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Al-Aqtash R, Collier DM. Ionotropic purinergic receptor 7 (P2X7) channel structure and pharmacology provides insight regarding non-nucleotide agonism. Channels (Austin) 2024; 18:2355150. [PMID: 38762911 PMCID: PMC11110710 DOI: 10.1080/19336950.2024.2355150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 05/10/2024] [Indexed: 05/21/2024] Open
Abstract
P2X7 is a member of the Ionotropic Purinergic Receptor (P2X) family. The P2X family of receptors is composed of seven (P2X1-7), ligand-gated, nonselective cation channels. Changes in P2X expression have been reported in multiple disease models. P2Xs have large complex extracellular domains that function as receptors for a variety of ligands, including endogenous and synthetic agonists and antagonists. ATP is the canonical agonist. ATP affinity ranges from nanomolar to micromolar for most P2XRs, but P2X7 has uniquely poor ATP affinity. In many physiological settings, it may be difficult to achieve the millimolar extracellular ATP concentrations needed for P2X7 channel activation; however, channel function is implicated in pain sensation, immune cell function, cardiovascular disease, cancer, and osteoporosis. Multiple high-resolution P2X7 structures have been solved in apo-, ATP-, and antagonist-bound states. P2X7 structural data reveal distinct allosteric and orthosteric antagonist-binding sites. Both allosteric and orthosteric P2X7 antagonists are well documented to inhibit ATP-evoked channel current. However, a growing body of evidence supports P2X7 activation by non-nucleotide agonists, including extracellular histone proteins and human cathelicidin-derived peptides (LL-37). Interestingly, P2X7 non-nucleotide agonism is not inhibited by allosteric antagonists, but is inhibited by orthosteric antagonists. Herein, we review P2X7 function with a focus on the efficacy of available pharmacology on P2X7 channel current activation by non-nucleotide agonists in effort to understand agonist/antagonist efficacy, and consider the impact of these data on the current understanding of P2X7 in physiology and disease given these limitations of P2X7-selective antagonists and incomplete knockout mouse models.
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Affiliation(s)
- Rua’a Al-Aqtash
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Daniel M. Collier
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
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Fu GJ, Wang LD, Chi XS, Liang X, Wei JJ, Huang ZH, Shen W, Zhang YL. Research Progress on the Experimental Model and Underlying Mechanistic Studies of Tension-Type Headaches. Curr Pain Headache Rep 2024; 28:439-451. [PMID: 38502437 PMCID: PMC11126509 DOI: 10.1007/s11916-024-01238-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2024] [Indexed: 03/21/2024]
Abstract
PURPOSE OF REVIEW Tension-type headaches (TTH) significantly diminish patients' quality of life and increase absenteeism, thereby imposing a substantial economic burden. Animal models are essential tools for studying disease mechanisms and drug development. However, until now, little focus has been placed on summarizing the animal models of TTH and associated mechanistic studies. This narrative review discusses the current animal models of TTH and related mechanistic studies to provide insights into the pathophysiological mechanisms of and treatments for TTH. RECENT FINDINGS The primary method for constructing an animal model of TTH involves injecting a solution of pain relievers, such as adenosine triphosphate, nerve growth factor, or a high concentration of salt solution, into the neck to initiate harmful cervical muscle responses. This model enables the examination of the interaction between peripheral muscles and central sensitization, which is crucial for understanding the pathophysiology of TTH. Mechanistic studies based on this model have investigated the effect of the P2X receptor antagonist, P2X7 receptor blockade, the P2Y1 receptor agonist 2-MESADP, P2Y1 receptor antagonist MRS2179, nitric oxide synthase inhibitors, and acetylsalicylic acid. Despite notable advancements, the current model of TTH has limitations, including surgical complexity and the inability to replicate chronic tension-type headache (CTTH). To gain a more comprehensive understanding and develop more effective treatment methods, future studies should focus on simplifying surgical procedures, examining other predisposing factors, and establishing a model for chronic TTH. This will offer a deeper insight into the pathophysiological mechanism of TTH and pave the way for improved treatment approaches.
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Affiliation(s)
- Guo-Jing Fu
- Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, 100,091, China
| | - Liu-Ding Wang
- Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, 100,091, China
| | - Xian-Su Chi
- Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, 100,091, China
| | - Xiao Liang
- Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, 100,091, China
| | - Jing-Jing Wei
- Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, 100,091, China
| | - Zhi-Hong Huang
- Yidu Central Hospital of Weifang, Weifang, 262,550, China
| | - Wei Shen
- Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, 100,091, China.
| | - Yun-Ling Zhang
- Xiyuan Hospital of China Academy of Chinese Medical Sciences, Beijing, 100,091, China.
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3
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Lopresti BJ, Royse SK, Mathis CA, Tollefson SA, Narendran R. Beyond monoamines: I. Novel targets and radiotracers for Positron emission tomography imaging in psychiatric disorders. J Neurochem 2023; 164:364-400. [PMID: 35536762 DOI: 10.1111/jnc.15615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 10/18/2022]
Abstract
With the emergence of positron emission tomography (PET) in the late 1970s, psychiatry had access to a tool capable of non-invasive assessment of human brain function. Early applications in psychiatry focused on identifying characteristic brain blood flow and metabolic derangements using radiotracers such as [15 O]H2 O and [18 F]FDG. Despite the success of these techniques, it became apparent that more specific probes were needed to understand the neurochemical bases of psychiatric disorders. The first neurochemical PET imaging probes targeted sites of action of neuroleptic (dopamine D2 receptors) and psychoactive (serotonin receptors) drugs. Based on the centrality of monoamine dysfunction in psychiatric disorders and the measured success of monoamine-enhancing drugs in treating them, the next 30 years witnessed the development of an armamentarium of PET radiopharmaceuticals and imaging methodologies for studying monoamines. Continued development of monoamine-enhancing drugs over this time however was less successful, realizing only modest gains in efficacy and tolerability. As patent protection for many widely prescribed and profitable psychiatric drugs lapsed, drug development pipelines shifted away from monoamines in search of novel targets with the promises of improved efficacy, or abandoned altogether. Over this period, PET radiopharmaceutical development activities closely paralleled drug development priorities resulting in the development of new PET imaging agents for non-monoamine targets. Part one of this review will briefly survey novel PET imaging targets with relevance to the field of psychiatry, which include the metabotropic glutamate receptor type 5 (mGluR5), purinergic P2 X7 receptor, type 1 cannabinoid receptor (CB1 ), phosphodiesterase 10A (PDE10A), and describe radiotracers developed for these and other targets that have matured to human subject investigations. Current limitations of the targets and techniques will also be discussed.
