
- Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9160000, Chile
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Shokoples BG, Berillo O, Comeau K, Chen HY, Higaki A, Caillon A, Ferreira NS, Engert JC, Thanassoulis G, Paradis P, Schiffrin EL. P2RX7 gene knockout or antagonism reduces angiotensin II-induced hypertension, vascular injury and immune cell activation. J Hypertens 2023; 41:1701-1712. [PMID: 37796207 DOI: 10.1097/hjh.0000000000003520] [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] [Indexed: 10/06/2023]
Abstract
OBJECTIVE Extracellular ATP is elevated in hypertensive mice and humans and may trigger immune activation through the purinergic receptor P2X7 (P2RX7) causing interleukin-1β production and T-cell activation and memory T-cell development. Furthermore, P2RX7 single nucleotide polymorphisms (SNP) are associated with hypertension. We hypothesized that P2RX7 activation contributes to hypertension and cardiovascular injury by promoting immune activation. METHODS Male wild-type and P2rx7-/- mice were infused or not with angiotensin II (AngII) for 14 days. A second group of AngII-infused wild-type mice were co-infused with the P2RX7 antagonist AZ10606120 or vehicle. BP was monitored by telemetry. Cardiac and mesenteric artery function and remodeling were assessed using ultrasound and pressure myography, respectively. T cells were profiled in thoracic aorta/perivascular adipose tissue by flow cytometry. Associations between SNPs within 50 kb of P2RX7 transcription, and BP or hypertension were modeled in 384 653 UK Biobank participants. RESULTS P2rx7 inactivation attenuated AngII-induced SBP elevation, and mesenteric artery dysfunction and remodeling. This was associated with decreased perivascular infiltration of activated and effector memory T-cell subsets. Surprisingly, P2rx7 knockout exaggerated AngII-induced cardiac dysfunction and remodeling. Treatment with a P2RX7 antagonist reduced BP elevation, preserved mesenteric artery function and reduced activated and effector memory T cell perivascular infiltration without adversely affecting cardiac function and remodeling in AngII-infused mice. Three P2RX7 SNPs were associated with increased odds of DBP elevation. CONCLUSION P2RX7 may represent a target for attenuating BP elevation and associated vascular damage by decreasing immune activation.
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Affiliation(s)
- Brandon G Shokoples
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research
| | - Olga Berillo
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research
| | - Kevin Comeau
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research
| | - Hao Yu Chen
- Preventive and Genomic Cardiology, McGill University Health Centre Research Institute
| | - Akinori Higaki
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research
| | - Antoine Caillon
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research
| | - Nathanne S Ferreira
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research
| | - James C Engert
- Preventive and Genomic Cardiology, McGill University Health Centre Research Institute
- Department of Medicine, McGill University, Montreal, Canada
| | - George Thanassoulis
- Preventive and Genomic Cardiology, McGill University Health Centre Research Institute
- Department of Medicine, McGill University, Montreal, Canada
| | - Pierre Paradis
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research
- Department of Medicine, McGill University, Montreal, Canada
| | - Ernesto L Schiffrin
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research
- Department of Medicine, Sir Mortimer B. Davis-Jewish General Hospital
- Department of Medicine, McGill University, Montreal, Canada
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7
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Tang Y, Qiao C, Li Q, Zhu X, Zhao R, Peng X. Research Progress in the Relationship Between P2X7R and Cervical Cancer. Reprod Sci 2023; 30:823-834. [PMID: 35799022 DOI: 10.1007/s43032-022-01022-w] [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: 02/27/2022] [Accepted: 06/16/2022] [Indexed: 11/28/2022]
Abstract
Cervical cancer is one of the most common and serious tumors in women. Finding new biomarkers and therapeutic targets plays an important role in the diagnosis, prognosis, and treatment of cervical cancer. Purinergic ligand-gated ion channel 7 receptor (P2X7R) is a purine ligand cation channel, activated by adenosine triphosphate (ATP). Studies have shown that P2X7R plays an important role in a variety of diseases and cancers. More and more studies have shown that P2X7R is also closely related to cervical cancer; therefore, the role of P2X7R in the development of cervical cancer deserves further discussion. The expression level of P2X7R in uterine epithelial cancer tissues was lower than that of the corresponding normal tissues. P2X7R plays an important role in the apoptotic process of cervical cancer through various mechanisms of action, and both antagonists and agonists of P2X7R can inhibit the proliferation of cervical cancer cells, while P2X7R is involved in the antitumor effect of Atr-I on cervical cancer cells. This review evaluates the current role of P2X7R in cervical cancer in order to develop more specific therapies for cervical cancer. In conclusion, P2X7R may become a biomarker for cervical cancer screening, and even a new target for clinical treatment of cervical cancer.
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Affiliation(s)
- Yiqing Tang
- School of Medical Laboratory, Weifang Medical University, Weifang, Shandong, China
| | - Cuicui Qiao
- School of Medical Laboratory, Weifang Medical University, Weifang, Shandong, China
| | - Qianqian Li
- School of Medical Laboratory, Weifang Medical University, Weifang, Shandong, China
| | - Xiaodi Zhu
- School of Medical Laboratory, Weifang Medical University, Weifang, Shandong, China
| | - Ronglan Zhao
- School of Medical Laboratory, Weifang Medical University, Weifang, Shandong, China.
| | - Xiaoxiang Peng
- School of Medical Laboratory, Weifang Medical University, Weifang, Shandong, China.
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8
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Jiang ZF, Wu W, Hu HB, Li ZY, Zhong M, Zhang L. P2X7 receptor as the regulator of T-cell function in intestinal barrier disruption. World J Gastroenterol 2022; 28:5265-5279. [PMID: 36185635 PMCID: PMC9521516 DOI: 10.3748/wjg.v28.i36.5265] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 06/20/2022] [Accepted: 09/01/2022] [Indexed: 02/06/2023] Open
Abstract
The intestinal mucosa is a highly compartmentalized structure that forms a direct barrier between the host intestine and the environment, and its dysfunction could result in a serious disease. As T cells, which are important components of the mucosal immune system, interact with gut microbiota and maintain intestinal homeostasis, they may be involved in the process of intestinal barrier dysfunction. P2X7 receptor (P2X7R), a member of the P2X receptors family, mediates the effects of extracellular adenosine triphosphate and is expressed by most innate or adaptive immune cells, including T cells. Current evidence has demonstrated that P2X7R is involved in inflammation and mediates the survival and differentiation of T lymphocytes, indicating its potential role in the regulation of T cell function. In this review, we summarize the available research about the regulatory role and mechanism of P2X7R on the intestinal mucosa-derived T cells in the setting of intestinal barrier dysfunction.
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Affiliation(s)
- Zhi-Feng Jiang
- Center of Emergency & Intensive Care Unit, Jinshan Hospital of Fudan University, Shanghai 201508, China
| | - Wei Wu
- Department of Critical Care Medicine, Zhongshan Hospital of Fudan University, Shanghai 200032, China
| | - Han-Bing Hu
- Center of Emergency & Intensive Care Unit, Jinshan Hospital of Fudan University, Shanghai 201508, China
| | - Zheng-Yang Li
- Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai 201508, China
| | - Ming Zhong
- Department of Critical Care Medicine, Zhongshan Hospital of Fudan University, Shanghai 200032, China
| | - Lin Zhang
- Center of Emergency & Intensive Care Unit, Jinshan Hospital of Fudan University, Shanghai 201508, China
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9
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Qiao C, Tang Y, Li Q, Zhu X, Peng X, Zhao R. ATP-gated P2X7 receptor as a potential target for prostate cancer. Hum Cell 2022; 35:1346-1354. [PMID: 35657562 DOI: 10.1007/s13577-022-00729-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/18/2022] [Indexed: 12/24/2022]
Abstract
Prostate cancer is the most common malignancy of the male genitourinary system and is one of the leading causes of male cancer death. The P2X7 receptor is an important member of purine receptor family. It is a gated ion channel with adenosine triphosphate (ATP) as the ligand, which exists in a variety of immune tissues and cells and can be involved in tumorigenesis and tumor progression. Studies have shown that the P2X7 receptor is abnormally expressed in prostate cancer, and is related to the level of prostate-specific antigen, P2X7 receptor may be an early biomarker of prostate cancer. The P2X7 receptor is essential in the occurrence and development of prostate cancer. The P2X7 receptor mainly affects the invasion and metastasis of prostate cancer cells through epithelial mesenchymal transition/invasion-related genes and the PI3K/AKT and ERK1/2 signaling pathways. The P2X7 receptor could be a promising therapeutic target for prostate cancer.
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Affiliation(s)
- Cuicui Qiao
- School of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
| | - Yiqing Tang
- School of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
| | - Qianqian Li
- School of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
| | - Xiaodi Zhu
- School of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
| | - Xiaoxiang Peng
- School of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China
| | - Ronglan Zhao
- School of Laboratory Medicine, Weifang Medical University, Weifang, 261053, Shandong, China.
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10
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Ma XF, Wang TT, Wang WH, Guan L, Guo CR, Li XH, Lei YT, Fan YZ, Yang XN, Hattori M, Nureki O, Zhu MX, Yu Y, Tian Y, Wang J. The long β2,3-sheets encoded by redundant sequences play an integral role in the channel function of P2X7 receptors. J Biol Chem 2022; 298:102002. [PMID: 35504351 PMCID: PMC9163701 DOI: 10.1016/j.jbc.2022.102002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 04/23/2022] [Accepted: 04/27/2022] [Indexed: 11/26/2022] Open
Abstract
P2X receptors are a class of nonselective cation channels widely distributed in the immune and nervous systems, and their dysfunction is a significant cause of tumors, inflammation, leukemia, and immune diseases. P2X7 is a unique member of the P2X receptor family with many properties that differ from other subtypes in terms of primary sequence, the architecture of N- and C-terminals, and channel function. Here, we suggest that the observed lengthened β2- and β3-sheets and their linker (loop β2,3), encoded by redundant sequences, play an indispensable role in the activation of the P2X7 receptor. We show that deletion of this longer structural element leads to the loss of P2X7 function. Furthermore, by combining mutagenesis, chimera construction, surface expression, and protein stability analysis, we found that the deletion of the longer β2,3-loop affects P2X7 surface expression but, more importantly, that this loop affects channel gating of P2X7. We propose that the longer β2,3-sheets may have a negative regulatory effect on a loop on the head domain and on the structural element formed by E171 and its surrounding regions. Understanding the role of the unique structure of the P2X7 receptor in the gating process will aid in the development of selective drugs targeting this subtype.
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Affiliation(s)
- Xue-Fei Ma
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China; School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Ting-Ting Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Wen-Hui Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Li Guan
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Chang-Run Guo
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Xing-Hua Li
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Yun-Tao Lei
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Ying-Zhe Fan
- Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiao-Na Yang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, China
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Ye Yu
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.
| | - Yun Tian
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China.
| | - Jin Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.
