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Huerta MÁ, Marcos-Frutos D, Nava JDL, García-Ramos A, Tejada MÁ, Roza C. P2X3 and P2X2/3 Receptors Inhibition Produces a Consistent Analgesic Efficacy: A Systematic Review and Meta-Analysis of Preclinical Studies. Eur J Pharmacol 2024; 984:177052. [PMID: 39393665 DOI: 10.1016/j.ejphar.2024.177052] [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: 06/10/2024] [Revised: 08/29/2024] [Accepted: 10/07/2024] [Indexed: 10/13/2024]
Abstract
BACKGROUND P2X3 and P2X2/3 receptors are promising therapeutic targets for pain treatment and selective inhibitors are under evaluation in ongoing clinical trials. Here we aim to consolidate and quantitatively evaluate the preclinical evidence on P2X3 and P2X2/3 receptors inhibitors for pain treatment. METHODS A literature search was conducted in PubMed, Scopus and Web-of-Science on August 5, 2023. Data was extracted and meta-analyzed using a random-effects model to estimate the analgesic efficacy of the intervention; then several subgroup analyses were performed. RESULTS 67 articles were included. The intervention induced a consistent pain reduction (66.5 [CI95% = 58.5, 74.5]; p < 0.0001), which was highest for visceral pain (114.3), followed by muscle (79.8) and neuropathic pain (71.1), but lower for cancer (64.1), joint (57.5) and inflammatory pain (49.0). Further analysis showed a greater effect for mechanical hypersensitivity (70.4) compared to heat hypersensitivity (64.5) and pain-related behavior (54.1). Sex (male or female) or interspecies (mice or rats) differences were not appreciated (p > 0.05). The most used molecule was A-317491, but other such as gefapixant or eliapixant were also effective (p < 0.0001 for all). The analgesic effect was higher for systemic or peripheral administration than for intrathecal administration. Conversely, intracerebroventricular administration was not analgesic, but potentiated pain. CONCLUSION P2X3 and P2X2/3 receptor inhibitors showed a good analgesic efficacy in preclinical studies, which was dependent on the pain etiology, pain outcome measured, the drug used and its route of administration. Further research is needed to assess the clinical utility of these preclinical findings. PROTOCOL REGISTRATION PROSPERO ID CRD42023450685.
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Affiliation(s)
- Miguel Á Huerta
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Biomedical Research Center, Institute of Neuroscience, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria de Granada (ibs.GRANADA), Granada, Spain
| | - Daniel Marcos-Frutos
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Javier de la Nava
- Unit for Active Coping Strategies for Pain in Primary Care, East-Valladolid Primary Care Management, Castilla and Leon Public Health System (Sacyl), Valladolid, Spain
| | - Amador García-Ramos
- Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain; Department of Sports Sciences and Physical Conditioning, Faculty of Education, Universidad Católica de la Santísima Concepción, Concepción, Chile
| | - Miguel Ángel Tejada
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Biomedical Research Center, Institute of Neuroscience, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria de Granada (ibs.GRANADA), Granada, Spain.
| | - Carolina Roza
- Department of System's Biology, Medical School, University of Alcala, Alcalá de Henares, 28871, Madrid, Spain
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Kim GR, Kim S, Kim YO, Han X, Nagel J, Kim J, Song DI, Müller CE, Yoon MH, Jin MS, Kim YC. Discovery of Triazolopyrimidine Derivatives as Selective P2X3 Receptor Antagonists Binding to an Unprecedented Allosteric Site as Evidenced by Cryo-Electron Microscopy. J Med Chem 2024; 67:14443-14465. [PMID: 39102524 DOI: 10.1021/acs.jmedchem.4c01214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/07/2024]
Abstract
The P2X3 receptor (P2X3R), an ATP-gated cation channel predominantly expressed in C- and Aδ-primary afferent neurons, has been proposed as a drug target for neurological inflammatory diseases, e.g., neuropathic pain, and chronic cough. Aiming to develop novel, selective P2X3R antagonists, tetrazolopyrimidine-based hit compound 9 was optimized through structure-activity relationship studies by modifying the tetrazole core as well as side chain substituents. The optimized antagonist 26a, featuring a cyclopropane-substituted triazolopyrimidine core, displayed potent P2X3R-antagonistic activity (IC50 = 54.9 nM), 20-fold selectivity versus the heteromeric P2X2/3R, and high selectivity versus other P2XR subtypes. Noncompetitive P2X3R blockade was experimentally confirmed by calcium influx assays. Cryo-electron microscopy revealed that 26a stabilizes the P2X3R in its desensitized state, acting as a molecular barrier to prevent ions from accessing the central pore. In vivo studies in a rat neuropathic pain model (spinal nerve ligation) showed dose-dependent antiallodynic effects of 26a, thus presenting a novel, promising lead structure.
