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Leite-Aguiar R, Bello-Santos VG, Castro NG, Coutinho-Silva R, Savio LEB. Techniques for evaluating the ATP-gated ion channel P2X7 receptor function in macrophages and microglial cells. J Immunol Methods 2024; 532:113727. [PMID: 38997100 DOI: 10.1016/j.jim.2024.113727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/31/2024] [Accepted: 07/08/2024] [Indexed: 07/14/2024]
Abstract
Resident macrophages are tissue-specific innate immune cells acting as sentinels, constantly patrolling their assigned tissue to maintain homeostasis, and quickly responding to pathogenic invaders or molecular danger signals molecules when necessary. Adenosine triphosphate (ATP), when released to the extracellular medium, acts as a danger signal through specific purinergic receptors. Interaction of ATP with the purinergic receptor P2X7 activates macrophages and microglial cells in different pathological conditions, triggering inflammation. The highly expressed P2X7 receptor in these cells induces cell membrane permeabilization, inflammasome activation, cell death, and the production of inflammatory mediators, including cytokines and nitrogen and oxygen-reactive species. This review explores the techniques to evaluate the functional and molecular aspects of the P2X7 receptor, particularly in macrophages and microglial cells. Polymerase chain reaction (PCR), Western blotting, and immunocytochemistry or immunohistochemistry are essential for assessing gene and protein expression in these cell types. Evaluation of P2X7 receptor function involves the use of ATP and selective agonists and antagonists and diverse techniques, including electrophysiology, intracellular calcium measurements, ethidium bromide uptake, and propidium iodide cell viability assays. These techniques are crucial for studying the role of P2X7 receptors in immune responses, neuroinflammation, and various pathological conditions. Therefore, a comprehensive understanding of the functional and molecular aspects of the P2X7 receptor in macrophages and microglia is vital for unraveling its involvement in immune modulation and its potential as a therapeutic target. The methodologies presented and discussed herein offer valuable tools for researchers investigating the complexities of P2X7 receptor signaling in innate immune cells in health and disease.
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Affiliation(s)
- Raíssa Leite-Aguiar
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Robson Coutinho-Silva
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiz Eduardo Baggio Savio
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil..
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2
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Markitantova YV, Simirskii VN. The Role of the Purinergic Signaling System in the Control of Histogenesis, Homeostasis, and Pathogenesis of the Vertebrate Retina. Russ J Dev Biol 2021. [DOI: 10.1134/s1062360421060084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Zyma M, Pawliczak R. Characteristics and the role of purinergic receptors in pathophysiology with focus on immune response. Int Rev Immunol 2020; 39:97-117. [PMID: 32037918 DOI: 10.1080/08830185.2020.1723582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The nucleotide adenosine-5'-triphosphate (ATP) is mostly thought to be energy carrier, but evidence presented in multiple studies proves ATP involvement into variety of processes, due to its neuromodulatory capabilities. ATP and its metabolite-adenosine, bind to the purinergic receptors, which are divided into two types: adenosine binding P1 receptor and ADP/ATP binding P2 receptor. These receptors are expressed in different tissues and organs. Recent studies report their immunomodulatory characteristics, connected with varying immunological processes, such as immunological response or antigen presentation. Besides, they seem to play an important role in medical conditions such as bronchial asthma or variety of cancers. In this article, we would like to review recent discoveries on the field of purinergic receptors research focusing on their role in immunological system, and shed a new light upon the importance of these receptors in modern medicine development.
