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Zhang Y, Yin HY, Rubini P, Tang Y, Illes P. A Possible Causal Involvement of Neuroinflammatory, Purinergic P2X7 Receptors in Psychiatric Disorders. Curr Neuropharmacol 2022; 20:2142-2155. [PMID: 35236262 PMCID: PMC9886837 DOI: 10.2174/1570159x20666220302152400] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/29/2022] [Accepted: 02/26/2022] [Indexed: 11/22/2022] Open
Abstract
P2X7 receptors (Rs) are prominent members of the P2XR family, which after binding ATP, open non-selective cationic channels, thereby allowing the transmembrane passage of Na+, Ca2+, and K+. Long-lasting and repetitive stimulation of the receptor by its agonist leads to the formation of large membrane pores permeable for organic cations of up to 900 Da molecular size. These pores are believed to play a role in apoptosis and inflammation. P2X7Rs are located primarily at peripheral macrophages and microglial cells, the resident macrophages of the CNS. The coactivation of toll-like receptors 4 (TLR4) by lipopolysaccharide, a constituent of the cell membrane of gram-negative bacteria, and the P2X7R by ATP leads to the generation and release of the proinflammatory cytokines interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α. Together with the microglial release of chemokines, reactive oxygen and nitrogen species, proteases, and excitotoxic glutamate, these cytokines result in neurodegeneration. P2X7Rs were found not only to amplify various neurodegenerative illnesses, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis, but also to participate in a range of psychiatric diseases, such as major depression, bipolar disorder, schizophrenia, and autism spectrum disorder. Based on the prevention/reversal of neuroinflammation, pharmacological antagonists of P2X7Rs and their genetic deletion in animal experiments counteract these deleterious psychiatric conditions. Hence, brain penetrant P2X7R antagonists are potential therapeutics for psychiatric diseases, although the available evidence still needs to be extended and validated by further clinical data.
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Affiliation(s)
- Ying Zhang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China;,International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Hai-Yan Yin
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Patrizia Rubini
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China;,International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Yong Tang
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China;,International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China;,Address correspondence to these authors at the Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107, Leipzig, Germany; Tel/Fax: (+49)341-9724614, (+49)341-9724609; E-mail: or at Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, 610075, Chengdu, China; Tel/Fax: (+86) 28-87689918, (+86) 28-87683962; E-mail:
| | - Peter Illes
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China;,International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China;,Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04109 Leipzig, Germany,Address correspondence to these authors at the Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107, Leipzig, Germany; Tel/Fax: (+49)341-9724614, (+49)341-9724609; E-mail: or at Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, 610075, Chengdu, China; Tel/Fax: (+86) 28-87689918, (+86) 28-87683962; E-mail:
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2
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Sattler C, Benndorf K. Enlightening activation gating in P2X receptors. Purinergic Signal 2022; 18:177-191. [PMID: 35188598 PMCID: PMC9123132 DOI: 10.1007/s11302-022-09850-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 02/04/2022] [Indexed: 12/20/2022] Open
Abstract
P2X receptors are trimeric nonselective cation channels gated by ATP. They assemble from seven distinct subunit isoforms as either homo- or heteromeric complexes and contain three extracellularly located binding sites for ATP. P2X receptors are expressed in nearly all tissues and are there involved in physiological processes like synaptic transmission, pain, and inflammation. Thus, they are a challenging pharmacological target. The determination of crystal and cryo-EM structures of several isoforms in the last decade in closed, open, and desensitized states has provided a firm basis for interpreting the huge amount of functional and biochemical data. Electrophysiological characterization in conjugation with optical approaches has generated significant insights into structure–function relationships of P2X receptors. This review focuses on novel optical and related approaches to better understand the conformational changes underlying the activation of these receptors.
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Affiliation(s)
- Christian Sattler
- Institut Für Physiologie II, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, 07740, Jena, Germany.
| | - Klaus Benndorf
- Institut Für Physiologie II, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, 07740, Jena, Germany.