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11
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Scarpellino G, Genova T, Quarta E, Distasi C, Dionisi M, Fiorio Pla A, Munaron L. P2X Purinergic Receptors Are Multisensory Detectors for Micro-Environmental Stimuli That Control Migration of Tumoral Endothelium. Cancers (Basel) 2022; 14:2743. [PMID: 35681724 PMCID: PMC9179260 DOI: 10.3390/cancers14112743] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 05/30/2022] [Indexed: 02/04/2023] Open
Abstract
The tumoral microenvironment often displays peculiar features, including accumulation of extracellular ATP, hypoxia, low pH-acidosis, as well as an imbalance in zinc (Zn2+) and calcium (Ca2+). We previously reported the ability of some purinergic agonists to exert an anti-migratory activity on tumor-derived human endothelial cells (TEC) only when applied at a high concentration. They also trigger calcium signals associated with release from intracellular stores and calcium entry from the external medium. Here, we provide evidence that high concentrations of BzATP (100 µM), a potent agonist of P2X receptors, decrease migration in TEC from different tumors, but not in normal microvascular ECs (HMEC). The same agonist evokes a calcium increase in TEC from the breast and kidney, as well as in HMEC, but not in TEC from the prostate, suggesting that the intracellular pathways responsible for the P2X-induced impairment of TEC migration could vary among different tumors. The calcium signal is mainly due to a long-lasting calcium entry from outside and is strictly dependent on the presence of the receptor occupancy. Low pH, as well as high extracellular Zn2+ and Ca2+, interfere with the response, a distinctive feature typically found in some P2X purinergic receptors. This study reveals that a BzATP-sensitive pathway impairs the migration of endothelial cells from different tumors through mechanisms finely tuned by environmental factors.
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Affiliation(s)
- Giorgia Scarpellino
- Department of Life Sciences & Systems Biology, University of Torino, 10123 Torino, Italy; (G.S.); (T.G.); (E.Q.); (A.F.P.)
| | - Tullio Genova
- Department of Life Sciences & Systems Biology, University of Torino, 10123 Torino, Italy; (G.S.); (T.G.); (E.Q.); (A.F.P.)
| | - Elisa Quarta
- Department of Life Sciences & Systems Biology, University of Torino, 10123 Torino, Italy; (G.S.); (T.G.); (E.Q.); (A.F.P.)
| | - Carla Distasi
- Department of Pharmaceutical Sciences, University of Piemonte Orientale, 28100 Novara, Italy; (C.D.); (M.D.)
| | - Marianna Dionisi
- Department of Pharmaceutical Sciences, University of Piemonte Orientale, 28100 Novara, Italy; (C.D.); (M.D.)
| | - Alessandra Fiorio Pla
- Department of Life Sciences & Systems Biology, University of Torino, 10123 Torino, Italy; (G.S.); (T.G.); (E.Q.); (A.F.P.)
| | - Luca Munaron
- Department of Life Sciences & Systems Biology, University of Torino, 10123 Torino, Italy; (G.S.); (T.G.); (E.Q.); (A.F.P.)
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12
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Huang S, Wang W, Li L, Wang T, Zhao Y, Lin Y, Huang W, Wang Y, Huang Z. P2X7 Receptor Deficiency Ameliorates STZ-induced Cardiac Damage and Remodeling Through PKCβ and ERK. Front Cell Dev Biol 2021; 9:692028. [PMID: 34395424 PMCID: PMC8358615 DOI: 10.3389/fcell.2021.692028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 07/12/2021] [Indexed: 12/18/2022] Open
Abstract
Diabetic cardiomyopathy (DCM) is a complication of diabetes mellitus which result in cardiac remodeling and subsequent heart failure. However, the role of P2X7 receptor (P2X7R) in DCM has yet to be elucidated. The principal objective of this study was to investigate whether P2X7R participates in the pathogenesis of DCM. In this study, the C57BL/6 diabetic mouse model was treated with a P2X7R inhibitor (A438079). Cardiac dysfunction and remodeling were attenuated by the intraperitoneal injection of A438079 or P2X7R deficiency. In vitro, A438079 reduced high glucose (HG) induced cell damage in H9c2 cells and primary rat cardiomyocytes. Furthermore, HG/streptozotocin (STZ)-induced P2X7R activation mediated downstream protein kinase C-β (PKCβ) and extracellular regulated protein kinases (ERK) activation. This study provided evidence that P2X7R plays an important role in the pathogenesis of STZ-induced diabetic cardiac damage and remodeling through the PKCβ/ERK axis and suggested that P2X7R might be a potential target in the treatment of diabetic cardiomyopathy.
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Affiliation(s)
- Shanjun Huang
- The Key Laboratory of Cardiovascular Disease of Wenzhou, Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.,Department of Cardiology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China
| | - Weiqi Wang
- The Key Laboratory of Cardiovascular Disease of Wenzhou, Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Li Li
- Department of Anesthesiology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China
| | - Ting Wang
- The Key Laboratory of Cardiovascular Disease of Wenzhou, Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yihan Zhao
- The Key Laboratory of Cardiovascular Disease of Wenzhou, Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Ya Lin
- The Key Laboratory of Cardiovascular Disease of Wenzhou, Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Weijian Huang
- The Key Laboratory of Cardiovascular Disease of Wenzhou, Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yonghua Wang
- Department of Physical Education, Wenzhou Medical University, Wenzhou, China
| | - Zhouqing Huang
- The Key Laboratory of Cardiovascular Disease of Wenzhou, Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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13
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Magni L, Bouazzi R, Heredero Olmedilla H, Petersen PSS, Tozzi M, Novak I. The P2X7 Receptor Stimulates IL-6 Release from Pancreatic Stellate Cells and Tocilizumab Prevents Activation of STAT3 in Pancreatic Cancer Cells. Cells 2021; 10:cells10081928. [PMID: 34440697 PMCID: PMC8391419 DOI: 10.3390/cells10081928] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/30/2021] [Accepted: 07/23/2021] [Indexed: 12/12/2022] Open
Abstract
Pancreatic stellate cells (PSCs) are important pancreatic fibrogenic cells that interact with pancreatic cancer cells to promote the progression of pancreatic ductal adenocarcinoma (PDAC). In the tumor microenvironment (TME), several factors such as cytokines and nucleotides contribute to this interplay. Our aim was to investigate whether there is an interaction between IL-6 and nucleotide signaling, in particular, that mediated by the ATP-sensing P2X7 receptor (P2X7R). Using human cell lines of PSCs and cancer cells, as well as primary PSCs from mice, we show that ATP is released from both PSCs and cancer cells in response to mechanical and metabolic cues that may occur in the TME, and thus activate the P2X7R. Functional studies using P2X7R agonists and inhibitors show that the receptor is involved in PSC proliferation, collagen secretion and IL-6 secretion and it promotes cancer cell migration in a human PSC-cancer cell co-culture. Moreover, conditioned media from P2X7R-stimulated PSCs activated the JAK/STAT3 signaling pathway in cancer cells. The monoclonal antibody inhibiting the IL-6 receptor, Tocilizumab, inhibited this signaling. In conclusion, we show an important mechanism between PSC-cancer cell interaction involving ATP and IL-6, activating P2X7 and IL-6 receptors, respectively, both potential therapeutic targets in PDAC.
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MESH Headings
- Animals
- Antibodies, Monoclonal, Humanized/pharmacology
- Antibodies, Monoclonal, Humanized/therapeutic use
- Antineoplastic Agents, Immunological/pharmacology
- Antineoplastic Agents, Immunological/therapeutic use
- Carcinoma, Pancreatic Ductal/drug therapy
- Carcinoma, Pancreatic Ductal/metabolism
- Carcinoma, Pancreatic Ductal/physiopathology
- Cell Communication
- Cell Line, Tumor
- Cell Movement
- Cell Proliferation
- Humans
- Interleukin-6/metabolism
- Male
- Mice
- Pancreatic Stellate Cells/metabolism
- Pancreatic Stellate Cells/physiology
- Receptors, Purinergic P2X7/metabolism
- STAT3 Transcription Factor/metabolism
- Signal Transduction
- Tumor Microenvironment
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14
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Feng W, Yang X, Wang L, Wang R, Yang F, Wang H, Liu X, Ren Q, Zhang Y, Zhu X, Zheng G. P2X7 promotes the progression of MLL-AF9 induced acute myeloid leukemia by upregulation of Pbx3. Haematologica 2021; 106:1278-1289. [PMID: 32165482 PMCID: PMC8094107 DOI: 10.3324/haematol.2019.243360] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Indexed: 12/21/2022] Open
Abstract
Nucleotides mediate intercellular communication by activating purinergic receptors and take part in various physiological and pathological processes. Abnormal purinergic signaling plays important roles in malignant progression. P2X7, which belongs to the P2X family of purinergic receptors, is abnormally expressed in various types of malignancies including leukemia. However, its role and molecular mechanism in leukemia have not been elucidated. Here, we analyzed the correlation between P2X7 expression and AML clinical outcome; explored the role and mechanism of P2X7 in AML progression by using mouse acute myeloid leukemia (AML), nude mouse xenograft and patient-derived xenograft models. High levels of P2X7 expression were correlated with worse survival in AML. P2X7 was highly expressed in MLL-rearranged AML. Furthermore, P2X7 accelerated the progression of MLL-rearranged AML by both promoting cell proliferation and increasing leukemia stem cell (LSC) levels. Moreover, P2X7 caused upregulation of Pbx3 accounts for its pro-leukemic effects. The P2X7-Pbx3 pathway might also contribute to the progression of other types of leukemia as well as solid tumors with high levels of P2X7 expression. Our study provides new insights into the malignant progression caused by abnormal purinergic signaling.
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Affiliation(s)
- Wenli Feng
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Xiao Yang
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Lina Wang
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Rong Wang
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Feifei Yang
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Hao Wang
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Xiaoli Liu
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Qian Ren
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Yingchi Zhang
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Xiaofan Zhu
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
| | - Guoguang Zheng
- Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, China
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15
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Chen YH, Lin RR, Tao QQ. The role of P2X7R in neuroinflammation and implications in Alzheimer's disease. Life Sci 2021; 271:119187. [PMID: 33577858 DOI: 10.1016/j.lfs.2021.119187] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 01/30/2021] [Accepted: 01/31/2021] [Indexed: 12/24/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia and is set to rise in prevalence as the global trends in population aging. The extracellular deposition of amyloid protein (Aβ) and the intracellular formation of neurofibrillary tangles in the brain have been recognized as the two core pathologies of AD. Over the past decades, the presence of neuroinflammation in the brain has been documented as the third core pathology of AD. In recent years, emerging evidence demonstrated that the purinergic receptor P2X7 (P2X7R) serves a critical role in microglia responses and neuroinflammation. Besides, targeting P2X7R by genetic or pharmacological strategies attenuates the symptoms and pathological changes of AD models, and P2X7R has been recognized as a promising therapeutic target for AD. In this review, we summarized the recent evidence concerning the roles of P2X7R in neuroinflammation and implications in AD pathogenesis.