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Affiliation(s)
- Marharyta Zyma
- Department of Immunopathology, Division of Biomedical Science, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - Rafał Pawliczak
- Department of Immunopathology, Division of Biomedical Science, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
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4
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Effect of Low Androgen Status on the Expression of P2Y Receptors in the Corpus Cavernosum of Rats. Urology 2018; 116:229.e1-229.e6. [DOI: 10.1016/j.urology.2018.03.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/23/2018] [Accepted: 03/14/2018] [Indexed: 01/11/2023]
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5
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Beamer E, Kovács G, Sperlágh B. ATP released from astrocytes modulates action potential threshold and spontaneous excitatory postsynaptic currents in the neonatal rat prefrontal cortex. Brain Res Bull 2017; 135:129-142. [PMID: 29030320 DOI: 10.1016/j.brainresbull.2017.10.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 10/04/2017] [Accepted: 10/06/2017] [Indexed: 01/12/2023]
Abstract
Maternal immune activation during pregnancy is a risk factor for neurodevelopmental disorders, such as schizophrenia; however, a full mechanistic understanding has yet to be established. The activity of a transient cell population, the subplate neurons, is critical for the development of cortical inhibition and functional thalamocortical connections. Sensitivity of these cells to factors released during inflammation, therefore, may offer a link between maternal immune activation and the aberrant cortical development underlying some neuropsychiatric disorders. An elevated extracellular ATP concentration is associated with inflammation and has been shown to have an effect on neuronal activity. Here, we investigated the effect of ATP on the electrophysiological properties of subplate neurons. Exogenous ATP increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) at micromolar concentrations. Further, ATP released by astrocytes activated by the PAR-1 agonist, TFLLR-NH2, also increased the amplitude and frequency of sEPSCs in subplate neurons. The electrophysiological properties of subplate neurons recorded from prefrontal cortical (PFC) slices from neonatal rats were also disrupted in a maternal immune activation rat model of schizophrenia, with a suramin-sensitive increase in frequency and amplitude of sEPSCs. An alternative neurodevelopmental rat model of schizophrenia, MAM-E17, which did not rely on maternal immune activation, however, showed no change in subplate neuron activity. Both models were validated with behavioral assays, showing schizophrenia-like endophenotypes in young adulthood. The purinergic modulation of subplate neuron activity offers a potential explanatory link between maternal immune activation and disruptions in cortical development that lead to the emergence of neuropsychiatric disorders.
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Affiliation(s)
- Edward Beamer
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Gergely Kovács
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Beata Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
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6
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Liu J, Prell T, Stubendorff B, Keiner S, Ringer T, Gunkel A, Tadic V, Goldhammer N, Malci A, Witte OW, Grosskreutz J. Down-regulation of purinergic P2X7 receptor expression and intracellular calcium dysregulation in peripheral blood mononuclear cells of patients with amyotrophic lateral sclerosis. Neurosci Lett 2016; 630:77-83. [PMID: 27453058 DOI: 10.1016/j.neulet.2016.07.039] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/11/2016] [Accepted: 07/20/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder associated with intracellular Ca(2+) dysregulation. The P2X receptor family is comprised of ligand-gated ion channels that respond to extracellular adenosine triphosphate (ATP) and increases permeability of calcium into the cell. The underlying mechanisms of purinergic signalling on peripheral blood mononuclear cells (PBMCs) in ALS remain unclear. Herein, we studied the expression of P2X4/P2X7 receptors and calcium homeostasis in blood cells of ALS patients. METHODS We used PBMCs from 42 ALS patients and 19 controls. Purinergic receptors P2X4 (P2X4R) and P2X7 (P2X7R) were examined using western blot analysis. The effect of exogenous ATP on intracellular Ca(2+) homeostasis in monocytes was measured using fluorimetry by Fura-2 on a single-cell level. RESULTS Western blot analysis revealed stable P2X4R expression in patients and controls. P2X7R expression was significantly reduced (p=0.012) in ALS patients. Repetitive long-term ATP stimulation caused a sustained decrease in Ca(2+) levels in the ALS group as measured by the area under the curve, peak amplitude and peak height. CONCLUSION These results confirm our hypothesis that Ca(2+) abnormalities in ALS are measurable in immune cells. These findings suggest that the reduction of P2X7 receptor expression on PBMCs leads to intracellular calcium dysregulation. Our study improves the understanding of ALS pathophysiology and proposes PBMCs as a non-invasive source to study ALS.