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Affiliation(s)
- Ga-Ram Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Subin Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Yeo-Ok Kim
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 42 Jebong-ro, Dong-gu, Gwangju 61469, Republic of Korea
| | - Xuehao Han
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 42 Jebong-ro, Dong-gu, Gwangju 61469, Republic of Korea
| | - Jessica Nagel
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, Bonn 53113, Germany
| | - Jihyun Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Dahin Irene Song
- Bioengineering, University of Pennsylvania, 3451 Walnut St, Philadelphia, Pennsylvania 19104, United States
| | - Christa E Müller
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, Bonn 53113, Germany
| | - Myung-Ha Yoon
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School, 42 Jebong-ro, Dong-gu, Gwangju 61469, Republic of Korea
| | - Mi Sun Jin
- School of Life Sciences, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
| | - Yong-Chul Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea
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Janzadeh A, Ramezani F, Yousefi S, Hamblin MR, Mojarad N, Nasirinezhad F. Time-dependent photobiomodulation management of neuropathic pain induced by spinal cord injury in male rats. Lasers Med Sci 2023; 38:120. [PMID: 37160475 DOI: 10.1007/s10103-023-03722-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 01/16/2023] [Indexed: 05/11/2023]
Abstract
Neuropathic pain (NP) following spinal cord injury (SCI) often lasts for a long time and causes a range of problems that reduce the quality of life. Current treatments are not generally effective; however, photobiomodulation therapy (PBMT) has made some progress in this area. Due to the novelty of this treatment, standard therapeutic protocols have not yet been agreed upon. In the present study, we compare the analgesic effect of two PBMT protocols (2 and 4 weeks of radiation). A total of thirty-two adult male Wistar rats were divided into four groups: control, SCI, 2 W PBMT, and 4 W PBMT. SCI was induced by an aneurism clip and PBMT used a 660-nm, initiated 30 min post-SCI, and continued daily for 2 or 4 weeks. Functional recovery, hyperalgesia, and allodynia were measured weekly. At the end of the study, the Gad65, interleukin 1-alpha (IL1α), interleukin 10 (IL10), IL4, and purinergic receptor (P2xR and P2yR) expressions were measured. Data were analyzed by Prism6. The results showed PBM irradiation for 2 and 4 weeks had the same effects in improving hyperalgesia. In the case of allodynia and functional recovery, 4 W PBMT was more effective (p<0.01). 4 W PBMT increased the Gad65 expression (p <0.001) and reduced P2Y4R (p <0.05) compared to SCI animals. The effects of 2 and 4 W PBMT were the same for IL1α, IL10, and P2X3 receptors. 4 W PBMT was more effective in reducing the complications of SCI such as pain and disability. PBMT therapy is an effective method aimed at immune system function modulation to reduce NP and motor dysfunction.
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Affiliation(s)
- Atousa Janzadeh
- Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Ramezani
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sogol Yousefi
- Department of Biology, Damghan Branch, Islamic Azad University, Damghan, Iran
| | - Michael R Hamblin
- Laser Research Center, Faculty of Health Science, University of Johannesburg, Doornfontein, 2028, South Africa
| | - Negin Mojarad
- Program in Neuroscience, Central Michigan University, Mt. Pleasant, MI, 48859, USA
| | - Farinaz Nasirinezhad
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran.
- Department of Physiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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4
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Eliapixant is a selective P2X3 receptor antagonist for the treatment of disorders associated with hypersensitive nerve fibers. Sci Rep 2021; 11:19877. [PMID: 34615939 PMCID: PMC8494816 DOI: 10.1038/s41598-021-99177-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 09/21/2021] [Indexed: 11/08/2022] Open
Abstract
ATP-dependent P2X3 receptors play a crucial role in the sensitization of nerve fibers and pathological pain pathways. They are also involved in pathways triggering cough and may contribute to the pathophysiology of endometriosis and overactive bladder. However, despite the strong therapeutic rationale for targeting P2X3 receptors, preliminary antagonists have been hampered by off-target effects, including severe taste disturbances associated with blocking the P2X2/3 receptor heterotrimer. Here we present a P2X3 receptor antagonist, eliapixant (BAY 1817080), which is both highly potent and selective for P2X3 over other P2X subtypes in vitro, including P2X2/3. We show that eliapixant reduces inflammatory pain in relevant animal models. We also provide the first in vivo experimental evidence that P2X3 antagonism reduces neurogenic inflammation, a phenomenon hypothesised to contribute to several diseases, including endometriosis. To test whether eliapixant could help treat endometriosis, we confirmed P2X3 expression on nerve fibers innervating human endometriotic lesions. We then demonstrate that eliapixant reduces vaginal hyperalgesia in an animal model of endometriosis-associated dyspareunia, even beyond treatment cessation. Our findings indicate that P2X3 antagonism could alleviate pain, including non-menstrual pelvic pain, and modify the underlying disease pathophysiology in women with endometriosis. Eliapixant is currently under clinical development for the treatment of disorders associated with hypersensitive nerve fibers.
