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Leite-Aguiar R, Bello-Santos VG, Castro NG, Coutinho-Silva R, Savio LEB. Techniques for evaluating the ATP-gated ion channel P2X7 receptor function in macrophages and microglial cells. J Immunol Methods 2024; 532:113727. [PMID: 38997100 DOI: 10.1016/j.jim.2024.113727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/31/2024] [Accepted: 07/08/2024] [Indexed: 07/14/2024]
Abstract
Resident macrophages are tissue-specific innate immune cells acting as sentinels, constantly patrolling their assigned tissue to maintain homeostasis, and quickly responding to pathogenic invaders or molecular danger signals molecules when necessary. Adenosine triphosphate (ATP), when released to the extracellular medium, acts as a danger signal through specific purinergic receptors. Interaction of ATP with the purinergic receptor P2X7 activates macrophages and microglial cells in different pathological conditions, triggering inflammation. The highly expressed P2X7 receptor in these cells induces cell membrane permeabilization, inflammasome activation, cell death, and the production of inflammatory mediators, including cytokines and nitrogen and oxygen-reactive species. This review explores the techniques to evaluate the functional and molecular aspects of the P2X7 receptor, particularly in macrophages and microglial cells. Polymerase chain reaction (PCR), Western blotting, and immunocytochemistry or immunohistochemistry are essential for assessing gene and protein expression in these cell types. Evaluation of P2X7 receptor function involves the use of ATP and selective agonists and antagonists and diverse techniques, including electrophysiology, intracellular calcium measurements, ethidium bromide uptake, and propidium iodide cell viability assays. These techniques are crucial for studying the role of P2X7 receptors in immune responses, neuroinflammation, and various pathological conditions. Therefore, a comprehensive understanding of the functional and molecular aspects of the P2X7 receptor in macrophages and microglia is vital for unraveling its involvement in immune modulation and its potential as a therapeutic target. The methodologies presented and discussed herein offer valuable tools for researchers investigating the complexities of P2X7 receptor signaling in innate immune cells in health and disease.
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Affiliation(s)
- Raíssa Leite-Aguiar
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Robson Coutinho-Silva
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiz Eduardo Baggio Savio
- Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil..
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Lv T, Li G, Zhao C, Ma J, Zhang F, Zhao M, Liu H, Wu H, Li K, Weng Z. P2X7 and P2Y 1 receptors in DRG mediate electroacupuncture to inhibit peripheral sensitization in rats with IBS visceral pain. Purinergic Signal 2024:10.1007/s11302-024-10028-9. [PMID: 38922475 DOI: 10.1007/s11302-024-10028-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 06/03/2024] [Indexed: 06/27/2024] Open
Abstract
Although multiple purinergic receptors mediate the analgesic effects of acupuncture, it remains unclear whether there is mutual interaction between purinergic receptors to jointly mediate the electroacupuncture inhibition of peripheral sensitization in visceral pain. Visceral hypersensitivity was induced by intracolonic 2,4,6-trinitrobenzene sulfonic acid (TNBS) in rat. The antinociception effect of electroacupuncture on visceral pain was evaluated by morphology, behaviors, neuroelectrophysiology and molecular biology techniques. After labeling the colon-related primary sensory neurons with neural retrograde tracer and employing neuropharmacology, neuroelectrophysiology, and molecular biotechnology, the mechanisms of P2X7R, P2Y1R, and P2X3R in colon-related dorsal root ganglion (DRG) neurons alleviating visceral hypersensitivity of irritable bowel syndrome (IBS) by electroacupuncture at Zusanli and Sanyinjiao acupoints.were elucidated from the perspective of peripheral sensitization. Electroacupuncture significantly inhibited TNBS-induced colonic hypersensitivity in rats with IBS, and Satellite Glial Cells (SGCs) in DRG were found to be involved in electroacupuncture-mediated regulation of the electrophysiological properties of neurons. P2X7R was found to play a pain-inducing role in IBS visceral hypersensitivity by affecting P2X3R, and electroacupuncture exerted an analgesic effect by inhibiting P2X7R activation. P2Y1R was found to play an analgesic role in the process of visceral pain, mediating electroacupuncture to relieve visceral hypersensitivity. P2Y1R relieved visceral pain by inhibiting P2X3R in neurons associated with nociception, with P2X7R identified as upstream of P2Y1R up-regulation by electroacupuncture. Our study suggests that the P2X7R → P2Y1R → P2X3R inhibitory pathway in DRG mediates the inhibition of peripheral sensitization by electroacupuncture in rats with IBS visceral hypersensitivity.
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Affiliation(s)
- Tingting Lv
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China
- Shanghai Research Institute of Acupuncture and Meridian, Shanghai, 200030, China
| | - Guona Li
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Chen Zhao
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Jindan Ma
- Shanghai Research Institute of Acupuncture and Meridian, Shanghai, 200030, China
| | - Fang Zhang
- Shanghai Research Institute of Acupuncture and Meridian, Shanghai, 200030, China
| | - Min Zhao
- Shanghai Research Institute of Acupuncture and Meridian, Shanghai, 200030, China
| | - Huirong Liu
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China
- Shanghai Research Institute of Acupuncture and Meridian, Shanghai, 200030, China
| | - Huangan Wu
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China
- Shanghai Research Institute of Acupuncture and Meridian, Shanghai, 200030, China
| | - Kunshan Li
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China.
- Shanghai Research Institute of Acupuncture and Meridian, Shanghai, 200030, China.
| | - Zhijun Weng
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China.
- Shanghai Research Institute of Acupuncture and Meridian, Shanghai, 200030, China.
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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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Kaur J, Dora S. Purinergic signaling: Diverse effects and therapeutic potential in cancer. Front Oncol 2023; 13:1058371. [PMID: 36741002 PMCID: PMC9889871 DOI: 10.3389/fonc.2023.1058371] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/02/2023] [Indexed: 01/19/2023] Open
Abstract
Regardless of improved biological insights and therapeutic advances, cancer is consuming multiple lives worldwide. Cancer is a complex disease with diverse cellular, metabolic, and physiological parameters as its hallmarks. This instigates a need to uncover the latest therapeutic targets to advance the treatment of cancer patients. Purines are building blocks of nucleic acids but also function as metabolic intermediates and messengers, as part of a signaling pathway known as purinergic signaling. Purinergic signaling comprises primarily adenosine triphosphate (ATP) and adenosine (ADO), their analogous membrane receptors, and a set of ectonucleotidases, and has both short- and long-term (trophic) effects. Cells release ATP and ADO to modulate cellular function in an autocrine or paracrine manner by activating membrane-localized purinergic receptors (purinoceptors, P1 and P2). P1 receptors are selective for ADO and have four recognized subtypes-A1, A2A, A2B, and A3. Purines and pyrimidines activate P2 receptors, and the P2X subtype is ligand-gated ion channel receptors. P2X has seven subtypes (P2X1-7) and forms homo- and heterotrimers. The P2Y subtype is a G protein-coupled receptor with eight subtypes (P2Y1/2/4/6/11/12/13/14). ATP, its derivatives, and purinoceptors are widely distributed in all cell types for cellular communication, and any imbalance compromises the homeostasis of the cell. Neurotransmission, neuromodulation, and secretion employ fast purinergic signaling, while trophic purinergic signaling regulates cell metabolism, proliferation, differentiation, survival, migration, invasion, and immune response during tumor progression. Thus, purinergic signaling is a prospective therapeutic target in cancer and therapy resistance.
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Affiliation(s)
- Jasmeet Kaur
- Department of Biophysics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Sanchit Dora
- Department of Biophysics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
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Abstract
Within the family of purinergic receptors, the P2X1 receptor is a ligand-gated ion channel that plays a role in urogenital, immune and cardiovascular function. Specifically, the P2X1 receptor has been implicated in controlling smooth muscle contractions of the vas deferens and therefore has emerged as an exciting drug target for male contraception. In addition, the P2X1 receptor contributes to smooth muscle contractions of the bladder and is a target to treat bladder dysfunction. Finally, platelets and neutrophils have populations of P2X1 receptors that could be targeted for thrombosis and inflammatory conditions. Drugs that specifically target the P2X1 receptor have been challenging to develop, and only recently have small molecule antagonists of the P2X1 receptor been available. However, these ligands need further biological validation for appropriate selectivity and drug-like properties before they will be suitable for use in preclinical models of disease. Although the atomic structure of the P2X1 receptor has yet to be determined, the recent discovery of several other P2X receptor structures and improvements in the field of structural biology suggests that this is now a distinct possibility. Such efforts may significantly improve drug discovery efforts at the P2X1 receptor.
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Qiao WL, Li Q, Hao JW, Wei S, Li XM, Liu TT, Qiu CY, Hu WP. Enhancement of P2X3 Receptor-Mediated Currents by Lysophosphatidic Acid in Rat Primary Sensory Neurons. Front Pharmacol 2022; 13:928647. [PMID: 35795546 PMCID: PMC9251206 DOI: 10.3389/fphar.2022.928647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
Lysophosphatidic acid (LPA), a lipid metabolite, plays a role in both neuropathic and inflammatory pain through LPA1 receptors. P2X3 receptor has also been shown to participate in these pathological processes. However, it is still unclear whether there is a link between LPA signaling and P2X3 receptors in pain. Herein, we show that a functional interaction between them in rat dorsal root ganglia (DRG) neurons. Pretreatment of LPA concentration-dependently enhanced α,β-methylene-ATP (α,β-meATP)-induced inward currents mediated by P2X3 receptors. LPA significantly increased the maximal current response of α,β-meATP, showing an upward shift of the concentration-response curve for α,β-meATP. The LPA enhancement was independent on the clamping-voltage. Enhancement of P2X3 receptor-mediated currents by LPA was prevented by the LPA1 receptor antagonist Ki16198, but not by the LPA2 receptor antagonist H2L5185303. The LPA-induced potentiation was also attenuated by intracellular dialysis of either G-protein inhibitor or protein kinase C (PKC) inhibitor, but not by Rho inhibitor. Moreover, LPA significantly changed the membrane potential depolarization and action potential burst induced by α,β-meATP in DRG neurons. Finally, LPA exacerbated α,β-meATP- induced nociceptive behaviors in rats. These results suggested that LPA potentiated the functional activity of P2X3 receptors in rat primary sensory neurons through activation of the LPA1 receptor and its downstream PKC rather than Rho signaling pathway, indicating a novel peripheral mechanism underlying the sensitization of pain.
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Affiliation(s)
- Wen-Long Qiao
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Qing Li
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Jia-Wei Hao
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Shuang Wei
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Xue-Mei Li
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Ting-Ting Liu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Chun-Yu Qiu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Wang-Ping Hu
- School of Basic Medical Sciences, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- Hubei College of Chinese Medicine, Jingzhou, China
- *Correspondence: Wang-Ping Hu,
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Bae J, Mook Kang K, Kim YC. Discovery of 5-methyl-1H-benzo[d]imidazole derivatives as novel P2X3 Receptor antagonists. Bioorg Med Chem Lett 2022; 72:128820. [PMID: 35644300 DOI: 10.1016/j.bmcl.2022.128820] [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: 04/04/2022] [Revised: 05/17/2022] [Accepted: 05/22/2022] [Indexed: 11/02/2022]
Abstract
Drug discovery programs targeting P2X3 receptors (P2X3R), an extracellular adenosine 5'-triphosphate (ATP) gated cation channel family, have been actively investigated for several CNS-related diseases. The current unmet need in the field of P2X3R targeted drugs is to avoid a side effect, the loss of taste, that could be reduced by increase of the P2X3R selectivity vs P2X2/3R. In this study, 5-methyl-1H-benzo[d]imidazole derivatives were designed and synthesized from the analysis of key pharmacophores of current antagonists. In the structure-activity relationship study, the most potent compounds 17a-b was discovered as potent P2X3R antagonists with IC50 values of 145 and 206 nM, and selectivity index of 60 and 41, respectively. In addition, 17a-b showed the not-competitive antagonism, but poor binding score in the docking study at the known allosteric binding site of Gefapixant binding site, indicating that another allosteric binding site might be existing for the novel P2X3R antagonists.