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3
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Ren W, Rubini P, Tang Y, Engel T, Illes P. Inherent P2X7 Receptors Regulate Macrophage Functions during Inflammatory Diseases. Int J Mol Sci 2021; 23:ijms23010232. [PMID: 35008658 PMCID: PMC8745241 DOI: 10.3390/ijms23010232] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/21/2021] [Accepted: 12/21/2021] [Indexed: 12/12/2022] Open
Abstract
Macrophages are mononuclear phagocytes which derive either from blood-borne monocytes or reside as resident macrophages in peripheral (Kupffer cells of the liver, marginal zone macrophages of the spleen, alveolar macrophages of the lung) and central tissue (microglia). They occur as M1 (pro-inflammatory; classic) or M2 (anti-inflammatory; alternatively activated) phenotypes. Macrophages possess P2X7 receptors (Rs) which respond to high concentrations of extracellular ATP under pathological conditions by allowing the non-selective fluxes of cations (Na+, Ca2+, K+). Activation of P2X7Rs by still higher concentrations of ATP, especially after repetitive agonist application, leads to the opening of membrane pores permeable to ~900 Da molecules. For this effect an interaction of the P2X7R with a range of other membrane channels (e.g., P2X4R, transient receptor potential A1 [TRPA1], pannexin-1 hemichannel, ANO6 chloride channel) is required. Macrophage-localized P2X7Rs have to be co-activated with the lipopolysaccharide-sensitive toll-like receptor 4 (TLR4) in order to induce the formation of the inflammasome 3 (NLRP3), which then activates the pro-interleukin-1β (pro-IL-1β)-degrading caspase-1 to lead to IL-1β release. Moreover, inflammatory diseases (e.g., rheumatoid arthritis, Crohn’s disease, sepsis, etc.) are generated downstream of the P2X7R-induced upregulation of intracellular second messengers (e.g., phospholipase A2, p38 mitogen-activated kinase, and rho G proteins). In conclusion, P2X7Rs at macrophages appear to be important targets to preserve immune homeostasis with possible therapeutic consequences.
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Affiliation(s)
- Wenjing Ren
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China; (W.R.); (P.R.); (Y.T.)
- School of Acupunct3ure and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Patrizia Rubini
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China; (W.R.); (P.R.); (Y.T.)
- School of Acupunct3ure and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Yong Tang
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China; (W.R.); (P.R.); (Y.T.)
- School of Acupunct3ure and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland;
- FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Peter Illes
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China; (W.R.); (P.R.); (Y.T.)
- School of Acupunct3ure and Tuina, Chengdu University of TCM, Chengdu 610075, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany
- Correspondence:
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4
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Eren-Koçak E, Dalkara T. Ion Channel Dysfunction and Neuroinflammation in Migraine and Depression. Front Pharmacol 2021; 12:777607. [PMID: 34858192 PMCID: PMC8631474 DOI: 10.3389/fphar.2021.777607] [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: 09/15/2021] [Accepted: 10/22/2021] [Indexed: 01/15/2023] Open
Abstract
Migraine and major depression are debilitating disorders with high lifetime prevalence rates. Interestingly these disorders are highly comorbid and show significant heritability, suggesting shared pathophysiological mechanisms. Non-homeostatic function of ion channels and neuroinflammation may be common mechanisms underlying both disorders: The excitation-inhibition balance of microcircuits and their modulation by monoaminergic systems, which depend on the expression and function of membrane located K+, Na+, and Ca+2 channels, have been reported to be disturbed in both depression and migraine. Ion channels and energy supply to synapses not only change excitability of neurons but can also mediate the induction and maintenance of inflammatory signaling implicated in the pathophysiology of both disorders. In this respect, Pannexin-1 and P2X7 large-pore ion channel receptors can induce inflammasome formation that triggers release of pro-inflammatory mediators from the cell. Here, the role of ion channels involved in the regulation of excitation-inhibition balance, synaptic energy homeostasis as well as inflammatory signaling in migraine and depression will be reviewed.