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5
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Guo J, Wang C, Niu X, Zhou F, Li H, Gao W. Effects of resveratrol in the signaling of neuropathic pain involving P2X3 in the dorsal root ganglion of rats. Acta Neurol Belg 2021; 121:365-372. [PMID: 30989502 DOI: 10.1007/s13760-019-01126-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 03/16/2019] [Indexed: 12/18/2022]
Abstract
Neuropathic pain is a major public health problem because it has a considerable impact on life quality of patients. Neuropathic pain caused by a lesion or disease of the somatosensory nervous system, which causes unpleasant and abnormal sensation (dysesthesia), an increased response to painful stimuli (hyperalgesia), and pain in response to a stimulus that does not normally provoke pain (allodynia). P2X receptors from dorsal root ganglion (DRG) play a crucial role in facilitating pain transmission at peripheral and spinal sites. Resveratrol (Res) has neuroprotective effects and improves the pathological and behavioral outcomes of various types of nerve injury. The present study examined the effects of Res on neuropathic pain. Neuropathic pain animal model was created by partial sciatic nerve ligation (pSNL) surgery. We found that consecutive intraperitoneal administration of Res for 21 days reduced the mechanical and thermal nociceptive responses induced by pSNL in a dose-dependent manner. Moreover, Res administration reversed P2X3 expression and phosphorylation of ERK in DRG neurons after peripheral nerve injury. Our results suggested that Res may ameliorate neuropathic pain by suppressing P2X3 up-regulation and ERK phosphorylation in DRG of neuropathic pain rats. Therefore, we concluded that Res has a significant analgesic effect on alleviating neuropathic pain, and thus may serve as a therapeutic approach for neuropathic pain.
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Affiliation(s)
- Jinhui Guo
- Department of Pharmaceutics, the First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui, 453100, Henan, People's Republic of China.
| | - Chaowei Wang
- Department of Neurology, the First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, People's Republic of China
| | - Xiaolu Niu
- Department of Neurology, the First Affiliated Hospital of Xinxiang Medical University, Weihui, 453100, Henan, People's Republic of China
| | - Fang Zhou
- Department of Pharmaceutics, the First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui, 453100, Henan, People's Republic of China
| | - Huiling Li
- Department of Pharmaceutics, the First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui, 453100, Henan, People's Republic of China
| | - Weifang Gao
- Department of Pharmaceutics, the First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui, 453100, Henan, People's Republic of China
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Moses AS, Demessie AA, Taratula O, Korzun T, Slayden OD, Taratula O. Nanomedicines for Endometriosis: Lessons Learned from Cancer Research. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2004975. [PMID: 33491876 PMCID: PMC7928207 DOI: 10.1002/smll.202004975] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/03/2020] [Indexed: 05/02/2023]
Abstract
Endometriosis is an incurable gynecological disease characterized by the abnormal growth of endometrium-like tissue, characteristic of the uterine lining, outside of the uterine cavity. Millions of people with endometriosis suffer from pelvic pain and infertility. This review aims to discuss whether nanomedicines that are promising therapeutic approaches for various diseases have the potential to create a paradigm shift in endometriosis management. For the first time, the available reports and achievements in the field of endometriosis nanomedicine are critically evaluated, and a summary of how nanoparticle-based systems can improve endometriosis treatment and diagnosis is provided. Parallels between cancer and endometriosis are also drawn to understand whether some fundamental principles of the well-established cancer nanomedicine field can be adopted for the development of novel nanoparticle-based strategies for endometriosis. This review provides the state of the art of endometriosis nanomedicine and perspective for researchers aiming to realize and exploit the full potential of nanoparticles for treatment and imaging of the disorder.
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Affiliation(s)
- Abraham S Moses
- College of Pharmacy, Oregon State University, 2730 S Moody Avenue, Portland, OR, 97201, USA
| | - Ananiya A Demessie
- College of Pharmacy, Oregon State University, 2730 S Moody Avenue, Portland, OR, 97201, USA
| | - Olena Taratula
- College of Pharmacy, Oregon State University, 2730 S Moody Avenue, Portland, OR, 97201, USA
| | - Tetiana Korzun
- College of Pharmacy, Oregon State University, 2730 S Moody Avenue, Portland, OR, 97201, USA
| | - Ov D Slayden
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR, 97006, USA
| | - Oleh Taratula
- College of Pharmacy, Oregon State University, 2730 S Moody Avenue, Portland, OR, 97201, USA
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7
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Krajewski JL. P2X3-Containing Receptors as Targets for the Treatment of Chronic Pain. Neurotherapeutics 2020; 17:826-838. [PMID: 33009633 PMCID: PMC7609758 DOI: 10.1007/s13311-020-00934-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2020] [Indexed: 02/06/2023] Open
Abstract
Current therapies for the treatment of chronic pain provide inadequate relief for millions of suffering patients, demonstrating the need for better therapies that will treat pain effectively and improve the quality of patient's lives. Better understanding of the mechanisms that mediate chronic pain is critical for developing drugs with improved clinical outcomes. Adenosine triphosphate (ATP) is a key modulator in nociceptive pathways. Release of ATP from injured tissue or sympathetic efferents has sensitizing effects on sensory neurons in the periphery, and presynaptic vesicular release of ATP from the central terminals can increase glutamate release thereby potentiating downstream central sensitization mechanisms, a condition thought to underlie many chronic pain conditions. The purinergic receptors on sensory nerves primarily responsible for ATP signaling are P2X3 and P2X2/3. Selective knockdown experiments, or inhibition with small molecules, demonstrate P2X3-containing receptors are key targets to modulate nociceptive signals. Preclinical studies have identified that P2X3-containing receptors are critical for sensory transduction for bladder function, and clinical studies have shown promise in treatment for bladder pain and pain associated with osteoarthritis. Further clinical characterization of antagonists to P2X3-containing receptors may lead to improved therapies in the treatment of chronic pain.