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Affiliation(s)
- Jinsu Bae
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST) 61005, Republic of Korea
| | - Koon Mook Kang
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST) 61005, Republic of Korea
| | - Yong-Chul Kim
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST) 61005, Republic of Korea; School of Life Sciences, Gwangju Institute of Science and Technology (GIST) 61005, Republic of Korea.
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Inoue K. Overview for the study of P2 receptors: From P2 receptor history to neuropathic pain studies. J Pharmacol Sci 2022; 149:73-80. [DOI: 10.1016/j.jphs.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 11/25/2022] Open
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Tozaki-Saitoh H, Takeda H, Inoue K. The Role of Microglial Purinergic Receptors in Pain Signaling. Molecules 2022; 27:molecules27061919. [PMID: 35335282 PMCID: PMC8949888 DOI: 10.3390/molecules27061919] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 12/25/2022] Open
Abstract
Pain is an essential modality of sensation in the body. Purinergic signaling plays an important role in nociceptive pain transmission, under both physiological and pathophysiological conditions, and is important for communication between both neuronal and non-neuronal cells. Microglia and astrocytes express a variety of purinergic effectors, and a variety of receptors play critical roles in the pathogenesis of neuropathic pain. In this review, we discuss our current knowledge of purinergic signaling and of the compounds that modulate purinergic transmission, with the aim of highlighting the importance of purinergic pathways as targets for the treatment of persistent pain.
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Affiliation(s)
- Hidetoshi Tozaki-Saitoh
- Department of Pharmacology, School of Pharmacy at Fukuoka, International University of Health and Welfare, 137-1 Enokizu, Okawa 831-8501, Japan;
- Correspondence: ; Tel.: +81-944-32-6137
| | - Hiroshi Takeda
- Department of Pharmacology, School of Pharmacy at Fukuoka, International University of Health and Welfare, 137-1 Enokizu, Okawa 831-8501, Japan;
| | - Kazuhide Inoue
- Institute for Advanced Study, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan;
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Synthesis and Structure-Activity Relationship Studies of Benzimidazole-4,7-dione-Based P2X3 Receptor Antagonists as Novel Anti-Nociceptive Agents. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27041337. [PMID: 35209126 PMCID: PMC8877008 DOI: 10.3390/molecules27041337] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 11/24/2022]
Abstract
P2X3 receptors (P2X3R) are ATP-gated ion channels predominantly expressed in C- and Aδ-fiber primary afferent neurons and have been introduced as a novel therapeutic target for neurological disorders, including neuropathic pain and chronic cough. Because of its localized distribution, antagonism of P2X3R has been thoroughly considered, and the avoidance of issues related to CNS side effects has been proven in clinical trials. In this article, benzimidazole-4,7-dione-based derivatives were introduced as a new chemical entity for the development of P2X3R antagonists. Starting from the discovery of a hit compound from the screening of 8364 random library compounds in the Korea Chemical Bank, which had an IC50 value of 1030 nM, studies of structure–activity and structure–property relationships enabled further optimization toward improving the antagonistic activities as well as the drug’s physicochemical properties, including metabolic stability. As for the results, the final optimized compound 14h was developed with an IC50 value of 375 nM at P2X3R with more than 23-fold selectivity versus P2X2/3R, along with properties of metabolic stability and improved solubility. In neuropathic pain animal models evoked by either nerve ligation or chemotherapeutics in male Sprague-Dawley rats, compound 14h showed anti-nociceptive effects through an increase in the mechanical withdrawal threshold as measured by von Frey filament following intravenous administration.
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Cyril AC, Jan RK, Radhakrishnan R. Pain in chronic prostatitis and the role of ion channels: a brief overview. Br J Pain 2022; 16:50-59. [PMID: 35111314 PMCID: PMC8801692 DOI: 10.1177/20494637211015265] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Prostatitis is the third most common urologic condition affecting more than half the male population at some point in their lives. There are different categories of prostatitis, of which approximately 90% of cases can be classified under the National Institute of Health (NIH) type III category (chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS)) with no causative agents identified. CP/CPPS is associated with several symptoms, of which the most prominent being chronic pain. Despite its high incidence, pain management in patients with CP/CPPS has been poor, possibly due to the lack of understanding of aetiological factors and mechanisms underlying pain development. METHODS An extensive literature search of published articles on the molecular mechanisms of pain in CP/CPPS was conducted using PubMed and Google Scholar search engines (https://pubmed.ncbi.nlm.nih.gov and https://scholar.google.com). The terms used for the search were: prostatitis, pain mechanism in CP/CPPS, prostatitis pain models, acid-sensing ion channels (ASICs), transient receptor potential vanilloid type 1 (TRPVs), purinergic channels (P2X) in prostatitis pain mechanism and inflammatory mediators in CP/CPPS. The papers were identified based on the title and abstract, and after excluding the articles that did not emphasize the pain mechanism in CP/CPPS. Ninety-five articles (36 review and 59 original research papers) met our criteria and were included in the review. RESULTS A number of inflammatory mediator molecules and pain channels, including ASICs, transient receptor potential vanilloid channels (TRPVs) and P2Xs have been investigated for their role in prostatitis pain pathology using various animal models. CONCLUSION This review summarizes the pain mechanisms in CP/CPPS focusing on the inflammatory mediators, neurotransmitters, pain-transducing ion channels and small animal models developed for studying prostatitis.
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Affiliation(s)
| | | | - Rajan Radhakrishnan
- Rajan Radhakrishnan, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Building 14, Dubai Healthcare City, P.O Box 505055, Dubai, UAE.
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The Role of ATP Receptors in Pain Signaling. Neurochem Res 2022; 47:2454-2468. [DOI: 10.1007/s11064-021-03516-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/11/2021] [Accepted: 12/22/2021] [Indexed: 12/21/2022]
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13
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Ceccarelli I, Bioletti L, Peparini S, Solomita E, Ricci C, Casini I, Miceli E, Aloisi AM. Estrogens and phytoestrogens in body functions. Neurosci Biobehav Rev 2021; 132:648-663. [PMID: 34890602 DOI: 10.1016/j.neubiorev.2021.12.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/03/2021] [Accepted: 12/04/2021] [Indexed: 12/23/2022]
Abstract
Estrogens are the hormones of reproduction in women as well as of many other important functions in the male and female body. They undergo significant changes in the different phases of life, e.g. during puberty, pregnancy or at menopause/andropause. Phytoestrogens are natural non-steroidal phenolic plant compounds that can mimic the activity of estrogens and their beneficial effects in women and in men. This narrative review summarizes the literature on the physiological role of estrogens and the several potential health benefits of phytoestrogens, with particular attention given to the possible role of phytoestrogens in aging.
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Affiliation(s)
- Ilaria Ceccarelli
- Department Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Lucia Bioletti
- Department Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Sofia Peparini
- Department Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Erminia Solomita
- Department Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Comasia Ricci
- Department Life Sciences, University of Siena, Siena, Italy
| | - Ilenia Casini
- Department Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Elisangela Miceli
- Department Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Anna Maria Aloisi
- Department Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy.
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Hao JW, Qiao WL, Li Q, Wei S, Liu TT, Qiu CY, Hu WP. Suppression of P2X3 receptor-mediated currents by the activation of α 2A -adrenergic receptors in rat dorsal root ganglion neurons. CNS Neurosci Ther 2021; 28:289-297. [PMID: 34862748 PMCID: PMC8739037 DOI: 10.1111/cns.13774] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 11/09/2021] [Accepted: 11/23/2021] [Indexed: 11/29/2022] Open
Abstract
Aims The α2‐adrenergic receptor (α2‐AR) agonists have been shown to be effective in the treatment of various pain. For example, dexmedetomidine (DEX), a selective α2A‐AR agonist, can be used for peripheral analgesia. However, it is not yet fully elucidated for the precise molecular mechanisms. P2X3 receptor is a major receptor processing nociceptive information in primary sensory neurons. Herein, we show that a functional interaction of α2A‐ARs and P2X3 receptors in dorsal root ganglia (DRG) neurons could contribute to peripheral analgesia of DEX. Methods Electrophysiological recordings were carried out on rat DRG neurons, and nociceptive behavior was quantified in rats. Results The activation of α2A‐ARs by DEX suppressed P2X3 receptor‐mediated and α,β‐methylene‐ATP (α,β‐meATP)‐evoked inward currents in a concentration‐dependent and voltage‐independent manner. Pre‐application of DEX shifted the α,β‐meATP concentration‐response curve downwards, with a decrease of 50.43 ± 4.75% in the maximal current response of P2X3 receptors to α,β‐meATP in the presence of DEX. Suppression of α,β‐meATP‐evoked currents by DEX was blocked by the α2A‐AR antagonist BRL44408 and prevented by intracellular application of the Gi/o protein inhibitor pertussis toxin, the adenylate cyclase activator forskolin, and the cAMP analog 8‐Br‐cAMP. DEX also suppressed α,β‐meATP‐evoked action potentials through α2A‐ARs in rat DRG neurons. Finally, the activation of peripheral α2A‐ARs by DEX had an analgesic effect on the α,β‐meATP‐induced nociception. Conclusions These results suggested that activation of α2A‐ARs by DEX suppressed P2X3 receptor‐mediated electrophysiological and behavioral activity via a Gi/o proteins and cAMP signaling pathway, which was a novel potential mechanism underlying analgesia of peripheral α2A‐AR agonists.
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Affiliation(s)
- Jia-Wei Hao
- School of Basic Medical Sciences, Hubei University of Science and Technology, Hubei, China.,Department of Pharmacology, School of Pharmacy, Hubei University of Science and Technology, Hubei, China
| | - Wen-Long Qiao
- School of Basic Medical Sciences, Hubei University of Science and Technology, Hubei, China.,Department of Pharmacology, School of Pharmacy, Hubei University of Science and Technology, Hubei, China
| | - Qing Li
- School of Basic Medical Sciences, Hubei University of Science and Technology, Hubei, China.,Department of Pharmacology, School of Pharmacy, Hubei University of Science and Technology, Hubei, China
| | - Shuang Wei
- School of Basic Medical Sciences, Hubei University of Science and Technology, Hubei, China.,Department of Pharmacology, School of Pharmacy, Hubei University of Science and Technology, Hubei, China
| | - Ting-Ting Liu
- School of Basic Medical Sciences, Hubei University of Science and Technology, Hubei, China
| | - Chun-Yu Qiu
- School of Basic Medical Sciences, Hubei University of Science and Technology, Hubei, China
| | - Wang-Ping Hu
- School of Basic Medical Sciences, Hubei University of Science and Technology, Hubei, China
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15
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Ford AP, Dillon MP, Kitt MM, Gever JR. The discovery and development of gefapixant. Auton Neurosci 2021; 235:102859. [PMID: 34403981 DOI: 10.1016/j.autneu.2021.102859] [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: 04/12/2021] [Revised: 07/06/2021] [Accepted: 07/21/2021] [Indexed: 01/02/2023]
Abstract
Gefapixant is the approved generic name for a compound also known as MK-7264, and prior to that AF-219 and RO-4926219. It is the first-in-class clinically developed antagonist for the P2X3 subtype of trimeric ionotropic purinergic receptors, a family of ATP-gated excitatory ion channels, showing nanomolar potency for the human P2X3 homotrimeric channel and essentially no activity at related channels devoid of P2X3 subunits. As the first P2X3 antagonist to have progressed into clinical studies it has now progressed to the point of successful completion of Phase 3 investigations for the treatment of cough, and the NDA application is under review with US FDA for treatment of refractory chronic cough or unexplained chronic cough. The molecule was discovered in the laboratories of Roche Pharmaceuticals in Palo Alto, California, but clinical development then continued with the formation of Afferent Pharmaceuticals for the purpose of identifying the optimal therapeutic indication for this novel mechanism and establishing a clinical plan for development in the optimal patient populations selected. Geoff Burnstock was a close collaborator and advisor to the P2X3 program for close to two decades of discovery and development. Progression of gefapixant through later stage clinical studies has been conducted by the research laboratories of Merck & Co., Inc., Kenilworth, NJ, USA (MRL; following acquisition of Afferent in 2016), who may commercialize the product once authorization has been granted by regulatory authorities.