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Affiliation(s)
- Brian J Lopresti
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Sarah K Royse
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Chester A Mathis
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Savannah A Tollefson
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rajesh Narendran
- Departments of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Departments of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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BDNF Participates in Chronic Constriction Injury-Induced Neuropathic Pain via Transcriptionally Activating P2X 7 in Primary Sensory Neurons. Mol Neurobiol 2021; 58:4226-4236. [PMID: 33963520 DOI: 10.1007/s12035-021-02410-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 04/27/2021] [Indexed: 12/11/2022]
Abstract
Neuropathic pain, resulting from the pathological changes of the somatosensory nervous system, remains a severe public health problem worldwide. The effect of treatment targeting neuropathic pain is very limited, as the underlying mechanism of neuropathic pain is largely unknown. In this study, we demonstrated that the expression level of brain-derived neurotrophic factor (BDNF) was remarkably and time-dependently increased in dorsal root ganglion (DRG) neurons. DRG microinjection of BDNF siRNA in DRG ameliorated chronic constriction injury (CCI) induced mechanical, thermal, and cold nociceptive hypersensitivities. Overexpressing BDNF through microinjection of the AAV5-BDNF in DRG caused enhanced responses to basal mechanical, thermal, and cold stimuli in mice exposed to CCI. Mechanically, the P2X7 promoter activity was enhanced by CCI-induced increase of DRG BDNF protein and was involved in the CCI-induced upregulation of DRG P2X7 protein. The overexpression of BDNF also increased P2X7 expression in DRG neurons, which was validated in in vivo and in vitro experiments. BDNF may exert crucial effect via transcriptionally activating the P2X7 gene in primary sensory neurons, since P2X7 acts as a role of endogenous agitator in neuropathic pain and BDNF largely co-expresses with P2X7 in DRG neurons. Therefore, our data provide evidence that BDNF may be a promising therapeutic target for neuropathic pain.
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Luo X, Zhang Q, Jiang Y, Wang C, Song X, Li J, Yan Q, Chan ASC, Zou Y. Copper-Catalyzed Lactamization of ( E)-2-(2-Bromophenyl)-3-arylacrylamides for the Synthesis of ( E)-3-Arylideneindolin-2-ones. J Org Chem 2021; 86:6698-6710. [PMID: 33881860 DOI: 10.1021/acs.joc.1c00452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A copper-catalyzed, ligand-free intramolecular C-N coupling of (E)-2-(2-bromophenyl)-3-arylacrylamides has been developed. This protocol provides an efficient and practical synthetic route for the biologically important (E)-3-arylideneindolin-2-ones from o-bromophenylacetic acids and aromatic or conjugated alkenyl aldehydes. Readily available starting materials, mild and noble metal-free conditions, high efficiency, and good tolerability for phenolic hydroxyl groups make this approach attractive and applicable.
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Affiliation(s)
- Xiang Luo
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Qianzhong Zhang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Yi Jiang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Chengxin Wang
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, People's Republic of China
| | - Xianheng Song
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Jianheng Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Qinfang Yan
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China
| | - Albert S C Chan
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China.,Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangzhou 510000, People's Republic of China
| | - Yong Zou
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China.,Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, Guangzhou 510000, People's Republic of China
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Xi Q, Wang M, Jia W, Yang M, Hu J, Jin J, Chen X, Yin D, Wang X. Design, Synthesis, and Biological Evaluation of Amidobenzimidazole Derivatives as Stimulator of Interferon Genes (STING) Receptor Agonists. J Med Chem 2019; 63:260-282. [DOI: 10.1021/acs.jmedchem.9b01567] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Qiumu Xi
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
| | - Mingjin Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
| | - Wenqiang Jia
- Department of Medicinal Chemistry, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
| | - Mingjian Yang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
| | - Jinping Hu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
| | - Jing Jin
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
| | - Xiaoguang Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
| | - Dali Yin
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
- Department of Medicinal Chemistry, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
| | - Xiaojian Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
- Department of Medicinal Chemistry, Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, P. R. China
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7
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Janssen B, Vugts DJ, Wilkinson SM, Ory D, Chalon S, Hoozemans JJM, Schuit RC, Beaino W, Kooijman EJM, van den Hoek J, Chishty M, Doméné A, Van der Perren A, Villa A, Maggi A, Molenaar GT, Funke U, Shevchenko RV, Baekelandt V, Bormans G, Lammertsma AA, Kassiou M, Windhorst AD. Identification of the allosteric P2X 7 receptor antagonist [ 11C]SMW139 as a PET tracer of microglial activation. Sci Rep 2018; 8:6580. [PMID: 29700413 PMCID: PMC5920098 DOI: 10.1038/s41598-018-24814-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/15/2018] [Indexed: 02/07/2023] Open
Abstract
The P2X7 receptor plays a significant role in microglial activation, and as a potential drug target, the P2X7 receptor is also an interesting target in positron emission tomography. The current study aimed at the development and evaluation of a potent tracer targeting the P2X7 receptor, to which end four adamantanyl benzamide analogues with high affinity for the human P2X7 receptor were labelled with carbon-11. All four analogues could be obtained in excellent radiochemical yield and high radiochemical purity and molar activity, and all analogues entered the rat brain. [11C]SMW139 showed the highest metabolic stability in rat plasma, and showed high binding to the hP2X7 receptor in vivo in a hP2X7 receptor overexpressing rat model. Although no significant difference in binding of [11C]SMW139 was observed between post mortem brain tissue of Alzheimer's disease patients and that of healthy controls in in vitro autoradiography experiments, [11C]SMW139 could be a promising tracer for P2X7 receptor imaging using positron emission tomography, due to high receptor binding in vivo in the hP2X7 receptor overexpressing rat model. However, further investigation of both P2X7 receptor expression and binding of [11C]SMW139 in other neurological diseases involving microglial activation is warranted.
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Affiliation(s)
- Bieneke Janssen
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
| | - Danielle J Vugts
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | | | - Dieter Ory
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Sylvie Chalon
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Jeroen J M Hoozemans
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands
| | - Robert C Schuit
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Wissam Beaino
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Esther J M Kooijman
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Johan van den Hoek
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Mansoor Chishty
- Pharmidex Pharmaceutical Services Ltd., London, United Kingdom
| | - Aurélie Doméné
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Anke Van der Perren
- Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Alessandro Villa
- Center of Excellence on Neurodegenerative Diseases and Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Adriana Maggi
- Center of Excellence on Neurodegenerative Diseases and Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Ger T Molenaar
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
- BV Cyclotron VU, Amsterdam, The Netherlands
| | - Uta Funke
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
- BV Cyclotron VU, Amsterdam, The Netherlands
| | | | - Veerle Baekelandt
- Neurobiology and Gene Therapy, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Guy Bormans
- Laboratory for Radiopharmaceutical Research, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Adriaan A Lammertsma
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - Michael Kassiou
- School of Chemistry, University of Sydney, Sydney, Australia
| | - Albert D Windhorst
- Department of Radiology & Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands.
