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Augusto-Oliveira M, Tremblay MÈ, Verkhratsky A. Receptors on Microglia. ADVANCES IN NEUROBIOLOGY 2024; 37:83-121. [PMID: 39207688 DOI: 10.1007/978-3-031-55529-9_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Microglial cells are the most receptive cells in the central nervous system (CNS), expressing several classes of receptors reflecting their immune heritage and newly acquired neural specialisation. Microglia possess, depending on the particular context, receptors to neurotransmitters and neuromodulators as well as immunocompetent receptors. This rich complement allows microglial cells to monitor the functional status of the nervous system, contribute actively to the regulation of neural activity and plasticity and homeostasis, and guard against pathogens as well as other challenges to the CNS's integrity and function.
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Affiliation(s)
- Marcus Augusto-Oliveira
- Laboratório de Farmacologia Molecular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
- Programa de Pós-Graduação em Farmacologia e Bioquímica, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Marie-Ève Tremblay
- Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, Canada
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec City, QC, Canada
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada
- Department of Molecular Medicine, Université Laval, Pavillon Ferdinand-Vandry, Québec City, QC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Life Sciences Center, Vancouver, BC, Canada
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, UK.
- Department of Neurosciences, University of the Basque Country, Leioa, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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Taher MG, Mohammed MR, Al-Mahdawi MAS, Halaf NKA, Jalil AT, Alsandook T. The role of protein kinases in diabetic neuropathic pain: an update review. J Diabetes Metab Disord 2023; 22:147-154. [PMID: 37255803 PMCID: PMC10225446 DOI: 10.1007/s40200-023-01217-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/23/2023] [Indexed: 06/01/2023]
Abstract
Objectives Diabetic neuropathic pain (DNP) is a debilitating symptom of diabetic neuropathy which seriously impairs patient's quality of life. Currently, there is no specific therapy for DNP except for duloxetine and gabapentin that show limited utility in alleviating DNP. The present review aims to discuss the central role of protein kinases in the pathogenesis of DNP and their therapeutic modulation. Methods Scopus, PubMed, and Google scholar were searched up to January 2022 to find relevant studies with English language in which the roles of proteins kinases in DNP were examined. Results DNP is associated with hyperactivity in pain sensory neurons and therapies aim to specifically suppress redundant discharges in these neurons without affecting the activity of other sensory and motor neurons. Transient receptor potential vanilloid 1 (TRPV1) and purinergic 2 × 7 receptors (P2 × 7R) are two receptor channels, highly expressed in pain sensory neurons and their blockade produces remarkable analgesic effects in DNP. The activities of receptor channels are mainly regulated by the protein kinases whose modulation provides remarkable analgesic effects in DNP models. Conclusion Capsaicin, TRPV1 modulator, is the only agent successfully examined in clinical trials with promising effects in patients with DNP. Current data suggest that blocking calcium calmodulin dependent protein kinase II (CaMKII) is superior to other approaches, considering its pivotal role in regulating the pain neuron potentials. By this means, DNP alleviation is achievable without affecting the activity of other sensory or motor neurons.