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Affiliation(s)
- Anthony P Ford
- CuraSen Therapeutics, 930 Brittan Avenue, Suite 306, San Carlos, CA 94070, USA.
| | - Michael P Dillon
- Ideaya Biosciences, 7000 Shoreline Court, Suite 350, South San Francisco, CA 94080, USA
| | - Michael M Kitt
- Axalbion LTD., C/O Medicines Evaluation Unit, The Langley Building, Southmoor Road, Wythenshawe, M23 9QZ Manchester, UK
| | - Joel R Gever
- CuraSen Therapeutics, 930 Brittan Avenue, Suite 306, San Carlos, CA 94070, USA
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16
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Zhuang J, Gao X, Wei W, Pelleg A, Xu F. Intralaryngeal application of ATP evokes apneic response mainly via acting on P2X3 (P2X2/3) receptors of the superior laryngeal nerve in postnatal rats. J Appl Physiol (1985) 2021; 131:986-996. [PMID: 34323594 DOI: 10.1152/japplphysiol.00091.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Aerosolized adenosine 5'-triphosphate (ATP) induces cough and bronchoconstriction by activating vagal sensory fibers' P2X3 and P2X2/3 receptors (P2X3R and P2X2/3R). The goal of this study is to determine the effect of these receptors on the superior laryngeal nerve (SLN)-mediated cardiorespiratory responses to ATP challenge. We compared the cardiorespiratory responses to intralaryngeal perfusion of either ATP or α,β-methylene ATP in rat pups before and after 1) intralaryngeal perfusion of A-317491 (a P2X3R and P2X2/3R antagonist); 2) bilateral section of the SLN; and 3) peri-SLN treatment with capsaicin (to block conduction in superior laryngeal C-fibers, SLCFs) or A-317491. The immunoreactivity (IR) of P2X3R and P2X2R was determined in laryngeal sensory neurons of the nodose/jugular ganglia. Lastly, a whole-cell patch clamp recording was used to determine ATP- or α,β-mATP-induced currents without and with A-317491 treatment. It was found that intralaryngeal perfusion of both ATP and α,β-mATP induced immediate apnea, hypertension, and bradycardia. The apnea was eliminated and the hypertension and bradycardia were blunted by intralaryngeal perfusion of A-317491 and peri-SLN treatment with either A-317491 or capsaicin, while all of the cardiorespiratory responses were abolished by bilateral section of the SLN. P2X3R- and P2X2R-IR were observed in nodose and jugular ganglionic neurons labeled by fluoro-gold (FG). ATP- and α,β-mATP-induced currents recorded in laryngeal C-neurons were reduced by 75% and 95% respectively by application of A-317491. It is concluded that in anesthetized rat pups, the cardiorespiratory responses to intralaryngeal perfusion of either ATP or α,β-mATP are largely mediated by activation of SLCFs' P2X3R-P2X2/3R.
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Affiliation(s)
- Jianguo Zhuang
- Pathophysiology Program, Lovelace Biomedical Institute, Albuquerque, NM, United States
| | - Xiuping Gao
- Pathophysiology Program, Lovelace Biomedical Institute, Albuquerque, NM, United States
| | - Wan Wei
- Pathophysiology Program, Lovelace Biomedical Institute, Albuquerque, NM, United States.,Graduate School, Beijing University of Chinese Medicine, Beijing, China
| | - Amir Pelleg
- Danmir Therapeutics, LLC, Haverford, PA, United States
| | - Fadi Xu
- Pathophysiology Program, Lovelace Biomedical Institute, Albuquerque, NM, United States
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17
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Iturriaga R, Alcayaga J, Chapleau MW, Somers VK. Carotid body chemoreceptors: physiology, pathology, and implications for health and disease. Physiol Rev 2021; 101:1177-1235. [PMID: 33570461 PMCID: PMC8526340 DOI: 10.1152/physrev.00039.2019] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The carotid body (CB) is the main peripheral chemoreceptor for arterial respiratory gases O2 and CO2 and pH, eliciting reflex ventilatory, cardiovascular, and humoral responses to maintain homeostasis. This review examines the fundamental biology underlying CB chemoreceptor function, its contribution to integrated physiological responses, and its role in maintaining health and potentiating disease. Emphasis is placed on 1) transduction mechanisms in chemoreceptor (type I) cells, highlighting the role played by the hypoxic inhibition of O2-dependent K+ channels and mitochondrial oxidative metabolism, and their modification by intracellular molecules and other ion channels; 2) synaptic mechanisms linking type I cells and petrosal nerve terminals, focusing on the role played by the main proposed transmitters and modulatory gases, and the participation of glial cells in regulation of the chemosensory process; 3) integrated reflex responses to CB activation, emphasizing that the responses differ dramatically depending on the nature of the physiological, pathological, or environmental challenges, and the interactions of the chemoreceptor reflex with other reflexes in optimizing oxygen delivery to the tissues; and 4) the contribution of enhanced CB chemosensory discharge to autonomic and cardiorespiratory pathophysiology in obstructive sleep apnea, congestive heart failure, resistant hypertension, and metabolic diseases and how modulation of enhanced CB reactivity in disease conditions may attenuate pathophysiology.
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Affiliation(s)
- Rodrigo Iturriaga
- Laboratorio de Neurobiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile, and Centro de Excelencia en Biomedicina de Magallanes, Universidad de Magallanes, Punta Arenas, Chile
| | - Julio Alcayaga
- Laboratorio de Fisiología Celular, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Mark W Chapleau
- Department of Internal Medicine, University of Iowa and Department of Veterans Affairs Medical Center, Iowa City, Iowa
| | - Virend K Somers
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
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18
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Jin Y, Wei S, Liu TT, Qiu CY, Hu WP. Acute P38-Mediated Enhancement of P2X3 Receptor Currents by TNF-α in Rat Dorsal Root Ganglion Neurons. J Inflamm Res 2021; 14:2841-2850. [PMID: 34234509 PMCID: PMC8254564 DOI: 10.2147/jir.s315774] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/05/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose Tumor necrosis factor-α (TNF-α) is a pro-inflammatory cytokine and involves in a variety of pain conditions. Some findings suggest that TNF-α may act directly on primary afferent neurons to induce acute pain hypersensitivity through non-transcriptional regulation. This study investigated whether TNF-α had an effect on functional activity of P2X3 receptors in primary sensory neurons. Herein, we report that a brief (5 min) application of TNF-α rapidly enhanced the electrophysiological activity of P2X3 receptors in rat dorsal root ganglia (DRG) neurons. Methods Electrophysiological recordings were carried out on rat DRG neurons, and nociceptive behavior was quantified in rats. Results A brief (5 min) exposure of TNF-α rapidly increased P2X3 receptor-mediated and α,β-methylene-ATP (α,β-meATP)-evoked inward currents in a dose-dependent manner. The potentiation of P2X3 receptor-mediated ATP currents by TNF-α was voltage-independent. TNF-α shifted the concentration-response curve for α,β-meATP upwards, with an increase of 31.57 ± 6.81% in the maximal current response to α,β-meATP. This acute potentiation of ATP currents by TNF-α was blocked by p38 mitogen-activated protein kinase (MAPK) inhibitor SB202190, but not by non-selective cyclooxygenase inhibitor indomethacin, suggesting involvement of p38 MAPK, but not cyclooxygenase. Moreover, intraplantar injection of TNF-α and α,β-meATP produced a synergistic effect on mechanical allodynia in rats. TNF-α-induced mechanical allodynia was also alleviated after local P2X3 receptors were blocked. Conclusion These results suggested that TNF-α rapidly sensitized P2X3 receptors in primary sensory neurons via a p38 MAPK dependent pathway, which revealed a novel peripheral mechanism underlying acute mechanical hypersensitivity by peripheral administration of TNF-α.
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Affiliation(s)
- Ying Jin
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning, Hubei, 437100, People's Republic of China
| | - Shuang Wei
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning, Hubei, 437100, People's Republic of China
| | - Ting-Ting Liu
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning, Hubei, 437100, People's Republic of China
| | - Chun-Yu Qiu
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning, Hubei, 437100, People's Republic of China
| | - Wang-Ping Hu
- Research Center of Basic Medical Sciences, School of Basic Medical Sciences, Hubei University of Science and Technology, Xianning, Hubei, 437100, People's Republic of China
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19
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Pathak S, Slovarp L, Clary MS, Jetté ME. Laryngeal Chemoreflex in Health and Disease: A Review. Chem Senses 2021; 45:823-831. [PMID: 33247587 DOI: 10.1093/chemse/bjaa069] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The larynx plays a key role in airway protection via the laryngeal chemoreflex (LCR). This involuntary reflex can be evoked when hazardous substances activate mucosal receptors, which send signals to be processed within the brainstem. Although the LCR is meant to be protective, the reflex can become hyperstimulated, even to benign stimuli, which can result in pathological disorders, such as chronic cough and inducible laryngeal obstruction. In this review, we will outline the mechanism of the LCR and its associated pathological disorders.
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Affiliation(s)
- Shivani Pathak
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Laurie Slovarp
- School of Speech, Language, Hearing, & Occupational Sciences, University of Montana, Missoula, MT, USA
| | - Matthew S Clary
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Marie E Jetté
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Colorado, Aurora, CO, USA
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20
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King BF. P2X3 receptors participate in purinergic inhibition of gastrointestinal smooth muscle. Auton Neurosci 2021; 234:102830. [PMID: 34116466 DOI: 10.1016/j.autneu.2021.102830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/11/2021] [Accepted: 05/28/2021] [Indexed: 10/21/2022]
Abstract
The ATP analogue α,β-meATP is a potent relaxant of gastrointestinal smooth muscle, but its molecular target is uncertain inside the gut. α,β-meATP relaxed the carbachol-precontracted guinea-pig taenia coli in a concentration-dependent manner (EC50, 2.0 ± 0.1 μM). A luciferase-based assay confirmed that α,β-meATP solutions were minimally contaminated with ATP. α,β-meATP-evoked relaxations were inhibited by the competitive P2Y1 antagonist MRS2179 (pA2 = 5.36), but also by the competitive P2X3 antagonist, A-317491 (pA2 = 5.51). When MRS2179 and A-317491 were applied together, residual α,β-meATP responses converted from brief to prolonged relaxations. Sodium nitroprusside (a nitric oxide donor) also caused prolonged relaxations. Immunohistochemistry revealed that P2X3 receptors were present in myenteric ganglion cells and their varicose nerve terminals. The amplitude of α,β-meATP responses was not inhibited by TTX (NaV channel blocker) and ωCgTx (N-type CaV channel blocker). However, responses to α,β-meATP were inhibited by TEA (non-selective K+-channel blocker), indicating that relaxations involved opening K+-channels. The findings of this study are consistent with the conclusion that α,β-meATP stimulates Ca2+-permeable P2X3 receptors on varicose nerve terminals to release inhibitory nucleotides: 1) ATP and β-NAD release results in P2Y1-mediated brief relaxations; 2) another released transmitter (possibly NO) results in prolonged relaxations. Prejunctional P2X3 receptors represent a purinergic feed-forward mechanism to augment the action of inhibitory nerves on gut motility. This positive feed-forward mechanism may counter-balance the known negative feedback mechanism caused by adenosine and prejunctional A1 receptors on inhibitory motor nerves.