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Fantoni ER, Dal Ben D, Falzoni S, Di Virgilio F, Lovestone S, Gee A. Design, synthesis and evaluation in an LPS rodent model of neuroinflammation of a novel 18F-labelled PET tracer targeting P2X7. EJNMMI Res 2017; 7:31. [PMID: 28374288 PMCID: PMC5378566 DOI: 10.1186/s13550-017-0275-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/08/2017] [Indexed: 01/08/2023] Open
Abstract
Background The P2X7 receptor has been shown to play a fundamental role in the initiation and sustenance of the inflammatory cascade. The development of a novel fluorine-18 PET tracer superior and with a longer half-life to those currently available is a promising step towards harnessing the therapeutic and diagnostic potential offered by this target. Inspired by the known antagonist A-804598, the present study outlines the design via molecular docking, synthesis and biological evaluation of the novel P2X7 tracer [18F]EFB. The tracer was radiolabelled via a three-step procedure, in vitro binding assessed in P2X7-transfected HEK293 and in B16 cells by calcium influx assays and an initial preclinical evaluation was performed in a lipopolysaccharide (LPS)-injected rat model of neuroinflammation. Results The novel tracer [18F]EFB was synthesised in 210 min in 3–5% decay-corrected radiochemical yield (DC RCY), >99% radiochemical purity (RCP) and >300 GBq/μmol and fully characterised. Functional assays showed that the compound binds with nM Ki to human, rat and mouse P2X7 receptors. In vivo, [18F]EFB displayed a desirable distribution profile, and while it showed low blood–brain barrier penetration, brain uptake was quantifiable and displayed significantly higher mean longitudinal uptake in inflamed versus control rat CNS regions. Conclusions [18F]EFB demonstrates strong in vitro affinity to human and rodent P2X7 and limited yet quantifiable BBB penetration. Considering the initial promising in vivo data in an LPS rat model with elevated P2X7 expression, this work constitutes an important step in the development of a radiotracer useful for the diagnosis and monitoring of clinical disorders with associated neuroinflammatory processes. Electronic supplementary material The online version of this article (doi:10.1186/s13550-017-0275-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Enrico Raffaele Fantoni
- Department of Imaging Sciences and Biomedical Engineering, King's College London, St Thomas' Hospital, 4th floor Lambeth Wing, SE1 7EH, London, UK
| | - Diego Dal Ben
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032, Camerino, MC, Italy
| | - Simonetta Falzoni
- Prof Francesco Di Virgilio and Dr Simonetta Falzoni, Dipartimento di Morfologia, Chirurgia e Medicina Sperimentale, Sezione di Patologia, Oncologia e Biologia Sperimentale, University of Ferrara, Ferrara, Italy
| | - Francesco Di Virgilio
- Prof Francesco Di Virgilio and Dr Simonetta Falzoni, Dipartimento di Morfologia, Chirurgia e Medicina Sperimentale, Sezione di Patologia, Oncologia e Biologia Sperimentale, University of Ferrara, Ferrara, Italy
| | - Simon Lovestone
- Department of Psychiatry, Warneford Hospital, University of Oxford, Warneford Lane, Oxford, OX3 7JX, UK
| | - Antony Gee
- Department of Imaging Sciences and Biomedical Engineering, King's College London, St Thomas' Hospital, 4th floor Lambeth Wing, SE1 7EH, London, UK.
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The protective effect of resveratrol in the transmission of neuropathic pain mediated by the P2X 7 receptor in the dorsal root ganglia. Neurochem Int 2016; 103:24-35. [PMID: 28027922 DOI: 10.1016/j.neuint.2016.12.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/24/2016] [Accepted: 12/15/2016] [Indexed: 02/02/2023]
Abstract
The P2X7 receptor mediates afferent nerve activation and is related to chronic neuropathic pain. Resveratrol (RES) has also been reported to exhibit anti-inflammatory effects. In this study, we investigated the neuroprotective effect of RES on the transmission of neuropathic pain mediated by the P2X7 receptor. The P2X7 mRNA and protein expression levels in L4-L5 dorsal root ganglia (DRG)s of the chronic constriction injury (CCI) group were significantly higher than those observed in the Ctrl + NS, Sham + RES and Sham groups. RES increased the threshold of thermal and mechanical hypersensitivity in rats with chronic neuropathic pain. The P2X7 mRNA and protein expression levels in the CCI + RES group were decreased compared with those in the CCI group. Our results showed that RES inhibited the upregulated co-expression of P2X7 and glial fibrillary acidic protein (GFAP, a marker of satellite glial cells) in satellite glial cells of DRG in the CCI group. The results demonstrated that the expression of GFAP was increased in the CCI group and that RES inhibited the upregulated expression of GFAP in the rats in the CCI group. In addition, the phosphorylation levels of p38 and extracellular regulated protein kinases (ERK)1/2 in the CCI group were markedly higher than those observed in the Ctrl + NS, Sham + RES and Sham groups, whereas the phosphorylation levels of p38 and ERK1/2 in CCI + RES group were markedly lower than those observed in the CCI group. RES inhibited BzATP-activated currents in DRG non-neurons in the CCI rats. Our data provide evidence that RES may suppress the transmission of neuropathic pain mediated by the P2X7 receptor in the satellite glial cells of dorsal root ganglia.
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10
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Sociali G, Visigalli D, Prukop T, Cervellini I, Mannino E, Venturi C, Bruzzone S, Sereda MW, Schenone A. Tolerability and efficacy study of P2X7 inhibition in experimental Charcot-Marie-Tooth type 1A (CMT1A) neuropathy. Neurobiol Dis 2016; 95:145-57. [PMID: 27431093 DOI: 10.1016/j.nbd.2016.07.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 06/24/2016] [Accepted: 07/13/2016] [Indexed: 12/24/2022] Open
Abstract
Charcot-Marie-Tooth 1A (CMT1A) is a demyelinating hereditary neuropathy for which pharmacological treatments are not yet available. An abnormally high intracellular Ca(2+) concentration was observed in Schwann cells (SC) from CMT1A rats, caused by the PMP22-mediated overexpression of the P2X7 purinoceptor. The purpose of this study was to investigate the tolerability and therapeutic potential of a pharmacological antagonist of the P2X7 receptor (A438079) in CMT1A. A438079 ameliorated in vitro myelination of organotypic DRG cultures from CMT1A rats. Furthermore, we performed an experimental therapeutic trial in PMP22 transgenic and in wild-type rats. A preliminary dose-escalation trial showed that 3mg/kg A438079 administered via intraperitoneal injection every 24h for four weeks was well tolerated by wild type and CMT1A rats. Affected rats treated with 3mg/kg A438079 revealed a significant improvement of the muscle strength, when compared to placebo controls. Importantly, histologic analysis revealed a significant increase of the total number of myelinated axons in tibial nerves. Moreover, a significant decrease of the hypermyelination of small caliber axons and a significant increase of the frequency and diameter of large caliber myelinated axons was highlighted. An improved distal motor latencies was recorded, whereas compound muscle action potentials (CMAP) remained unaltered. A438079 reduced the SC differentiation defect in CMT1A rats. These results show that pharmacological inhibition of the P2X7 receptor is well tolerated in CMT1A rats and represents a proof-of-principle that antagonizing this pathway may correct the molecular derangements and improve the clinical phenotype in the CMT1A neuropathy.
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Affiliation(s)
- Giovanna Sociali
- DIMES, Section of Biochemistry, and CEBR, University of Genova, Viale Benedetto XV, 1, 16132, Italy
| | - Davide Visigalli
- DINOGMI and CEBR, University of Genova, Largo P. Daneo 3, 16132 Genova, Italy
| | - Thomas Prukop
- Max Planck Institute of Experimental Medicine, Research Group "Molecular and Translational Neurology", Department of Neurogenetics, Hermann-Rein-Str. 3, 37075 Göttingen, Germany; University Medical Center Göttingen, Institute of Clinical Pharmacology, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Ilaria Cervellini
- Max Planck Institute of Experimental Medicine, Research Group "Molecular and Translational Neurology", Department of Neurogenetics, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Elena Mannino
- DIMES, Section of Biochemistry, and CEBR, University of Genova, Viale Benedetto XV, 1, 16132, Italy
| | - Consuelo Venturi
- DINOGMI and CEBR, University of Genova, Largo P. Daneo 3, 16132 Genova, Italy
| | - Santina Bruzzone
- DIMES, Section of Biochemistry, and CEBR, University of Genova, Viale Benedetto XV, 1, 16132, Italy.