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Affiliation(s)
- Yi-He Chen
- Department of Neurology, Zhejiang University School of Medicine, Hangzhou, China; Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Rong-Rong Lin
- Department of Neurology, Zhejiang University School of Medicine, Hangzhou, China; Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Qing-Qing Tao
- Department of Neurology, Zhejiang University School of Medicine, Hangzhou, China; Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China.
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16
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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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17
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Kitabatake K, Kaji T, Tsukimoto M. ATP and ADP enhance DNA damage repair in γ-irradiated BEAS-2B human bronchial epithelial cells through activation of P2X7 and P2Y12 receptors. Toxicol Appl Pharmacol 2020; 407:115240. [PMID: 32941855 DOI: 10.1016/j.taap.2020.115240] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 09/03/2020] [Accepted: 09/10/2020] [Indexed: 10/23/2022]
Abstract
Agents that promote DNA repair may be useful as radioprotectants to minimize side effects such as radiation pneumonia caused by damage to normal cells during radiation therapy to treat lung cancer. We have reported that extracellular nucleotides and nucleosides are involved in the P2 or P1 receptor-mediated DNA damage response (DDR) after γ-irradiation. Here, we investigated the effects of ATP, UTP, GTP, ITP and their metabolites on the γH2AX/53BP1 focus formation in nuclei (a measure of γ-irradiation-induced DDR) and the survival of γ-irradiated immortalized human bronchial epithelial (BEAS-2B) cells. Fluorescence immunostaining showed that ATP and ADP increase DDR and DNA repair, and exhibit radioprotective effects as evaluated by colony formation assay. These effects of ATP or ADP were blocked by inhibitors of P2X7 or P2Y12 receptor, respectively, and by ERK1/2 inhibitor. ATP and ADP enhanced phosphorylation of ERK1/2 by suppressing MKP-1 and MKP-3 expression after γ-irradiation. These results indicate that ATP and ADP exhibit radioprotective effects by phosphorylation of ERK1/2 via activation of P2X7 and P2Y12 receptors, respectively, to promote γ-irradiation-induced DDR and DNA repair. ATP and ADP appear to be candidates for radioprotectants to reduce damage to non-cancerous cells during lung cancer radiotherapy by promoting DDR and DNA repair.
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Affiliation(s)
- Kazuki Kitabatake
- Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-0022, Japan
| | - Toshiyuki Kaji
- Department of Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-0022, Japan
| | - Mitsutoshi Tsukimoto
- Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-0022, Japan.
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18
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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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19
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Lara R, Adinolfi E, Harwood CA, Philpott M, Barden JA, Di Virgilio F, McNulty S. P2X7 in Cancer: From Molecular Mechanisms to Therapeutics. Front Pharmacol 2020; 11:793. [PMID: 32581786 PMCID: PMC7287489 DOI: 10.3389/fphar.2020.00793] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/13/2020] [Indexed: 12/18/2022] Open
Abstract
P2X7 is a transmembrane receptor expressed in multiple cell types including neurons, dendritic cells, macrophages, monocytes, B and T cells where it can drive a wide range of physiological responses from pain transduction to immune response. Upon activation by its main ligand, extracellular ATP, P2X7 can form a nonselective channel for cations to enter the cell. Prolonged activation of P2X7, via high levels of extracellular ATP over an extended time period can lead to the formation of a macropore, leading to depolarization of the plasma membrane and ultimately to cell death. Thus, dependent on its activation state, P2X7 can either drive cell survival and proliferation, or induce cell death. In cancer, P2X7 has been shown to have a broad range of functions, including playing key roles in the development and spread of tumor cells. It is therefore unsurprising that P2X7 has been reported to be upregulated in several malignancies. Critically, ATP is present at high extracellular concentrations in the tumor microenvironment (TME) compared to levels observed in normal tissues. These high levels of ATP should present a survival challenge for cancer cells, potentially leading to constitutive receptor activation, prolonged macropore formation and ultimately to cell death. Therefore, to deliver the proven advantages for P2X7 in driving tumor survival and metastatic potential, the P2X7 macropore must be tightly controlled while retaining other functions. Studies have shown that commonly expressed P2X7 splice variants, distinct SNPs and post-translational receptor modifications can impair the capacity of P2X7 to open the macropore. These receptor modifications and potentially others may ultimately protect cancer cells from the negative consequences associated with constitutive activation of P2X7. Significantly, the effects of both P2X7 agonists and antagonists in preclinical tumor models of cancer demonstrate the potential for agents modifying P2X7 function, to provide innovative cancer therapies. This review summarizes recent advances in understanding of the structure and functions of P2X7 and how these impact P2X7 roles in cancer progression. We also review potential therapeutic approaches directed against P2X7.
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Affiliation(s)
- Romain Lara
- Biosceptre (UK) Limited, Cambridge, United Kingdom
| | - Elena Adinolfi
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Catherine A Harwood
- Centre for Cell Biology and Cutaneous Research, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Mike Philpott
- Centre for Cutaneous Research, Blizard Institute, Bart's & The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | | | - Francesco Di Virgilio
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
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20
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Wilkaniec A, Cieślik M, Murawska E, Babiec L, Gąssowska-Dobrowolska M, Pałasz E, Jęśko H, Adamczyk A. P2X7 Receptor is Involved in Mitochondrial Dysfunction Induced by Extracellular Alpha Synuclein in Neuroblastoma SH-SY5Y Cells. Int J Mol Sci 2020; 21:ijms21113959. [PMID: 32486485 PMCID: PMC7312811 DOI: 10.3390/ijms21113959] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022] Open
Abstract
The purinergic P2X7 receptor (P2X7R) belongs to a family of trimeric ion channels that are gated by extracellular adenosine 5′-triphosphate (ATP). Several studies have pointed to a role of P2X7R-dependent signalling in Parkinson's disease (PD)-related neurodegeneration. The pathology of (PD) is characterized by the formation of insoluble alpha-synuclein (α-Syn) aggregates—Lewy bodies, but the mechanisms underlying α-Syn-induced dopaminergic cell death are still partially unclear. Our previous studies indicate that extracellular α-Syn directly interact with neuronal P2X7R and induces intracellular free calcium mobilization in neuronal cells. The main objective of this study was to examine the involvement of P2X7R receptor in α-Syn-induced mitochondrial dysfunction and cell death. We found that P2X7R stimulation is responsible for α-Syn-induced oxidative stress and activation of the molecular pathways of programmed cell death. Exogenous α-Syn treatment led to P2X7R-dependent decrease in mitochondrial membrane potential as well as elevation of mitochondrial ROS production resulting in breakdown of cellular energy production. Moreover, P2X7R-dependent deregulation of AMP-activated protein kinase as well as decrease in parkin protein level could be responsible for α-Syn-induced mitophagy impairment and accumulation of dysfunctional mitochondria. P2X7R might be putative pharmacological targets in molecular mechanism of extracellular α-Syn toxicity.
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Affiliation(s)
- Anna Wilkaniec
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
- Correspondence: ; Tel.: +48-22-608-66-00; Fax: +48-22-608-64-13
| | - Magdalena Cieślik
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Emilia Murawska
- Department of Applied Microbiology, Institute of Microbiology, Warsaw University, Miecznikowa 1 Street, 02-096 Warsaw, Poland;
| | - Lidia Babiec
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Magdalena Gąssowska-Dobrowolska
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Ewelina Pałasz
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Henryk Jęśko
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
| | - Agata Adamczyk
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences Pawińskiego 5, 02-106 Warsaw, Poland; (M.C.); (L.B.); (M.G.-D.); (E.P.); (H.J.); (A.A.)
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21
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Kopp R, Krautloher A, Ramírez-Fernández A, Nicke A. P2X7 Interactions and Signaling - Making Head or Tail of It. Front Mol Neurosci 2019; 12:183. [PMID: 31440138 PMCID: PMC6693442 DOI: 10.3389/fnmol.2019.00183] [Citation(s) in RCA: 156] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/11/2019] [Indexed: 12/14/2022] Open
Abstract
Extracellular adenine nucleotides play important roles in cell-cell communication and tissue homeostasis. High concentrations of extracellular ATP released by dying cells are sensed as a danger signal by the P2X7 receptor, a non-specific cation channel. Studies in P2X7 knockout mice and numerous disease models have demonstrated an important role of this receptor in inflammatory processes. P2X7 activation has been shown to induce a variety of cellular responses that are not usually associated with ion channel function, for example changes in the plasma membrane composition and morphology, ectodomain shedding, activation of lipases, kinases, and transcription factors, as well as cytokine release and apoptosis. In contrast to all other P2X family members, the P2X7 receptor contains a long intracellular C-terminus that constitutes 40% of the whole protein and is considered essential for most of these effects. So far, over 50 different proteins have been identified to physically interact with the P2X7 receptor. However, few of these interactions have been confirmed in independent studies and for the majority of these proteins, the interaction domains and the physiological consequences of the interactions are only poorly described. Also, while the structure of the P2X7 extracellular domain has recently been resolved, information about the organization and structure of its C-terminal tail remains elusive. After shortly describing the structure and assembly of the P2X7 receptor, this review gives an update of the identified or proposed interaction domains within the P2X7 C-terminus, describes signaling pathways in which this receptor has been involved, and provides an overlook of the identified interaction partners.
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Affiliation(s)
- Robin Kopp
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Anna Krautloher
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Antonio Ramírez-Fernández
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany
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22
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Guerra Martinez C. P2X7 receptor in cardiovascular disease: The heart side. Clin Exp Pharmacol Physiol 2019; 46:513-526. [PMID: 30834550 DOI: 10.1111/1440-1681.13079] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 02/21/2019] [Accepted: 02/28/2019] [Indexed: 01/10/2023]
Abstract
The P2X7 receptor is a ligand-gated purinergic receptor activated by extracellular ATP. The receptor is highly expressed in immune cells and in the brain, and, upon activation, the P2X7 receptor allows a cation flux, leading to the distinct activation of intracellular signalling pathways as the secretion of pro-inflammatory cytokines, and modulation of cell survival. Through these molecular mechanisms, P2X7 is known to play important roles in physiology and pathophysiology of a wide spectrum of diseases, including cancer, inflammatory diseases, neurological, respiratory and more recently cardiovascular diseases. Recent studies demonstrated that the P2X7 could modulate the assembly of the NLRP3 inflammasome, leading to the secretion of pro-inflammatory factors and worsen the cardiac disease phenotypes. This review discusses the critical molecular function of P2X7 in the modulation of the onset, progression and resolution of cardiovascular diseases and analyses the putative future use of P2X7-based therapies that modulate the IL-1β secretion arm and direct P2X7 antagonists.