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Affiliation(s)
- Mustafa Gheni Taher
- Department of Pathology and Forensic Medicine, College of Medicine, University of Diyala, Baquba, Diyala Iraq
| | | | | | | | - Abduladheem Turki Jalil
- Department of Medical Laboratories Techniques, Al-Mustaqbal University College, Hilla, Babylon, Iraq
| | - Tahani Alsandook
- Department of Dentistry, Al-Turath University College, Baghdad, Iraq
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袁 巧, 谢 丽, 陈 朝. [Astragalus polysaccharide protects against blood-brain barrier damage in MCAO rats by inhibiting P2X7R channel]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2022; 42:1705-1711. [PMID: 36504064 PMCID: PMC9742771 DOI: 10.12122/j.issn.1673-4254.2022.11.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To investigate the protective effect of astragalus polysaccharide (APS) against blood-brain barrier in a rat model of middle cerebral artery occlusion (MCAO) and the role of P2X7R channel in the protective mechanism. METHODS In rat microglial cell models of oxygen and glucose deprivation (OGD) or ATP treatment, the formation of blood-brain barrier in vitro was assessed using the leak test, and the effect of APS on the permeability of the blood-brain barrier was determined using LC-MS. In 12 SD rats, MCAO model was established followed by treatment with intraperitoneal injection of normal saline (n= 6) or APS (45 mg/kg, n=6) for 3 consecutive days, with another 6 rats without MCAO receiving saline injections as the control group. The permeability of the blood-brain barrier of the rats was evaluated by determining Evans blue (EB) extravasation, and ATP content in the brain tissue was detected using ELISA; the expression levels of matrix metalloproteinase-9 (MMP-9) and P2X7R in the brain tissue were detected with Western blot. RESULTS In the in vitro cell model of OGD or ATP treatment, APS treatment obviously promoted the repair of blood-brain barrier integrity. In the rat models, the EB content in the brain tissue and the blood-brain barrier permeability increased significantly in MCAO+saline group and MCAO+APS group as compared with those in the control group (P < 0.01). Compared with saline treatment, APS treatment significantly decreased EB content in the brain tissue and improved the blood-brain barrier permeability in the MCAO rats (P < 0.05). MCAO caused a significant reduction of ATP content and obviously increased the expression levels of MMP-9 and P2X7R in the brain tissue of the rats (P < 0.01), and these changes were significantly alleviated after APS treatment (P < 0.01 or 0.05). CONCLUSION APS can protect the brain tissue of MCAO rats by stabilizing the internal environment, down-regulating the expression of MMP-9 and improving the permeability of blood-brain barrier under cerebral ischemia and hypoxia, and its mechanism may involve the inhibition of P2X7R channel.
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Affiliation(s)
- 巧 袁
- 广州中医药大学,广东 广州 510800Guangzhou University of Chinese Medicine, Guangzhou 510800, China
| | - 丽英 谢
- 广州中医药大学附属广州中西医结合医院脑病科,广东 广州 510800Department of Encephalopathy, Guangzhou Hospital of Integrated Traditional Chinese and Western Medicine, Guangzhou 510800, China
| | - 朝俊 陈
- 广州中医药大学附属广州中西医结合医院脑病科,广东 广州 510800Department of Encephalopathy, Guangzhou Hospital of Integrated Traditional Chinese and Western Medicine, Guangzhou 510800, China
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Wang A, Shi X, Yu R, Qiao B, Yang R, Xu C. The P2X 7 Receptor Is Involved in Diabetic Neuropathic Pain Hypersensitivity Mediated by TRPV1 in the Rat Dorsal Root Ganglion. Front Mol Neurosci 2021; 14:663649. [PMID: 34163328 PMCID: PMC8215290 DOI: 10.3389/fnmol.2021.663649] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 05/05/2021] [Indexed: 12/30/2022] Open
Abstract
The purinergic 2X7 (P2X7) receptor expressed in satellite glial cells (SGCs) is involved in the inflammatory response, and transient receptor potential vanilloid 1 (TRPV1) participates in the process of neurogenic inflammation, such as that in diabetic neuropathic pain (DNP) and peripheral neuralgia. The main purpose of this study was to explore the role of the P2X7 receptor in DNP hypersensitivity mediated by TRPV1 in the rat and its possible mechanism. A rat model of type 2 diabetes mellitus-related neuropathic pain (NPP) named the DNP rat model was established in this study. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) of DNP rats were increased after intrathecal injection of the P2X7 receptor antagonist A438079, and the mRNA and protein levels of TRPV1 in the dorsal root ganglion (DRG) were decreased in DNP rats treated with A438079 compared to untreated DNP rats; in addition, A438079 also decreased the phosphorylation of p38 and extracellular signal-regulated kinase 1/2 (ERK1/2) in the DNP group. Based on these results, the P2X7 receptor might be involved in DNP mediated by TRPV1.