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8
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Identification of aurintricarboxylic acid as a potent allosteric antagonist of P2X1 and P2X3 receptors. Neuropharmacology 2019; 158:107749. [PMID: 31461640 DOI: 10.1016/j.neuropharm.2019.107749] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/14/2019] [Accepted: 08/23/2019] [Indexed: 12/13/2022]
Abstract
The homotrimeric P2X3 receptor, one of the seven members of the ATP-gated P2X receptor family, plays a crucial role in sensory neurotransmission. P2X3 receptor antagonists have been identified as promising drugs to treat chronic cough and are suggested to offer pain relief in chronic pain such as neuropathic pain. Here, we analysed whether compounds affect P2X3 receptor activity by high-throughput screening of the Spectrum Collection of 2000 approved drugs, natural products and bioactive substances. We identified aurintricarboxylic acid (ATA) as a nanomolar-potency antagonist of P2X3 receptor-mediated responses. Two-electrode voltage clamp electrophysiology-based concentration-response analysis and selectivity profiling revealed that ATA strongly inhibits the rP2X1 and rP2X3 receptors (with IC50 values of 8.6 nM and 72.9 nM, respectively) and more weakly inhibits P2X2/3, P2X2, P2X4 or P2X7 receptors (IC50 values of 0.76 μM, 22 μM, 763 μM or 118 μM, respectively). Patch-clamp analysis of mouse DRG neurons revealed that ATA inhibited native P2X3 and P2X2/3 receptors to a similar extent than rat P2X3 and P2X2/3 receptors expressed in Xenopus oocytes. In a radioligand binding assay, up to 30 μM ATA did not compete with [3H]-ATP for rP2X3 receptor binding, indicating a non-competitive mechanism of action. Molecular docking studies, site-directed mutagenesis and concentration-response analysis revealed that ATA binds to the negative allosteric site of the hP2X3 receptor. In summary, ATA as a drug-like pharmacological tool compound is a nanomolar-potency, allosteric antagonist with selectivity towards αβ-methylene-ATP-sensitive P2X1 and P2X3 receptors.
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Vincetti P, Kaptein SJF, Costantino G, Neyts J, Radi M. Scaffold Morphing Approach To Expand the Toolbox of Broad-Spectrum Antivirals Blocking Dengue/Zika Replication. ACS Med Chem Lett 2019; 10:558-563. [PMID: 30996796 DOI: 10.1021/acsmedchemlett.8b00583] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/23/2019] [Indexed: 12/17/2022] Open
Abstract
We have recently discovered a family of 2,6-diaminopurine derivatives acting as DENV inhibitors by targeting an allosteric pocket on the thumb of the viral NS5 polymerase. Although the following target-based optimization allowed conversion of the hits into broad-spectrum DENV/ZIKV inhibitors, no improvement of the antiviral potency was reached. Herein, we applied a phenotypic scaffold-morphing approach to explore additional biologically relevant chemical space around the original hits by converting the flat purine derivatives into more complex chemotypes characterized by a higher degree of saturation. A new microwave-assisted one-pot three-step protocol was also developed to quickly generate chemotypes 6 and 7. Cell-based phenotypic screening allowed identification of promising antiflaviviral agents belonging to different chemotypes. Compound 9d emerged as the most promising broad-spectrum antiviral, being 6 times more potent than ribavirin (RBV) against DENV and 3 times more potent than 7-deaza-2'-C-methyladenosine (7DMA) against ZIKV with good selectivity indexes (>46 and >41, respectively).