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Affiliation(s)
- Brian F King
- University College London (UCL), Research Department of Neuroscience, Pharmacology & Physiology (NPP), Gower Street, London WC1E 6BT, United Kingdom.
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21
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Bone marrow derived mast cells injected into the osteoarthritic knee joints of mice induced by sodium monoiodoacetate enhanced spontaneous pain through activation of PAR2 and action of extracellular ATP. PLoS One 2021; 16:e0252590. [PMID: 34086763 PMCID: PMC8177436 DOI: 10.1371/journal.pone.0252590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/18/2021] [Indexed: 12/12/2022] Open
Abstract
Conditions that resemble osteoarthritis (OA) were produced by injection of sodium monoiodoacetate (MIA) into the knee joints of mice. Bone marrow derived mast cells (BMMCs) injected into the OA knee joints enhanced spontaneous pain. Since no spontaneous pain was observed when BMMCs were injected into the knee joints of control mice that had not been treated with MIA, BMMCs should be activated within the OA knee joints and release some pain-inducible factors. Protease activated receptor-2 (PAR2) antagonist (FSLLRY-NH2) almost abolished the pain-enhancing effects of BMMCs injected into the OA knee joints, suggesting that tryptase, a mast cell protease that is capable of activating PAR2, should be released from the injected BMMCs and enhance pain through activation of PAR2. When PAR2 agonist (SLIGKV-NH2) instead of BMMCs was injected into the OA knee joints, it was also enhanced pain. Apyrase, an ATP degrading enzyme, injected into the OA knee joints before BMMCs suppressed the pain enhanced by BMMCs. We showed that purinoceptors (P2X4 and P2X7) were expressed in BMMCs and that extracellular ATP stimulated the release of tryptase from BMMCs. These observations suggest that ATP may stimulate degranulation of BMMCs and thereby enhanced pain. BMMCs injected into the OA knee joints stimulated expression of IL-1β, IL-6, TNF-α, CCL2, and MMP9 genes in the infrapatellar fat pads, and PAR2 antagonist suppressed the stimulatory effects of BMMCs. Our study suggests that intermittent pain frequently observed in OA knee joints may be due, at least partly, to mast cells through activation of PAR2 and action of ATP, and that intraarticular injection of BMMCs into the OA knee joints may provide a useful experimental system for investigating molecular mechanisms by which pain is induced in OA knee joints.
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22
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Sun L, Yao K, Zhang H, Chen W. Activation of the ATP-P2X pathway by TRPV4 in acute ocular hypertension. Int J Ophthalmol 2020; 13:1697-1704. [PMID: 33214998 DOI: 10.18240/ijo.2020.11.03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 08/06/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To measure the expression of transient receptor potential cation channel subfamily V member 4 (TRPV4) in the rat cornea and determine whether it is related to adenosine triphosphate (ATP) generation in a rat model of acute ocular hypertension (AOH). METHODS Immunofluorescence staining of TRPV4, P2X2 receptor, P2X3 receptor, and β3-tubulin in rat corneal longitudinal sections and paved was performed to clearly display histological structures. Rat models of AOH and agonist/antagonist-treated groups were established and corneal ATP was measured using an ATP assay. The independent t-test and simple linear correlation model were adopted for statistical analyses. RESULTS Immunofluorescence staining of rat cornea sections revealed that epithelial and endothelial membranes showed strong immunoreactivity for TRPV4 and P2X2 receptor and coexpression with β3-tubulin in the rat corneal epithelial layer. Corneal ATP was significantly higher in the AOH rat model than in the control (P<0.05) and apparently lower after pretreatment by applying eyedrops of TRPV4 antagonist RN1734 with 30-40 mm Hg intraocular pressure (IOP; P<0.05). A simple linear regression model showed a positive correlation between rat corneal ATP and IOP values (R 2=0.996, P=0.0134) from the normal IOP (113 mm Hg) to 40 mm Hg. At 10-40min after anterior chamber injection of GSK1016790A (0.01 mL, 50 nmol/L in 0.9% NaCl), corneal ATP was significantly higher than in the control group (P<0.05), which peaked at 10min. The ATP concentration of the normal epithelium was higher than that of the endothelium in the AOH rat model and after anterior chamber injection of GSK1016790A (P<0.05). CONCLUSION The ATP concentration in the AOH rat cornea is increased by TRPV4 activation.
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Affiliation(s)
- Li Sun
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, Hubei Province, China
| | - Ke Yao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, Hubei Province, China
| | - Hong Zhang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, Hubei Province, China
| | - Wei Chen
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, Hubei Province, China
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23
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Hirakawa M, Yokoyama T, Yamamoto Y, Saino T. Distribution and morphology of P2X3-immunoreactive subserosal afferent nerve endings in the rat gastric antrum. J Comp Neurol 2020; 529:2014-2028. [PMID: 33190284 DOI: 10.1002/cne.25069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/27/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022]
Abstract
The present study investigated the morphological characteristics of subserosal afferent nerve endings with immunoreactivity for the P2X3 purinoceptor (P2X3) in the rat stomach by immunohistochemistry of whole-mount preparations using confocal scanning laser microscopy. P2X3 immunoreactivity was observed in subserosal nerve endings proximal and lateral to the gastric sling muscles in the distal antrum of the lesser curvature. Parent axons ramified into several lamellar processes to form net-like complex structures that extended two-dimensionally in every direction on the surface of the longitudinal smooth muscle layer. The axon terminals in the periphery of P2X3-immunoreactive net-like structures were flat and looped or leaf-like in shape. Some net-like lamellar structures and their axon terminals with P2X3 immunoreactivity were also immunoreactive for P2X2. P2X3-immunoreactive nerve fibers forming net-like terminal structures were closely surrounded by S100B-immunoreactive terminal Schwann cells, whereas axon terminals twined around these cells and extended club-, knob-, or thread-like protrusions in the surrounding tissues. Furthermore, a retrograde tracing method using fast blue dye indicated that most of these nerve endings originated from the nodose ganglia of the vagus nerve. These results suggest that P2X3-immunoreactive subserosal nerve endings have morphological characteristics of mechanoreceptors and contribute to sensation of a mechanical deformation of the distal antral wall associated with antral peristalsis.
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Affiliation(s)
- Masato Hirakawa
- Department of Anatomy (Cell Biology), Iwate Medical University, Yahaba-cho, Japan
| | - Takuya Yokoyama
- Department of Anatomy (Cell Biology), Iwate Medical University, Yahaba-cho, Japan
| | - Yoshio Yamamoto
- Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan
| | - Tomoyuki Saino
- Department of Anatomy (Cell Biology), Iwate Medical University, Yahaba-cho, Japan
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Inoue K, Tsuda M. Nociceptive signaling mediated by P2X3, P2X4 and P2X7 receptors. Biochem Pharmacol 2020; 187:114309. [PMID: 33130129 DOI: 10.1016/j.bcp.2020.114309] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/22/2020] [Accepted: 10/27/2020] [Indexed: 12/18/2022]
Abstract
Chronic pain is a debilitating condition that often occurs following peripheral tissue inflammation and nerve injury. This pain, especially neuropathic pain, is a significant clinical problem because of the ineffectiveness of clinically available drugs. Since Burnstock proposed new roles of nucleotides as neurotransmitters, the roles of extracellular ATP and P2 receptors (P2Rs) in pain signaling have been extensively studied, and ATP-P2R signaling has subsequently received much attention as it can provide clues toward elucidating the mechanisms underlying chronic pain and serve as a potential therapeutic target. This review summarizes the literature regarding the role of ATP signaling via P2X3Rs (as well as P2X2/3Rs) in primary afferent neurons and via P2X4Rs and P2X7Rs in spinal cord microglia in chronic pain, and discusses their respective therapeutic potentials.
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Affiliation(s)
- Kazuhide Inoue
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-8582, Japan
| | - Makoto Tsuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-8582, Japan; Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-8582, Japan
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25
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Potentiation of P2X3 receptor mediated currents by endothelin-1 in rat dorsal root ganglion neurons. Neuropharmacology 2020; 181:108356. [PMID: 33069757 DOI: 10.1016/j.neuropharm.2020.108356] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/23/2020] [Accepted: 10/12/2020] [Indexed: 11/21/2022]
Abstract
Endothelin-1 (ET-1), an endogenous vasoconstrictor, has been known as a pro-nociceptive agent involved in multitude of pain. ET-1 acts on endothelin receptors on vascular endothelial cells, sensitizes release of ATP, which then acts on P2X3 receptors on nociceptors and results in mechanical hyperalgesia. Both endothelin receptors and P2X3 receptors are present in primary sensory neuron, where it remains unclear whether there is an interaction between them. Herein, we reported that ET-1 potentiated the electrophysiological activity of P2X3 receptors in rat dorsal root ganglia (DRG) neurons. ET-1 concentration-dependently increased α,β-methylene-ATP (α,β-meATP)-evoked inward currents, which were mediated by P2X3 receptors. ET-1 shifted the α,β-meATP concentration-response curve upwards, with an increase of 34.38 ± 4.72% in the maximal current response to α,β-meATP in the presence of ET-1. ET-1 potentiation of α,β-meATP-evoked currents was voltage-independent. ET-1 potentiated P2X3 receptor-mediated currents through endothelin-A receptors (ETAR), but not endothelin-B receptors (ETBR). ET-1 potentiation was supressed by blockade of intracellular G-protein or protein kinase C (PKC) signaling. Moreover, there is a synergistic effect on mechanical allodynia induced by intraplantar injection of ET-1 and α,β-meATP in rats. Pharmacological blockade of P2X3 receptors also alleviated ET-1-induced mechanical allodynia. These results suggested that ET-1 sensitized P2X3 receptors in primary sensory neurons via an ETAR and PKC signaling pathway. Our data provide evidence that cutaneous ET-1 induced mechanical allodynia not only by increasing the release of ATP from vascular endothelial cells, but also by sensitizing P2X3 receptors on nociceptive DRG neurons.
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Development of a Mouse Reporter Strain for the Purinergic P2X 2 Receptor. eNeuro 2020; 7:ENEURO.0203-20.2020. [PMID: 32669344 PMCID: PMC7418537 DOI: 10.1523/eneuro.0203-20.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/23/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023] Open
Abstract
The ATP-sensitive P2X2 ionotropic receptor plays a critical role in a number of signal processes including taste and hearing, carotid body detection of hypoxia, the exercise pressor reflex and sensory transduction of mechanical stimuli in the airways and bladder. Elucidation of the role of P2X2 has been hindered by the lack of selective tools. In particular, detection of P2X2 using established pharmacological and biochemical techniques yields dramatically different expression patterns, particularly in the peripheral and central nervous systems. Here, we have developed a knock-in P2X2-cre mouse, which we crossed with a cre-sensitive tdTomato reporter mouse to determine P2X2 expression. P2X2 was found in more than 80% of nodose vagal afferent neurons, but not in jugular vagal afferent neurons. Reporter expression correlated in vagal neurons with sensitivity to α,β methylene ATP (αβmATP). P2X2 was expressed in 75% of petrosal afferents, but only 12% and 4% of dorsal root ganglia (DRG) and trigeminal afferents, respectively. P2X2 expression was limited to very few cell types systemically. Together with the central terminals of P2X2-expressing afferents, reporter expression in the CNS was mainly found in brainstem neurons projecting mossy fibers to the cerebellum, with little expression in the hippocampus or cortex. The structure of peripheral terminals of P2X2-expressing afferents was demonstrated in the tongue (taste buds), carotid body, trachea and esophagus. P2X2 was observed in hair cells and support cells in the cochlear, but not in spiral afferent neurons. This mouse strain provides a novel approach to the identification and manipulation of P2X2-expressing cell types.