| | - Michael W Sereda
- Max Planck Institute of Experimental Medicine, Research Group "Molecular and Translational Neurology", Department of Neurogenetics, Hermann-Rein-Str. 3, 37075 Göttingen, Germany; University Medical Center Göttingen, Department of Clinical Neurophysiology, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Angelo Schenone
- DINOGMI and CEBR, University of Genova, Largo P. Daneo 3, 16132 Genova, Italy
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11
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De Marchi E, Orioli E, Dal Ben D, Adinolfi E. P2X7 Receptor as a Therapeutic Target. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 104:39-79. [PMID: 27038372 DOI: 10.1016/bs.apcsb.2015.11.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
P2X7 receptor is an ATP-gated cation channel that upon agonist interaction leads to cellular influx of Na(+) and Ca(2+) and efflux of K(+). P2X7 is expressed by a wide variety of cells and its activation mediates a large number of biological processes like inflammation, neuromodulation, cell death or cell proliferation and it has been associated to related pathological conditions including infectious, inflammatory, autoimmune, neurological, and musculoskeletal disorders and, in the last years, to cancer. This chapter describes structural features of P2X7, chemical properties of its agonist, antagonist, and allosteric modulators and summarizes recent advances on P2X7 receptor as therapeutic target in the aforementioned diseases. We also give an overview on recent literature suggesting that P2X7 single-nucleotide polymorphisms could be exploited as diagnostic biomarkers for the development of tailored therapies.
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Affiliation(s)
- Elena De Marchi
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Elisa Orioli
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Diego Dal Ben
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Camerino, Italy
| | - Elena Adinolfi
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy.
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12
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Kwak SH, Lee WG, Lee YJ, Lee SD, Kim YC, Ko H. Discovery of novel purine-based heterocyclic P2X7 receptor antagonists. Bioorg Chem 2015; 61:58-65. [DOI: 10.1016/j.bioorg.2015.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 06/15/2015] [Accepted: 06/16/2015] [Indexed: 11/30/2022]
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13
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Bartlett R, Stokes L, Sluyter R. The P2X7 receptor channel: recent developments and the use of P2X7 antagonists in models of disease. Pharmacol Rev 2015; 66:638-75. [PMID: 24928329 DOI: 10.1124/pr.113.008003] [Citation(s) in RCA: 309] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The P2X7 receptor is a trimeric ATP-gated cation channel found predominantly, but not exclusively, on immune cells. P2X7 activation results in a number of downstream events, including the release of proinflammatory mediators and cell death and proliferation. As such, P2X7 plays important roles in various inflammatory, immune, neurologic and musculoskeletal disorders. This review focuses on the use of P2X7 antagonists in rodent models of neurologic disease and injury, inflammation, and musculoskeletal and other disorders. The cloning and characterization of human, rat, mouse, guinea pig, dog, and Rhesus macaque P2X7, as well as recent observations regarding the gating and permeability of P2X7, are discussed. Furthermore, this review discusses polymorphic and splice variants of P2X7, as well as the generation and use of P2X7 knockout mice. Recent evidence for emerging signaling pathways downstream of P2X7 activation and the growing list of negative and positive modulators of P2X7 activation and expression are also described. In addition, the use of P2X7 antagonists in numerous rodent models of disease is extensively summarized. Finally, the use of P2X7 antagonists in clinical trials in humans and future directions exploring P2X7 as a therapeutic target are described.
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Affiliation(s)
- Rachael Bartlett
- School of Biological Sciences, University of Wollongong, New South Wales, Australia and Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia (R.B., R.S.); and Health Innovations Research Institute, School of Medical Sciences, RMIT University, Bundoora, Victoria, Australia (L.S.)
| | - Leanne Stokes
- School of Biological Sciences, University of Wollongong, New South Wales, Australia and Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia (R.B., R.S.); and Health Innovations Research Institute, School of Medical Sciences, RMIT University, Bundoora, Victoria, Australia (L.S.)
| | - Ronald Sluyter
- School of Biological Sciences, University of Wollongong, New South Wales, Australia and Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia (R.B., R.S.); and Health Innovations Research Institute, School of Medical Sciences, RMIT University, Bundoora, Victoria, Australia (L.S.)
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14
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Chemobrain: a critical review and causal hypothesis of link between cytokines and epigenetic reprogramming associated with chemotherapy. Cytokine 2015; 72:86-96. [PMID: 25573802 DOI: 10.1016/j.cyto.2014.12.006] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 10/29/2014] [Accepted: 12/08/2014] [Indexed: 01/21/2023]
Abstract
One consequence of modern cancer therapy is chemotherapy related cognitive dysfunction or "chemobrain", the subjective experience of cognitive deficits at any point during or following chemotherapy. Chemobrain, a well-established clinical syndrome, has become an increasing concern because the number of long-term cancer survivors is growing dramatically. There is strong evidence that correlates changes in peripheral cytokines with the development of chemobrain in commonly used chemotherapeutic drugs for different types of cancer. However, the mechanisms by which these cytokines elicit change in the central nervous system are still unclear. In this review, we hypothesize that the administration of chemotherapy agents initiates a cascade of biological changes, with short-lived alterations in the cytokine milieu inducing persistent epigenetic alterations. These epigenetic changes lead to changes in gene expression, alterations in metabolic activity and neuronal transmission that are responsible for generating the subjective experience of cognition. This speculative but testable hypothesis should help to gain a comprehensive understanding of the mechanism underlying cognitive dysfunction in cancer patients. Such knowledge is critical to identify pharmaceutical targets with the potential to prevent and treat cancer-treatment related cognitive dysfunction and similar disorders.
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15
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The purinergic system and glial cells: emerging costars in nociception. BIOMED RESEARCH INTERNATIONAL 2014; 2014:495789. [PMID: 25276794 PMCID: PMC4168030 DOI: 10.1155/2014/495789] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 07/08/2014] [Indexed: 12/23/2022]
Abstract
It is now well established that glial cells not only provide mechanical and trophic support to neurons but can directly contribute to neurotransmission, for example, by release and uptake of neurotransmitters and by secreting pro- and anti-inflammatory mediators. This has greatly changed our attitude towards acute and chronic disorders, paving the way for new therapeutic approaches targeting activated glial cells to indirectly modulate and/or restore neuronal functions. A deeper understanding of the molecular mechanisms and signaling pathways involved in neuron-to-glia and glia-to-glia communication that can be pharmacologically targeted is therefore a mandatory step toward the success of this new healing strategy. This holds true also in the field of pain transmission, where the key involvement of astrocytes and microglia in the central nervous system and satellite glial cells in peripheral ganglia has been clearly demonstrated, and literally hundreds of signaling molecules have been identified. Here, we shall focus on one emerging signaling system involved in the cross talk between neurons and glial cells, the purinergic system, consisting of extracellular nucleotides and nucleosides and their membrane receptors. Specifically, we shall summarize existing evidence of novel “druggable” glial purinergic targets, which could help in the development of innovative analgesic approaches to chronic pain states.