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Affiliation(s)
- Paolo Vincetti
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Viale delle Scienze, 27/A, 43124 Parma, Italy
| | - Suzanne J. F. Kaptein
- KU Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, B-3000 Leuven, Belgium
| | - Gabriele Costantino
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Viale delle Scienze, 27/A, 43124 Parma, Italy
| | - Johan Neyts
- KU Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, B-3000 Leuven, Belgium
| | - Marco Radi
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Viale delle Scienze, 27/A, 43124 Parma, Italy
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Tao J, Liu L, Fan Y, Wang M, Li L, Zou L, Yuan H, Shi L, Yang R, Liang S, Liu S. Role of hesperidin in P2X3 receptor-mediated neuropathic pain in the dorsal root ganglia. Int J Neurosci 2019; 129:784-793. [PMID: 30621504 DOI: 10.1080/00207454.2019.1567512] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Aim: This study investigated whether the neuronal P2X3 receptor in rat dorsal root ganglia (DRG) mediated the effects of hesperidin on neuropathic pain. Materials and methods: The chronic constriction injury (CCI) model was used as a model of neuropathic pain. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured. The mRNA and protein expression levels were assayed by real-time RT-PCR and Western blotting. Results: The results showed that mechanical and thermal hyperalgesia in the CCI rats were increased as compared to those in the sham group. The expression levels of P2X3 mRNA and protein in CCI rats were higher than those in the sham group. Dual-labelling immunofluorescence showed that the elevated P2X3 receptor was co-expressed with the neuronal marker NeuN in the DRG of CCI rats. Hesperidin treatment decreased both the mechanical and thermal hyperalgesia, and upregulated P2X3 expression in the CCI rats. Hesperidin treatment also reduced the ERK1/2 phosphorylation in the DRG of CCI rats. Moreover, hesperidin inhibited the P2X3 agonist ATP-induced currents in HEK293 cells transfected with the P2X3 plasmid. Therefore, hesperidin treatment could reverse the elevated expression of neuronal P2X3 receptor and reduce the activation of ERK1/2 in the DRG of CCI rats. Conclusions: Our findings suggested that hesperidin inhibited the nociceptive transmission mediated by the P2X3 receptor in neurons of DRG, and thus, relieved the mechanical and thermal hyperalgesia in CCI rats.
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Affiliation(s)
- Jun Tao
- a Department of Orthopaedics , The Second Affiliated Hospital of Nanchang University , Nanchang , PR China
| | - Li Liu
- a Department of Orthopaedics , The Second Affiliated Hospital of Nanchang University , Nanchang , PR China
| | - Yang Fan
- b Class 152 of Prevention , Grade 2015, School of Public Health of Nanchang University , Nanchang , PR China
| | - Mengke Wang
- c Department of Physiology , Medical School of Nanchang University , Nanchang , PR China.,d Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease , Nanchang , PR China
| | - Lin Li
- c Department of Physiology , Medical School of Nanchang University , Nanchang , PR China.,d Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease , Nanchang , PR China
| | - Lifang Zou
- c Department of Physiology , Medical School of Nanchang University , Nanchang , PR China.,d Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease , Nanchang , PR China
| | - Huilong Yuan
- c Department of Physiology , Medical School of Nanchang University , Nanchang , PR China.,d Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease , Nanchang , PR China
| | - Liran Shi
- c Department of Physiology , Medical School of Nanchang University , Nanchang , PR China.,d Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease , Nanchang , PR China
| | - Runan Yang
- c Department of Physiology , Medical School of Nanchang University , Nanchang , PR China.,d Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease , Nanchang , PR China
| | - Shangdong Liang
- c Department of Physiology , Medical School of Nanchang University , Nanchang , PR China.,d Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease , Nanchang , PR China
| | - Shuangmei Liu
- c Department of Physiology , Medical School of Nanchang University , Nanchang , PR China.,d Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease , Nanchang , PR China
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Yuan M, Ding S, Meng T, Lu B, Shao S, Zhang X, Yuan H, Hu F. Effect of A-317491 delivered by glycolipid-like polymer micelles on endometriosis pain. Int J Nanomedicine 2017; 12:8171-8183. [PMID: 29184406 PMCID: PMC5687452 DOI: 10.2147/ijn.s146569] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Endometriosis is a common gynecological disease with a lack of effective clinical treatment. Current therapy often results in endometriosis pain recurrence and serious side effects. P2X3 receptor, an adenosine triphosphate (ATP)-gated ion channel, might be implicated in endometriosis pain. In this study, chitosan oligosaccharide-g-stearic acid (CSOSA) polymer micelles-coated nanostructured lipid carriers (NLCs) were developed as a novel delivery system for A-317491, a selective P2X3 receptor antagonist for endometriosis pain therapy. A-317491-loaded NLC (NLC/A-317491) could be coated by CSOSA micelles to form CSOSA/NLC/A-317491 nanoparticles. Pheochromocytoma PC12 cells, which highly expressed P2X3 receptors, were used as a cell model, and the CSOSA/NLC/A-317491 partly blocked the Ca2+ influx induced by ATP stimulation. In nude mouse and rat endometriotic models, CSOSA/NLC could accumulate into endometriotic lesions after vein injection. In endometriotic rats, CSOSA/NLC/A-317491 reversed mechanical and heat hyperalgesia with long-term efficacy, which might be attributed to the massive CSOSA/NLC/A-317491 distribution in the endometriotic lesions. In conclusion, A-317491 delivered by CSOSA/NLC nanoparticles attenuated endometriosis pain in rats, and CSOSA/NLC/A-317491 could be used as an effective treatment strategy for P2X3-targeted therapy in endometriosis pain.