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Affiliation(s)
- Camila Guerra Martinez
- Department of Microbial Pathogenesis and Immunology, Texas A&M University, College Station, Texas
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23
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Mantione ME, Lombardi M, Baccellieri D, Ferrara D, Castellano R, Chiesa R, Alfieri O, Foglieni C. IL-1β/MMP9 activation in primary human vascular smooth muscle-like cells: Exploring the role of TNFα and P2X7. Int J Cardiol 2018; 278:202-209. [PMID: 30583923 DOI: 10.1016/j.ijcard.2018.12.047] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 12/17/2018] [Indexed: 12/16/2022]
Abstract
BACKGROUND Vascular smooth muscle cells exhibit phenotypic plasticity in response to microenvironmental stimuli and contribute to vascular remodelling through mechanisms only partially understood. In atherosclerosis, P2X-purinoceptor7 (P2X7) has been related to interleukin-1β (IL-1β) and metalloproteinase 9 (MMP9). The hypoxia-inducible factor-1alpha (HIF1α) was associated to remodelling. Here the activation of IL-1β and MMP9 was studied in relationship to P2X7 and HIF1α in cells exploited from human carotid plaque and internal mammary artery. METHODS AND RESULTS Migrating cells expressed HIF1α-regulated canopy FGF-signalling regulator 2 and CD117, and led to primary cells with SMC-like phenotype (VSMC), P2X7+. We investigated in VSMC the effects of hypoxia, of treatment with tumour necrosis factor-α (TNFα) and/or with P2X7 antagonist, A740003. Quantitative RT-PCR showed that hypoxia unaffected IL-1β and down-regulated MMP9 mRNAs, without activating HIF1α. TNFα increased IL-1β mRNA via NLR Family Pyrin Domain-Containing 3, with production of proIL-1β but no rise of mature IL-1β. Zymography demonstrated that A740003 triggered MMP9 secretion from VSMC. Combination of A740003 with TNFα abrogated this effect. Combination was ineffective on IL-1β activation elicited by TNFα, but down-regulated HIF1α mRNA. A740003 induced the intracellular P2X7 aggregation and differently perturbed lysosome and mitochondria network compared to TNFα. CONCLUSIONS Cells migration from human arteries leads to partially differentiated VSMC analogous to neointimal cells within atherosclerotic lesions. Down-regulated HIF1α in stimulated VSMC translates in resilience in atherosclerotic lesions. P2X7-independent partial activation of IL-1β elicited by TNFα underlines complexity of the cytokine secretion. Data also supported P2X7 as modulator of MMP9 secretion, important for atherosclerosis progression.
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Affiliation(s)
- Maria Elena Mantione
- Cardiovascular Research Area, IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Maria Lombardi
- Cardiovascular Research Area, IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Domenico Baccellieri
- Cardio-thoracic-vascular Department, IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - David Ferrara
- Cardio-thoracic-vascular Department, IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Renata Castellano
- Cardio-thoracic-vascular Department, IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Roberto Chiesa
- Cardio-thoracic-vascular Department, IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Ottavio Alfieri
- Cardio-thoracic-vascular Department, IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Chiara Foglieni
- Cardiovascular Research Area, IRCCS San Raffaele Scientific Institute, Milano, Italy.
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24
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Lin JP, Chen CQ, Huang LE, Li NN, Yang Y, Zhu SM, Yao YX. Dexmedetomidine Attenuates Neuropathic Pain by Inhibiting P2X7R Expression and ERK Phosphorylation in Rats. Exp Neurobiol 2018; 27:267-276. [PMID: 30181689 PMCID: PMC6120967 DOI: 10.5607/en.2018.27.4.267] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/21/2018] [Accepted: 08/23/2018] [Indexed: 01/24/2023] Open
Abstract
α2-Adrenoceptor agonists attenuate hypersensitivity under neuropathic conditions. However, the mechanisms underlying this attenuation remain largely unknown. In the present study, we explored the potential roles of purinergic receptor 7 (P2X7R)/extracellular signal-regulated kinase (ERK) signaling in the anti-nociceptive effect of dexmedetomidine in a rat model of neuropathic pain induced by chronic constriction injury (CCI) of the sciatic nerve. An animal model of CCI was adopted to mimic the clinical neuropathic pain state. Behavioral hypersensitivity to mechanical and thermal stimuli was determined by von Frey filament and Hargreaves' tests, and the spinal P2X7R expression level and ERK phosphorylation were analyzed using western blot analysis and immunohistochemistry. In parallel with the development of mechanical and thermal hyperalgesia, a significant increase in P2X7R expression was noted in the ipsilateral spinal cord on day 7 after CCI. Intrathecal administration of dexmedetomidine (2.5 µg) for 3 days not only attenuated neuropathic pain but also inhibited the CCI-induced P2X7R upregulation and ERK phosphorylation. Intrathecal dexmedetomidine administration did not produce obvious effects on locomotor function. The present study demonstrated that dexmedetomidine attenuates the neuropathic pain induced by CCI of the sciatic nerve in rats by inhibiting spinal P2X7R expression and ERK phosphorylation, indicating the potential therapeutic implications of dexmedetomidine administration for the treatment of neuropathic pain.
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Affiliation(s)
- Jia-Piao Lin
- Department of Anesthesia, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, P.R. China
| | - Chao-Qin Chen
- Department of Anesthesia, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, P.R. China
| | - Ling-Er Huang
- Department of Anesthesia, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, P.R. China
| | - Na-Na Li
- Department of Anesthesia, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, P.R. China
| | - Yan Yang
- Centre for Neuroscience, Zhejiang University School of Medicine, Hangzhou 310016, P.R. China
| | - Sheng-Mei Zhu
- Department of Anesthesia, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, P.R. China
| | - Yong-Xing Yao
- Department of Anesthesia, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, P.R. China
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25
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Tozzi M, Larsen AT, Lange SC, Giannuzzo A, Andersen MN, Novak I. The P2X7 receptor and pannexin-1 are involved in glucose-induced autocrine regulation in β-cells. Sci Rep 2018; 8:8926. [PMID: 29895988 PMCID: PMC5997690 DOI: 10.1038/s41598-018-27281-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 05/31/2018] [Indexed: 01/02/2023] Open
Abstract
Extracellular ATP is an important short-range signaling molecule that promotes various physiological responses virtually in all cell types, including pancreatic β-cells. It is well documented that pancreatic β-cells release ATP through exocytosis of insulin granules upon glucose stimulation. We hypothesized that glucose might stimulate ATP release through other non-vesicular mechanisms. Several purinergic receptors are found in β-cells and there is increasing evidence that purinergic signaling regulates β-cell functions and survival. One of the receptors that may be relevant is the P2X7 receptor, but its detailed role in β-cell physiology is unclear. In this study we investigated roles of the P2X7 receptor and pannexin-1 in ATP release, intracellular ATP, Ca2+ signals, insulin release and cell proliferation/survival in β-cells. Results show that glucose induces rapid release of ATP and significant fraction of release involves the P2X7 receptor and pannexin-1, both expressed in INS-1E cells, rat and mouse β-cells. Furthermore, we provide pharmacological evidence that extracellular ATP, via P2X7 receptor, stimulates Ca2+ transients and cell proliferation in INS-1E cells and insulin secretion in INS-1E cells and rat islets. These data indicate that the P2X7 receptor and pannexin-1 have important functions in β-cell physiology, and should be considered in understanding and treatment of diabetes.
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Affiliation(s)
- Marco Tozzi
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anna T Larsen
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Sofie C Lange
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Andrea Giannuzzo
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Martin N Andersen
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ivana Novak
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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26
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Dreisig K, Kristensen NP, Dommer MW, Jørgensen NR, Kornum BR. N-terminal tagging of human P2X7 receptor disturbs calcium influx and dye uptake. Purinergic Signal 2018; 14:83-90. [PMID: 29290027 DOI: 10.1007/s11302-017-9598-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 12/13/2017] [Indexed: 11/26/2022] Open
Abstract
The P2X7 receptor is a frequently studied member of the purinergic receptor family signalling via channel opening and membrane pore formation. Fluorescent imaging is an important molecular method for studying cellular receptor expression and localization. Fusion of receptors to fluorescent proteins might cause major functional changes and requires careful functional evaluation such as has been done for the rat P2X7 receptor. This study examines fusion constructs of the human P2X7 receptor. We assessed surface expression, channel opening with calcium influx, and pore formation using YO-PRO-1 dye uptake in response to BzATP stimulation in transfected cells. We found that tagging at the N-terminal of the human P2X7 receptor with the enhanced green fluorescent protein (eGFP) disturbed channel opening and pore formation despite intact surface expression. A triple hemagglutinin (3HA) fused to the N-terminal also disrupted pore formation but not channel opening showing that even a small tag alters the normal function of the receptor. Together, this suggests that in contrast to what has been observed for the rat P2X7 receptor, the human P2X7 receptor contains N-terminal motifs important for signalling that prevent the construction of a functionally active fusion protein.
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Affiliation(s)
- Karin Dreisig
- Department of Clinical Biochemistry, Rigshospitalet, Glostrup, Denmark
| | | | | | - Niklas Rye Jørgensen
- Department of Clinical Biochemistry, Rigshospitalet, Glostrup, Denmark
- OPEN, Odense Patient Data Explorative Network Odense University Hospital/Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Birgitte Rahbek Kornum
- Department of Clinical Biochemistry, Rigshospitalet, Glostrup, Denmark.
- Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark.
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27
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Sáez-Orellana F, Fuentes-Fuentes MC, Godoy PA, Silva-Grecchi T, Panes JD, Guzmán L, Yévenes GE, Gavilán J, Egan TM, Aguayo LG, Fuentealba J. P2X receptor overexpression induced by soluble oligomers of amyloid beta peptide potentiates synaptic failure and neuronal dyshomeostasis in cellular models of Alzheimer's disease. Neuropharmacology 2017; 128:366-378. [PMID: 29079292 DOI: 10.1016/j.neuropharm.2017.10.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 10/13/2017] [Accepted: 10/21/2017] [Indexed: 12/17/2022]
Abstract
The most common cause of dementia is Alzheimer's disease. The etiology of the disease is unknown, although considerable evidence suggests a critical role for the soluble oligomers of amyloid beta peptide (Aβ). Because Aβ increases the expression of purinergic receptors (P2XRs) in vitro and in vivo, we studied the functional correlation between long-term exposure to Aβ and the ability of P2XRs to modulate network synaptic tone. We used electrophysiological recordings and Ca2+ microfluorimetry to assess the effects of chronic exposure (24 h) to Aβ oligomers (0.5 μM) together with known inhibitors of P2XRs, such as PPADS and apyrase on synaptic function. Changes in the expression of P2XR were quantified using RT-qPCR. We observed changes in the expression of P2X1R, P2X7R and an increase in P2X2R; and also in protein levels in PC12 cells (143%) and hippocampal neurons (120%) with Aβ. In parallel, the reduction on the frequency and amplitude of mEPSCs (72% and 35%, respectively) were prevented by P2XR inhibition using a low PPADS concentration. Additionally, the current amplitude and intracellular Ca2+ signals evoked by extracellular ATP were increased (70% and 75%, respectively), suggesting an over activation of purinergic neurotransmission in cells pre-treated with Aβ. Taken together, our findings suggest that Aβ disrupts the main components of synaptic transmission at both pre- and post-synaptic sites, and induces changes in the expression of key P2XRs, especially P2X2R; changing the neuromodulator function of the purinergic tone that could involve the P2X2R as a key factor for cytotoxic mechanisms. These results identify novel targets for the treatment of dementia and other diseases characterized by increased purinergic transmission.