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Affiliation(s)
- Jingyu Liu
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Tino Prell
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany.
| | - Beatrice Stubendorff
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Silke Keiner
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Thomas Ringer
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Anne Gunkel
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Vedrana Tadic
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Nadine Goldhammer
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Ayse Malci
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Otto W Witte
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
| | - Julian Grosskreutz
- Hans Berger Department of Neurology, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany
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Shcherbatko A, Foletti D, Poulsen K, Strop P, Zhu G, Hasa-Moreno A, Melton Witt J, Loo C, Krimm S, Pios A, Yu J, Brown C, Lee JK, Stroud R, Rajpal A, Shelton D. Modulation of P2X3 and P2X2/3 Receptors by Monoclonal Antibodies. J Biol Chem 2016; 291:12254-70. [PMID: 27129281 DOI: 10.1074/jbc.m116.722330] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Indexed: 01/06/2023] Open
Abstract
Purinergic homomeric P2X3 and heteromeric P2X2/3 receptors are ligand-gated cation channels activated by ATP. Both receptors are predominantly expressed in nociceptive sensory neurons, and an increase in extracellular ATP concentration under pathological conditions, such as tissue damage or visceral distension, induces channel opening, membrane depolarization, and initiation of pain signaling. Hence, these receptors are considered important therapeutic targets for pain management, and development of selective antagonists is currently progressing. To advance the search for novel analgesics, we have generated a panel of monoclonal antibodies directed against human P2X3 (hP2X3). We have found that these antibodies produce distinct functional effects, depending on the homomeric or heteromeric composition of the target, its kinetic state, and the duration of antibody exposure. The most potent antibody, 12D4, showed an estimated IC50 of 16 nm on hP2X3 after short term exposure (up to 18 min), binding to the inactivated state of the channel to inhibit activity. By contrast, with the same short term application, 12D4 potentiated the slow inactivating current mediated by the heteromeric hP2X2/3 channel. Extending the duration of exposure to ∼20 h resulted in a profound inhibition of both homomeric hP2X3 and heteromeric hP2X2/3 receptors, an effect mediated by efficient antibody-induced internalization of the channel from the plasma membrane. The therapeutic potential of mAb12D4 was assessed in the formalin, complete Freund's adjuvant, and visceral pain models. The efficacy of 12D4 in the visceral hypersensitivity model indicates that antibodies against P2X3 may have therapeutic potential in visceral pain indications.
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Affiliation(s)
- Anatoly Shcherbatko
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080,
| | - Davide Foletti
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Kris Poulsen
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Pavel Strop
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Guoyun Zhu
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Adela Hasa-Moreno
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Jody Melton Witt
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Carole Loo
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Stellanie Krimm
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Ariel Pios
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Jessica Yu
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - Colleen Brown
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - John K Lee
- the Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, and
| | - Robert Stroud
- the Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158
| | - Arvind Rajpal
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
| | - David Shelton
- From the Rinat Laboratories, Pfizer Inc., South San Francisco, California 94080
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8
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Chen L, Liu YW, Yue K, Ru Q, Xiong Q, Ma BM, Tian X, Li CY. Differential expression of ATP-gated P2X receptors in DRG between chronic neuropathic pain and visceralgia rat models. Purinergic Signal 2015; 12:79-87. [PMID: 26531254 DOI: 10.1007/s11302-015-9481-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 10/26/2015] [Indexed: 12/22/2022] Open
Abstract
There are divergences between neuropathic pain and visceralgia in terms of the duration, location, and character of hyperalgesia. It is generally recognized that nociceptive receptors, including P2X receptors, may play different roles in nociceptive mechanisms. The different roles of P2X1-7 receptors have not been fully understood both in neuropathic pain and visceral hyperalgesia. In order to explore the different expressions of P2X1-7 receptors in these two hyperalgesia models, the lumbosacral dorsal root ganglion (DRG) neurons from rat sciatic nerve chronic constriction injury (CCI) model and neonatal colorectal distention (NCRD) model were studied (both the primary nociceptive neuron afferents of those two models projected to the same segment of spinal cord). Both immunohistochemistry (IHC) technique and real-time fluorescence quantitative polymerase chain reaction (RT-PCR) technology were applied to analyze the protein expression levels and nucleic acid of P2X1-7 receptors. We found that except P2X2 and P2X3, the expression levels of P2X1 and P2X5 receptors increased in neuropathic pain while those expression levels of P2X4, P2X6, and P2X7 receptors increased in visceral pain. Our results also suggested that in addition to P2X2/3 heteromeric, other P2X subunits may also involved in generation heteromeric such as P2X1/5 and/or P2X2/5 in neuropathic pain and P2X4/6 and/or P2X4/7 in visceral pain.