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16
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Nobbio L, Visigalli D, Mannino E, Fiorese F, Kassack MU, Sturla L, Prada V, De Flora A, Zocchi E, Bruzzone S, Schenone A. The diadenosine homodinucleotide P18 improves in vitro myelination in experimental Charcot-Marie-Tooth type 1A. J Cell Biochem 2014; 115:161-7. [PMID: 23959806 DOI: 10.1002/jcb.24644] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 08/02/2013] [Indexed: 11/05/2022]
Abstract
Charcot-Marie-Tooth 1A (CMT1A) is a demyelinating hereditary neuropathy whose pathogenetic mechanisms are still poorly defined and an etiologic treatment is not yet available. An abnormally high intracellular Ca(2+) concentration ([Ca(2+)]i) occurs in Schwann cells from CMT1A rats (CMT1A SC) and is caused by overexpression of the purinoceptor P2X7. Normalization of the Ca(2+) levels through down-regulation of P2X7 appears to restore the normal phenotype of CMT1A SC in vitro. We recently demonstrated that the diadenosine 5',5'''-P1, P2-diphosphate (Ap2A) isomer P18 behaves as an antagonist of the P2X7 purinergic receptor, effectively blocking channel opening induced by ATP. In addition, P18 behaves as a P2Y11 agonist, inducing cAMP overproduction in P2Y11-overexpressing cells. Here we investigated the in vitro effects of P18 on CMT1A SC. We observed that basal levels of intracellular cAMP ([cAMP]i), a known regulator of SC differentiation and myelination, are significantly lower in CMT1A SC than in wild-type (wt) cells. P18 increased [cAMP]i in both CMT1A and wt SC, and this effects was blunted by NF157, a specific P2Y11 antagonist. Prolonged treatment of organotypic dorsal root ganglia (DRG) cultures with P18 significantly increased expression of myelin protein zero, a marker of myelin production, in both CMT1A and wt cultures. Interestingly, P18 decreased the content of non-phosphorylated neurofilaments, a marker of axonal damage, only in CMT1A DRG cultures. These results suggest that P2X7 antagonists, in combination with [cAMP]i-increasing agents, could represent a therapeutic strategy aimed at correcting the molecular derangements causing the CMT1A phenotype.
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Affiliation(s)
- Lucilla Nobbio
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Mother and Child Sciences and CEBR, University of Genova, Genova, Italy
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Janssen B, Vugts DJ, Funke U, Spaans A, Schuit RC, Kooijman E, Rongen M, Perk LR, Lammertsma AA, Windhorst AD. Synthesis and initial preclinical evaluation of the P2X7 receptor antagonist [¹¹C]A-740003 as a novel tracer of neuroinflammation. J Labelled Comp Radiopharm 2014; 57:509-16. [PMID: 24995673 DOI: 10.1002/jlcr.3206] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 04/09/2014] [Accepted: 04/11/2014] [Indexed: 11/10/2022]
Abstract
Neuroinflammation, in particular activation of microglia, is thought to play an important role in the progression of neurodegenerative diseases. In activated microglia, the purinergic P2X7 receptor is upregulated. A-740003, a highly affine and selective P2X7 receptor antagonist, is a promising candidate for the development of a radiotracer for imaging of neuroinflammation by positron emission tomography. For this purpose, [(11)C]A-740003 was synthesised and evaluated in vivo with respect to both tracer metabolism and biodistribution. In plasma, a moderate metabolic rate was seen. In healthy rat brain, only marginal uptake of [(11)C]A-740003 was observed and, therefore, metabolites in brain could not be determined. Whether the minimal brain uptake is due to the low expression levels of the P2X7 receptor in healthy brain or to limited transport across the blood-brain barrier has yet to be elucidated.
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Affiliation(s)
- Bieneke Janssen
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
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18
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Chrovian CC, Rech JC, Bhattacharya A, Letavic MA. P2X7 antagonists as potential therapeutic agents for the treatment of CNS disorders. PROGRESS IN MEDICINAL CHEMISTRY 2014; 53:65-100. [PMID: 24418608 DOI: 10.1016/b978-0-444-63380-4.00002-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The use of P2X7 antagonists to treat inflammatory disorders has garnered considerable interest in recent years. An increasing number of literature reports support the role of P2X7 in inflammatory pathways of the peripheral and central nervous systems (CNSs). A number of CNS indications such as neuropsychiatric and neurodegenerative disorders and neuropathic pain have been linked to a neuroinflammatory response, and clinical studies have shown that inflammatory biomarkers can be mitigated by modulating P2X7. Recent scientific and patent literature describing novel P2X7 antagonists has indicated their use in CNS disorders. In addition, several reports have disclosed the results of administering P2X7 antagonists in pre-clinical models of CNS disease or investigating brain uptake. This review describes small molecule P2X7 antagonists that have first appeared in the literature since 2009 and have potential therapeutic utility in the CNS, or for which new data have emerged implicating their use in CNS indications.
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Affiliation(s)
| | - Jason C Rech
- Janssen Research and Development, LLC, San Diego, CA, USA
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19
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P2X7 Cell Death Receptor Activation and Mitochondrial Impairment in Oxaliplatin-Induced Apoptosis and Neuronal Injury: Cellular Mechanisms and In Vivo Approach. PLoS One 2013; 8:e66830. [PMID: 23826152 PMCID: PMC3695015 DOI: 10.1371/journal.pone.0066830] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 05/10/2013] [Indexed: 12/25/2022] Open
Abstract
Limited information is available regarding the cellular mechanisms of oxaliplatin-induced painful neuropathy during exposure of patients to this drug. We therefore determined oxidative stress in cultured cells and evaluated its occurrence in C57BL/6 mice. Using both cultured neuroblastoma (SH-SY5Y) and macrophage (RAW 264.7) cell lines and also brain tissues of oxaliplatin-treated mice, we investigated whether oxaliplatin (OXA) induces oxidative stress and apoptosis. Cultured cells were treated with 2–200 µM OXA for 24 h. The effects of pharmacological inhibitors of oxidative stress or inflammation (N-acetyl cysteine, ibuprofen, acetaminophen) were also tested. Inhibitors were added 30 min before OXA treatment and then in combination with OXA for 24 h. In SH-SY5Y cells, OXA caused a significant dose-dependent decrease in viability, a large increase in ROS and NO production, lipid peroxidation and mitochondrial impairment as assessed by a drop in mitochondrial membrane potential, which are deleterious for the cell. An increase in levels of negatively charged phospholipids such as cardiolipin but also phosphatidylserine and phosphatidylinositol, was also observed. Additionally, OXA caused concentration-dependent P2X7 receptor activation, increased chromatin condensation and caspase-3 activation associated with TNF-α and IL-6 release. The majority of these toxic effects were equally observed in Raw 264.7 which also presented high levels of PGE2. Pretreatment of SH-SY5Y cells with pharmacological inhibitors significantly reduced or blocked all the neurotoxic OXA effects. In OXA-treated mice (28 mg/kg cumulated dose) significant cold hyperalgesia and oxidative stress in the tested brain areas were shown. Our study suggests that targeting P2X7 receptor activation and mitochondrial impairment might be a potential therapeutic strategy against OXA-induced neuropathic pain.
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20
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Purinergic mechanisms and pain--an update. Eur J Pharmacol 2013; 716:24-40. [PMID: 23524093 DOI: 10.1016/j.ejphar.2013.01.078] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 12/11/2012] [Accepted: 01/09/2013] [Indexed: 12/12/2022]
Abstract
There is a brief summary of the background literature about purinergic signalling. The review then considers purinergic mechanosensory transduction involved in visceral, cutaneous and musculoskeletal nociception and on the roles played by P2X3, P2X2/3, P2X4, P2X7 and P2Y₁₂ receptors in neuropathic and inflammatory pain. Current developments of compounds for the therapeutic treatment of both visceral and neuropathic pain are discussed.