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Affiliation(s)
- Emine Eren-Koçak
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.,Department of Psychiatry, Medical Faculty, Hacettepe University, Ankara, Turkey
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
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5
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Huang Z, Tan S. P2X7 Receptor as a Potential Target for Major Depressive Disorder. Curr Drug Targets 2021; 22:1108-1120. [PMID: 33494675 DOI: 10.2174/1389450122666210120141908] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/04/2020] [Accepted: 11/06/2020] [Indexed: 11/22/2022]
Abstract
Major depressive disorder (MDD) is a common mental disorder. Although the genetic, biochemical, and psychological factors have been related to the development of MDD, it is generally believed that a series of pathological changes in the brain caused by chronic stress is the main cause of MDD. However, the specific mechanisms underlying chronic stress-induced MDD are largely undermined. Recent investigations have found that increased pro-inflammatory cytokines and changes in the inflammatory pathway in the microglia cells in the brain are the potential pathophysiological mechanism of MDD. P2X7 receptor (P2X7R) and its mediated signaling pathway play a key role in microglia activation. The present review aimed to present and discuss the accumulating data on the role of P2X7R in MDD. Firstly, we summarized the research progress in the correlation between P2X7R and MDD. Subsequently, we presented the P2X7R mediated microglia activation in MDD and the role of P2X7R in increased blood-brain barrier (BBB) permeability caused by chronic stress. Lastly, we also discussed the potential mechanism underlying-P2X7R expression changes after chronic stress. In conclusion, P2X7R is a key molecule regulating the activation of microglia. Chronic stress activates microglia in the hippocampus by secreting interleukin- 1β (IL-1β) and other inflammatory cytokines, and increasing the BBB permeability, thus promoting the occurrence and development of MDD, which indicated that P2X7R might be a promising therapeutic target for MDD.
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Affiliation(s)
- Zeyi Huang
- Department of Histology and Embryology, Institute of Clinical Anatomy & Reproductive Medicine, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, 421001, Hunan, China
| | - Sijie Tan
- Department of Histology and Embryology, Institute of Clinical Anatomy & Reproductive Medicine, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, 421001, Hunan, China
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6
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Territo PR, Zarrinmayeh H. P2X 7 Receptors in Neurodegeneration: Potential Therapeutic Applications From Basic to Clinical Approaches. Front Cell Neurosci 2021; 15:617036. [PMID: 33889073 PMCID: PMC8055960 DOI: 10.3389/fncel.2021.617036] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 03/02/2021] [Indexed: 12/27/2022] Open
Abstract
Purinergic receptors play important roles in central nervous system (CNS), where the bulk of these receptors are implicated in neuroinflammatory responses and regulation of cellular function of neurons, microglial and astrocytes. Within the P2X receptor family, P2X7 receptor is generally known for its inactivity in normal conditions and activation by moderately high concentrations (>100 μM) of extracellular adenosine 5′-triphosphate (ATP) released from injured cells as a result of brain injury or pathological conditions. Activation of P2X7R contributes to the activation and proliferation of microglia and directly contribute to neurodegeneration by provoking microglia-mediated neuronal death, glutamate-mediated excitotoxicity, and NLRP3 inflammasome activation that results in initiation, maturity and release of the pro-inflammatory cytokines and generation of reactive oxygen and nitrogen species. These components of the inflammatory response play important roles in many neural pathologies and neurodegeneration disorders. In CNS, expression of P2X7R on microglia, astrocytes, and oligodendrocytes are upregulated under neuroinflammatory conditions. Several in vivo studies have demonstrated beneficial effects of the P2X7 receptor antagonists in animal model systems of neurodegenerative diseases. A number of specific and selective P2X7 receptor antagonists have been developed, but only few of them have shown efficient brain permeability. Finding potent and selective P2X7 receptor inhibitors which are also CNS penetrable and display acceptable pharmacokinetics (PK) has presented challenges for both academic researchers and pharmaceutical companies. In this review, we discuss the role of P2X7 receptor function in neurodegenerative diseases, the pharmacological inhibition of the receptor, and PET radiopharmaceuticals which permit non-invasive monitoring of the P2X7 receptor contribution to neuroinflammation associated with neurodegeneration.