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Affiliation(s)
- Francisco Sáez-Orellana
- Neuroactive Compounds Screening Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - María C Fuentes-Fuentes
- Neuroactive Compounds Screening Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - Pamela A Godoy
- Neuroactive Compounds Screening Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - Tiare Silva-Grecchi
- Neuroactive Compounds Screening Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - Jessica D Panes
- Neuroactive Compounds Screening Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - Leonardo Guzmán
- Molecular Neurobiology Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - Gonzalo E Yévenes
- Neuropharmacology Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - Javiera Gavilán
- Neuroactive Compounds Screening Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - Terrance M Egan
- Department of Pharmacology and Physiology, School of Medicine, Saint Louis University, St. Louis, MO, USA
| | - Luis G Aguayo
- Neuropharmacology Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile
| | - Jorge Fuentealba
- Neuroactive Compounds Screening Laboratory, Physiology Department, Biological Sciences Faculty, Universidad de Concepción, Concepción, Chile.
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28
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Gentile D, Lazzerini PE, Gamberucci A, Natale M, Selvi E, Vanni F, Alì A, Taddeucci P, Del-Ry S, Cabiati M, Della-Latta V, Abraham DJ, Morales MA, Fulceri R, Laghi-Pasini F, Capecchi PL. Searching Novel Therapeutic Targets for Scleroderma: P2X7-Receptor Is Up-regulated and Promotes a Fibrogenic Phenotype in Systemic Sclerosis Fibroblasts. Front Pharmacol 2017; 8:638. [PMID: 28955239 PMCID: PMC5602350 DOI: 10.3389/fphar.2017.00638] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 08/29/2017] [Indexed: 11/13/2022] Open
Abstract
Objectives: Systemic sclerosis (SSc) is a connective tissue disorder presenting fibrosis of the skin and internal organs, for which no effective treatments are currently available. Increasing evidence indicates that the P2X7 receptor (P2X7R), a nucleotide-gated ionotropic channel primarily involved in the inflammatory response, may also have a key role in the development of tissue fibrosis in different body districts. This study was aimed at investigating P2X7R expression and function in promoting a fibrogenic phenotype in dermal fibroblasts from SSc patients, also analyzing putative underlying mechanistic pathways. Methods: Fibroblasts were isolated by skin biopsy from 9 SSc patients and 8 healthy controls. P2X7R expression, and function (cytosolic free Ca2+ fluxes, α-smooth muscle actin [α-SMA] expression, cell migration, and collagen release) were studied. Moreover, the role of cytokine (interleukin-1β, interleukin-6) and connective tissue growth factor (CTGF) production, and extracellular signal-regulated kinases (ERK) activation in mediating P2X7R-dependent pro-fibrotic effects in SSc fibroblasts was evaluated. Results: P2X7R expression and Ca2+ permeability induced by the selective P2X7R agonist 2'-3'-O-(4-benzoylbenzoyl)ATP (BzATP) were markedly higher in SSc than control fibroblasts. Moreover, increased αSMA expression, cell migration, CTGF, and collagen release were observed in lipopolysaccharides-primed SSc fibroblasts after BzATP stimulation. While P2X7-induced cytokine changes did not affect collagen production, it was completely abrogated by inhibition of the ERK pathway. Conclusion: In SSc fibroblasts, P2X7R is overexpressed and its stimulation induces Ca2+-signaling activation and a fibrogenic phenotype characterized by increased migration and collagen production. These data point to the P2X7R as a potential, novel therapeutic target for controlling exaggerated collagen deposition and tissue fibrosis in patients with SSc.
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Affiliation(s)
- Daniela Gentile
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Pietro E Lazzerini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Alessandra Gamberucci
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Mariarita Natale
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Enrico Selvi
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Francesca Vanni
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Alessandra Alì
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Paolo Taddeucci
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | | | | | | | - David J Abraham
- Division of Medicine, Department of Inflammation, Centre for Rheumatology and Connective Tissue Diseases, University College London, London, United Kingdom
| | | | - Rosella Fulceri
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Franco Laghi-Pasini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Pier L Capecchi
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
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29
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Blom K, Senkowski W, Jarvius M, Berglund M, Rubin J, Lenhammar L, Parrow V, Andersson C, Loskog A, Fryknäs M, Nygren P, Larsson R. The anticancer effect of mebendazole may be due to M1 monocyte/macrophage activation via ERK1/2 and TLR8-dependent inflammasome activation. Immunopharmacol Immunotoxicol 2017; 39:199-210. [PMID: 28472897 DOI: 10.1080/08923973.2017.1320671] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Mebendazole (MBZ), a drug commonly used for helminitic infections, has recently gained substantial attention as a repositioning candidate for cancer treatment. However, the mechanism of action behind its anticancer activity remains unclear. To address this problem, we took advantage of the curated MBZ-induced gene expression signatures in the LINCS Connectivity Map (CMap) database. The analysis revealed strong negative correlation with MEK/ERK1/2 inhibitors. Moreover, several of the most upregulated genes in response to MBZ exposure were related to monocyte/macrophage activation. The MBZ-induced gene expression signature in the promyeloblastic HL-60 cell line was strongly enriched in genes involved in monocyte/macrophage pro-inflammatory (M1) activation. This was subsequently validated using MBZ-treated THP-1 monocytoid cells that demonstrated gene expression, surface markers and cytokine release characteristic of the M1 phenotype. At high concentrations MBZ substantially induced the release of IL-1β and this was further potentiated by lipopolysaccharide (LPS). At low MBZ concentrations, cotreatment with LPS was required for MBZ-stimulated IL-1β secretion to occur. Furthermore, we show that the activation of protein kinase C, ERK1/2 and NF-kappaB were required for MBZ-induced IL-1β release. MBZ-induced IL-1β release was found to be dependent on NLRP3 inflammasome activation and to involve TLR8 stimulation. Finally, MBZ induced tumor-suppressive effects in a coculture model with differentiated THP-1 macrophages and HT29 colon cancer cells. In summary, we report that MBZ induced a pro-inflammatory (M1) phenotype of monocytoid cells, which may, at least partly, explain MBZ's anticancer activity observed in animal tumor models and in the clinic.
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Affiliation(s)
- Kristin Blom
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Wojciech Senkowski
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Malin Jarvius
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Malin Berglund
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Jenny Rubin
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Lena Lenhammar
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Vendela Parrow
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Claes Andersson
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Angelica Loskog
- b Department of Immunology, Genetics and Pathology, Science for Life Laboratory , Uppsala University , Uppsala , Sweden
| | - Mårten Fryknäs
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
| | - Peter Nygren
- b Department of Immunology, Genetics and Pathology, Science for Life Laboratory , Uppsala University , Uppsala , Sweden
| | - Rolf Larsson
- a Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine , Uppsala University , Uppsala , Sweden
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Abstract
The P2X7 receptor is a trimeric ion channel gated by extracellular adenosine 5'-triphosphate. The receptor is present on an increasing number of different cells types including stem, blood, glial, neural, ocular, bone, dental, exocrine, endothelial, muscle, renal and skin cells. The P2X7 receptor induces various downstream events in a cell-specific manner, including inflammatory molecule release, cell proliferation and death, metabolic events, and phagocytosis. As such this receptor plays important roles in heath and disease. Increasing knowledge about the P2X7 receptor has been gained from studies of, but not limited to, protein chemistry including cloning, site-directed mutagenesis, crystal structures and atomic modeling, as well as from studies of primary tissues and transgenic mice. This chapter focuses on the P2X7 receptor itself. This includes the P2RX7 gene and its products including splice and polymorphic variants. This chapter also reviews modulators of P2X7 receptor activation and inhibition, as well as the transcriptional regulation of the P2RX7 gene via its promoter and enhancer regions, and by microRNA and long-coding RNA. Furthermore, this chapter discusses the post-translational modification of the P2X7 receptor by N-linked glycosylation, adenosine 5'-diphosphate ribosylation and palmitoylation. Finally, this chapter reviews interaction partners of the P2X7 receptor, and its cellular localisation and trafficking within cells.
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Affiliation(s)
- Ronald Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
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Toki Y, Takenouchi T, Harada H, Tanuma SI, Kitani H, Kojima S, Tsukimoto M. Extracellular ATP induces P2X7 receptor activation in mouse Kupffer cells, leading to release of IL-1β, HMGB1, and PGE2, decreased MHC class I expression and necrotic cell death. Biochem Biophys Res Commun 2015; 458:771-6. [PMID: 25681768 DOI: 10.1016/j.bbrc.2015.02.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 02/03/2015] [Indexed: 01/14/2023]
Abstract
Kupffer cells, which are resident macrophages in liver, can produce various cytokines and chemokines that induce hepatitis and liver fibrosis. It is suggested that extracellular ATP-induced activation of macrophage P2X7 receptor plays an important role in inflammation via release of pro-inflammatory mediators, but the role of P2X7 receptor in Kupffer cells remains unclear. Here, we show that activation of P2X7 receptor in Kupffer cells causes multiple inflammatory responses, using the clonal mouse Kupffer cell line (KUP5) that we previously established. Treatment of LPS-primed Kupffer cells with 3 mM ATP induced Ca(2+) influx, non-selective large pore formation, activation of MAPK, cell lysis, IL-1β release, prostaglandin E2 (PGE2) release, high mobility group box1 (HMGB1) release, and major histocompatibility complex (MHC) class I shedding. These events were significantly suppressed by pretreatment with P2X7 antagonist A438079, indicating involvement of P2X7 receptor activation in these inflammatory responses. Our results suggest that extracellular ATP-induced activation of P2X7 receptor of Kupffer cells plays multiple roles in the inflammatory response in liver. P2X7 receptor might be a new therapeutic target for treatment of liver diseases.