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21
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Brain-derived neurotrophic factor from microglia: a molecular substrate for neuropathic pain. ACTA ACUST UNITED AC 2012; 7:99-108. [PMID: 22613083 DOI: 10.1017/s1740925x12000087] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
One of the most significant advances in pain research is the realization that neurons are not the only cell type involved in the etiology of chronic pain. This realization has caused a radical shift from the previous dogma that neuronal dysfunction alone accounts for pain pathologies to the current framework of thinking that takes into account all cell types within the central nervous system (CNS). This shift in thinking stems from growing evidence that glia can modulate the function and directly shape the cellular architecture of nociceptive networks in the CNS. Microglia, in particular, are increasingly recognized as active principal players that respond to changes in physiological homeostasis by extending their processes toward the site of neural damage, and by releasing specific factors that have profound consequences on neuronal function and that contribute to CNS pathologies caused by disease or injury. A key molecule that modulates microglia activity is ATP, an endogenous ligand of the P2 receptor family. Microglia expresses several P2 receptor subtypes, and of these the P2X4 receptor subtype has emerged as a core microglia-neuron signaling pathway: activation of this receptor drives the release of brain-derived neurotrophic factor (BDNF), a cellular substrate that causes disinhibition of pain-transmitting spinal lamina I neurons. Converging evidence points to BDNF from spinal microglia as being a critical microglia-neuron signaling molecule that gates aberrant nociceptive processing in the spinal cord. The present review highlights recent advances in our understanding of P2X4 receptor-mediated signaling and regulation of BDNF in microglia, as well as the implications for microglia-neuron interactions in the pathobiology of neuropathic pain.
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22
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Kaczmarek-Hájek K, Lörinczi E, Hausmann R, Nicke A. Molecular and functional properties of P2X receptors--recent progress and persisting challenges. Purinergic Signal 2012; 8:375-417. [PMID: 22547202 PMCID: PMC3360091 DOI: 10.1007/s11302-012-9314-7] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 10/18/2011] [Indexed: 12/16/2022] Open
Abstract
ATP-gated P2X receptors are trimeric ion channels that assemble as homo- or heteromers from seven cloned subunits. Transcripts and/or proteins of P2X subunits have been found in most, if not all, mammalian tissues and are being discovered in an increasing number of non-vertebrates. Both the first crystal structure of a P2X receptor and the generation of knockout (KO) mice for five of the seven cloned subtypes greatly advanced our understanding of their molecular and physiological function and their validation as drug targets. This review summarizes the current understanding of the structure and function of P2X receptors and gives an update on recent developments in the search for P2X subtype-selective ligands. It also provides an overview about the current knowledge of the regulation and modulation of P2X receptors on the cellular level and finally on their physiological roles as inferred from studies on KO mice.
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Affiliation(s)
- Karina Kaczmarek-Hájek
- Max Planck Institute for Experimental Medicine, Hermann Rein Str. 3, 37075, Göttingen, Germany
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23
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P2X4 purinoceptor signaling in chronic pain. Purinergic Signal 2012; 8:621-8. [PMID: 22528681 DOI: 10.1007/s11302-012-9306-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 02/14/2012] [Indexed: 01/19/2023] Open
Abstract
ATP, acting via P2 purinergic receptors, is a known mediator of inflammatory and neuropathic pain. There is increasing evidence that the ATP-gated P2X4 receptor (P2X4R) subtype is a locus through which activity of spinal microglia and peripheral macrophages instigate pain hypersensitivity caused by inflammation or by injury to a peripheral nerve. The present article highlights the recent advances in our understanding of microglia-neuron interactions in neuropathic pain by focusing on the signaling and regulation of the P2X4R. We will also develop a framework for understanding converging lines of evidence for involvement of P2X4Rs expressed on macrophages in peripheral inflammatory pain.
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24
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Lee WG, Lee SD, Cho JH, Jung Y, Kim JH, Hien TT, Kang KW, Ko H, Kim YC. Structure–Activity Relationships and Optimization of 3,5-Dichloropyridine Derivatives As Novel P2X7Receptor Antagonists. J Med Chem 2012; 55:3687-98. [DOI: 10.1021/jm2012326] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Won-Gil Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - So-Deok Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Joong-Heui Cho
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Younghwan Jung
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Jeong-hyun Kim
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Tran T. Hien
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Keon-Wook Kang
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Hyojin Ko
- Graduate Program of Medical System Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Yong-Chul Kim
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
- Graduate Program of Medical System Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
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Trang T, Beggs S, Salter MW. ATP receptors gate microglia signaling in neuropathic pain. Exp Neurol 2011; 234:354-61. [PMID: 22116040 DOI: 10.1016/j.expneurol.2011.11.012] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 10/31/2011] [Accepted: 11/08/2011] [Indexed: 01/30/2023]
Abstract
Microglia were described by Pio del Rio-Hortega (1932) as being the 'third element' distinct from neurons and astrocytes. Decades after this observation, the function and even the very existence of microglia as a distinct cell type were topics of intense debate and conjecture. However, considerable advances have been made towards understanding the neurobiology of microglia resulting in a radical shift in our view of them as being passive bystanders that have solely immune and supportive roles, to being active principal players that contribute to central nervous system pathologies caused by disease or following injury. Converging lines of evidence implicate microglia as being essential in the pathogenesis of neuropathic pain, a debilitating chronic pain condition that can occur after peripheral nerve damage caused by disease, infection, or physical injury. A key molecule that modulates microglial activity is ATP, an endogenous ligand of the P2-purinoceptor family consisting of P2X ionotropic and P2Y metabotropic receptors. Microglia express several P2 receptor subtypes, and of these the P2X4, P2X7, and P2Y12 receptor subtypes have been implicated in neuropathic pain. The P2X4 receptor has emerged as the core microglia-neuron signaling pathway: activation of this receptor causes release of brain-derived neurotrophic factor (BDNF) which causes disinhibition of pain-transmission neurons in spinal lamina I. The present review highlights recent advances in understanding the signaling and regulation of P2 receptors expressed in microglia and the implications for microglia-neuron interactions for the management of neuropathic pain.
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Affiliation(s)
- Tuan Trang
- Program in Neuroscience and Mental Health, Hospital for Sick Children, University of Toronto Centre for the Study of Pain, Toronto, Ontario, Canada M5G 1X8
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26
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Abstract
The use of Quantitative Structure-Activity Relationship models to address problems in drug discovery has a mixed history, generally resulting from the misapplication of QSAR models that were either poorly constructed or used outside of their domains of applicability. This situation has motivated the development of a variety of model performance metrics (r(2), PRESS r(2), F-tests, etc.) designed to increase user confidence in the validity of QSAR predictions. In a typical workflow scenario, QSAR models are created and validated on training sets of molecules using metrics such as Leave-One-Out or many-fold cross-validation methods that attempt to assess their internal consistency. However, few current validation methods are designed to directly address the stability of QSAR predictions in response to changes in the information content of the training set. Since the main purpose of QSAR is to quickly and accurately estimate a property of interest for an untested set of molecules, it makes sense to have a means at hand to correctly set user expectations of model performance. In fact, the numerical value of a molecular prediction is often less important to the end user than knowing the rank order of that set of molecules according to their predicted end point values. Consequently, a means for characterizing the stability of predicted rank order is an important component of predictive QSAR. Unfortunately, none of the many validation metrics currently available directly measure the stability of rank order prediction, making the development of an additional metric that can quantify model stability a high priority. To address this need, this work examines the stabilities of QSAR rank order models created from representative data sets, descriptor sets, and modeling methods that were then assessed using Kendall Tau as a rank order metric, upon which the Shannon entropy was evaluated as a means of quantifying rank-order stability. Random removal of data from the training set, also known as Data Truncation Analysis (DTA), was used as a means for systematically reducing the information content of each training set while examining both rank order performance and rank order stability in the face of training set data loss. The premise for DTA ROE model evaluation is that the response of a model to incremental loss of training information will be indicative of the quality and sufficiency of its training set, learning method, and descriptor types to cover a particular domain of applicability. This process is termed a "rank order entropy" evaluation or ROE. By analogy with information theory, an unstable rank order model displays a high level of implicit entropy, while a QSAR rank order model which remains nearly unchanged during training set reductions would show low entropy. In this work, the ROE metric was applied to 71 data sets of different sizes and was found to reveal more information about the behavior of the models than traditional metrics alone. Stable, or consistently performing models, did not necessarily predict rank order well. Models that performed well in rank order did not necessarily perform well in traditional metrics. In the end, it was shown that ROE metrics suggested that some QSAR models that are typically used should be discarded. ROE evaluation helps to discern which combinations of data set, descriptor set, and modeling methods lead to usable models in prioritization schemes and provides confidence in the use of a particular model within a specific domain of applicability.