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Affiliation(s)
- Lin Chen
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, 430056, China
| | - Yu-wei Liu
- School of Medicine, Jianghan University, Wuhan, 430056, China
| | - Kai Yue
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, 430056, China
| | - Qin Ru
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, 430056, China
| | - Qi Xiong
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, 430056, China
| | - Bao-miao Ma
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, 430056, China
| | - Xiang Tian
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, 430056, China
| | - Chao-ying Li
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, 430056, China.
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9
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Menzies RI, Howarth AR, Unwin RJ, Tam FWK, Mullins JJ, Bailey MA. Inhibition of the purinergic P2X7 receptor improves renal perfusion in angiotensin-II-infused rats. Kidney Int 2015; 88:1079-87. [PMID: 26108066 DOI: 10.1038/ki.2015.182] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 04/19/2015] [Accepted: 04/23/2015] [Indexed: 12/14/2022]
Abstract
Chronic activation of the renin-angiotensin system promotes hypertension, renal microvascular dysfunction, tissue hypoxia, and inflammation. Despite similar hypertension, an injurious response to excess angiotensin II is greater in F344 than in Lewis rats; the latter displaying renoprotection. Here we studied whether p2rx7, encoding the P2X7 receptor (P2X7R), is a candidate gene for the differential susceptibility to vascular dysfunction under high angiotensin II tone. A 14-day infusion of angiotensin II into F344 rats increased blood pressure by about 15 mm Hg without inducing fibrosis or albuminuria. In vivo pressure natriuresis was suppressed, medullary perfusion reduced by half, and the corticomedullary oxygenation gradient disrupted. Selective P2X7R antagonism restored pressure natriuresis, promoting a significant leftward shift in the intercept and increasing the slope. Sodium excretion was increased sixfold and blood pressure normalized. The specific P2X7R antagonist AZ11657312 increased renal medullary perfusion, but only in angiotensin II-treated rats. Tissue oxygenation was improved by P2X7R blockade, particularly in poorly oxygenated regions of the kidney. Thus, activation of P2X7R induces microvascular dysfunction and regional hypoxia when angiotensin II is elevated and these effects may contribute to progression of renal injury induced by chronic angiotensin II.
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Affiliation(s)
- Robert I Menzies
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK.,Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| | - Amelia R Howarth
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
| | - Robert J Unwin
- Cardiovascular and Metabolic Diseases (iMed CVMD) R&D, AstraZeneca, Mölndal, Sweden.,UCL Centre for Nephrology, University College London, London, UK
| | - Frederick W K Tam
- Imperial College Renal and Transplant Centre, Department of Medicine, Imperial College London, London, UK
| | - John J Mullins
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
| | - Matthew A Bailey
- University/British Heart Foundation Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK
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10
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Wilkinson TCI, Gardener MJ, Williams WA. Discovery of Functional Antibodies Targeting Ion Channels. ACTA ACUST UNITED AC 2014; 20:454-67. [DOI: 10.1177/1087057114560698] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ion channels play critical roles in physiology and disease by modulation of cellular functions such as electrical excitability, secretion, cell migration, and gene transcription. Ion channels represent an important target class for drug discovery that has been largely addressed, to date, using small-molecule approaches. A significant opportunity exists to target these channels with antibodies and alternative formats of biologics. Antibodies display high specificity and affinity for their target antigen, and they have the potential to target ion channels very selectively. Nevertheless, isolating antibodies to this target class is challenging due to the difficulties in expression and purification of ion channels in a format suitable for antibody drug discovery in addition to the complexity of screening for function. In this article, we will review the current state of ion channel biologics discovery and the progress that has been made. We will also highlight the challenges in isolating functional antibodies to these targets and how these challenges may be addressed. Finally, we also illustrate successful approaches to isolating functional monoclonal antibodies targeting ion channels by way of a number of case studies drawn from recent publications.