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Affiliation(s)
- Paul R Territo
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Hamideh Zarrinmayeh
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States
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7
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Silberstein S, Liberman AC, Dos Santos Claro PA, Ugo MB, Deussing JM, Arzt E. Stress-Related Brain Neuroinflammation Impact in Depression: Role of the Corticotropin-Releasing Hormone System and P2X7 Receptor. Neuroimmunomodulation 2021; 28:52-60. [PMID: 33845478 DOI: 10.1159/000515130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 02/07/2021] [Indexed: 11/19/2022] Open
Abstract
Depression and other psychiatric stress-related disorders are leading causes of disability worldwide. Up to date, treatments of mood disorders have limited success, most likely due to the multifactorial etiology of these conditions. Alterations in inflammatory processes have been identified as possible pathophysiological mechanisms in psychiatric conditions. Here, we review the main features of 2 systems involved in the control of these inflammatory pathways: the CRH system as a key regulator of the stress response and the ATP-gated ion-channel P2X7 receptor (P2X7R) involved in the control of immune functions. The pathophysiology of depression as a stress-related psychiatric disorder is depicted in terms of the impact of CRH and P2X7R function on inflammatory pathways in the brain. Understanding pathogenesis of affective disorders will lead to the development of therapies for treatment of depression and other stress-related diseases.
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Affiliation(s)
- Susana Silberstein
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Ana Clara Liberman
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Paula Ayelén Dos Santos Claro
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Maria Belén Ugo
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | | | - Eduardo Arzt
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
- DFBMC, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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8
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Heterologous Expression and Patch-Clamp Recording of P2X Receptors in HEK293 Cells. Methods Mol Biol 2020; 2041:261-273. [PMID: 31646495 DOI: 10.1007/978-1-4939-9717-6_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
P2X receptors (P2XRs) are ligand-gated ion channels gated by extracellular adenosine 5'-triphosphate (ATP) and play a critical role in mediating ATP-induced purinergic signaling in physiological and pathological processes. Heterologous expression of P2XR in human embryonic kidney 293 (HEK293) cells and measurement of P2XR-mediated currents using patch-clamp recording technique have been widely used to study the biophysical and pharmacological properties of these receptors. Combination of electrophysiology with site-directed mutagenesis and structural information has shed light on the molecular basis for receptor activation and mechanisms of actions by receptor antagonists and modulators. It is anticipated that such methodologies will continue helping us to provide more mechanistic understanding of P2XRs and to test novel receptor antagonists and allosteric modulators for therapeutical purposes. In this chapter, we describe protocols of transiently or stably expressing the P2XR in HEK293 cells and measuring P2XR-mediated currents by using whole-cell recording.
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9
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Illes P, Verkhratsky A, Tang Y. Pathological ATPergic Signaling in Major Depression and Bipolar Disorder. Front Mol Neurosci 2020; 12:331. [PMID: 32076399 PMCID: PMC7006450 DOI: 10.3389/fnmol.2019.00331] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 12/26/2019] [Indexed: 12/11/2022] Open
Abstract
The mood disorders, major depression (MD) and bipolar disorder (BD), have a high lifetime prevalence in the human population and accordingly generate huge costs for health care. Efficient, rapidly acting, and side-effect-free pharmaceuticals are hitherto not available, and therefore, the identification of new therapeutic targets is an imperative task for (pre)clinical research. Such a target may be the purinergic P2X7 receptor (P2X7R), which is localized in the central nervous system (CNS) at microglial and neuroglial cells mediating neuroinflammation. MD and BD are due to neuroinflammation caused in the first line by the release of the pro-inflammatory cytokine interleukin-1β (IL-1β) from the microglia. IL-1β in turn induces the secretion of corticotropin-releasing hormone (CRH) and in consequence the secretion of adrenocorticotropic hormone (ACTH) and cortisol, which together with a plethora of further cytokines/chemokines lead to mood disorders. A number of biochemical/molecular biological measurements including the use of P2X7R- or IL-1β-deficient mice confirmed this chain of events. More recent studies showed that a decrease in the astrocytic release of ATP in the prefrontal cortex and hippocampus is a major cause of mood disorders. It is an attractive hypothesis that compensatory increases in P2X7Rs in these areas of the brain are the immediate actuators of MD and BD. Hence, blood-brain barrier-permeable P2X7R antagonists may be promising therapeutic tools to improve depressive disorders in humans.