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Affiliation(s)
- Anhui Wang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, China
| | - Xiangchao Shi
- Medical Department, Queen Mary School, Nanchang University, Nanchang, China
| | - Ruoyang Yu
- Medical Department, Queen Mary School, Nanchang University, Nanchang, China
| | - Bao Qiao
- Medical Department, Queen Mary School, Nanchang University, Nanchang, China
| | - Runan Yang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, China
| | - Changshui Xu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, China.,Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang, China
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Jiang LH, Caseley EA, Muench SP, Roger S. Structural basis for the functional properties of the P2X7 receptor for extracellular ATP. Purinergic Signal 2021; 17:331-344. [PMID: 33987781 PMCID: PMC8410900 DOI: 10.1007/s11302-021-09790-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/19/2021] [Indexed: 02/06/2023] Open
Abstract
The P2X7 receptor, originally known as the P2Z receptor due to its distinctive functional properties, has a structure characteristic of the ATP-gated ion channel P2X receptor family. The P2X7 receptor is an important mediator of ATP-induced purinergic signalling and is involved the pathogenesis of numerous conditions as well as in the regulation of diverse physiological functions. Functional characterisations, in conjunction with site-directed mutagenesis, molecular modelling, and, recently, structural determination, have provided significant insights into the structure–function relationships of the P2X7 receptor. This review discusses the current understanding of the structural basis for the functional properties of the P2X7 receptor.
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Affiliation(s)
- Lin-Hua Jiang
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
| | - Emily A Caseley
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
- Faculty of Medicine and Health, Leeds Institute of Rheumatic and Musculoskeletal Medicine, St James's University Hospital, Leeds, UK
| | - Steve P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Sébastien Roger
- EA4245, Transplantation, Immunology and Inflammation, Faculty of Medicine, University of Tours, Tours, France
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P2X7 receptor and the NLRP3 inflammasome: Partners in crime. Biochem Pharmacol 2020; 187:114385. [PMID: 33359010 DOI: 10.1016/j.bcp.2020.114385] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 12/13/2022]
Abstract
Adenosine triphosphate (ATP) is a molecule that on one hand plays a central role in cellular energetics and which on the other is a ubiquitous signaling molecule when released into the extracellular media. Extracellular ATP accumulates in inflammatory environments where it acts as a damage-associated molecular pattern and activates the purinergic P2X receptor 7 (P2X7) in immune cells. P2X7 receptor activation induces the formation of the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing 3 (NLRP3) inflammasome and the activation of the inflammatory caspase-1. Caspase-1 causes an inflammatory type of cell death called pyroptosis through the release of pro-inflammatory cytokines and intracellular content. Consequently, intense research efforts have been devoted to the design of novel anti-inflammatory therapies, focusing in particular on the P2X7 receptor and the NLRP3 pathway and the introduction of new blocking molecules in early phase clinical trials.
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Abstract
Cancer metastasis is the second leading cause of death in the United States. Despite its morbidity, metastasis is an inefficient process that few cells can survive. However, cancer cells can overcome these metastatic barriers via cellular responses to microenvironmental cues, such as through mechanotransduction. This review focuses on the mechanosensitive ion channels TRPV4 and P2X7, and their roles in metastasis, as both channels have been shown to significantly affect tumor cell dissemination. Upon activation, these channels help form tumor neovasculature, promote transendothelial migration, and increase cell motility. Conversely, they have also been linked to forms of cancer cell death dependent upon levels of activation, implying the complex functionality of mechanosensitive ion channels. Understanding the roles of TRPV4, P2X7 and other mechanosensitive ion channels in these processes may reveal new possible drug targets that modify channel function to reduce a tumor's metastatic potential.
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Janks L, Sharma CVR, Egan TM. A central role for P2X7 receptors in human microglia. J Neuroinflammation 2018; 15:325. [PMID: 30463629 PMCID: PMC6247771 DOI: 10.1186/s12974-018-1353-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 10/30/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The ATP-gated ionotropic P2X7 receptor (P2X7R) has the unusual ability to function as a small cation channel and a trigger for permeabilization of plasmalemmal membranes. In murine microglia, P2X7R-mediated permeabilization is fundamental to microglial activation, proliferation, and IL-1β release. However, the role of the P2X7R in primary adult human microglia is poorly understood. METHODS We used patch-clamp electrophysiology to record ATP-gated current in cultured primary human microglia; confocal microscopy to measure membrane blebbing; fluorescence microscopy to demonstrate membrane permeabilization, caspase-1 activation, phosphatidylserine translocation, and phagocytosis; and kit-based assays to measure cytokine levels. RESULTS We found that ATP-gated inward currents facilitated with repetitive applications of ATP as expected for current through P2X7Rs and that P2X7R antagonists inhibited these currents. P2X7R antagonists also prevented the ATP-induced uptake of large cationic fluorescent dyes whereas drugs that target pannexin-1 channels had no effect. In contrast, ATP did not induce uptake of anionic dyes. The uptake of cationic dyes was blocked by drugs that target Cl- channels. Finally, we found that ATP activates caspase-1 and inhibits phagocytosis, and these effects are blocked by both P2X7R and Cl- channel antagonists. CONCLUSIONS Our results demonstrate that primary human microglia in culture express functional P2X7Rs that stimulate both ATP-gated cationic currents and uptake of large molecular weight cationic dyes. Importantly, our data demonstrate that hypotheses drawn from work on murine immune cells accurately predict the essential role of P2X7Rs in a number of human innate immune functions such as phagocytosis and caspase-1 activation. Therefore, the P2X7R represents an attractive target for therapeutic intervention in human neuroinflammatory disorders.