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Affiliation(s)
- Yusuke Toki
- Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, Japan; Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan
| | - Takato Takenouchi
- Animal Immune and Cell Biology Research Unit, Division of Animal Sciences, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Hitoshi Harada
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, 3500-3 Minamitamagaki-cho, Suzuka-shi, Mie, Japan
| | - Sei-ichi Tanuma
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan
| | - Hiroshi Kitani
- Animal Immune and Cell Biology Research Unit, Division of Animal Sciences, National Institute of Agrobiological Sciences, 1-2 Ohwashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Shuji Kojima
- Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, Japan
| | - Mitsutoshi Tsukimoto
- Department of Radiation Biosciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, Japan.
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Muzzachi S, Blasi A, Ciani E, Favia M, Cardone RA, Marzulli D, Reshkin SJ, Merizzi G, Casavola V, Soleti A, Guerra L. MED1101: A new dialdehydic compound regulating P2×7 receptor cell surface expression in U937 cells. Biol Cell 2013; 105:399-413. [DOI: 10.1111/boc.201200088] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 05/24/2013] [Indexed: 12/17/2022]
Affiliation(s)
- Stefania Muzzachi
- Department of Biosciences; Biotechnologies and Biopharmaceutics; University of Bari; Bari; 70126; Italy
| | | | - Elena Ciani
- Department of Biosciences; Biotechnologies and Biopharmaceutics; University of Bari; Bari; 70126; Italy
| | - Maria Favia
- Department of Biosciences; Biotechnologies and Biopharmaceutics; University of Bari; Bari; 70126; Italy
| | - Rosa A. Cardone
- Department of Biosciences; Biotechnologies and Biopharmaceutics; University of Bari; Bari; 70126; Italy
| | - Domenico Marzulli
- Institute of Biomembranes and Bioenergetics; CNR; Bari; 70126; Italy
| | - Stephan J. Reshkin
- Department of Biosciences; Biotechnologies and Biopharmaceutics; University of Bari; Bari; 70126; Italy
| | | | - Valeria Casavola
- Department of Biosciences; Biotechnologies and Biopharmaceutics; University of Bari; Bari; 70126; Italy
| | | | - Lorenzo Guerra
- Department of Biosciences; Biotechnologies and Biopharmaceutics; University of Bari; Bari; 70126; Italy
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An IP3R3- and NPY-expressing microvillous cell mediates tissue homeostasis and regeneration in the mouse olfactory epithelium. PLoS One 2013; 8:e58668. [PMID: 23516531 PMCID: PMC3596314 DOI: 10.1371/journal.pone.0058668] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 02/05/2013] [Indexed: 11/19/2022] Open
Abstract
Calcium-dependent release of neurotrophic factors plays an important role in the maintenance of neurons, yet the release mechanisms are understudied. The inositol triphosphate (IP3) receptor is a calcium release channel that has a physiological role in cell growth, development, sensory perception, neuronal signaling and secretion. In the olfactory system, the IP3 receptor subtype 3 (IP3R3) is expressed exclusively in a microvillous cell subtype that is the predominant cell expressing neurotrophic factor neuropeptide Y (NPY). We hypothesized that IP3R3-expressing microvillous cells secrete sufficient NPY needed for both the continual maintenance of the neuronal population and for neuroregeneration following injury. We addressed this question by assessing the release of NPY and the regenerative capabilities of wild type, IP3R3(+/-), and IP3R3(-/-) mice. Injury, simulated using extracellular ATP, induced IP3 receptor-mediated NPY release in wild-type mice. ATP-evoked NPY release was impaired in IP3R3(-/-) mice, suggesting that IP3R3 contributes to NPY release following injury. Under normal physiological conditions, both IP3R3(-/-) mice and explants from these mice had fewer progenitor cells that proliferate and differentiate into immature neurons. Although the number of mature neurons and the in vivo rate of proliferation were not altered, the proliferative response to the olfactotoxicant satratoxin G and olfactory bulb ablation injury was compromised in the olfactory epithelium of IP3R3(-/-) mice. The reductions in both NPY release and number of progenitor cells in IP3R3(-/-) mice point to a role of the IP3R3 in tissue homeostasis and neuroregeneration. Collectively, these data suggest that IP3R3 expressing microvillous cells are actively responsive to injury and promote recovery.
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Bourzac JF, L'Ériger K, Larrivée JF, Arguin G, Bilodeau MS, Stankova J, Gendron FP. Glucose transporter 2 expression is down regulated following P2X7 activation in enterocytes. J Cell Physiol 2012; 228:120-9. [PMID: 22566162 DOI: 10.1002/jcp.24111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
With the diabetes epidemic affecting the world population, there is an increasing demand for means to regulate glycemia. Dietary glucose is first absorbed by the intestine before entering the blood stream. Thus, the regulation of glucose absorption by intestinal epithelial cells (IECs) could represent a way to regulate glycemia. Among the molecules involved in glycemia homeostasis, extracellular ATP, a paracrine signaling molecule, was reported to induce insulin secretion from pancreatic β cells by activating P2Y and P2X receptors. In rat's jejunum, P2X7 expression was previously immunolocalized to the apex of villi, where it has been suspected to play a role in apoptosis. However, using an antibody recognizing the receptor extracellular domain and thus most of the P2X7 isoforms, we showed that expression of this receptor is apparent in the top two-thirds of villi. These data suggest a different role for this receptor in IECs. Using the non-cancerous IEC-6 cells and differentiated Caco-2 cells, glucose transport was reduced by more than 30% following P2X7 stimulation. This effect on glucose transport was not due to P2X7-induced cell apoptosis, but rather was the consequence of glucose transporter 2 (Glut2)'s internalization. The signaling pathway leading to P2X7-dependent Glut2 internalization involved the calcium-independent activation of phospholipase Cγ1 (PLCγ1), PKCδ, and PKD1. Although the complete mechanism regulating Glut2 internalization following P2X7 activation is not fully understood, modulation of P2X7 receptor activation could represent an interesting approach to regulate intestinal glucose absorption.
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Affiliation(s)
- Jean-François Bourzac
- Department of Anatomy and Cell Biology, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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35
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Haanes KA, Schwab A, Novak I. The P2X7 receptor supports both life and death in fibrogenic pancreatic stellate cells. PLoS One 2012; 7:e51164. [PMID: 23284663 PMCID: PMC3524122 DOI: 10.1371/journal.pone.0051164] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 10/30/2012] [Indexed: 12/29/2022] Open
Abstract
The pancreatic stellate cells (PSCs) have complex roles in pancreas, including tissue repair and fibrosis. PSCs surround ATP releasing exocrine cells, but little is known about purinergic receptors and their function in PSCs. Our aim was to resolve whether PSCs express the multifunctional P2X7 receptor and elucidate how it regulates PSC viability. The number of PSCs isolated from wild type (WT) mice was 50% higher than those from the Pfizer P2X7 receptor knock out (KO) mice. The P2X7 receptor protein and mRNA of all known isoforms were expressed in WT PSCs, while KO PSCs only expressed truncated versions of the receptor. In culture, the proliferation rate of the KO PSCs was significantly lower. Inclusion of apyrase reduced the proliferation rate in both WT and KO PSCs, indicating importance of endogenous ATP. Exogenous ATP had a two-sided effect. Proliferation of both WT and KO cells was stimulated with ATP in a concentration-dependent manner with a maximum effect at 100 µM. At high ATP concentration (5 mM), WT PSCs, but not the KO PSCs died. The intracellular Ca2+ signals and proliferation rate induced by micromolar ATP concentrations were inhibited by the allosteric P2X7 receptor inhibitor az10606120. The P2X7 receptor-pore inhibitor A438079 partially prevented cell death induced by millimolar ATP concentrations. This study shows that ATP and P2X7 receptors are important regulators of PSC proliferation and death, and therefore might be potential targets for treatments of pancreatic fibrosis and cancer.
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Affiliation(s)
| | - Albrecht Schwab
- Institut für Physiologie II, Universität Münster, Münster, Germany
| | - Ivana Novak
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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Chao CC, Huang CC, Lu DY, Wong KL, Chen YR, Cheng TH, Leung YM. Ca2+ store depletion and endoplasmic reticulum stress are involved in P2X7 receptor-mediated neurotoxicity in differentiated NG108-15 cells. J Cell Biochem 2012; 113:1377-85. [PMID: 22134903 DOI: 10.1002/jcb.24010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
P2X7 receptor (P2X7R) activation by extracellular ATP triggers influx of Na(+) and Ca(2+), cytosolic Ca(2+) overload and consequently cytotoxicity. Whether disturbances in endoplasmic reticulum (ER) Ca(2+) homeostasis and ER stress are involved in P2X7R-mediated cell death is unknown. In this study, a P2X7R agonist (BzATP) was used to activate P2X7R in differentiated NG108-15 neuronal cells. In a concentration-dependent manner, application of BzATP (10-100 µM) immediately raised cytosolic Ca(2+) concentration ([Ca(2+)]i) and caused cell death after a 24-h incubation. P2X7R activation for 2 h did not cause cell death but resulted in a sustained reduction in ER Ca2+ pool size, as evidenced by a diminished cyclopiazonic acid-induced Ca(2+) discharge (fura 2 assay) and a lower fluorescent signal in cells loaded with Mag-fura 2 (ER-specific Ca(2+)-fluorescent dye). Furthermore, P2X7R activation (2 h) led to the appearance of markers of ER stress [phosphorylated α subunit of eukaryotic initiation factor 2 (p-eIF2α) and C/EBP homologous protein (CHOP)] and apoptosis (cleaved caspase 3). Xestospongin C (XeC), an antagonist of inositol-1,4,5-trisphosphate (IP3) receptor (IP3R), strongly inhibited BzATP-triggered [Ca(2+)]i elevation, suggesting that the latter involved Ca(2+) release via IP3R. XeC pretreatment not only attenuated the reduction in Ca(2+) pool size in BzATP-treated cells, but also rescued cell death and prevented BzATP-induced appearance of ER stress and apoptotic markers. These novel observations suggest that P2X7R activation caused not only Ca(2+) overload, but also Ca(2+) release via IP3R, sustained Ca(2+) store depletion, ER stress and eventually apoptotic cell death.