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Affiliation(s)
| | | | - Wendy A. Williams
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, UK
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11
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Liu J, Li G, Peng H, Tu G, Kong F, Liu S, Gao Y, Xu H, Qiu S, Fan B, Zhu Q, Yu S, Zheng C, Wu B, Peng L, Song M, Wu Q, Li G, Liang S. Sensory-sympathetic coupling in superior cervical ganglia after myocardial ischemic injury facilitates sympathoexcitatory action via P2X7 receptor. Purinergic Signal 2013; 9:463-79. [PMID: 23754120 PMCID: PMC3757147 DOI: 10.1007/s11302-013-9367-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 05/13/2013] [Indexed: 12/17/2022] Open
Abstract
P2X receptors participate in cardiovascular regulation and disease. After myocardial ischemic injury, sensory-sympathetic coupling between rat cervical DRG nerves and superior cervical ganglia (SCG) facilitated sympathoexcitatory action via P2X7 receptor. The results showed that after myocardial ischemic injury, the systolic blood pressure, heart rate, serum cardiac enzymes, IL-6, and TNF-α were increased, while the levels of P2X7 mRNA and protein in SCG were also upregulated. However, these alterations diminished after treatment of myocardial ischemic (MI) rats with the P2X7 antagonist oxATP. After siRNA P2X7 in MI rats, the systolic blood pressure, heart rate, serum cardiac enzymes, the expression levels of the satellite glial cell (SGC) or P2X7 were significantly lower than those in MI group. The phosphorylation of ERK 1/2 in SCG participated in the molecular mechanism of the sympathoexcitatory action induced by the myocardial ischemic injury. Retrograde tracing test revealed the sprouting of CGRP or SP sensory nerves (the markers of sensory afferent fibers) from DRG to SCG neurons. The upregulated P2X7 receptor promoted the activation of SGCs in SCG, resulting in the formation of sensory-sympathetic coupling which facilitated the sympathoexcitatory action. P2X7 antagonist oxATP could inhibit the activation of SGCs and interrupt the formation of sensory-sympathetic coupling in SCG after the myocardial ischemic injury. Our findings may benefit the treatment of coronary heart disease and other cardiovascular diseases.
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Affiliation(s)
- Jun Liu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Guilin Li
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Haiying Peng
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Guihua Tu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Fanjun Kong
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Shuangmei Liu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Yun Gao
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Hong Xu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Shuyi Qiu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Bo Fan
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Qicheng Zhu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Shicheng Yu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Chaoran Zheng
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Bing Wu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Lichao Peng
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Miaomiao Song
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Qin Wu
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Guodong Li
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
| | - Shangdong Liang
- />Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
- />Key Laboratory of Basic Medicine, Medical College of Nanchang University, Nanchang, Jiangxi 330006 People’s Republic of China
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12
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Yu W, Hill WG. Lack of specificity shown by P2Y6 receptor antibodies. Naunyn Schmiedebergs Arch Pharmacol 2013; 386:885-91. [PMID: 23793102 DOI: 10.1007/s00210-013-0894-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 06/04/2013] [Indexed: 01/11/2023]
Abstract
P2Y6 receptor in bladder smooth muscle responds to UDP by increasing muscle tone and augmenting bladder contractions. The exact cellular location of the receptor is however unknown. Three commercially available antibodies to P2Y6 receptor gave clean bands on Western blot which were eliminated by specific peptide competition. Two of the three also immunostained bladder smooth muscle cells while leaving adjacent interstitial cells of Cajal unstained. However, attempts to validate the specificity of these antibodies by performing the same assays on bladders from P2Y6 knockout mice were unsuccessful. In Western blots, all three antibodies bound similar proteins in both wild type and P2Y6 knockout tissue. Immunostaining of knockout tissue sections also showed no difference in staining patterns or intensity. We conclude that rigorous controls are required when using commercial reagents to this G-protein coupled receptor and perhaps to other members of the P2Y receptor family.