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Affiliation(s)
- Laura Janks
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 South Grand Boulevard, St. Louis, MO, 63104, USA
| | | | - Terrance M Egan
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 South Grand Boulevard, St. Louis, MO, 63104, USA.
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Peverini L, Beudez J, Dunning K, Chataigneau T, Grutter T. New Insights Into Permeation of Large Cations Through ATP-Gated P2X Receptors. Front Mol Neurosci 2018; 11:265. [PMID: 30108481 PMCID: PMC6080412 DOI: 10.3389/fnmol.2018.00265] [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: 05/29/2018] [Accepted: 07/13/2018] [Indexed: 11/28/2022] Open
Abstract
The permeability of large cations through the P2X pore has remained arguably the most controversial and complicated topic in P2X-related research, with the emergence of conflicting studies on the existence, mechanism and physiological relevance of a so-called “dilated” state. Due to the important role of several “dilating” P2X subtypes in numerous diseases, a clear and detailed understanding of this phenomenon represents a research priority. Recent advances, however, have challenged the existence of a progressive, ATP-induced pore dilation, by demonstrating that this phenomenon is an artifact of the method employed. Here, we discuss briefly the history of this controversial and enigmatic dilated state, from its initial discovery to its recent reconsideration. We will discuss the literature in which mechanistic pathways to a large cation-permeable state are proposed, as well as important advances in the methodology employed to study this elusive state. Considering recent literature, we will also open the discussion as to whether an intrinsically dilating P2X pore exists, as well as the physiological relevance of such a large cation-permeable pore and its potential use as therapeutic pathway.
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Affiliation(s)
- Laurie Peverini
- CNRS, CAMB UMR 7199, Équipe de Chimie et Neurobiologie Moléculaire, Université de Strasbourg, Strasbourg, France
| | - Juline Beudez
- CNRS, CAMB UMR 7199, Équipe de Chimie et Neurobiologie Moléculaire, Université de Strasbourg, Strasbourg, France
| | - Kate Dunning
- CNRS, CAMB UMR 7199, Équipe de Chimie et Neurobiologie Moléculaire, Université de Strasbourg, Strasbourg, France
| | - Thierry Chataigneau
- CNRS, CAMB UMR 7199, Équipe de Chimie et Neurobiologie Moléculaire, Université de Strasbourg, Strasbourg, France
| | - Thomas Grutter
- CNRS, CAMB UMR 7199, Équipe de Chimie et Neurobiologie Moléculaire, Université de Strasbourg, Strasbourg, France
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Wei L, Syed Mortadza SA, Yan J, Zhang L, Wang L, Yin Y, Li C, Chalon S, Emond P, Belzung C, Li D, Lu C, Roger S, Jiang LH. ATP-activated P2X7 receptor in the pathophysiology of mood disorders and as an emerging target for the development of novel antidepressant therapeutics. Neurosci Biobehav Rev 2018; 87:192-205. [PMID: 29453990 DOI: 10.1016/j.neubiorev.2018.02.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 02/01/2018] [Accepted: 02/08/2018] [Indexed: 12/11/2022]
Abstract
Mood disorders are a group of psychiatric conditions that represent leading global disease burdens. Increasing evidence from clinical and preclinical studies supports that innate immune system dysfunction plays an important part in the pathophysiology of mood disorders. P2X7 receptor, belonging to the ligand-gated ion channel P2X subfamily of purinergic P2 receptors for extracellular ATP, is highly expressed in immune cells including microglia in the central nervous system (CNS) and has a vital role in mediating innate immune response. The P2X7 receptor is also important in neuron-glia signalling in the CNS. The gene encoding human P2X7 receptor is located in a locus of susceptibility to mood disorders. In this review, we will discuss the recent progress in understanding the role of the P2X7 receptor in the pathogenesis and development of mood disorders and in discovering CNS-penetrable P2X7 antagonists for potential uses in in vivo imaging to monitor brain inflammation and antidepressant therapeutics.