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Affiliation(s)
- Chia-Chia Chao
- Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan
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Young CNJ, Brutkowski W, Lien CF, Arkle S, Lochmüller H, Zabłocki K, Górecki DC. P2X7 purinoceptor alterations in dystrophic mdx mouse muscles: relationship to pathology and potential target for treatment. J Cell Mol Med 2012; 16:1026-37. [PMID: 21794079 PMCID: PMC4365874 DOI: 10.1111/j.1582-4934.2011.01397.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal inherited muscle disorder. Pathological characteristics of DMD skeletal muscles include, among others, abnormal Ca(2+) homeostasis and cell signalling. Here, in the mdx mouse model of DMD, we demonstrate significant P2X7 receptor abnormalities in isolated primary muscle cells and cell lines and in dystrophic muscles in vivo. P2X7 mRNA expression in dystrophic muscles was significantly up-regulated but without alterations of specific splice variant patterns. P2X7 protein was also up-regulated and this was associated with altered function of P2X7 receptors producing increased responsiveness of cytoplasmic Ca(2+) and extracellular signal-regulated kinase (ERK) phosphorylation to purinergic stimulation and altered sensitivity to NAD. Ca(2+) influx and ERK signalling were stimulated by ATP and BzATP, inhibited by specific P2X7 antagonists and insensitive to ivermectin, confirming P2X7 receptor involvement. Despite the presence of pannexin-1, prolonged P2X7 activation did not trigger cell permeabilization to propidium iodide or Lucifer yellow. In dystrophic mice, in vivo treatment with the P2X7 antagonist Coomassie Brilliant Blue reduced the number of degeneration-regeneration cycles in mdx skeletal muscles. Altered P2X7 expression and function is thus an important feature in dystrophic mdx muscle and treatments aiming to inhibit P2X7 receptor might slow the progression of this disease.
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Affiliation(s)
- Christopher N J Young
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
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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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The P2X(7) receptor regulates proteoglycan expression in the corneal stroma. Mol Vis 2012; 18:128-38. [PMID: 22275804 PMCID: PMC3265178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 01/13/2012] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Previously, the authors demonstrated that the lack of the P2X(7) receptor impairs epithelial wound healing and stromal collagen organization in the cornea. The goal here is to characterize specific effects of the P2X(7) receptor on components of the corneal stroma extracellular matrix. METHODS Unwounded corneas from P2X(7) knockout mice (P2X(7) (-/-)) and C57BL/6J wild type mice (WT) were fixed and prepared for quantitative and qualitative analysis of protein expression and localization using Real Time PCR and immunohistochemistry. Corneas were stained also with Cuprolinic blue for electron microscopy to quantify proteoglycan sulfation in the stroma. RESULTS P2X(7) (-/-) mice showed decreased mRNA expression in the major components of the corneal stroma: collagen types I and V and small leucine-rich proteoglycans decorin, keratocan, and lumican. In contrast P2X(7) (-/-) mice showed increased mRNA expression in lysyl oxidase and biglycan. Additionally, we observed increases in syndecan 1, perlecan, and type III collagen. There was a loss of perlecan along the basement membrane and enhanced expression throughout the stroma, in contrast with the decreased localization of other proteoglycans throughout the stroma. In the absence of lyase digestion there was a significantly smaller number of proteoglycan units per 100 nm of collagen fibrils in the P2X(7) (-/-) compared to WT mice. While digestion was more pronounced in the WT group, double digestion with Keratanase I and Chondroitinase ABC removed 88% of the GAG filaments in the WT, compared to 72% of those in the P2X(7) (-/-) mice, indicating that there are more heparan sulfate proteoglycans in the latter. CONCLUSIONS Our results indicate that loss of P2X(7) alters both the expression of proteins and the sulfation of proteoglycans in the corneal stroma.
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Corneal epithelium expresses a variant of P2X(7) receptor in health and disease. PLoS One 2011; 6:e28541. [PMID: 22163032 PMCID: PMC3232242 DOI: 10.1371/journal.pone.0028541] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 11/10/2011] [Indexed: 12/18/2022] Open
Abstract
Improper wound repair of the corneal epithelium can alter refraction of light resulting in impaired vision. We have shown that ATP is released after injury, activates purinergic receptor signaling pathways and plays a major role in wound closure. In many cells or tissues, ATP activates P2X(7) receptors leading to cation fluxes and cytotoxicity. The corneal epithelium is an excellent model to study the expression of both the full-length P2X(7) form (defined as the canonical receptor) and its truncated forms. When Ca(2+) mobilization is induced by BzATP, a P2X(7) agonist, it is attenuated in the presence of extracellular Mg(2+) or Zn(2+), negligible in the absence of extracellular Ca(2+), and inhibited by the competitive P2X7 receptor inhibitor, A438079. BzATP enhanced phosphorylation of ERK. Together these responses indicate the presence of a canonical or full-length P2X(7) receptor. In addition BzATP enhanced epithelial cell migration, and transfection with siRNA to the P2X(7) receptor reduced cell migration. Furthermore, sustained activation did not induce dye uptake indicating the presence of truncated or variant forms that lack the ability to form large pores. Reverse transcription-polymerase chain reaction and Northern blot analysis revealed a P2X(7) splice variant. Western blots identified a full-length and truncated form, and the expression pattern changed as cultures progressed from monolayer to stratified. Cross-linking gels demonstrated the presence of homo- and heterotrimers. We examined epithelium from age matched diabetic and non-diabetic corneas patients and detected a 4-fold increase in P2X(7) mRNA from diabetic corneal epithelium compared to non-diabetic controls and an increased trend in expression of P2X(7)variant mRNA. Taken together, these data indicate that corneal epithelial cells express full-length and truncated forms of P2X(7), which ultimately allows P2X(7) to function as a multifaceted receptor that can mediate cell proliferation and migration or cell death.
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Lipopolysaccharide inhibits the channel activity of the P2X7 receptor. Mediators Inflamm 2011; 2011:152625. [PMID: 21941410 PMCID: PMC3173735 DOI: 10.1155/2011/152625] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 06/03/2011] [Accepted: 06/20/2011] [Indexed: 11/29/2022] Open
Abstract
The purinergic P2X7 receptor (P2X7R) plays an important role during the immune response, participating in several events such as cytokine release, apoptosis, and necrosis. The bacterial endotoxin lipopolysaccharide (LPS) is one of the strongest stimuli of the immune response, and it has been shown that P2X7R activation can modulate LPS-induced responses. Moreover, a C-terminal binding site for LPS has been proposed. In order to evaluate if LPS can directly modulate the activity of the P2X7R, we tested several signaling pathways associated with P2X7R activation in HEK293 cells that do not express the TLR-4 receptor. We found that LPS alone was unable to induce any P2X7R-related activity, suggesting that the P2X7R is not directly activated by the endotoxin. On the other hand, preapplication of LPS inhibited ATP-induced currents, intracellular calcium increase, and ethidium bromide uptake and had no effect on ERK activation in HEK293 cells. In splenocytes-derived T-regulatory cells, in which ATP-induced apoptosis is driven by the P2X7R, LPS inhibited ATP-induced apoptosis. Altogether, these results demonstrate that LPS modulates the activity of the P2X7R and suggest that this effect could be of physiological relevance.
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Ortega F, Pérez-Sen R, Delicado EG, Teresa Miras-Portugal M. ERK1/2 activation is involved in the neuroprotective action of P2Y13 and P2X7 receptors against glutamate excitotoxicity in cerebellar granule neurons. Neuropharmacology 2011; 61:1210-21. [PMID: 21798274 DOI: 10.1016/j.neuropharm.2011.07.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 07/05/2011] [Accepted: 07/08/2011] [Indexed: 10/17/2022]
Abstract
Cerebellar granule neurons express several types of nucleotide receptors, with the metabotropic P2Y(13) and the ionotropic P2X7 being the most relevant in this model. In the present study we investigated the role of P2Y(13) and P2X7 nucleotide receptors in ERK1/2 signalling. The nucleotidic agonists 2MeSADP (2-methylthioadenosine-5'-diphosphate) for P2Y(13) and BzATP (2'(3')-O-(4-benzoylbenzoyl)adenosine-5'-triphosphate) for P2X7 receptors were coupled to ERK1/2 activation in granule neurons, being able to increase around two-fold the levels of ERK1/2 phosphorylation. These effects were sensitive to the inhibitory action of the antagonists MRS-2211 and A-438079, specific for P2Y(13) and P2X7 receptors, respectively. Although both receptor subtypes shared the same pattern of transient ERK1/2 phosphorylation, they differed in the intracellular cascades they triggered, being PI3K-dependent for P2Y(13) and calcium/calmodulin kinase II (CaMKII)-dependent for P2X7. These two different ERK-mediated pathways were involved in the neuroprotective effects displayed by both P2Y(13) and P2X7 receptors against apoptosis induced by an excitotoxic concentration of glutamate, in a similar manner to the neurotrophin, BDNF. In addition, P2Y(13) and P2X7 receptor agonists were also able to phosphorylate and activate the ERK-dependent target CREB, which could be involved in their neuroprotective effect. These results indicate that nucleotide receptors share with trophic factors the same survival routes in neurons, such as the ERK signalling route, and therefore, can contribute to the maintenance of granule neurons in conditions in which survival is being compromised.
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Affiliation(s)
- Felipe Ortega
- Department of Biochemistry, Veterinary Faculty, Complutense University of Madrid, 28040 Madrid, Spain.
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Novak I. Purinergic signalling in epithelial ion transport: regulation of secretion and absorption. Acta Physiol (Oxf) 2011; 202:501-22. [PMID: 21073662 DOI: 10.1111/j.1748-1716.2010.02225.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intracellular ATP, the energy source for many reactions, is crucial for the activity of plasma membrane pumps and, thus, for the maintenance of transmembrane ion gradients. Nevertheless, ATP and other nucleotides/nucleosides are also extracellular molecules that regulate diverse cellular functions, including ion transport. In this review, I will first introduce the main components of the extracellular ATP signalling, which have become known as the purinergic signalling system. With more than 50 components or processes, just at cell membranes, it ranks as one of the most versatile signalling systems. This multitude of system components may enable differentiated regulation of diverse epithelial functions. As epithelia probably face the widest variety of potential ATP-releasing stimuli, a special attention will be given to stimuli and mechanisms of ATP release with a focus on exocytosis. Subsequently, I will consider membrane transport of major ions (Cl(-) , HCO(3)(-) , K(+) and Na(+) ) and integrate possible regulatory functions of P2Y2, P2Y4, P2Y6, P2Y11, P2X4, P2X7 and adenosine receptors in some selected epithelia at the cellular level. Some purinergic receptors have noteworthy roles. For example, many studies to date indicate that the P2Y2 receptor is one common denominator in regulating ion channels on both the luminal and basolateral membranes of both secretory and absorptive epithelia. In exocrine glands though, P2X4 and P2X7 receptors act as cation channels and, possibly, as co-regulators of secretion. On an organ level, both receptor types can exert physiological functions and together with other partners in the purinergic signalling, integrated models for epithelial secretion and absorption are emerging.
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Affiliation(s)
- I Novak
- Department of Biology, August Krogh Building, University of Copenhagen, Denmark.