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Affiliation(s)
- Weiqun Yu
- Harvard Medical School, Harvard University, Boston, MA, USA
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13
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P2X7 receptors at adult neural progenitor cells of the mouse subventricular zone. Neuropharmacology 2013; 73:122-37. [PMID: 23727220 DOI: 10.1016/j.neuropharm.2013.05.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 05/01/2013] [Accepted: 05/04/2013] [Indexed: 02/07/2023]
Abstract
Neurogenesis requires the balance between the proliferation of newly formed progenitor cells and subsequent death of surplus cells. RT-PCR and immunocytochemistry demonstrated the presence of P2X7 receptor mRNA and immunoreactivity in cultured neural progenitor cells (NPCs) prepared from the adult mouse subventricular zone (SVZ). Whole-cell patch-clamp recordings showed a marked potentiation of the inward current responses both to ATP and the prototypic P2X7 receptor agonist dibenzoyl-ATP (Bz-ATP) at low Ca(2+) and zero Mg(2+) concentrations in the bath medium. The Bz-ATP-induced currents reversed their polarity near 0 mV; in NPCs prepared from P2X7(-/-) mice, Bz-ATP failed to elicit membrane currents. The general P2X/P2Y receptor antagonist PPADS and the P2X7 selective antagonists Brilliant Blue G and A-438079 strongly depressed the effect of Bz-ATP. Long-lasting application of Bz-ATP induced an initial current, which slowly increased to a steady-state response. In combination with the determination of YO-PRO uptake, these experiments suggest the dilation of a receptor-channel and/or the recruitment of a dye-uptake pathway. Ca(2+)-imaging by means of Fura-2 revealed that in a Mg(2+)-deficient bath medium Bz-ATP causes [Ca(2+)](i) transients fully depending on the presence of external Ca(2+). The MTT test indicated a concentration-dependent decrease in cell viability by Bz-ATP treatment. Correspondingly, Bz-ATP led to an increase in active caspase 3 immunoreactivity, indicating a P2X7-controlled apoptosis. In acute SVZ brain slices of transgenic Tg(nestin/EGFP) mice, patch-clamp recordings identified P2X7 receptors at NPCs with pharmacological properties identical to those of their cultured counterparts. We suggest that the apoptotic/necrotic P2X7 receptors at NPCs may be of particular relevance during pathological conditions which lead to increased ATP release and thus could counterbalance the ensuing excessive cell proliferation.