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Affiliation(s)
- Linyu Wei
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China; School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, United Kingdom
| | - Sharifah A Syed Mortadza
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, United Kingdom; Faculty of Medicine and Health Science, University Putra Malaysia, Selangor, Malaysia
| | - Jing Yan
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China
| | - Libin Zhang
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China
| | - Lu Wang
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China
| | - Yaling Yin
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China
| | - Chaokun Li
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China
| | - Sylvie Chalon
- Inserm UMR 1253, iBrain, Université de Tours, Tours, France
| | - Patrick Emond
- Inserm UMR 1253, iBrain, Université de Tours, Tours, France; CHRU de Tours, Service de Médecine Nucléaire In Vitro, Tours, France
| | | | - Dongliang Li
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China; Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, China
| | - Chengbiao Lu
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China; Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, China
| | - Sebastien Roger
- Inserm UMR1069, Nutrition, Croissance et Cancer, Université de Tours, France; Institut Universitaire de France, Paris Cedex 05, France
| | - Lin-Hua Jiang
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, China; School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, United Kingdom; Institut Universitaire de France, Paris Cedex 05, France.
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Liu CL, Deng ZY, Du ER, Xu CS. Long non‑coding RNA BC168687 small interfering RNA reduces high glucose and high free fatty acid‑induced expression of P2X7 receptors in satellite glial cells. Mol Med Rep 2018; 17:5851-5859. [PMID: 29436679 PMCID: PMC5866030 DOI: 10.3892/mmr.2018.8601] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/12/2017] [Indexed: 12/19/2022] Open
Abstract
Purinergic signaling contributes to inflammatory and immune responses. The activation of the P2X purinoceptor 7 (P2X7) in satellite glial cells (SGCs) may be an essential component in the promotion of inflammation and neuropathic pain. Long non-coding RNAs (lncRNAs) are involved in multiple physiological and pathological processes. The aim of the present study was to investigate the effects of a small interfering RNA for the lncRNA BC168687 on SGC P2X7 expression in a high glucose and high free fatty acids (HGHF) environment. It was demonstrated that BC168687 small interfering (si)RNA downregulated the co-expression of the P2X7 and glial fibrillary acidic protein and P2X7 mRNA expression. Additionally, HGHF may activate the mitogen-activated protein kinase signaling pathway by increasing the release of nitric oxide and reactive oxygen species in SGCs. Taken together, these results indicate that silencing BC168687 expression may downregulate the increased expression of P2X7 receptors in SGCs induced by a HGHF environment.
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Affiliation(s)
- Cheng-Long Liu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Ze-Yu Deng
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Er-Rong Du
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Chang-Shui Xu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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Deciphering the regulation of P2X4 receptor channel gating by ivermectin using Markov models. PLoS Comput Biol 2017; 13:e1005643. [PMID: 28708827 PMCID: PMC5533465 DOI: 10.1371/journal.pcbi.1005643] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 07/28/2017] [Accepted: 06/22/2017] [Indexed: 12/02/2022] Open
Abstract
The P2X4 receptor (P2X4R) is a member of a family of purinergic channels activated by extracellular ATP through three orthosteric binding sites and allosterically regulated by ivermectin (IVM), a broad-spectrum antiparasitic agent. Treatment with IVM increases the efficacy of ATP to activate P2X4R, slows both receptor desensitization during sustained ATP application and receptor deactivation after ATP washout, and makes the receptor pore permeable to NMDG+, a large organic cation. Previously, we developed a Markov model based on the presence of one IVM binding site, which described some effects of IVM on rat P2X4R. Here we present two novel models, both with three IVM binding sites. The simpler one-layer model can reproduce many of the observed time series of evoked currents, but does not capture well