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P2X3 receptors contribute to transition from acute to chronic muscle pain. Purinergic Signal 2020; 16:403-414. [PMID: 32766958 DOI: 10.1007/s11302-020-09718-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 07/23/2020] [Indexed: 12/14/2022] Open
Abstract
This study aimed to evaluate whether the development and/or maintenance of chronic-latent muscle hyperalgesia is modulated by P2X3 receptors. We also evaluate the expression of P2X3 receptors and PKCε of dorsal root ganglions during these processes. A mouse model of chronic-latent muscle hyperalgesia, induced by carrageenan and evidenced by PGE2, was used. Mechanical muscle hyperalgesia was measured by Randall-Selitto analgesimeter. The involvement of P2X3 receptors was analyzed by using the selective P2X3 receptors antagonist A-317491 by intramuscular or intrathecal injections. Expression of P2X3 and PKCε in dorsal root ganglion (L4-S1) were evaluated by Western blotting. Intrathecal blockade of P2X3 receptors previously to carrageenan prevented the development and maintenance of acute and chronic-latent muscle hyperalgesia, while intramuscular blockade of P2X3 receptors previously to carrageenan only reduced the acute muscle hyperalgesia and had no effect on chronic-latent muscle hyperalgesia. Intrathecal, but not intramuscular, blockade of P2X3 receptors immediately before PGE2, in animals previously sensitized by carrageenan, reversed the chronic-latent muscle hyperalgesia. There was an increase in total and phosphorylated PKCε 48 h after the beginning of acute muscle hyperalgesia, and in P2X3 receptors at the period of chronic muscle hyperalgesia. P2X3 receptors expressed on spinal cord dorsal horn contribute to transition from acute to chronic muscle pain. We also suggest an interaction of PKCε and P2X3 receptors in this process. Therefore, we point out P2X3 receptors of the spinal cord dorsal horn as a pharmacological target to prevent the development or reverse the chronic muscle pain conditions.
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Cystitis-Related Bladder Pain Involves ATP-Dependent HMGB1 Release from Macrophages and Its Downstream H 2S/Ca v3.2 Signaling in Mice. Cells 2020; 9:cells9081748. [PMID: 32707767 PMCID: PMC7463894 DOI: 10.3390/cells9081748] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 07/19/2020] [Indexed: 12/12/2022] Open
Abstract
Cystitis-related bladder pain involves RAGE activation by HMGB1, and increased Cav3.2 T-type Ca2+ channel activity by H2S, generated by upregulated cystathionine-γ-lyase (CSE) in mice treated with cyclophosphamide (CPA). We, thus, investigated possible crosstalk between the HMGB1/RAGE and CSE/H2S/Cav3.2 pathways in the bladder pain development. Bladder pain (nociceptive behavior/referred hyperalgesia) and immuno-reactive CSE expression in the bladder were determined in CPA-treated female mice. Cell signaling was analyzed in urothelial T24 and macrophage-like RAW264.7 cells. The CPA-induced bladder pain was abolished by pharmacological inhibition of T-type Ca2+ channels or CSE, and genetic deletion of Cav3.2. The CPA-induced CSE upregulation, as well as bladder pain was prevented by HMGB1 inactivation, inhibition of HMGB1 release from macrophages, antagonists of RAGE or P2X4/P2X7 receptors, and N-acetylcysteine, an antioxidant. Acrolein, a metabolite of CPA, triggered ATP release from T24 cells. Adenosine triphosphate (ATP) stimulated cell migration via P2X7/P2X4, and caused HMGB1 release via P2X7 in RAW264.7 cells, which was dependent on p38MAPK/NF-κB signaling and reactive oxygen species (ROS) accumulation. Together, our data suggest that CPA, once metabolized to acrolein, causes urothelial ATP-mediated, redox-dependent HMGB1 release from macrophages, which in turn causes RAGE-mediated CSE upregulation and subsequent H2S-targeted Cav3.2-dependent nociceptor excitation, resulting in bladder pain.
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Sun LH, Zhang WX, Xu Q, Wu H, Jiao CC, Chen XZ. Estrogen modulation of visceral pain. J Zhejiang Univ Sci B 2020; 20:628-636. [PMID: 31273960 DOI: 10.1631/jzus.b1800582] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
It is commonly accepted that females and males differ in their experience of pain. Gender differences have been found in the prevalence and severity of pain in both clinical and animal studies. Sex-related hormones are found to be involved in pain transmission and have critical effects on visceral pain sensitivity. Studies have pointed out the idea that serum estrogen is closely related to visceral nociceptive sensitivity. This review aims to summarize the literature relating to the role of estrogen in modulating visceral pain with emphasis on deciphering the potential central and peripheral mechanisms.
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Affiliation(s)
- Li-Hong Sun
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Wen-Xin Zhang
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Qi Xu
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Hui Wu
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Cui-Cui Jiao
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Xin-Zhong Chen
- Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
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Matsuka Y, Afroz S, Dalanon JC, Iwasa T, Waskitho A, Oshima M. The role of chemical transmitters in neuron-glia interaction and pain in sensory ganglion. Neurosci Biobehav Rev 2020; 108:393-399. [DOI: 10.1016/j.neubiorev.2019.11.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 09/20/2019] [Accepted: 11/25/2019] [Indexed: 01/10/2023]
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Wang Y, Chen Z, Liu C, Lu X, Yang C, Qiu S. Distributive differences of P2Xs between the forelimb and hind limb of adjuvant arthritis rats and intervention by Notopterygh rhizoma et radix. PHARMACEUTICAL BIOLOGY 2019; 57:82-89. [PMID: 30724643 PMCID: PMC6366419 DOI: 10.1080/13880209.2018.1561730] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
CONTEXT Notopterygium incisum Ting ex H. T. Chang (Umbelliferae) (NI) specializes in treatment of upper limb rheumatoid arthritis (RA), but the exact mechanism is unclear. P2Xs are useful targets for inflammatory pain therapy. It led us to hypothesize that NI may preferentially act on particular P2Xs and these receptors may be unevenly distributed in the upper/lower limb. OBJECTIVE To investigate P2Xs distribution in the upper/lower limb and NI's targets in upper limb RA. MATERIALS AND METHODS The SD rats were randomized into 11 groups of 10 animals each. Eight experimental groups were established by the injection of 0.1 mL FCA into the plantar surface of rat paw. Three control groups suffered the same volume of saline. The articular cavities were then taken on the seventh day to detect P2Xs expression. NI (3 g/kg) and prednisone (10 mg/kg) were respectively given by oral gavage once daily for 14 d. The swelling degree and P2Xs were evaluated individually. RESULTS In normal rats, the expressions of P2X3 and P2X6 in forelimb were markedly higher than that of in hind limb (P < 0.05). After induced by FCA, P2X1, P2X3, P2X4, P2X5 and P2X7 were increased significantly (P < 0.01). The biggest difference was P2X3. In NI treatment rats, swelling degree of the 7th/14th day in forelimb was 68.24%/38.89%, whereas that of in hind limb was 88.72%/79.92%. P2X3 mRNA and protein expression was significantly reduced as contrasted with the control group (P < 0.05). CONCLUSIONS P2X3 receptor was predominantly expressed in the forelimb RA rat. NI relieved the FCA-induced RA by inhibiting upper limb's P2X3 receptor.
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Affiliation(s)
- Yinghao Wang
- College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, PR China
- CONTACT Yinghao Wang
| | - Zhihuang Chen
- College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, PR China
| | - Chen Liu
- College of Chemical and Material Science Engineering, Kaili University, Guizhou, PR China
| | - Xuehua Lu
- Fujian Medical Science Research Institute, Fuzhou, PR China
| | - Ce Yang
- College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, PR China
| | - Songping Qiu
- College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, PR China
- Songping Qiu College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou350122, PR China
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Silva-Ramos M, Silva I, Faria M, Ferreirinha F, Correia-de-Sá P. Activation of Prejunctional P2x2/3 Heterotrimers by ATP Enhances the Cholinergic Tone in Obstructed Human Urinary Bladders. J Pharmacol Exp Ther 2019; 372:63-72. [PMID: 31636173 DOI: 10.1124/jpet.119.261610] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/15/2019] [Indexed: 12/13/2022] Open
Abstract
The objective of this study was to investigate the role of ATP in cholinergic neurotransmission in the urinary bladder of control men and of patients obstructed as a result of benign prostatic hyperplasia (BPH). Human detrusor samples were collected from 41 patients who submitted to transvesical prostatectomy resulting from BPH and 26 male organ donors. The release of [3H]acetylcholine ([3H]ACh) was evoked by electrical field stimulation (10 Hz, 200 pulses) in urothelium-denuded detrusor strips. Myographic recordings were performed to test detrusor strip sensitivity to ACh and ATP. Nerve-evoked [3H]ACh release was 1.5-fold higher in detrusor strips from BPH patients compared with controls. This difference was abolished after desensitization of ionotropic P2X1-3 receptors with an ATP analog, α,β-methylene ATP (30 μM, applied for 15 minutes). TNP-ATP (10 nM, a preferential P2X2/3 antagonist) and A317491 (100 nM, a selective P2X3 antagonist) were about equipotent in decreasing nerve-evoked [3H]ACh release in control detrusor strips, but the selective P2X1 receptor antagonist NF023 (3 μM) was devoid of effect. The inhibitory effect of TNP-ATP (10 nM) increased from 27% ± 9% to 43% ± 6% in detrusor strips of BPH patients, but the effect of A317491 (100 nM) [3H]ACh release unaltered (20% ± 2% vs. 24% ± 4%). The amplitude of ACh (0.1-100 μM)-induced myographic recordings decreased, whereas sensitivity to ATP (0.01-3 mM) increased in detrusor strips from BPH patients. Besides the well characterized P2X1 receptor-mediated contractile activity of ATP in pathologic human bladders, we show here for the first time that cholinergic hyperactivity in the detrusor of BPH patients is facilitated by activation of ATP-sensitive P2X2/3 heterotrimers. SIGNIFICANCE STATEMENT: Bladder outlet obstruction often leads to detrusor overactivity and reduced bladder compliance in parallel to atropine-resistant increased purinergic tone. Our data show that P2X1 purinoceptors are overexpressed in the detrusor of patients with benign prostatic hyperplasia. Besides the P2X1 receptor-mediated detrusor contractions, ATP favors nerve-evoked acetylcholine release via the activation of prejunctional P2X2/3 excitatory receptors in these patients Thus, our hypothesis is that manipulation of the purinergic tone may be therapeutically useful to counteract cholinergic overstimulation in obstructed patients.
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Affiliation(s)
- M Silva-Ramos
- Laboratório de Farmacologia e Neurobiologia and Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal (M.S.-R., I.S., M.F., F.F., P.C.-S.); and Serviço de Urologia, Centro Hospitalar Universitário do Porto (CHUP), Porto, Portugal (M.S.-R.)
| | - I Silva
- Laboratório de Farmacologia e Neurobiologia and Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal (M.S.-R., I.S., M.F., F.F., P.C.-S.); and Serviço de Urologia, Centro Hospitalar Universitário do Porto (CHUP), Porto, Portugal (M.S.-R.)
| | - M Faria
- Laboratório de Farmacologia e Neurobiologia and Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal (M.S.-R., I.S., M.F., F.F., P.C.-S.); and Serviço de Urologia, Centro Hospitalar Universitário do Porto (CHUP), Porto, Portugal (M.S.-R.)
| | - F Ferreirinha
- Laboratório de Farmacologia e Neurobiologia and Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal (M.S.-R., I.S., M.F., F.F., P.C.-S.); and Serviço de Urologia, Centro Hospitalar Universitário do Porto (CHUP), Porto, Portugal (M.S.-R.)
| | - P Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia and Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal (M.S.-R., I.S., M.F., F.F., P.C.-S.); and Serviço de Urologia, Centro Hospitalar Universitário do Porto (CHUP), Porto, Portugal (M.S.-R.)