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Affiliation(s)
- Ming Yuan
- Institute of Marine Biology, Ocean College, Zhejiang University, Zhoushan
| | - Shaojie Ding
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou
| | - Tingting Meng
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Binbin Lu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shihong Shao
- Institute of Marine Biology, Ocean College, Zhejiang University, Zhoushan
| | - Xinmei Zhang
- Department of Gynecology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou
| | - Hong Yuan
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Fuqiang Hu
- Institute of Marine Biology, Ocean College, Zhejiang University, Zhoushan.,Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
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12
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Burnstock G. Purinergic Signalling: Therapeutic Developments. Front Pharmacol 2017; 8:661. [PMID: 28993732 PMCID: PMC5622197 DOI: 10.3389/fphar.2017.00661] [Citation(s) in RCA: 275] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/05/2017] [Indexed: 12/15/2022] Open
Abstract
Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990's when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine) receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A2A receptor antagonists are promising for the treatment of Parkinson's disease. Clopidogrel, a P2Y12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical SchoolLondon, United Kingdom
- Department of Pharmacology and Therapeutics, The University of Melbourne, MelbourneVIC, Australia
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13
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Ding S, Zhu L, Tian Y, Zhu T, Huang X, Zhang X. P2X3 receptor involvement in endometriosis pain via ERK signaling pathway. PLoS One 2017; 12:e0184647. [PMID: 28898282 PMCID: PMC5595329 DOI: 10.1371/journal.pone.0184647] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 08/28/2017] [Indexed: 11/21/2022] Open
Abstract
The purinergic receptor P2X ligand-gated ion channel 3 (P2X3) is crucially involved in peripheral nociceptive processes of somatic and visceral pain. Endometriosis pain is considered as a kind of inflammatory and neuropathic pain. However, whether P2X3 is involved in endometriosis pain has not been reported up to date. Here, we aimed to determine whether P2X3 expression in endometriotic lesions is involved in endometriosis pain, which is regulated by inflammatory mediators through extracellular regulated protein kinases (ERK) signalling pathway. We found that P2X3 expressions in endometriosis endometrium and endometriotic lesions were both significantly higher as compared with control endometrium (P<0.05), and both positively correlated with pain (P<0.05). The expression levels of phosphorylated –ERK (p-ERK), phosphorylated-cAMP-response element binding protein (p-CREB), and P2X3 in endometriotic stromal cells (ESCs) were all significantly increased in comparison to the initial levels after treated with interleukin (IL)-1β (P<0.05) or adenosine triphosphate (ATP) (P<0.05), respectively, and did not increase after the ESCs were pre-treated with ERK1/2 inhibitor. Additionally, P2X3 and calcitonin gene related peptide (CGRP) were co-expressed in endometriotic lesions. These obtained results suggest that P2X3 might be involved in endometriosis pain signal transduction via ERK signal pathway.
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Affiliation(s)
- Shaojie Ding
- Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Libo Zhu
- Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Yonghong Tian
- Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Tianhong Zhu
- Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Xiufeng Huang
- Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Xinmei Zhang
- Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
- * E-mail:
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14
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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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15
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Future Targets for Female Sexual Dysfunction. J Sex Med 2016; 13:1147-65. [DOI: 10.1016/j.jsxm.2016.05.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/22/2016] [Accepted: 05/27/2016] [Indexed: 12/18/2022]
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16
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Abstract
There is a brief introductory summary of purinergic signaling involving ATP storage, release, and ectoenzymatic breakdown, and the current classification of receptor subtypes for purines and pyrimidines. The review then describes purinergic mechanosensory transduction involved in visceral, cutaneous, and musculoskeletal nociception and on the roles played by receptor subtypes in neuropathic and inflammatory pain. Multiple purinoceptor subtypes are involved in pain pathways both as an initiator and modulator. Activation of homomeric P2X3 receptors contributes to acute nociception and activation of heteromeric P2X2/3 receptors appears to modulate longer-lasting nociceptive sensitivity associated with nerve injury or chronic inflammation. In neuropathic pain activation of P2X4, P2X7, and P2Y12 receptors on microglia may serve to maintain nociceptive sensitivity through complex neural-glial cell interactions and antagonists to these receptors reduce neuropathic pain. Potential therapeutic approaches involving purinergic mechanisms will be discussed.
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17
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Abstract
This review provides a concise summary of the molecular properties of the ligand-gated P2X receptors, in particular those containing the X3 subunit, as well as an overview comprising the most important patent applications on P2X3 and P2X2/3 receptor antagonists published since 2001. This review is mainly focused on small molecules with P2X3 and/or P2X2/3 antagonist properties. The most important classes of the patented compounds and conditions frequently claimed as their therapeutic targets are also discussed. Moreover, biological activity data from the cited patents and general prediction of druglikeness of the claimed compounds are also provided.
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18
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Bourinet E, Altier C, Hildebrand ME, Trang T, Salter MW, Zamponi GW. Calcium-permeable ion channels in pain signaling. Physiol Rev 2014; 94:81-140. [PMID: 24382884 DOI: 10.1152/physrev.00023.2013] [Citation(s) in RCA: 221] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The detection and processing of painful stimuli in afferent sensory neurons is critically dependent on a wide range of different types of voltage- and ligand-gated ion channels, including sodium, calcium, and TRP channels, to name a few. The functions of these channels include the detection of mechanical and chemical insults, the generation of action potentials and regulation of neuronal firing patterns, the initiation of neurotransmitter release at dorsal horn synapses, and the ensuing activation of spinal cord neurons that project to pain centers in the brain. Long-term changes in ion channel expression and function are thought to contribute to chronic pain states. Many of the channels involved in the afferent pain pathway are permeable to calcium ions, suggesting a role in cell signaling beyond the mere generation of electrical activity. In this article, we provide a broad overview of different calcium-permeable ion channels in the afferent pain pathway and their role in pain pathophysiology.