the short time scales of activation, desensitization, and deactivation. A more complex two-layer model can reproduce the transient changes in desensitization observed upon IVM application, the significant increase in ATP-induced current amplitudes at low IVM concentrations, and the modest increase in the unitary conductance. In addition, the two-layer model suggests that this receptor can exist in a deeply inactivated state, not responsive to ATP, and that its desensitization rate can be altered by each of the three IVM binding sites. In summary, this study provides a detailed analysis of P2X4R kinetics and elucidates the orthosteric and allosteric mechanisms regulating its channel gating. Ligand-gated ion channels play a crucial role in controlling many physiological and pathophysiological processes. Deciphering the gating kinetics of these channels is thus fundamental to understanding how these processes work. ATP-gated purinergic P2X receptors (P2XRs) are prototypic examples of such channels. They are ubiquitously expressed and play roles in numerous cellular processes, including neurotransmission, inflammation, and chronic pain. Seven P2X subunits, named P2X1 through P2X7, and several splice forms of these subunits have been identified in mammal. The receptors are organized as homo- or heterotrimers, each possessing three ATP-binding sites that, when occupied, lead to receptor activation and channel opening. The P2XRs are non-selective cation channels and the gating properties differ between the various receptors. Previously, we have used biophysical and mathematical modeling approaches to decipher the kinetics of homomeric P2X2aR, P2X2bR, P2X4R, and P2X7R. Here we extended our work on P2X4R gating. We developed two mathematical models that could capture the various patterns of ionic currents recorded experimentally and explain the particularly complex kinetics of the receptor during orthosteric activation and allosteric modulation. This was achieved by designing a computationally efficient, inference-based fitting algorithm that allowed for parameter optimization and model comparisons.
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Jiang LH, Mousawi F, Yang X, Roger S. ATP-induced Ca 2+-signalling mechanisms in the regulation of mesenchymal stem cell migration. Cell Mol Life Sci 2017; 74:3697-3710. [PMID: 28534085 PMCID: PMC5597679 DOI: 10.1007/s00018-017-2545-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/03/2017] [Accepted: 05/18/2017] [Indexed: 12/13/2022]
Abstract
The ability of cells to migrate to the destined tissues or lesions is crucial for physiological processes from tissue morphogenesis, homeostasis and immune responses, and also for stem cell-based regenerative medicines. Cytosolic Ca2+ is a primary second messenger in the control and regulation of a wide range of cell functions including cell migration. Extracellular ATP, together with the cognate receptors on the cell surface, ligand-gated ion channel P2X receptors and a subset of G-protein-coupled P2Y receptors, represents common autocrine and/or paracrine Ca2+ signalling mechanisms. The P2X receptor ion channels mediate extracellular Ca2+ influx, whereas stimulation of the P2Y receptors triggers intracellular Ca2+ release from the endoplasmic reticulum (ER), and activation of both type of receptors thus can elevate the cytosolic Ca2+ concentration ([Ca2+]c), albeit with different kinetics and capacity. Reduction in the ER Ca2+ level following the P2Y receptor activation can further induce store-operated Ca2+ entry as a distinct Ca2+ influx pathway that contributes in ATP-induced increase in the [Ca2+]c. Mesenchymal stem cells (MSC) are a group of multipotent stem cells that grow from adult tissues and hold promising applications in tissue engineering and cell-based therapies treating a great and diverse number of diseases. There is increasing evidence to show constitutive or evoked ATP release from stem cells themselves or mature cells in the close vicinity. In this review, we discuss the mechanisms for ATP release and clearance, the receptors and ion channels participating in ATP-induced Ca2+ signalling and the roles of such signalling mechanisms in mediating ATP-induced regulation of MSC migration.
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Affiliation(s)
- Lin-Hua Jiang
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. .,Sino-UK Joint Laboratory of Brain Function and Injury, Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, 453003, Henan, People's Republic of China. .,Inserm UMR1069, Nutrition, Croissance et Cancer, Université François-Rabelais de Tours, 37032, Tours, France.