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Key Words
- 2-MeSATP
- 2-methylthio ATP
- 2′(3′)-O-(4-benzoylbenzoyl)adenosine-5′-triphosphate
- 2′,3′-O-(2,4,6-trinitrophenyl) adenosine 5′-triphosphate
- 3-(4,5-dimethylthioazol-2-yl)-2,5-diphenyltetrazoliumbromid
- 5-(3-bromophenyl)-1,3-dihydro-2H-benzofuro[3,2-e]-1,4-diazepin-2-one
- 5-BDBD
- Adult neural progenitor cells
- BBG
- Brain subventricular zone
- Brilliant Blue G
- Bz-ATP
- CNS
- E(max)
- EC(50)
- EGF
- Extracellular ATP
- FGF-2
- GAPDH
- GFAP
- MTT
- Msi1
- NPC
- P2X7 receptors
- PPADS
- SVZ
- TNP-ATP
- X(2) concentration
- [Ca(2+)](i)
- central nervous system
- concentration of agonist producing 50% of E(max)
- divalent cation concentration
- epidermal growth factor
- fibroblast growth factor-2
- glial fibrillary acidic protein
- glyceraldehyde 3-phosphate dehydrogenase
- intracellular Ca(2+) concentration
- maximal effect
- musashi1
- neural progenitor cell
- pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid
- subventricular zone
- wild-type
- wt
- α,β-meATP
- α,β-methylene ATP
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14
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Govindan S, Taylor CW. P2Y receptor subtypes evoke different Ca2+ signals in cultured aortic smooth muscle cells. Purinergic Signal 2012; 8:763-77. [PMID: 22767215 PMCID: PMC3486169 DOI: 10.1007/s11302-012-9323-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 06/12/2012] [Indexed: 12/14/2022] Open
Abstract
Adenine and uridine nucleotides evoke Ca(2+) signals via four subtypes of P2Y receptor in cultured aortic smooth muscle cells, but the mechanisms underlying the different patterns of these Ca(2+) signals are unresolved. Cytosolic Ca(2+) signals were recorded from single cells and populations of cultured rat aortic smooth muscle cells, loaded with a fluorescent Ca(2+) indicator and stimulated with agonists that allow subtype-selective activation of P2Y1, P2Y2, P2Y4, or P2Y6 receptors. Activation of P2Y1, P2Y2, and P2Y6 receptors caused homologous desensitisation, while activation of P2Y2 receptors also caused heterologous desensitisation of the other subtypes. The Ca(2+) signals evoked by each P2Y receptor subtype required activation of phospholipase C and release of Ca(2+) from intracellular stores via inositol 1,4,5-trisphosphate (IP(3)) receptors, but they were unaffected by inhibition of ryanodine or nicotinic acid adenine dinucleotide phosphate (NAADP) receptors. Sustained Ca(2+) signals were independent of the Na(+)/Ca(2+) exchanger and were probably mediated by store-operated Ca(2+) entry. Analyses of single cells established that most cells express P2Y2 receptors and at least two other P2Y receptor subtypes. We conclude that four P2Y receptor subtypes evoke Ca(2+) signals in cultured aortic smooth muscle cells using the same intracellular (IP(3) receptors) and Ca(2+) entry pathways (store-operated Ca(2+) entry). Different rates of homologous desensitisation and different levels of receptor expression account for the different patterns of Ca(2+) signal evoked by each P2Y receptor subtype.
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Affiliation(s)
- Sriram Govindan
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD UK
- Novartis Institutes of Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB UK
| | - Colin W. Taylor
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD UK
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15
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Weisman GA, Camden JM, Peterson TS, Ajit D, Woods LT, Erb L. P2 receptors for extracellular nucleotides in the central nervous system: role of P2X7 and P2Y₂ receptor interactions in neuroinflammation. Mol Neurobiol 2012; 46:96-113. [PMID: 22467178 DOI: 10.1007/s12035-012-8263-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 03/21/2012] [Indexed: 12/16/2022]
Abstract
Extracellular nucleotides induce cellular responses in the central nervous system (CNS) through the activation of ionotropic P2X and metabotropic P2Y nucleotide receptors. Activation of these receptors regulates a wide range of physiological and pathological processes. In this review, we present an overview of the current literature regarding P2X and P2Y receptors in the CNS with a focus on the contribution of P2X7 and P2Y(2) receptor-mediated responses to neuroinflammatory and neuroprotective mechanisms.
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Affiliation(s)
- Gary A Weisman
- Department of Biochemistry, University of Missouri, 540E Life Sciences Center, 1201 Rollins Road, Columbia, MO 65211-7310, USA.
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