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Affiliation(s)
- Peter Illes
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, Germany.,Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.,Achucarro Centre for Neuroscience, Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
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10
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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: 154] [Impact Index Per Article: 30.8] [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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11
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Regulation of P2X7 receptor expression and function in the brain. Brain Res Bull 2018; 151:153-163. [PMID: 30593878 DOI: 10.1016/j.brainresbull.2018.12.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/19/2018] [Accepted: 12/12/2018] [Indexed: 02/07/2023]
Abstract
Because of its prominent role in driving inflammatory processes, the ATP-gated purinergic P2X7 receptor has attracted much attention over the past decade as a potential therapeutic target for numerous human conditions, particularly diseases of the central nervous system, including neurodegenerative diseases (e.g. Alzheimer's and Huntington's disease), psychiatric disorders (e.g. schizophrenia and depression) and the neurological disease, epilepsy. Evidence stems from studies using experimental models and patient tissue showing changes in P2X7 expression and function under pathological conditions and beneficial effects provided by P2X7 antagonism. Apart from promoting neuroinflammation, P2X7, however, also impacts on other pathological processes in the brain, including cell death, hyperexcitability, changes in neurotransmitter release and neurogenesis. Reports also suggest a role for P2X7 in the maintenance of blood-brain-barrier integrity. It therefore comes as no surprise that the regulation of P2X7 expression and function is complex, providing tight control on P2X7 activation. Much progress has been made in understanding how P2X7 is regulated during physiological and pathological conditions and what the consequences are of pathological P2X7 expression and function. Regulatory mechanisms altering P2X7 expression include transcriptional and post-translational regulation including nucleotide polymorphisms, promoter regulation via DNA methylation, transcription factors (e.g. Sp1 and HIF-1α), the generation of different splice variants and receptor phosphorylation, glycosylation and palmitoylation. Finally, more recently, reports have also shown P2X7-targeting by microRNAs, blocking P2X7 translation into functional proteins. The present review provides a broad overview of what is known to-date about the complex regulation of P2X7 expression with a particular emphasis on the brain and how each of these regulatory mechanisms impacts on receptor function and pathology.
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12
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Deussing JM, Arzt E. P2X7 Receptor: A Potential Therapeutic Target for Depression? Trends Mol Med 2018; 24:736-747. [PMID: 30093269 DOI: 10.1016/j.molmed.2018.07.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 02/07/2023]
Abstract
Depression is a prime contributor to global disease burden with 300 million affected patients worldwide. The persistent lack of progress with regards to pharmacotherapy stands in stark contrast to the pandemic magnitude of the disease. Alterations of inflammatory pathways in depressed patients, including altered circulating pro-inflammatory cytokines, have been put forward as a potential pathophysiological mechanism. The P2X7 receptor (P2X7R) plays an important role regulating the release of interleukin-1β and other cytokines. Comprehensive investigation of the P2X7R Gln460Arg missense mutation (rs2230912), which has been associated with major depression and bipolar disorder, has substantially contributed to validate P2X7R as a potential genetic risk factor. We propose that P2X7R is a putative target with good prospects for therapeutic intervention in depressive disorders.
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Affiliation(s)
- Jan M Deussing
- Molecular Neurogenetics, Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany.