| | - Fatema Mousawi
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Xuebin Yang
- Department of Oral Biology, University of Leeds, WTBB, St James University Hospital, Leeds, LS97TF, UK
| | - Sėbastien Roger
- Inserm UMR1069, Nutrition, Croissance et Cancer, Université François-Rabelais de Tours, 37032, Tours, France
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14
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On the permeation of large organic cations through the pore of ATP-gated P2X receptors. Proc Natl Acad Sci U S A 2017; 114:E3786-E3795. [PMID: 28442564 DOI: 10.1073/pnas.1701379114] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Pore dilation is thought to be a hallmark of purinergic P2X receptors. The most commonly held view of this unusual process posits that under prolonged ATP exposure the ion pore expands in a striking manner from an initial small-cation conductive state to a dilated state, which allows the passage of larger synthetic cations, such as N-methyl-d-glucamine (NMDG+). However, this mechanism is controversial, and the identity of the natural large permeating cations remains elusive. Here, we provide evidence that, contrary to the time-dependent pore dilation model, ATP binding opens an NMDG+-permeable channel within milliseconds, with a conductance that remains stable over time. We show that the time course of NMDG+ permeability superimposes that of Na+ and demonstrate that the molecular motions leading to the permeation of NMDG+ are very similar to those that drive Na+ flow. We found, however, that NMDG+ "percolates" 10 times slower than Na+ in the open state, likely due to a conformational and orientational selection of permeating molecules. We further uncover that several P2X receptors, including those able to desensitize, are permeable not only to NMDG+ but also to spermidine, a large natural cation involved in ion channel modulation, revealing a previously unrecognized P2X-mediated signaling. Altogether, our data do not support a time-dependent dilation of the pore on its own but rather reveal that the open pore of P2X receptors is wide enough to allow the permeation of large organic cations, including natural ones. This permeation mechanism has considerable physiological significance.
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15
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Abstract
P2X7, a ligand-gated purinergic ion channel, has been at the center of intense efforts in the pharmaceutical industry in the last 15 years due to the growing appreciation of its role in inflammation. Since 2008-2009, increased focus on CNS available compounds has led to the publication of various patents on behalf of several pharmaceutical companies. This patent review aims at analyzing the recent patent literature (2008-2016) with a particular emphasis on those patents that are thought to deal with CNS penetrant compounds on the basis of their physicochemical features, the assays described in the patents and the uses these compounds are claimed for.
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16
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Pupovac A, Sluyter R. Roles of extracellular nucleotides and P2 receptors in ectodomain shedding. Cell Mol Life Sci 2016; 73:4159-4173. [PMID: 27180276 PMCID: PMC11108277 DOI: 10.1007/s00018-016-2274-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 05/10/2016] [Indexed: 02/03/2023]
Abstract
Ectodomain shedding of integral membrane receptors results in the release of soluble molecules and modification of the transmembrane portions to mediate or modulate extracellular and intracellular signalling. Ectodomain shedding is stimulated by a variety of mechanisms, including the activation of P2 receptors by extracellular nucleotides. This review describes in detail the roles of extracellular nucleotides and P2 receptors in the shedding of various cell surface molecules, including amyloid precursor protein, CD23, CD62L, and members of the epidermal growth factor, immunoglobulin and tumour necrosis factor families. This review discusses the mechanisms involved in P2 receptor-mediated shedding, demonstrating central roles for the P2 receptors, P2X7 and P2Y2, and the sheddases, ADAM10 and ADAM17, in this process in a number of cell types.
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Affiliation(s)
- Aleta Pupovac
- 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
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, 3800, Australia
| | - 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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17
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Caseley EA, Muench SP, Fishwick CW, Jiang LH. Structure-based identification and characterisation of structurally novel human P2X7 receptor antagonists. Biochem Pharmacol 2016; 116:130-9. [PMID: 27481062 PMCID: PMC5012888 DOI: 10.1016/j.bcp.2016.07.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 07/28/2016] [Indexed: 12/13/2022]
Abstract
The P2X7 receptor (P2X7R) plays an important role in diverse conditions associated with tissue damage and inflammation, meaning that the human P2X7R (hP2X7R) is an attractive therapeutic target. The crystal structures of the zebrafish P2X4R in the closed and ATP-bound open states provide an unprecedented opportunity for structure-guided identification of new ligands. The present study performed virtual screening of ∼100,000 structurally diverse compounds against the ATP-binding pocket in the hP2X7R. This identified three compounds (C23, C40 and C60) out of 73 top-ranked compounds by testing against hP2X7R-mediated Ca(2+) responses. These compounds were further characterised using Ca(2+) imaging, patch-clamp current recording, YO-PRO-1 uptake and propidium iodide cell death assays. All three compounds inhibited BzATP-induced Ca(2+) responses concentration-dependently with IC50s of 5.1±0.3μM, 4.8±0.8μM and 3.2±0.2μM, respectively. C23 and C40 inhibited BzATP-induced currents in a reversible and concentration-dependent manner, with IC50s of 0.35±0.3μM and 1.2±0.1μM, respectively, but surprisingly C60 did not affect BzATP-induced currents up to 100μM. They suppressed BzATP-induced YO-PRO-1 uptake with IC50s of 1.8±0.9μM, 1.0±0.1μM and 0.8±0.2μM, respectively. Furthermore, these three compounds strongly protected against ATP-induced cell death. Among them, C40 and C60 exhibited strong specificity towards the hP2X7R over the hP2X4R and rP2X3R. In conclusion, our study reports the identification of three novel hP2X7R antagonists with micromolar potency for the first time using a structure-based approach, including the first P2X7R antagonist with preferential inhibition of large pore formation.