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Abstract
The myriad pain pathophysiology has intrigued and challenged humanity for centuries. In this regard, the traditional pain therapies such as opioids and nonsteroidal anti-inflammatory drugs have been highly successful in treating acute and chronic pain. However, their drawback includes adverse events such as psychotropic effects, addiction potential, and gastrointestinal toxicities, to mention a few. These factors combined with the likelihood of an increase in chronic pain conditions due to an aging population calls for the development of novel mechanism-based or "site-specific" agents to target novel pain pathways. In this regard, rapid progress has been made in understanding the molecular mechanisms of novel pain targets such as cannabinoid receptors, fatty acid hydrolase, voltage-gated and ligand-gated ion channels such as P2 receptors, transient receptor potential channels and glial cell modulators. Accordingly, preclinical studies indicate that the site-specific/selective agents exhibit sufficient efficacy and reduced side effects such as lack of psychotropic effects indicating their clinical potential. This review provides a brief summary of some "at-site" pain targets and their role in the pain pathophysiology, and describes the efforts in developing some small molecules as novel pain therapeutics.
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Affiliation(s)
- Praveen Pn Rao
- School of Pharmacy, Health Sciences Campus, University of Waterloo, Waterloo, ON, Canada
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28
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Burnstock G, Krügel U, Abbracchio MP, Illes P. Purinergic signalling: from normal behaviour to pathological brain function. Prog Neurobiol 2011; 95:229-74. [PMID: 21907261 DOI: 10.1016/j.pneurobio.2011.08.006] [Citation(s) in RCA: 310] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/12/2011] [Accepted: 08/15/2011] [Indexed: 02/07/2023]
Abstract
Purinergic neurotransmission, involving release of ATP as an efferent neurotransmitter was first proposed in 1972. Later, ATP was recognised as a cotransmitter in peripheral nerves and more recently as a cotransmitter with glutamate, noradrenaline, GABA, acetylcholine and dopamine in the CNS. Both ATP, together with some of its enzymatic breakdown products (ADP and adenosine) and uracil nucleotides are now recognised to act via P2X ion channels and P1 and P2Y G protein-coupled receptors, which are widely expressed in the brain. They mediate both fast signalling in neurotransmission and neuromodulation and long-term (trophic) signalling in cell proliferation, differentiation and death. Purinergic signalling is prominent in neurone-glial cell interactions. In this review we discuss first the evidence implicating purinergic signalling in normal behaviour, including learning and memory, sleep and arousal, locomotor activity and exploration, feeding behaviour and mood and motivation. Then we turn to the involvement of P1 and P2 receptors in pathological brain function; firstly in trauma, ischemia and stroke, then in neurodegenerative diseases, including Alzheimer's, Parkinson's and Huntington's, as well as multiple sclerosis and amyotrophic lateral sclerosis. Finally, the role of purinergic signalling in neuropsychiatric diseases (including schizophrenia), epilepsy, migraine, cognitive impairment and neuropathic pain will be considered.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK.
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Coddou C, Yan Z, Obsil T, Huidobro-Toro JP, Stojilkovic SS. Activation and regulation of purinergic P2X receptor channels. Pharmacol Rev 2011; 63:641-83. [PMID: 21737531 DOI: 10.1124/pr.110.003129] [Citation(s) in RCA: 394] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mammalian ATP-gated nonselective cation channels (P2XRs) can be composed of seven possible subunits, denoted P2X1 to P2X7. Each subunit contains a large ectodomain, two transmembrane domains, and intracellular N and C termini. Functional P2XRs are organized as homomeric and heteromeric trimers. This review focuses on the binding sites involved in the activation (orthosteric) and regulation (allosteric) of P2XRs. The ectodomains contain three ATP binding sites, presumably located between neighboring subunits and formed by highly conserved residues. The detection and coordination of three ATP phosphate residues by positively charged amino acids are likely to play a dominant role in determining agonist potency, whereas an AsnPheArg motif may contribute to binding by coordinating the adenine ring. Nonconserved ectodomain histidines provide the binding sites for trace metals, divalent cations, and protons. The transmembrane domains account not only for the formation of the channel pore but also for the binding of ivermectin (a specific P2X4R allosteric regulator) and alcohols. The N- and C- domains provide the structures that determine the kinetics of receptor desensitization and/or pore dilation and are critical for the regulation of receptor functions by intracellular messengers, kinases, reactive oxygen species and mercury. The recent publication of the crystal structure of the zebrafish P2X4.1R in a closed state provides a major advance in the understanding of this family of receptor channels. We will discuss data obtained from numerous site-directed mutagenesis experiments accumulated during the last 15 years with reference to the crystal structure, allowing a structural interpretation of the molecular basis of orthosteric and allosteric ligand actions.
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Affiliation(s)
- Claudio Coddou
- Section on Cellular Signaling, Program in Developmental Neuroscience, National Institute of Child Health and Human Developmant, National Institutes of Health, Bethesda, MD 20892-4510, USA
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Jorgensen WL, Trofimov A, Du X, Hare AA, Leng L, Bucala R. Benzisothiazolones as modulators of macrophage migration inhibitory factor. Bioorg Med Chem Lett 2011; 21:4545-9. [PMID: 21719283 DOI: 10.1016/j.bmcl.2011.05.127] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 05/27/2011] [Accepted: 05/31/2011] [Indexed: 02/02/2023]
Abstract
Substituted N-phenylbenzisothiazolones have been investigated as inhibitors of the tautomerase activity of the proinflammatory cytokine MIF (macrophage migration inhibitory factor). Numerous compounds were found to possess antagonist activity in the low micromolar range with the most potent being the 6-hydroxy analog 1w. Compound 1w and the p-cyano analog 1c were also shown to exhibit significant inhibition of the binding of MIF to its transmembrane receptor CD74. Consistently, both compounds were also found to retard the MIF-dependent phosphorylation of ERK1/2 in human synovial fibroblasts.