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Tafani M, Schito L, Pellegrini L, Villanova L, Marfe G, Anwar T, Rosa R, Indelicato M, Fini M, Pucci B, Russo MA. Hypoxia-increased RAGE and P2X7R expression regulates tumor cell invasion through phosphorylation of Erk1/2 and Akt and nuclear translocation of NF-{kappa}B. Carcinogenesis 2011; 32:1167-75. [PMID: 21642357 DOI: 10.1093/carcin/bgr101] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The role of hypoxia in regulating tumor progression is still controversial. Here, we demonstrate that, similarly to what previously observed by us in human prostate and breast tumor samples, hypoxia increases expression of the receptor for advanced glycation end products (RAGE) and the purinergic receptor P2X7 (P2X7R). The role of hypoxia was shown by the fact that hypoxia-inducible factor (HIF)-1α silencing downregulated RAGE and P2X7R protein levels as well as nuclear factor-kappaB (NF-κB) expression. In contrast, NF-κB silencing reduced P2X7R expression without affecting RAGE protein levels or nuclear accumulation of HIF-1α. Treatment of hypoxic tumor cells with HMGB1 and BzATP ligands, respectively, of RAGE and P2X7R, activated a signaling pathway that, through Akt and Erk phosphorylation, determines nuclear accumulation of NF-κB and increases cell invasion. Inhibition of Akt by SH5 and Erk by INH1 prevented both nuclear translocation of NF-κB and cell invasion. Moreover, silencing RAGE and P2X7R abolished nuclear accumulation of NF-κB as well as cell invasion without affecting HIF-1α stabilization. Once in the nucleus, NF-κB would contribute to cell survival and invasion under hypoxia, by maintaining RAGE and P2X7R expression levels and matrix metalloproteinases 2 and 9 synthesis. These results show that, hypoxia can upregulate expression levels of membrane receptors that, by binding extracellular molecules eventually released by necrotic cells, contribute to the increased invasiveness of transformed tumor cells. Moreover, these observations strengthen our working hypothesis that upregulation of damage-associated molecular patterns receptors by HIF-1α represents the crucial event bridging hypoxia and inflammation in obtaining the malignant phenotype.
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Affiliation(s)
- Marco Tafani
- Department of Experimental Medicine, Sapienza University, Rome, Italy.
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Chang MY, Lu JK, Tian YC, Chen YC, Hung CC, Huang YH, Chen YH, Wu MS, Yang CW, Cheng YC. Inhibition of the P2X7 receptor reduces cystogenesis in PKD. J Am Soc Nephrol 2011; 22:1696-706. [PMID: 21636640 DOI: 10.1681/asn.2010070728] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The P2X7 receptor participates in purinergic signaling, which may promote the progression of ADPKD. We examined the effects of a P2X7 receptor antagonist and a P2X7 receptor agonist on cyst development in a zebrafish model of polycystic kidney disease in which we knocked down pkd2 by morpholinos. We used live wt-1b pronephric-specific GFP-expressing zebrafish embryos to directly observe changes in the pronephros. Exposure of pkd2-morphant zebrafish to a P2X7 receptor antagonist (oxidized ATP [OxATP]) significantly reduced the frequency of the cystic phenotype compared with either exposure to a P2X7 receptor agonist (BzATP) or with no treatment (P < 0.01). Histology confirmed improvement of glomerular cysts in OxATP-treated pkd2 morphants. OxATP also reduced p-ERK activity and cell proliferation in pronephric kidneys in pkd2 morphants. Inhibition of P2X7 with an additional specific antagonist (A-438079), and through morpholino-mediated knockdown of p2rx7, confirmed these effects. In conclusion, blockade of the P2X7 receptor reduces cyst formation via ERK-dependent pathways in a zebrafish model of polycystic kidney disease, suggesting that P2X7 antagonists may have therapeutic potential in ADPKD.
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Affiliation(s)
- Ming-Yang Chang
- Kidney Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
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Targeting P2X₇ receptor inhibits the metastasis of murine P388D1 lymphoid neoplasm cells to lymph nodes. Cell Biol Int 2011; 34:1205-11. [PMID: 20722629 DOI: 10.1042/cbi20090428] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The P2X₇R (P2X₇ receptor) is an ATP-gated cation channel expressed in normal cells that participates in both cell proliferation and apoptosis. Here, we have confirmed P2X₇R expression on murine P388D1 lymphoid neoplasm cells. In addition, ATP-stimulated P2X₇R expression was found to trigger increased intracellular calcium flux. Furthermore, silencing with short hairpin RNA and blocking with P2X₇R antibody significantly reduced the metastasis of P388D1 cells to lymph nodes. These results indicate that inhibition of the expression and function of P2X₇R attenuates the metastatic ability of murine lymphoid neoplasm cell line P388D1, which represents a new potential target for anti-metastatic therapy.
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C terminus of the P2X7 receptor: treasure hunting. Purinergic Signal 2011; 7:7-19. [PMID: 21484094 DOI: 10.1007/s11302-011-9215-1] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 01/05/2011] [Indexed: 12/21/2022] Open
Abstract
P2X receptor (P2XR) is a family of the ATP-gated ion channel family and can permeabilize the plasma membrane to small cations such as potassium, sodium, and calcium, resulting in cellular depolarization. There are seven P2XR that have been described and cloned, with 45% identity in amino acid sequence. Each P2X receptors has two transmembrane domains that are separated by an extracellular loop and an intracellular N and C terminus. Unlike the other P2X receptors, the P2X7R has a larger C terminus with an extra 200 amino acid residues compared with the other receptors. The C terminus of the P2X7R has been implicated in regulating receptor function including signaling pathway activation, cellular localization, protein-protein interactions, and post-translational modification (PTM). In the present review, we discuss the role of the P2X7R C terminus in regards to receptor function, describe the specific domains and motifs found therein and compare the C terminus sequence with others proteins to discover predicted domains or sites of PTM.
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Ivison SM, Himmel ME, Mayer M, Yao Y, Kifayet A, Levings MK, Steiner TS. The stress signal extracellular ATP modulates antiflagellin immune responses in intestinal epithelial cells. Inflamm Bowel Dis 2011; 17:319-33. [PMID: 20722064 DOI: 10.1002/ibd.21428] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 06/17/2010] [Indexed: 12/11/2022]
Abstract
BACKGROUND Although intestinal epithelial cells (IECs) are continually exposed to commensal microbes, under healthy conditions they contribute to intestinal homeostasis while keeping inflammatory responses in check. In response to invading pathogens, however, IECs respond vigorously by producing inflammatory mediators. To better understand the signals that regulate the inflammatory responses of IECs, we investigated whether the danger signal ATP (which is released from injured cells) could alter responses to bacterial products. METHODS We measured chemokine production from Caco-2 cells stimulated with the Toll-like receptor 5 agonist flagellin with or without ATP. ATP increased flagellin-induced IL-8 secretion but reduced CCL20 secretion via distinct signaling pathways. RESULTS ATP-enhanced IL-8 production was only partly blocked by the P(2) receptor antagonist suramin and required activation of NF-κB while ATP-mediated reduction of CCL20 was completely blocked by suramin and required activation of ERK1/2. The effects of ATP on both chemokines required extracellular calcium but not phospholipase C, implicating P(2) X receptor involvement. To investigate how ATP alters IEC responses to bacterial products in vivo, mice receiving dextran sodium sulfate were given intrarectal flagellin with or without ATP. Addition of ATP to flagellin caused greater weight loss and increased antiflagellin antibody titers, as well as decreased colonic interferon gamma (IFN-γ) and higher antiflagellin IgG1/IgG2 ratios, which indicate decreased Th1 polarization. CONCLUSIONS Together, these data indicate that stress, in the form of extracellular ATP, reshapes both the inflammatory response of flagellin-stimulated IECs and downstream adaptive immunity, representing a possible strategy by which these cells differentiate between commensal and pathogenic bacteria.
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Affiliation(s)
- Sabine M Ivison
- Division of Infectious Diseases, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
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Taylor JM, Han Z. Purinergic receptor functionality is necessary for infection of human hepatocytes by hepatitis delta virus and hepatitis B virus. PLoS One 2010; 5:e15784. [PMID: 21187936 PMCID: PMC3004961 DOI: 10.1371/journal.pone.0015784] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 11/22/2010] [Indexed: 12/18/2022] Open
Abstract
Hepatitis B virus (HBV) and hepatitis delta virus (HDV) are major sources of acute and chronic hepatitis. HDV requires the envelope proteins of HBV for the processes of assembly and infection of new cells. Both viruses are able to infect hepatocytes though previous studies have failed to determine the mechanism of entry into such cells. This study began with evidence that suramin, a symmetrical hexasulfated napthylurea, could block HDV entry into primary human hepatocytes (PHH) and was then extrapolated to incorporate findings of others that suramin is one of many compounds that can block activation of purinergic receptors. Thus other inhibitors, pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonate (PPADS) and brilliant blue G (BBG), both structurally unrelated to suramin, were tested and found to inhibit HDV and HBV infections of PHH. BBG, unlike suramin and PPADS, is known to be more specific for just one purinergic receptor, P2X7. These studies provide the first evidence that purinergic receptor functionality is necessary for virus entry. Furthermore, since P2X7 activation is known to be a major component of inflammatory responses, it is proposed that HDV and HBV attachment to susceptible cells, might also contribute to inflammation in the liver, that is, hepatitis.
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Affiliation(s)
- John M Taylor
- Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America.
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Chong JH, Zheng GG, Ma YY, Zhang HY, Nie K, Lin YM, Wu KF. The hyposensitive N187D P2X7 mutant promotes malignant progression in nude mice. J Biol Chem 2010; 285:36179-87. [PMID: 20837475 DOI: 10.1074/jbc.m110.128488] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Nucleotides are new players in the intercellular communication network. P2X7 is a member of the P2X family of receptors, which are ATP-gated plasma membrane ion channels with diverse biological functions. Abnormal expression and dysfunction of P2X7 have been reported in leukemias. Here, we report a new P2X7 mutant (an A(559)-to-G substitution causing N187D P2X7) cloned from J6-1 leukemia cells. The characteristics of N187D P2X7 were studied by establishing stably transfected K562 cell lines. Our results show that N187D P2X7 required a higher concentration of agonist for its activation, leading to Ca(2+) influx (EC(50) = 293.3 ± 6.6 μm for the mutant and 93.6 ± 2.2 μm for wild-type P2X7) and ERK phosphorylation, which were not caused by differential cell-surface expression or related to high ATPase activity on the cell surface and in the extracellular space. K562 cells expressing this N187D mutant showed a proliferative advantage and reduced pro-apoptosis effects in vitro and in vivo. Furthermore, elevated angiogenesis and CD206-positive macrophage infiltration were found in tumor tissues formed by K562-M cells. In addition, higher expression of VEGF and MCP1 could be detected in tumor tissues formed by K562-M cells. Our results suggest that N187D P2X7, representing mutants hyposensitive to agonist, might be a positive regulator in the progression of hematopoietic malignancies.
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Affiliation(s)
- Jing-Hui Chong
- State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 288 Nanjing Road, Tianjin 300020, China
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