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MESH Headings
- Adenosine Triphosphate/analogs & derivatives
- Adenosine Triphosphate/chemistry
- Adenosine Triphosphate/metabolism
- Adenosine Triphosphate/pharmacology
- Amides/chemistry
- Amides/metabolism
- Amides/pharmacology
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/chemistry
- Anti-Inflammatory Agents, Non-Steroidal/metabolism
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Binding Sites
- Calcium Signaling/drug effects
- HEK293 Cells
- Hepatocytes/cytology
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Humans
- Image Processing, Computer-Assisted
- Indoles/chemistry
- Indoles/metabolism
- Indoles/pharmacology
- Ligands
- Microscopy, Fluorescence
- Models, Molecular
- Patch-Clamp Techniques
- Purinergic P2X Receptor Antagonists/chemistry
- Purinergic P2X Receptor Antagonists/metabolism
- Purinergic P2X Receptor Antagonists/pharmacology
- Rats
- Receptors, Purinergic P2X3/chemistry
- Receptors, Purinergic P2X3/genetics
- Receptors, Purinergic P2X3/metabolism
- Receptors, Purinergic P2X4/chemistry
- Receptors, Purinergic P2X4/genetics
- Receptors, Purinergic P2X4/metabolism
- Receptors, Purinergic P2X7/chemistry
- Receptors, Purinergic P2X7/genetics
- Receptors, Purinergic P2X7/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
- Single-Cell Analysis
- Small Molecule Libraries
- Structure-Activity Relationship
- Thiophenes/chemistry
- Thiophenes/metabolism
- Thiophenes/pharmacology
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Affiliation(s)
- Emily A Caseley
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, UK
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, UK
| | | | - Lin-Hua Jiang
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, UK.
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18
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Jiang LH, Hao Y, Mousawi F, Peng H, Yang X. Expression of P2 Purinergic Receptors in Mesenchymal Stem Cells and Their Roles in Extracellular Nucleotide Regulation of Cell Functions. J Cell Physiol 2016; 232:287-297. [PMID: 27403750 DOI: 10.1002/jcp.25484] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 07/11/2016] [Indexed: 12/15/2022]
Abstract
Extracellular ATP and other nucleotides induce autocrine and/or paracrine purinergic signalling via activation of the P2 receptors on the cell surface, which represents one of the most common signalling mechanisms. Mesenchymal stem cells (MSC) are a type of multipotent adult stem cells that have many promising applications in regenerative medicine. There is increasing evidence to show that extracellular nucleotides regulate MSC functions and P2 receptor-mediated purinergic signalling plays an important role in such functional regulation. P2 receptors comprise ligand-gated ion channel P2X receptors and G-protein-coupled P2Y receptors. In this review, we provide an overview of the current understanding with respect to expression of the P2X and P2Y receptors in MSC and their roles in mediating extracellular nucleotide regulation of MSC proliferation, migration and differentiation. J. Cell. Physiol. 232: 287-297, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Lin-Hua Jiang
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom. .,Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China.
| | - Yunjie Hao
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Fatema Mousawi
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Hongsen Peng
- Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China
| | - Xuebin Yang
- Faculty of Medicine and Health, Department of Oral Biology, University of Leeds, Leeds, United Kingdom
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