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Synthesis and in vitro activity of N-benzyl-1-(2,3-dichlorophenyl)-1H-tetrazol-5-amine P2X7 antagonists. Bioorg Med Chem Lett 2011; 21:3297-300. [DOI: 10.1016/j.bmcl.2011.04.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2010] [Revised: 04/04/2011] [Accepted: 04/07/2011] [Indexed: 11/21/2022]
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Role of different brain areas in peripheral nerve injury-induced neuropathic pain. Brain Res 2011; 1381:187-201. [DOI: 10.1016/j.brainres.2011.01.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 12/16/2010] [Accepted: 01/03/2011] [Indexed: 02/07/2023]
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Identification of 2-oxo-N-(phenylmethyl)-4-imidazolidinecarboxamide antagonists of the P2X7 receptor. Bioorg Med Chem Lett 2010; 20:6370-4. [DOI: 10.1016/j.bmcl.2010.09.101] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 09/15/2010] [Accepted: 09/16/2010] [Indexed: 11/20/2022]
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Abdi MH, Beswick PJ, Billinton A, Chambers LJ, Charlton A, Collins SD, Collis KL, Dean DK, Fonfria E, Gleave RJ, Lejeune CL, Livermore DG, Medhurst SJ, Michel AD, Moses AP, Page L, Patel S, Roman SA, Senger S, Slingsby B, Steadman JG, Stevens AJ, Walter DS. Discovery and structure–activity relationships of a series of pyroglutamic acid amide antagonists of the P2X7 receptor. Bioorg Med Chem Lett 2010; 20:5080-4. [DOI: 10.1016/j.bmcl.2010.07.033] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 07/06/2010] [Accepted: 07/08/2010] [Indexed: 11/25/2022]
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Beswick PJ, Billinton A, Chambers LJ, Dean DK, Fonfria E, Gleave RJ, Medhurst SJ, Michel AD, Moses AP, Patel S, Roman SA, Roomans S, Senger S, Stevens AJ, Walter DS. Structure-activity relationships and in vivo activity of (1H-pyrazol-4-yl)acetamide antagonists of the P2X(7) receptor. Bioorg Med Chem Lett 2010; 20:4653-6. [PMID: 20579878 DOI: 10.1016/j.bmcl.2010.05.107] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 05/26/2010] [Accepted: 05/29/2010] [Indexed: 10/19/2022]
Abstract
Structure-activity relationships (SAR) of analogues of lead compound 1 were investigated and compound 16 was selected for further study in animal models of pain. Compound 16 was shown to be a potent antihyperalgesic agent in both the rat acute complete Freund's adjuvant (CFA) model of inflammatory pain [Iadarola, M. J.; Douglass, J.; Civelli, O.; Naranjo, J. R. rain Res.1988, 455, 205] and the knee joint model of chronic inflammatory pain [Wilson, A. W.; Medhurst, S. J.; Dixon, C. I.; Bontoft, N. C.; Winyard, L. A.; Brackenborough, K. T.; De Alba, J.; Clarke, C. J.; Gunthorpe, M. J.; Hicks, G. A.; Bountra, C.; McQueen, D. S.; Chessell, I. P. Eur. J. Pain2006, 10, 537].
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Affiliation(s)
- Paul J Beswick
- Neurosciences Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park, Harlow, Essex CM19 5AW, UK
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Synthesis and structure–activity relationships of a series of (1H-pyrazol-4-yl)acetamide antagonists of the P2X7 receptor. Bioorg Med Chem Lett 2010; 20:3161-4. [DOI: 10.1016/j.bmcl.2010.03.096] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 03/25/2010] [Accepted: 03/25/2010] [Indexed: 11/21/2022]
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Abstract
Neuropathic pain, a severe chronic pain condition characterized by a complex pathophysiology, is a largely unmet medical need. Ion channels, which underlie cell excitability, are heavily implicated in the biological mechanisms that generate and sustain neuropathic pain. This review highlights the biological evidence supporting the involvement of voltage-, proton- and ligand-gated ion channels in the neuropathic pain setting. Ion channel modulators at different research or development stages are reviewed and referenced. Ion channel modulation is one of the main avenues to achieve novel, improved neuropathic pain treatments. Voltage-gated sodium and calcium channel and glutamate receptor modulators are likely to produce new, improved agents in the future. Rationally targeting subtypes of known ion channels, tackling recently discovered ion channel targets or combining drugs with different mechanism of action will be primary sources of new drugs in the longer term.
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Andó RD, Méhész B, Gyires K, Illes P, Sperlágh B. A comparative analysis of the activity of ligands acting at P2X and P2Y receptor subtypes in models of neuropathic, acute and inflammatory pain. Br J Pharmacol 2010; 159:1106-17. [PMID: 20136836 DOI: 10.1111/j.1476-5381.2009.00596.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND AND PURPOSE This study was undertaken to compare the analgesic activity of antagonists acting at P2X1, P2X7, and P2Y12 receptors and agonists acting at P2Y1, P2Y2, P2Y4, and P2Y6 receptors in neuropathic, acute, and inflammatory pain. EXPERIMENTAL APPROACH The effect of the wide spectrum P2 receptor antagonist PPADS, the selective P2X7 receptor antagonist Brilliant Blue G (BBG), the P2X1 receptor antagonist (4,4',4'',4-[carbonylbis(imino-5,1,3-benzenetriyl-bis(carbonylimino))]tetrakis-1,3-benzenedisulfonic acid, octasodium salt (NF449) and (8,8'-[carbonylbis(imino-3,1-phenylenecarbonylimino)]bis-1,3,5-naphthalene-trisulphonic acid, hexasodium salt (NF023), the P2Y12 receptor antagonist (2,2-dimethyl-propionic acid 3-(2-chloro-6-methylaminopurin-9-yl)-2-(2,2-dimethyl-propionyloxymethyl)-propylester (MRS2395), the selective P2Y1 receptor agonist ([[(1R,2R,3S,4R,5S)-4-[6-amino-2-(methylthio)-9H-purin-9-yl]-2,3-dihydroxybicyclo[3.1.0]hex-1-yl]methyl] diphosphoric acid mono ester trisodium salt (MRS2365), the P2Y2/P2Y4 agonist uridine-5'-triphosphate (UTP), and the P2Y4/P2Y6 agonist uridine-5'-diphosphate (UDP) were examined on mechanical allodynia in the Seltzer model of neuropathic pain, on acute thermal nociception, and on the inflammatory pain and oedema induced by complete Freund's adjuvant (CFA). KEY RESULTS MRS2365, MRS2395 and UTP, but not the other compounds, significantly alleviated mechanical allodynia in the neuropathic pain model, with the following rank order of minimal effective dose (mED) values: MRS2365 > MRS2395 > UTP. All compounds had a dose-dependent analgesic action in acute pain except BBG, which elicited hyperalgesia at a single dose. The rank order of mED values in acute pain was the following: MRS2365 > MRS2395 > NF449 > NF023 > UDP = UTP > PPADS. MRS2365 and MRS2395 had a profound, while BBG had a mild effect on inflammatory pain, with a following rank order of mED values: MRS2395 > MRS2365 > BBG. None of the tested compounds had significant action on oedema evoked by intraplantar injection of CFA. CONCLUSIONS AND IMPLICATIONS Our results show that antagonism at P2X1, P2Y12, and P2X7 receptors and agonism at P2Y1 receptors define promising therapeutic strategies in acute, neuropathic, and inflammatory pain respectively.
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Affiliation(s)
- R D Andó
- Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
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Martyn DC, Cortese JF, Tyndall E, Dick J, Mazitschek R, Munoz B, Clardy J. Antiplasmodial activity of piperazine sulfonamides. Bioorg Med Chem Lett 2010; 20:218-21. [DOI: 10.1016/j.bmcl.2009.10.130] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 10/26/2009] [Accepted: 10/29/2009] [Indexed: 10/20/2022]
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