| | - Eduardo Arzt
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society; and University of Buenos Aires, Argentina, Godoy Cruz 2390, C1425FQD Buenos Aires, Argentina
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13
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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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14
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Czamara D, Müller-Myhsok B, Lucae S. The P2RX7 polymorphism rs2230912 is associated with depression: A meta-analysis. Prog Neuropsychopharmacol Biol Psychiatry 2018; 82:272-277. [PMID: 29122639 DOI: 10.1016/j.pnpbp.2017.11.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 12/01/2022]
Abstract
Various studies have investigated whether single nucleotide polymorphisms (SNPs) in the gene purinergic receptor P2X7 (P2RX7), and rs2230912 specifically, were associated with mood disorders. While some studies found positive evidence, a large number of studies reported no significant associations. In a previously published meta-analysis, Feng et al. did not find a significant association and only moderate odds ratios (ORs) in case-control studies. They reported significant findings only for family-based studies. We revisited this finding and conducted a meta-analysis including 8,652 cases and 11,153 controls, adding unpublished results from the Munich Antidepressant Response Signature (MARS) study. We found a significant association between rs2230912 and combined mood disorders (major depressive disorder (MDD) or bipolar disorder (BD)) for the allelic, dominant and heterozygous-disadvantage model, all withstanding the threshold of correction for multiple testing. Stratifying by disorder revealed significant findings for the MDD-subgroup (OR of 1.12 for the allelic model), while the BD-subgroup presented with a lower effect size (OR of 1.05) and no significance. P2RX7 encodes a purinergic receptor which is expressed in the brain and also localized in immune cells. Animal studies and functional studies will be necessary to enlighten its involvement in the etiology of mood disorders and its applicability for pharmacological purposes.
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Affiliation(s)
- D Czamara
- Max Planck Institute of Psychiatry, Munich, Germany.
| | - B Müller-Myhsok
- Max Planck Institute of Psychiatry, Munich, Germany; Munich Cluster of Systems Biology, SyNergy, Germany; Institute of Translational Medicine, University of Liverpool, United Kingdom
| | - S Lucae
- Max Planck Institute of Psychiatry, Munich, Germany
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15
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Burnstock G, Knight GE. The potential of P2X7 receptors as a therapeutic target, including inflammation and tumour progression. Purinergic Signal 2018; 14:1-18. [PMID: 29164451 PMCID: PMC5842154 DOI: 10.1007/s11302-017-9593-0] [Citation(s) in RCA: 171] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 11/01/2017] [Indexed: 12/22/2022] Open
Abstract
Seven P2X ion channel nucleotide receptor subtypes have been cloned and characterised. P2X7 receptors (P2X7R) are unusual in that there are extra amino acids in the intracellular C terminus. Low concentrations of ATP open cation channels sometimes leading to cell proliferation, whereas high concentrations of ATP open large pores that release inflammatory cytokines and can lead to apoptotic cell death. Since many diseases involve inflammation and immune responses, and the P2X7R regulates inflammation, there has been recent interest in the pathophysiological roles of P2X7R and the potential of P2X7R antagonists to treat a variety of diseases. These include neurodegenerative diseases, psychiatric disorders, epilepsy and a number of diseases of peripheral organs, including the cardiovascular, airways, kidney, liver, bladder, skin and musculoskeletal. The potential of P2X7R drugs to treat tumour progression is discussed.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK.
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia.
- Florey Institute of Neuroscience and Mental Health, Parkville, Melbourne, Australia.
| | - Gillian E Knight
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK
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Liberman AC, Trias E, da Silva Chagas L, Trindade P, Dos Santos Pereira M, Refojo D, Hedin-Pereira C, Serfaty CA. Neuroimmune and Inflammatory Signals in Complex Disorders of the Central Nervous System. Neuroimmunomodulation 2018; 25:246-270. [PMID: 30517945 DOI: 10.1159/000494761] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 10/17/2018] [Indexed: 11/19/2022] Open
Abstract
An extensive microglial-astrocyte-monocyte-neuronal cross talk seems to be crucial for normal brain function, development, and recovery. However, under certain conditions neuroinflammatory interactions between brain cells and neuroimmune cells influence disease outcome and brain pathology. Microglial cells express a range of functional states with dynamically pleomorphic profiles from a surveilling status of synaptic transmission to an active player in major events of development such as synaptic elimination, regeneration, and repair. Also, inflammation mediates a series of neurotoxic roles in neuropsychiatric conditions and neurodegenerative diseases. The present review discusses data on the involvement of neuroinflammatory conditions that alter neuroimmune interactions in four different pathologies. In the first section of this review, we discuss the ability of the early developing brain to respond to a focal lesion with a rapid compensatory plasticity of intact axons and the role of microglial activation and proinflammatory cytokines in brain repair. In the second section, we present data of neuroinflammation and neurodegenerative disorders and discuss the role of reactive astrocytes in motor neuron toxicity and the progression of amyotrophic lateral sclerosis. In the third section, we discuss major depressive disorders as the consequence of dysfunctional interactions between neural and immune signals that result in increased peripheral immune responses and increase proinflammatory cytokines. In the last section, we discuss autism spectrum disorders and altered brain circuitries that emerge from abnormal long-term responses of innate inflammatory cytokines and microglial phenotypic dysfunctions.