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Hausmann R, Bahrenberg G, Kuhlmann D, Schumacher M, Braam U, Bieler D, Schlusche I, Schmalzing G. A hydrophobic residue in position 15 of the rP2X3 receptor slows desensitization and reveals properties beneficial for pharmacological analysis and high-throughput screening. Neuropharmacology 2014; 79:603-15. [PMID: 24452010 DOI: 10.1016/j.neuropharm.2014.01.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 12/24/2013] [Accepted: 01/09/2014] [Indexed: 11/19/2022]
Abstract
The homotrimeric P2X3 subtype, one of the seven members of the ATP-gated P2X receptor family, plays a role in sensory neurotransmission, including nociception. To overcome the bias resulting from fast desensitization of the P2X3 receptor in dose-response analyses, a non-desensitizing P2X2-X3 receptor chimera has been repeatedly used as a surrogate for the P2X3 receptor for functional analysis. Here, we show that only three of the P2X2-specific amino acid residues of the P2X2-X3 chimera, (19)P(21)V(22)I, are needed to confer a slowly desensitizing phenotype to the P2X3 receptor. The strongest delay in desensitization of the P2X3 receptor by a single residue was observed when (15)Ser was replaced by Val or another hydrophobic residue. Pharmacologically, the S(15)V-rP2X3 mutant behaved similarly to the wt-P2X3 receptor. Analysis of the S(15)V-rP2X3 receptor in 1321N1 astrocytoma cells by a common calcium-imaging-based assay showed 10-fold higher calcium transients relative to those of the wt-rP2X3 receptor. The S(15)V-rP2X3 cell line enabled reliable analysis of antagonistic potencies and correctly reported the mechanism of action of the P2X3 receptor antagonists A-317491 and TNP-ATP by a calcium-imaging assay. Together, these data suggest that the S(15)V-rP2X3 mutant may be suitable not only for automated fluorescence-based screening of molecule libraries for identification of lead compounds but also for facilitated pharmacological characterization of specific P2X3 receptor ligands. We suggest that the mechanism of desensitization of the P2X3 receptor may involve the movement of an N-terminal inactivation particle, in analogy to the "hinged-lid" or "ball and chain" mechanisms of voltage-gated NaV and Shaker KV channels, respectively.
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Affiliation(s)
- Ralf Hausmann
- Department of Molecular Pharmacology, Medical Faculty of the RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany.
| | - Gregor Bahrenberg
- Grünenthal GmbH, Global Drug Discovery, Department of Molecular Pharmacology, Zieglerstrasse 6, 52078 Aachen, Germany
| | - Daniel Kuhlmann
- Department of Molecular Pharmacology, Medical Faculty of the RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Michaela Schumacher
- Department of Molecular Pharmacology, Medical Faculty of the RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Ursula Braam
- Department of Molecular Pharmacology, Medical Faculty of the RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Dagmar Bieler
- Grünenthal GmbH, Global Drug Discovery, Department of Molecular Pharmacology, Zieglerstrasse 6, 52078 Aachen, Germany
| | - Ilka Schlusche
- Grünenthal GmbH, Global Drug Discovery, Department of Molecular Pharmacology, Zieglerstrasse 6, 52078 Aachen, Germany
| | - Günther Schmalzing
- Department of Molecular Pharmacology, Medical Faculty of the RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
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Janardhan S, Seth S, Viswanadhan VN. Pyrid-2-yl and 2-CyanoPhenyl fused heterocyclic compounds as human P2X $$_{3}$$ 3 inhibitors: a combined approach based on homology modelling, docking and QSAR analysis. Mol Divers 2013; 18:161-81. [DOI: 10.1007/s11030-013-9486-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Accepted: 10/05/2013] [Indexed: 10/26/2022]
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21
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Cho JH, Jung KY, Jung Y, Kim MH, Ko H, Park CS, Kim YC. Design and synthesis of potent and selective P2X₃ receptor antagonists derived from PPADS as potential pain modulators. Eur J Med Chem 2013; 70:811-30. [PMID: 24246730 DOI: 10.1016/j.ejmech.2013.10.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/07/2013] [Accepted: 10/11/2013] [Indexed: 11/17/2022]
Abstract
Pyridoxalphosphate-6-azophenyl-2',4'-disulfonate (7a, PPADS), a nonselective P2X receptor antagonist, was extensively modified to develop more stable, potent, and selective P2X₃ receptor antagonists as potential antinociceptive agents. Based on the results of our previous report, all strong anionic groups in PPADS including phosphate and sulfonate groups were changed to carboxylic acids or deleted. The unstable azo (-NN-) linkage of 7a was transformed to more stable carbon-carbon, ether or amide linkages through the synthesis of the 5-hydroxyl-pyridine moieties with substituents at 2 position via a Diels-Alder reaction. This resulted in the retention of antagonistic activity (IC50 = 400 ∼ 700 nM) at the hP2X₃ receptor in the two-electrode voltage clamp (TEVC) assay system on the Xenopus oocytes. Introduction of bulky aromatic groups at the carbon linker, as in compounds 13 h-n, dramatically improved the selectivity profiles of hP2X₃ when compared with mP2X₁ and hP2X₇ receptors. Among the substituents tested at the 2-position, the m-phenoxybenzyl group showed optimum selectivity and potency at the hP2X₃ receptor. In searching for effective substituents at the 4- and 3-positions, we found that compound 36j, with 4-carboxaldehyde, 3-propenoic acid and 2-(m-phenoxy)benzyl groups, was the most potent and selective hP2X₃ receptor antagonist with an IC50 of 60 nM at hP2X₃ and marginal antagonistic activities of 10 μM at mP2X₁ and hP2X₇. Furthermore, using an ex-vivo assay system, we found that compound 36j potently inhibited pain signaling in the rat dorsal horn with 20 μM 36j displaying 65% inhibition while 20 μM pregabalin, a clinically available drug, showed only 31% inhibition.