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de Melo Aquino B, da Silva Dos Santos DF, Jorge CO, Marques ACS, Teixeira JM, Parada CA, Oliveira-Fusaro MCG. P2X3 receptors contribute to muscle pain induced by static contraction by a mechanism dependent on neutrophil migration. Purinergic Signal 2019; 15:167-175. [PMID: 31115830 DOI: 10.1007/s11302-019-09659-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 05/13/2019] [Indexed: 01/02/2023] Open
Abstract
P2X3 receptors are involved with several pain conditions. Muscle pain induced by static contraction has an important socioeconomic impact. Here, we evaluated the involvement of P2X3 receptors on mechanical muscle hyperalgesia and neutrophil migration induced by static contraction in rats. Also, we evaluated whether static contraction would be able to increase muscle levels of TNF-α and IL-1β. Male Wistar rats were pretreated with the selective P2X3 receptor antagonist, A-317491, by intramuscular or intrathecal injection and the static contraction-induced mechanical muscle hyperalgesia was evaluated using the Randall-Selitto test. Neutrophil migration was evaluated by measurement of myeloperoxidase (MPO) kinetic-colorimetric assay and the cytokines TNF-α and IL-1β by enzyme-linked immunosorbent assay. Intramuscular or intrathecal pretreatment with A-317491 prevented static contraction-induced mechanical muscle hyperalgesia. In addition, A-317491 reduced static contraction-induced mechanical muscle hyperalgesia when administered 30 and 60 min of the beginning of static contraction, but not after 30 and 60 min of the end of static contraction. Intramuscular A-317491 also prevented static contraction-induced neutrophil migration. In a period of 24 h, static contraction did not increase muscle levels of TNF-α and IL-1β. These findings demonstrated that mechanical muscle hyperalgesia and neutrophil migration induced by static contraction are modulated by P2X3 receptors expressed on the gastrocnemius muscle and spinal cord dorsal horn. Also, we suggest that P2X3 receptors are important to the development but not to maintenance of muscle hyperalgesia. Therefore, P2X3 receptors can be pointed out as a target to musculoskeletal pain conditions induced by daily or work-related activities.
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Affiliation(s)
- Bruna de Melo Aquino
- Laboratory of Pain and Inflammation Research, School of Applied Sciences, State University of Campinas, Pedro Zaccaria 1300, Limeira, Sao Paulo, Brazil
| | - Diogo Francisco da Silva Dos Santos
- Laboratory of Pain and Inflammation Research, School of Applied Sciences, State University of Campinas, Pedro Zaccaria 1300, Limeira, Sao Paulo, Brazil
| | - Carolina Ocanha Jorge
- Laboratory of Pain and Inflammation Research, School of Applied Sciences, State University of Campinas, Pedro Zaccaria 1300, Limeira, Sao Paulo, Brazil
| | - Aline Carolina Salgado Marques
- Laboratory of Pain and Inflammation Research, School of Applied Sciences, State University of Campinas, Pedro Zaccaria 1300, Limeira, Sao Paulo, Brazil
| | - Juliana Maia Teixeira
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Monteiro Lobato 255, Campinas, Sao Paulo, Brazil
| | - Carlos Amilcar Parada
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas, Monteiro Lobato 255, Campinas, Sao Paulo, Brazil
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Abstract
A large series of different ion channels have been identified and investigated as potential targets for new medicines for the treatment of a variety of human diseases, including pain. Among these channels, the voltage gated calcium channels (VGCC) are inhibited by drugs for the treatment of migraine, neuropathic pain or intractable pain. Transient receptor potential (TRP) channels are emerging as important pain transducers as they sense low pH media or oxidative stress and other mediators and are abundantly found at sites of inflammation or tissue injury. Low pH may also activate acid sensing ion channels (ASIC) and mechanical forces stimulate the PIEZO channels. While potent agonists of TRP channels due to their desensitizing action on pain transmission are used as topical applications, the potential of TRP antagonists as pain therapeutics remains an exciting field of investigation. The study of ASIC or PIEZO channels in pain signaling is in an early stage, whereas antagonism of the purinergic P2X3 channels has been reported to provide beneficial effects in chronic intractable cough. The present chapter covers these intriguing channels in great detail, highlighting their diverse mechanisms and broad potential for therapeutic utility.
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Affiliation(s)
- Francesco De Logu
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Pierangelo Geppetti
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy.
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Selective tracking of FFAR3-expressing neurons supports receptor coupling to N-type calcium channels in mouse sympathetic neurons. Sci Rep 2018; 8:17379. [PMID: 30478340 PMCID: PMC6255804 DOI: 10.1038/s41598-018-35690-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/08/2018] [Indexed: 12/30/2022] Open
Abstract
Activation of short-chain free fatty acid receptors 3 (FFAR3) has been suggested to promote sympathetic outflow in postganglionic sympathetic neurons or hamper it by a negative coupling to N-type calcium (CaV2.2) channels. Heterogeneity of FFAR3 expression in sympathetic neurons, however, renders single neurons studies extremely time-consuming in wild-type mice. Previous studies demonstrated large variability of the degree of CaV2.2 channel inhibition by FFAR3 in a global population of rat sympathetic neurons. Therefore, we focused on a small subpopulation of mouse sympathetic neurons using an FFAR3 antibody and an Ffar3 reporter mouse to perform immunofluorescent and electrophysiological studies. Whole-cell patch-clamp recordings of identified FFAR3-expressing neurons from reporter mice revealed a 2.5-fold decrease in the CaV2.2-FFAR3 inhibitory coupling variability and 1.5-fold increase in the mean ICa2+ inhibition, when compared with unlabeled neurons from wild-type mice. Further, we found that the ablation of Ffar3 gene expression in two knockout mouse models led to a complete loss-of-function. Subpopulations of sympathetic neurons are associated with discrete functional pathways. However, little is known about the neural pathways of the FFAR3-expressing subpopulation. Our data indicate that FFAR3 is expressed primarily in neurons with a vasoconstrictor phenotype. Thus, fine-tuning of chemically-coded neurotransmitters may accomplish an adequate outcome.
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Distribution and morphology of baroreceptors in the rat carotid sinus as revealed by immunohistochemistry for P2X3 purinoceptors. Histochem Cell Biol 2018; 151:161-173. [PMID: 30244428 DOI: 10.1007/s00418-018-1734-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2018] [Indexed: 01/08/2023]
Abstract
The morphological characteristics of baroreceptors in the rat carotid sinus were reevaluated by whole-mount preparations with immunohistochemistry for P2X3 purinoceptors using confocal scanning laser microscopy. Immunoreactive nerve endings for P2X3 were distributed in the internal carotid artery proximal to the carotid bifurcation, particularly in the region opposite the carotid body. Some pre-terminal axons in nerve endings were ensheathed by myelin sheaths immunoreactive for myelin basic protein. Pre-terminal axons ramified into several branches that extended two-dimensionally in every direction. The axon terminals of P2X3-immunoreactive nerve endings were flat and leaf-like in shape, and extended hederiform- or knob-like protrusions in the adventitial layer. Some axons and axon terminals with P2X3 immunoreactivity were also immunoreactive for P2X2, and axon terminals were closely surrounded by terminal Schwann cells with S100 or S100B immunoreactivity. These results revealed the detailed morphology of P2X3-immunoreactive nerve endings and suggested that these endings respond to a mechanical deformation of the carotid sinus wall with their flat leaf-like terminals.
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Nakamura M, Jang IS. Characterization of dural afferent neurons innervating cranial blood vessels within the dura in rats. Brain Res 2018; 1696:91-102. [PMID: 29886250 DOI: 10.1016/j.brainres.2018.06.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 06/05/2018] [Accepted: 06/07/2018] [Indexed: 12/16/2022]
Abstract
Dural afferent neurons are implicated in primary headaches including migraine. Although a significant portion of primary afferent neurons innervating the dura are myelinated A-type neurons, previous electrophysiological studies have primarily characterized the functional properties of small-sized C-type sensory neurons. Here we show the functional characterization of dural afferent neurons identified with the fluorescent dye DiI. DiI-positive neurons were divided into three types: small-, medium-, and large-sized neurons, based on their diameter, area, and membrane capacitance. The immunoreactivity of NF200, a marker of A-type myelinated neurons, was detected in most large-sized, but it was also present in a limited number of small- and medium-sized DiI-positive neurons. Capsaicin, a transient receptor potential vanilloid 1 agonist, induced the membrane currents in most small- and medium-sized neurons, but not in large-sized DiI-positive neurons. Tetrodotoxin-resistant Na+ channels were expressed in almost all types of DiI-positive neurons. Mechanosensitive currents were detected from a majority of large-sized, and to a lesser extent, small- and medium-sized DiI-positive neurons. The results suggest that most dural afferent neurons are nociceptive, e.g., polymodal C-type for small- and medium-sized neurons, and high-threshold nociceptive A-type mechanoreceptors for large-sized neurons. We also found that DiI-positive neurons differed with respect to passive and active membrane properties, and that sumatriptan, a representative drug used for the acute treatment of migraine attack, inhibited voltage-gated Ca2+ currents in all types of DiI-positive neurons. The present results showing the nociceptive properties of dural afferent neurons would contribute to understand the pathophysiology of primary headaches.
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Affiliation(s)
- Michiko Nakamura
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu 41940, Republic of Korea
| | - Il-Sung Jang
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu 41940, Republic of Korea.
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De Col R, Messlinger K, Hoffmann T. Differential conduction and CGRP release in visceral versus cutaneous peripheral nerves in the mouse. J Neurosci Res 2018; 96:1398-1405. [DOI: 10.1002/jnr.24255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/23/2018] [Accepted: 04/16/2018] [Indexed: 01/05/2023]
Affiliation(s)
- Roberto De Col
- Institute for Physiology and Pathophysiology; University of Erlangen-Nuremberg; Erlangen Germany
| | - Karl Messlinger
- Institute for Physiology and Pathophysiology; University of Erlangen-Nuremberg; Erlangen Germany
| | - Tali Hoffmann
- Institute for Physiology and Pathophysiology; University of Erlangen-Nuremberg; Erlangen Germany
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39
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Do TP, Hvedstrup J, Schytz HW. Botulinum toxin: A review of the mode of action in migraine. Acta Neurol Scand 2018; 137:442-451. [PMID: 29405250 DOI: 10.1111/ane.12906] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2018] [Indexed: 12/30/2022]
Abstract
Botulinum toxin serotype A (BoNT/A) was originally used in neurology for the treatment of dystonia and blepharospasms, but is now clinically used worldwide for the treatment of chronic migraine. Still, the possible mode of action of BoNT/A in migraine is not fully known. However, the mode of action of BoNT/A has been investigated in experimental pain as well as migraine models, which may elucidate the underlying mechanisms in migraine. The aim of this study was to review studies on the possible mode of action of BoNT/A in relation to chronic migraine treatment. Observations suggest that the mode of action of BoNT/A may not be limited to the injection site, but also includes anatomically connected sites due to axonal transport. The mechanisms behind the effect of BoNT/A in chronic migraine may also include modulation of neurotransmitter release, changes in surface expression of receptors and cytokines as well as enhancement of opioidergic transmission. Clinical and experimental studies with botulinum toxin in the last decade have advanced our understanding of headache and other pain states. More research into botulinum toxin as treatment for headache is warranted as it can be an attractive alternative for patients who do not respond positively to other drugs.