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Affiliation(s)
- Ana Clara Liberman
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina,
| | - Emiliano Trias
- Neurodegeneration Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | | | - Pablo Trindade
- D'OR Institute for Research and Education, Rio de Janeiro, Brazil
| | - Marissol Dos Santos Pereira
- National Institute of Science and Technology on Neuroimmunomodulation - INCT-NIM, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- Laboratory for Cellular NeuroAnatomy, Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Damian Refojo
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Cecilia Hedin-Pereira
- National Institute of Science and Technology on Neuroimmunomodulation - INCT-NIM, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- Laboratory for Cellular NeuroAnatomy, Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- VPPCB, Fiocruz, Rio de Janeiro, Brazil
| | - Claudio A Serfaty
- Neuroscience Program, Federal Fluminense University, Niterói, Brazil
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Purinergic system in psychiatric diseases. Mol Psychiatry 2018; 23:94-106. [PMID: 28948971 DOI: 10.1038/mp.2017.188] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 07/15/2017] [Accepted: 07/20/2017] [Indexed: 12/14/2022]
Abstract
Psychiatric disorders are debilitating diseases, affecting >80 million people worldwide. There are no causal cures for psychiatric disorders and available therapies only treat the symptoms. The etiology of psychiatric disorders is unknown, although it has been speculated to be a combination of environmental, stress and genetic factors. One of the neurotransmitter systems implicated in the biology of psychiatric disorders is the purinergic system. In this review, we performed a comprehensive search of the literature about the role and function of the purinergic system in the development and predisposition to psychiatric disorders, with a focus on depression, schizophrenia, bipolar disorder, autism, anxiety and attention deficit/hyperactivity disorder. We also describe how therapeutics used for psychiatric disorders act on the purinergic system.
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18
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Heterozygosity for the Mood Disorder-Associated Variant Gln460Arg Alters P2X7 Receptor Function and Sleep Quality. J Neurosci 2017; 37:11688-11700. [PMID: 29079688 DOI: 10.1523/jneurosci.3487-16.2017] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 05/31/2017] [Indexed: 12/21/2022] Open
Abstract
A single nucleotide polymorphism substitution from glutamine (Gln, Q) to arginine (Arg, R) at codon 460 of the purinergic P2X7 receptor (P2X7R) has repeatedly been associated with mood disorders. The P2X7R-Gln460Arg variant per se is not compromised in its function. However, heterologous expression of P2X7R-Gln460Arg together with wild-type P2X7R has recently been demonstrated to impair receptor function. Here we show that this also applies to humanized mice coexpressing both human P2X7R variants. Primary hippocampal cells derived from heterozygous mice showed an attenuated calcium uptake upon agonist stimulation. While humanized mice were unaffected in their behavioral repertoire under basal housing conditions, mice that harbor both P2X7R variants showed alterations in their sleep quality resembling signs of a prodromal disease stage. Also healthy heterozygous human subjects showed mild changes in sleep parameters. These results indicate that heterozygosity for the wild-type P2X7R and its mood disorder-associated variant P2X7R-Gln460Arg represents a genetic risk factor, which is potentially able to convey susceptibility to mood disorders.SIGNIFICANCE STATEMENT Depression and bipolar disorder are the most common mood disorders. The P2X7 receptor (P2X7R) regulates many cellular functions. Its polymorphic variant Gln460Arg has repeatedly been associated with mood disorders. Genetically engineered mice, with human P2X7R, revealed that heterozygous mice (i.e., they coexpress the disease-associated Gln460Arg variant together with its normal version) have impaired receptor function and showed sleep disturbances. Human participants with the heterozygote genotype also had subtle alterations in their sleep profile. Our findings suggest that altered P2X7R function in heterozygote individuals disturbs sleep and might increase the risk for developing mood disorders.