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Affiliation(s)
- Joong-Heui Cho
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
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22
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Naviaux RK. Metabolic features of the cell danger response. Mitochondrion 2013; 16:7-17. [PMID: 23981537 DOI: 10.1016/j.mito.2013.08.006] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 08/12/2013] [Accepted: 08/16/2013] [Indexed: 12/12/2022]
Abstract
The cell danger response (CDR) is the evolutionarily conserved metabolic response that protects cells and hosts from harm. It is triggered by encounters with chemical, physical, or biological threats that exceed the cellular capacity for homeostasis. The resulting metabolic mismatch between available resources and functional capacity produces a cascade of changes in cellular electron flow, oxygen consumption, redox, membrane fluidity, lipid dynamics, bioenergetics, carbon and sulfur resource allocation, protein folding and aggregation, vitamin availability, metal homeostasis, indole, pterin, 1-carbon and polyamine metabolism, and polymer formation. The first wave of danger signals consists of the release of metabolic intermediates like ATP and ADP, Krebs cycle intermediates, oxygen, and reactive oxygen species (ROS), and is sustained by purinergic signaling. After the danger has been eliminated or neutralized, a choreographed sequence of anti-inflammatory and regenerative pathways is activated to reverse the CDR and to heal. When the CDR persists abnormally, whole body metabolism and the gut microbiome are disturbed, the collective performance of multiple organ systems is impaired, behavior is changed, and chronic disease results. Metabolic memory of past stress encounters is stored in the form of altered mitochondrial and cellular macromolecule content, resulting in an increase in functional reserve capacity through a process known as mitocellular hormesis. The systemic form of the CDR, and its magnified form, the purinergic life-threat response (PLTR), are under direct control by ancient pathways in the brain that are ultimately coordinated by centers in the brainstem. Chemosensory integration of whole body metabolism occurs in the brainstem and is a prerequisite for normal brain, motor, vestibular, sensory, social, and speech development. An understanding of the CDR permits us to reframe old concepts of pathogenesis for a broad array of chronic, developmental, autoimmune, and degenerative disorders. These disorders include autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), asthma, atopy, gluten and many other food and chemical sensitivity syndromes, emphysema, Tourette's syndrome, bipolar disorder, schizophrenia, post-traumatic stress disorder (PTSD), chronic traumatic encephalopathy (CTE), traumatic brain injury (TBI), epilepsy, suicidal ideation, organ transplant biology, diabetes, kidney, liver, and heart disease, cancer, Alzheimer and Parkinson disease, and autoimmune disorders like lupus, rheumatoid arthritis, multiple sclerosis, and primary sclerosing cholangitis.
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Affiliation(s)
- Robert K Naviaux
- The Mitochondrial and Metabolic Disease Center, Departments of Medicine, Pediatrics, and Pathology, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467, USA; Veterans Affairs Center for Excellence in Stress and Mental Health (CESAMH), La Jolla, CA, USA.
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23
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Abstract
The study of P2X receptors has long been handicapped by a poverty of small-molecule tools that serve as selective agonists and antagonists. There has been progress, particularly in the past 10 years, as cell-based high-throughput screening methods were applied, together with large chemical libraries. This has delivered some drug-like molecules in several chemical classes that selectively target P2X1, P2X3, or P2X7 receptors. Some of these are, or have been, in clinical trials for rheumatoid arthritis, pain, and cough. Current preclinical research programs are studying P2X receptor involvement in pain, inflammation, osteoporosis, multiple sclerosis, spinal cord injury, and bladder dysfunction. The determination of the atomic structure of P2X receptors in closed and open (ATP-bound) states by X-ray crystallography is now allowing new approaches by molecular modeling. This is supported by a large body of previous work using mutagenesis and functional expression, and is now being supplemented by molecular dynamic simulations and in silico ligand docking. These approaches should lead to P2X receptors soon taking their place alongside other ion channel proteins as therapeutically important drug targets.
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Affiliation(s)
- R Alan North
- Faculty of Medical and Human Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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