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Affiliation(s)
- T. P. Do
- Headache Diagnostic Laboratory; Danish Headache Center and Department of Neurology; Rigshospitalet-Glostrup; Faculty of Health Sciences, University of Copenhagen; Glostrup Denmark
| | - J. Hvedstrup
- Headache Diagnostic Laboratory; Danish Headache Center and Department of Neurology; Rigshospitalet-Glostrup; Faculty of Health Sciences, University of Copenhagen; Glostrup Denmark
| | - H. W. Schytz
- Headache Diagnostic Laboratory; Danish Headache Center and Department of Neurology; Rigshospitalet-Glostrup; Faculty of Health Sciences, University of Copenhagen; Glostrup Denmark
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40
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Lee J, Bae JY, Lee CJ, Bae YC. Electrophysiological Evidence for Functional Astrocytic P2X 3 Receptors in the Mouse Trigeminal Caudal Nucleus. Exp Neurobiol 2018; 27:88-93. [PMID: 29731674 PMCID: PMC5934546 DOI: 10.5607/en.2018.27.2.88] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/12/2018] [Accepted: 04/12/2018] [Indexed: 12/20/2022] Open
Abstract
Recently, we reported that astrocytes in the trigeminal caudal nucleus (Vc) of the brain stem express a purinergic receptor P2X3, which is involved in the craniofacial pathologic pain. Although we observed protein expression of P2X3 receptors (P2X3 Rs) in the astrocyte of the Vc, it is still unclear that astrocyte has functional P2X3Rs in Vc. To address this issue, we recorded asrtocytic P2X3Rs by using whole cell voltage-clamp recording in the Vc of the GFAP-GFP mice, which was used as a guide to astrocytes with green fluorescence. While measuring voltage ramp-induced astrocytic membrane current, we found the amplitude of the current was increased when we applied P2-purinoreceptor agonist, α,β-meATP. This increase was blocked by co-application of A317491, P2X3R antagonist. These results demonstrate that astrocytes in the Vc express functional P2X3Rs, which might be critical in craniofacial pathologic pain.
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Affiliation(s)
- Jaekwang Lee
- Division of Functional Food Research, Korea Food Research Institute, Jeonju 55365, Korea.,Center for Neuroscience and Functional Connectomics, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Jin Young Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
| | - C Justin Lee
- Center for Neuroscience and Functional Connectomics, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
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41
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Queme LF, Ross JL, Jankowski MP. Peripheral Mechanisms of Ischemic Myalgia. Front Cell Neurosci 2017; 11:419. [PMID: 29311839 PMCID: PMC5743676 DOI: 10.3389/fncel.2017.00419] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 12/13/2017] [Indexed: 12/18/2022] Open
Abstract
Musculoskeletal pain due to ischemia is present in a variety of clinical conditions including peripheral vascular disease (PVD), sickle cell disease (SCD), complex regional pain syndrome (CRPS), and even fibromyalgia (FM). The clinical features associated with deep tissue ischemia are unique because although the subjective description of pain is common to other forms of myalgia, patients with ischemic muscle pain often respond poorly to conventional analgesic therapies. Moreover, these patients also display increased cardiovascular responses to muscle contraction, which often leads to exercise intolerance or exacerbation of underlying cardiovascular conditions. This suggests that the mechanisms of myalgia development and the role of altered cardiovascular function under conditions of ischemia may be distinct compared to other injuries/diseases of the muscles. It is widely accepted that group III and IV muscle afferents play an important role in the development of pain due to ischemia. These same muscle afferents also form the sensory component of the exercise pressor reflex (EPR), which is the increase in heart rate and blood pressure (BP) experienced after muscle contraction. Studies suggest that afferent sensitization after ischemia depends on interactions between purinergic (P2X and P2Y) receptors, transient receptor potential (TRP) channels, and acid sensing ion channels (ASICs) in individual populations of peripheral sensory neurons. Specific alterations in primary afferent function through these receptor mechanisms correlate with increased pain related behaviors and altered EPRs. Recent evidence suggests that factors within the muscles during ischemic conditions including upregulation of growth factors and cytokines, and microvascular changes may be linked to the overexpression of these different receptor molecules in the dorsal root ganglia (DRG) that in turn modulate pain and sympathetic reflexes. In this review article, we will discuss the peripheral mechanisms involved in the development of ischemic myalgia and the role that primary sensory neurons play in EPR modulation.
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Affiliation(s)
- Luis F Queme
- Department of Anesthesia, Division of Pain Management, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Jessica L Ross
- Department of Anesthesia, Division of Pain Management, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Michael P Jankowski
- Department of Anesthesia, Division of Pain Management, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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42
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Yamamoto Y, Nakamuta N. Morphology of P2X3-immunoreactive nerve endings in the rat tracheal mucosa. J Comp Neurol 2017; 526:550-566. [PMID: 29124772 DOI: 10.1002/cne.24351] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 10/24/2017] [Accepted: 10/30/2017] [Indexed: 01/28/2023]
Abstract
Nerve endings with immunoreactivity for the P2X3 purinoreceptor (P2X3) in the rat tracheal mucosa were examined by immunohistochemistry of whole-mount preparations with confocal scanning laser microscopy. P2X3 immunoreactivity was observed in ramified endings distributed in the whole length of the trachea. The myelinated parent axons of P2X3-immunoreactive nerve endings ramified into several branches that extended two-dimensionally in every direction at the interface between the epithelial layer and lamina propria. The axonal branches of P2X3-immunoreactive endings branched off many twigs located just beneath the epithelium, and continued to intraepithelial axon terminals. The axon terminals of P2X3-immunoreactive endings were beaded, rounded, or club-like in shape and terminated between tracheal epithelial cells. Flat axon terminals sometimes partly ensheathed neuroendocrine cells with immunoreactivity for SNAP25 or CGRP. Some axons and axon terminals with P2X3 immunoreactivity were immunoreactive for P2X2, while some terminals were immunoreactive for vGLUT2. Furthermore, a retrograde tracing method using fast blue (FB) revealed that 88.4% of FB-labeled cells with P2X3 immunoreactivity originated from the nodose ganglion. In conclusion, P2X3-immunoreactive nerve endings in the rat tracheal mucosa have unique morphological characteristics, and these endings may be rapidly adapting receptors and/or irritant receptors that are activated by mucosal irritant stimuli.
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Affiliation(s)
- Yoshio Yamamoto
- Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
| | - Nobuaki Nakamuta
- Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
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CB 1 Receptors Mediated Inhibition of ATP-Induced [Ca 2+]i Increase in Cultured Rat Spinal Dorsal Horn Neurons. Neurochem Res 2017; 43:267-275. [PMID: 29127599 DOI: 10.1007/s11064-017-2414-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 09/25/2017] [Accepted: 10/04/2017] [Indexed: 10/18/2022]
Abstract
Spinal cannabinoid receptor 1 (CB1R) and purinergic P2X receptors (P2XR) play a critical role in the process of pathological pain. Both CB1R and P2XR are expressed in spinal dorsal horn (DH) neurons. It is not clear whether CB1 receptor activation modulates the function of P2X receptor channels within dorsal horn. For this reason, we observed the effect of CP55940 (cannabinoid receptor agonist) on ATP-induced Ca2+ mobilization in cultured rat DH neurons. The changes of intracellular calcium concentration ([Ca2+]i) were detected with confocal laser scanning microscopy using fluo-4/AM as a calcium fluorescent indicator. 100 μM ATP caused [Ca2+]i increase in cultured DH neurons. ATP-evoked [Ca2+]i increase in DH neurons was blocked by chelating extracellular Ca2+ and P2 purinoceptor antagonist PPADS. At the same time, ATP-γ-S (a non-hydrolyzable ATP analogue) mimicked the ATP action, while P2Y receptor agonist ADP failed to evoke [Ca2+]i increase in cultured DH neurons. These data suggest that ATP-induced [Ca2+]i elevation in cultured DH neurons is mediated by P2X receptor. Subsequently, we noticed that, in cultured rat DH neurons, ATP-induced Ca2+ mobilization was inhibited after pretreated with CP55940 with a concentration-dependent manner, which implies that the opening of P2X receptor channels are down-regulated by activation of cannabinoid receptor. The inhibitory effect of CP55940 on ATP-induced Ca2+ response was mimicked by ACEA (CB1R agonist), but was not influenced by AM1241 (CB2R agonist). Moreover, the inhibitory effect of CP55940 on ATP-induced Ca2+ mobilization was blocked by AM251 (CB1 receptor antagonist), but was not influenced by AM630 (CB2 receptor antagonist). In addition, we also observed that forskolin (an activator of adenylate cyclase) and 8-Br-cAMP (a cell-permeable cAMP analog) reversed the inhibitory effect of CP55940, respectively. In a summary, our observations raise a possibility that CB1R rather than CB2R can downregulate the opening of P2X receptor channels in DH neurons. The reduction of cAMP/PKA signaling is a key element in the inhibitory effect of CB1R on P2X-channel-induced Ca2+ mobilization.
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44
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A role for the purinergic receptor P2X 3 in astrocytes in the mechanism of craniofacial neuropathic pain. Sci Rep 2017; 7:13627. [PMID: 29051582 PMCID: PMC5648840 DOI: 10.1038/s41598-017-13561-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 09/26/2017] [Indexed: 11/18/2022] Open
Abstract
The purinergic receptor P2X3, expressed in the central terminals of primary nociceptive neurons in the brainstem, plays an important role in pathological pain. However, little is known about expression of P2X3 in the brainstem astrocytes and its involvement in craniofacial pathologic pain. To address this issue, we investigated the expression of P2X3 in astrocytes in the trigeminal caudal nucleus (Vc) in a rat model of craniofacial neuropathic pain, chronic constriction injury of infraorbital nerve (CCI-ION). We found that 1) P2X3-immunoreactivity is observed in the brainstem astrocytes, preferentially in their fine processes, 2) the number of P2X3-positive fine astrocytic processes and the density of P2X3 in these processes were increased significantly in CCI-ION rats, compared to control rats, and 3) administration of MPEP, a specific mGluR5 antagonist, alleviated the mechanical allodynia and abolished the increase in density of P2X3 in fine astrocytic processes caused by CCI-ION. These findings reveal preferential expression of P2X3 in the fine astrocytic processes in the brainstem, propose a novel role of P2X3 in the fine astrocytic process in the mechanism of craniofacial neuropathic pain, and suggest that the expression of astrocytic P2X3 may be regulated by astrocytic mGluR5.
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45
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Djenoune L, Wyart C. Light on a sensory interface linking the cerebrospinal fluid to motor circuits in vertebrates. J Neurogenet 2017; 31:113-127. [PMID: 28789587 DOI: 10.1080/01677063.2017.1359833] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The cerebrospinal fluid (CSF) is circulating around the entire central nervous system (CNS). The main function of the CSF has been thought to insure the global homeostasis of the CNS. Recent evidence indicates that the CSF also dynamically conveys signals modulating the development and the activity of the nervous system. The later observation implies that cues from the CSF could act on neurons in the brain and the spinal cord via bordering receptor cells. Candidate neurons to enable such modulation are the cerebrospinal fluid-contacting neurons (CSF-cNs) that are located precisely at the interface between the CSF and neuronal circuits. The atypical apical extension of CSF-cNs bears a cluster of microvilli bathing in the CSF indicating putative sensory or secretory roles in relation with the CSF. In the brainstem and spinal cord, CSF-cNs have been described in over two hundred species by Kolmer and Agduhr, suggesting an important function within the spinal cord. However, the lack of specific markers and the difficulty to access CSF-cNs hampered their physiological investigation. The transient receptor potential channel PKD2L1 is a specific marker of spinal CSF-cNs in vertebrate species. The transparency of zebrafish at early stages eases the functional characterization of pkd2l1+ CSF-cNs. Recent studies demonstrate that spinal CSF-cNs detect spinal curvature via the channel PKD2L1 and modulate locomotion and posture by projecting onto spinal interneurons and motor neurons in vivo. In vitro recordings demonstrated that spinal CSF-cNs are sensing pH variations mainly through ASIC channels, in combination with PKD2L1. Altogether, neurons contacting the CSF appear as a novel sensory modality enabling the detection of mechanical and chemical stimuli from the CSF and modulating the excitability of spinal circuits underlying locomotion and posture.