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19
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Burnstock G. Purinergic Signalling: Therapeutic Developments. Front Pharmacol 2017; 8:661. [PMID: 28993732 PMCID: PMC5622197 DOI: 10.3389/fphar.2017.00661] [Citation(s) in RCA: 263] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/05/2017] [Indexed: 12/15/2022] Open
Abstract
Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990's when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine) receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A2A receptor antagonists are promising for the treatment of Parkinson's disease. Clopidogrel, a P2Y12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical SchoolLondon, United Kingdom
- Department of Pharmacology and Therapeutics, The University of Melbourne, MelbourneVIC, Australia
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20
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Metzger MW, Walser SM, Aprile-Garcia F, Dedic N, Chen A, Holsboer F, Arzt E, Wurst W, Deussing JM. Genetically dissecting P2rx7 expression within the central nervous system using conditional humanized mice. Purinergic Signal 2017; 13:153-170. [PMID: 27858314 PMCID: PMC5432476 DOI: 10.1007/s11302-016-9546-z] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/26/2016] [Indexed: 12/16/2022] Open
Abstract
The purinergic P2X7 receptor (P2X7R) has attracted considerable interest as a potential target for various central nervous system (CNS) pathologies including affective and neurodegenerative disorders. To date, the distribution and cellular localization of the P2X7R in the brain are not fully resolved and a matter of debate mainly due to the limitations of existing tools. However, this knowledge should be a prerequisite for understanding the contribution of the P2X7R to brain disease. Here, we generated a genetic mouse model by humanizing the P2X7R in the mouse as mammalian model organism. We demonstrated its functionality and revealed species-specific characteristics of the humanized receptor, compared to the murine ortholog, regarding its receptivity to activation and modulation by 2',3'-O-(benzoyl-4-benzoyl)-adenosine 5'-triphosphate (BzATP) and trifluoperazine (TFP). This humanized P2rx7 allele is accessible to spatially and temporally controlled Cre recombinase-mediated inactivation. In contrast to previously generated knockout (KO) mice, none of the described P2rx7 splice variants evade this null allele. By selective disruption and assessment of human P2RX7 expression in different brain regions and cell types, we were able to demonstrate that the P2X7R is specifically expressed in glutamatergic pyramidal neurons of the hippocampus. Also, P2X7R is expressed in major non-neuronal lineages throughout the brain, i.e., astrocytes, oligodendrocytes, and microglia. In conclusion, this humanized mouse model provides the means for detailed assessment of human P2X7R function in vivo including evaluation of agonists or antagonists. In addition, this conditional allele will enable future loss-of-function studies in conjunction with mouse models for CNS disorders.
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Affiliation(s)
| | | | - Fernando Aprile-Garcia
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina
- Max Planck Institute of Immunbiology and Epigenetics, 79108, Freiburg, Germany
| | - Nina Dedic
- Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Alon Chen
- Max Planck Institute of Psychiatry, 80804, Munich, Germany
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, 85764, Neuherberg, Germany
| | - Florian Holsboer
- Max Planck Institute of Psychiatry, 80804, Munich, Germany
- HMNC Brain Health, 80539, Munich, Germany
| | - Eduardo Arzt
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET- Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Wolfgang Wurst
- German Center for Neurodegenerative Diseases (DZNE), Site Munich, 81377, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Adolf-Butenandt-Institut, Ludwig-Maximilians-Universität München, 80336, Munich, Germany
- Department of Neurobiology, Weizmann Institute of Science, 7610001, Rehovot, Israel
- Chair of Developmental Genetics c/o Helmholtz Zentrum München, Technische Universität München-Weihenstephan, 85764, Neuherberg, Germany
| | - Jan M Deussing
- Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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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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