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Affiliation(s)
- Lydia Djenoune
- a Institut du Cerveau et de la Moelle épinière (ICM) , Paris , France
| | - Claire Wyart
- a Institut du Cerveau et de la Moelle épinière (ICM) , Paris , France
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46
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Jung YH, Kim YO, Lin H, Cho JH, Park JH, Lee SD, Bae J, Kang KM, Kim YG, Pae AN, Ko H, Park CS, Yoon MH, Kim YC. Discovery of Potent Antiallodynic Agents for Neuropathic Pain Targeting P2X3 Receptors. ACS Chem Neurosci 2017; 8:1465-1478. [PMID: 28323403 DOI: 10.1021/acschemneuro.6b00401] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Antagonism of the P2X3 receptor is one of the potential therapeutic strategies for the management of neuropathic pain because P2X3 receptors are predominantly localized on small to medium diameter C- and Aδ-fiber primary afferent neurons, which are related to the pain-sensing system. In this study, 5-hydroxy pyridine derivatives were designed, synthesized, and evaluated for their in vitro biological activities by two-electrode voltage clamp assay at hP2X3 receptors. Among the novel hP2X3 receptor antagonists, intrathecal treatment of compound 29 showed parallel efficacy with pregabalin (calcium channel modulator) and higher efficacy than AF353 (P2X3 receptor antagonist) in the evaluation of its antiallodynic effects in spinal nerve ligation rats. However, because compound 29 was inactive by intraperitoneal administration in neuropathic pain animal models due to low cell permeability, the corresponding methyl ester analogue, 28, which could be converted to compound 29 in vivo, was investigated as a prodrug concept. Intravenous injection of compound 28 resulted in potent antiallodynic effects, with ED50 values of 2.62 and 2.93 mg/kg in spinal nerve ligation and chemotherapy-induced peripheral neuropathy rats, respectively, indicating that new drug development targeting the P2X3 receptor could be promising for neuropathic pain, a disease with high unmet medical needs.
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Affiliation(s)
- Young-Hwan Jung
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | | | | | - Joong-Heui Cho
- New Drug Development Center
(NDDC), Daegu-Gyeongbuk Medical Innovation Foundation (DGMIF), 80
Cheombok-ro, Dong-gu, Daegu 41061, Republic of Korea
| | - Jin-Hee Park
- New Drug Development Center
(NDDC), Daegu-Gyeongbuk Medical Innovation Foundation (DGMIF), 80
Cheombok-ro, Dong-gu, Daegu 41061, Republic of Korea
| | - So-Deok Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Jinsu Bae
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Koon Mook Kang
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Yoon-Gyoon Kim
- College of Pharmacy, Dankook University, Cheonan 330-714, Republic of Korea
| | - Ae Nim Pae
- Convergence Research Center for Diagnosis, Treatment
and Care System of Dementia, Korea Institute of Science and Technology, PO Box 131, Cheongryang, Seoul 130-650, Republic of Korea
| | - Hyojin Ko
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | - Chul-Seung Park
- School of Life Sciences, 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
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
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47
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Nascimento DSM, Potes CS, Soares ML, Ferreira AC, Malcangio M, Castro-Lopes JM, Neto FLM. Drug-Induced HSP90 Inhibition Alleviates Pain in Monoarthritic Rats and Alters the Expression of New Putative Pain Players at the DRG. Mol Neurobiol 2017; 55:3959-3975. [PMID: 28550532 DOI: 10.1007/s12035-017-0628-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/19/2017] [Indexed: 01/17/2023]
Abstract
Purinergic receptors (P2XRs) have been widely associated with pain states mostly due to their involvement in neuron-glia communication. Interestingly, we have previously shown that satellite glial cells (SGC), surrounding dorsal root ganglia (DRG) neurons, become activated and proliferate during monoarthritis (MA) in the rat. Here, we demonstrate that P2X7R expression increases in ipsilateral DRG after 1 week of disease, while P2X3R immunoreactivity decreases. We have also reported a significant induction of the activating transcriptional factor 3 (ATF3) in MA. In this study, we show that ATF3 knocked down in DRG cell cultures does not affect the expression of P2X7R, P2X3R, or glial fibrillary acidic protein (GFAP). We suggest that P2X7R negatively regulates P2X3R, which, however, is unlikely mediated by ATF3. Interestingly, we found that ATF3 knockdown in vitro induced significant decreases in the heat shock protein 90 (HSP90) expression. Thus, we evaluated in vivo the involvement of HSP90 in MA and demonstrated that the HSP90 messenger RNA levels increase in ipsilateral DRG of inflamed animals. We also show that HSP90 is mostly found in a cleaved form in this condition. Moreover, administration of a HSP90 inhibitor, 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), attenuated MA-induced mechanical allodynia in the first hours. The drug also reversed the HSP90 upregulation and cleavage. 17-DMAG seemed to attenuate glial activation and neuronal sensitization (as inferred by downregulation of GFAP and P2X3R in ipsilateral DRG) which might correlate with the observed pain alleviation. Our data indicate a role of HSP90 in MA pathophysiology, but further investigation is necessary to clarify the underlying mechanisms.
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Affiliation(s)
- Diana Sofia Marques Nascimento
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Catarina Soares Potes
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Miguel Luz Soares
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Laboratório de Apoio à Investigação em Medicina Molecular (LAIMM), Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - António Carlos Ferreira
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Laboratório de Apoio à Investigação em Medicina Molecular (LAIMM), Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Marzia Malcangio
- Wolfson Centre for Age Related Diseases, King's College London, London, UK
| | - José Manuel Castro-Lopes
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Fani Lourença Moreira Neto
- Departamento de Biomedicina-Unidade de Biologia Experimental, Centro de Investigação Médica (CIM), Faculdade de Medicina da Universidade do Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal. .,Pain Group, Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal. .,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.
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48
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Kozyreva TV, Meyta ES, Kozaruk VP. Participation of Purinergic P 2X Receptors in the Thermoregulatory Response to Cooling. Bull Exp Biol Med 2017; 162:606-610. [PMID: 28361417 DOI: 10.1007/s10517-017-3668-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Indexed: 10/19/2022]
Abstract
We studied the role of purinergic P2X receptors in the body response to cooling. In experiments on rats, P2X receptor antagonist PPADS was administered in different modes, which resulted in changes of different characteristics of the thermoregulatory response to cold. Iontophoresis of P2X antagonist into the skin decreased the thermal thresholds of all thermoregulatory responses to cooling, which can attest to a modulating effect of P2X receptors on peripheral thermosensitive afferents. Intraperitoneal administration of P2X antagonist suppressed thermoregulatory activity of skeletal muscles (shivering) developing during cooling without changing the thresholds of thermoregulatory responses. The findings suggest that ATP and P2X receptors play an important role in the formation of the response to cooling.
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Affiliation(s)
- T V Kozyreva
- Laboratory of Thermophysiology, Research Institute of Physiology and Fundamental Medicine, Novosibirsk, Russia.
| | - E S Meyta
- Laboratory of Thermophysiology, Research Institute of Physiology and Fundamental Medicine, Novosibirsk, Russia
| | - V P Kozaruk
- Laboratory of Thermophysiology, Research Institute of Physiology and Fundamental Medicine, Novosibirsk, Russia
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49
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Dal Ben D, Marchenkova A, Thomas A, Lambertucci C, Spinaci A, Marucci G, Nistri A, Volpini R. 2',3'-O-Substituted ATP derivatives as potent antagonists of purinergic P2X3 receptors and potential analgesic agents. Purinergic Signal 2017; 13:61-74. [PMID: 27757785 PMCID: PMC5334199 DOI: 10.1007/s11302-016-9539-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/19/2016] [Indexed: 11/29/2022] Open
Abstract
Blocking membrane currents evoked by the activation of purinergic P2X3 receptors localized on nociceptive neurons represents a promising strategy for the development of agents useful for the treatment of chronic pain conditions. Among compounds endowed with such antagonistic action, 2',3'-O-(2,4,6-trinitrophenyl)-ATP (TNP-ATP) is an ATP analogue, whose inhibitory activity on P2X receptors has been previously reported. Based on the results of molecular modelling studies performed with homology models of the P2X3 receptor, novel adenosine nucleotide analogues bearing cycloalkyl or arylalkyl substituents replacing the trinitrophenyl moiety of TNP-ATP were designed and synthesized. These new compounds were functionally evaluated on native P2X3 receptors from mouse trigeminal ganglion (TG) sensory neurons using patch clamp recordings under voltage clamp configuration. Our data show that some of these molecules are potent (nanomolar range) and reversible inhibitors of P2X3 receptors, without any apparent effect on trigeminal GABAA and 5-HT3 receptors, whose membrane currents were unaffected by the tested compounds.
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Affiliation(s)
- Diego Dal Ben
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032, Camerino, (MC), Italy
| | - Anna Marchenkova
- Neuroscience Department, International School for Advanced Studies (SISSA), Via Bonomea 265, 34136, Trieste, Italy
| | - Ajiroghene Thomas
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032, Camerino, (MC), Italy
| | - Catia Lambertucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032, Camerino, (MC), Italy
| | - Andrea Spinaci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032, Camerino, (MC), Italy
| | - Gabriella Marucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032, Camerino, (MC), Italy
| | - Andrea Nistri
- Neuroscience Department, International School for Advanced Studies (SISSA), Via Bonomea 265, 34136, Trieste, Italy
| | - Rosaria Volpini
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, via S. Agostino 1, 62032, Camerino, (MC), Italy.
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Xie AX, Lee JJ, McCarthy KD. Ganglionic GFAP + glial Gq-GPCR signaling enhances heart functions in vivo. JCI Insight 2017; 2:e90565. [PMID: 28138563 DOI: 10.1172/jci.insight.90565] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The sympathetic nervous system (SNS) accelerates heart rate, increases cardiac contractility, and constricts resistance vessels. The activity of SNS efferent nerves is generated by a complex neural network containing neurons and glia. Gq G protein-coupled receptor (Gq-GPCR) signaling in glial fibrillary acidic protein-expressing (GFAP+) glia in the central nervous system supports neuronal function and regulates neuronal activity. It is unclear how Gq-GPCR signaling in GFAP+ glia affects the activity of sympathetic neurons or contributes to SNS-regulated cardiovascular functions. In this study, we investigated whether Gq-GPCR activation in GFAP+ glia modulates the regulatory effect of the SNS on the heart; transgenic mice expressing Gq-coupled DREADD (designer receptors exclusively activated by designer drugs) (hM3Dq) selectively in GFAP+ glia were used to address this question in vivo. We found that acute Gq-GPCR activation in peripheral GFAP+ glia significantly accelerated heart rate and increased left ventricle contraction. Pharmacological experiments suggest that the glial-induced cardiac changes were due to Gq-GPCR activation in satellite glial cells within the sympathetic ganglion; this activation led to increased norepinephrine (NE) release and beta-1 adrenergic receptor activation within the heart. Chronic glial Gq-GPCR activation led to hypotension in female Gfap-hM3Dq mice. This study provides direct evidence that Gq-GPCR activation in peripheral GFAP+ glia regulates cardiovascular functions in vivo.
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