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Zhang Z, Yao J, Huo J, Wang R, Duan X, Chen Y, Xu H, Wang C, Chai Z, Huang R. Action potential-independent spontaneous microdomain Ca 2+ transients-mediated continuous neurotransmission regulates hyperalgesia. Proc Natl Acad Sci U S A 2025; 122:e2406741122. [PMID: 39823298 PMCID: PMC11759901 DOI: 10.1073/pnas.2406741122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 12/09/2024] [Indexed: 01/19/2025] Open
Abstract
Neurotransmitters and neuromodulators can be released via either action potential (AP)-evoked transient or AP-independent continuous neurotransmission. The elevated AP-evoked neurotransmission in the primary sensory neurons plays crucial roles in hyperalgesia. However, whether and how the AP-independent continuous neurotransmission contributes to hyperalgesia remains largely unknown. Here, we show that primary sensory dorsal root ganglion (DRG) neurons exhibit frequent spontaneous microdomain Ca2+ (smCa) activities independent of APs across the cell bodies and axons, which are mediated by the spontaneous opening of TRPA1 channels and trigger continuous neurotransmission via the cyclic adenosine monophosphate-protein kinase A signaling pathway. More importantly, the frequency of smCa activity and its triggered continuous neurotransmission in DRG neurons increased dramatically in mice experiencing inflammatory pain, inhibition of which alleviates hyperalgesia. Collectively, this work revealed the AP-independent continuous neurotransmission triggered by smCa activities in DRG neurons, which may serve as a unique mechanism underlying the nociceptive sensitization in hyperalgesia and offer a potential target for the treatment of chronic pain.
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Affiliation(s)
- Zhuoyu Zhang
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
- Neurological Department of Tongji Hospital, School of Medicine, Tongji University, Shanghai200333, China
| | - Jingyu Yao
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
| | - Jingxiao Huo
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
| | - Ruolin Wang
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
| | - Xueting Duan
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
| | - Yang Chen
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
| | - Huadong Xu
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
| | - Changhe Wang
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou646000, China
| | - Zuying Chai
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Rong Huang
- Department of Neurology, the Second Affiliated Hospital, Neuroscience Research Center, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an710000, China
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Bavencoffe A, Zhu MY, Neerukonda SV, Johnson KN, Dessauer CW, Walters ET. Induction of long-term hyperexcitability by memory-related cAMP signaling in isolated nociceptor cell bodies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.13.603393. [PMID: 39071414 PMCID: PMC11275899 DOI: 10.1101/2024.07.13.603393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Persistent hyperactivity of nociceptors is known to contribute significantly to long-lasting sensitization and ongoing pain in many clinical conditions. It is often assumed that nociceptor hyperactivity is mainly driven by continuing stimulation from inflammatory mediators. We have tested an additional possibility: that persistent increases in excitability promoting hyperactivity can be induced by a prototypical cellular signaling pathway long known to induce late-phase long-term potentiation (LTP) of synapses in brain regions involved in memory formation. This cAMP-PKA-CREB-gene transcription-protein synthesis pathway was tested using whole-cell current clamp methods on small dissociated sensory neurons (primarily nociceptors) from dorsal root ganglia (DRGs) excised from previously uninjured ("naïve") rats. Six-hour treatment with the specific Gαs-coupled 5-HT4 receptor agonist, prucalopride, or with the adenylyl cyclase activator, forskolin, induced long-term hyperexcitability (LTH) in DRG neurons that manifested 12-24 hours later as action potential (AP) discharge (ongoing activity, OA) during artificial depolarization to -45 mV, a membrane potential that is normally subthreshold for AP generation. Prucalopride treatment also induced significant long-lasting depolarization of resting membrane potential (from -69 to -66 mV), enhanced depolarizing spontaneous fluctuations (DSFs) of membrane potential, and indications of reduced AP threshold and rheobase. LTH was prevented by co-treatment of prucalopride with inhibitors of PKA, CREB, gene transcription, and protein synthesis. As in the induction of synaptic memory, many other cellular signals are likely to be involved. However, the discovery that this prototypical memory induction pathway can induce nociceptor LTH, along with reports that cAMP signaling and CREB activity in DRGs can induce hyperalgesic priming, suggest that early, temporary, cAMP-induced transcriptional and translational mechanisms can induce nociceptor LTH that might last for long periods. An interesting possibility is that these mechanisms can also be reactivated by re-exposure to inflammatory mediators such as serotonin during subsequent challenges to bodily integrity, "reconsolidating" the cellular memory and thereby extending the duration of persistent nociceptor hyperexcitability.
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Affiliation(s)
- Alexis Bavencoffe
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UTHealth, Houston, Texas, USA 77030
| | - Michael Y. Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UTHealth, Houston, Texas, USA 77030
| | - Sanjay V. Neerukonda
- Medical Scientist Training Program, McGovern Medical School at UTHealth, Houston, Texas, USA 77030
| | - Kayla N. Johnson
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UTHealth, Houston, Texas, USA 77030
| | - Carmen W. Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UTHealth, Houston, Texas, USA 77030
| | - Edgar T. Walters
- Department of Integrative Biology and Pharmacology, McGovern Medical School at UTHealth, Houston, Texas, USA 77030
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Bavencoffe A, Zhu MY, Neerukonda SV, Johnson KN, Dessauer CW, Walters ET. Induction of long-term hyperexcitability by memory-related cAMP signaling in isolated nociceptor cell bodies. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2024; 16:100166. [PMID: 39399224 PMCID: PMC11470187 DOI: 10.1016/j.ynpai.2024.100166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2024] [Revised: 09/10/2024] [Accepted: 09/11/2024] [Indexed: 10/15/2024]
Abstract
Persistent hyperactivity of nociceptors is known to contribute significantly to long-lasting sensitization and ongoing pain in many clinical conditions. It is often assumed that nociceptor hyperactivity is mainly driven by continuing stimulation from inflammatory mediators. We have tested an additional possibility: that persistent increases in excitability promoting hyperactivity can be induced by a prototypical cellular signaling pathway long known to induce late-phase long-term potentiation (LTP) of synapses in brain regions involved in memory formation. This cAMP-PKA-CREB-gene transcription-protein synthesis pathway was tested using whole-cell current clamp methods on small dissociated sensory neurons (primarily nociceptors) from dorsal root ganglia (DRGs) excised from previously uninjured ("naïve") male rats. Six-hour treatment with the specific Gαs-coupled 5-HT4 receptor agonist, prucalopride, or with the adenylyl cyclase activator forskolin induced long-term hyperexcitability (LTH) in DRG neurons that manifested 12-24 h later as action potential (AP) discharge (ongoing activity, OA) during artificial depolarization to -45 mV, a membrane potential that is normally subthreshold for AP generation. Prucalopride treatment also induced significant long-lasting depolarization of resting membrane potential (from -69 to -66 mV), enhanced depolarizing spontaneous fluctuations (DSFs) of membrane potential, and produced trends for reduced AP threshold and rheobase. LTH was prevented by co-treatment of prucalopride with inhibitors of PKA, CREB, gene transcription, or protein synthesis. As in the induction of synaptic memory, many other cellular signals are likely to be involved. However, the discovery that this prototypical memory induction pathway can induce nociceptor LTH, along with reports that cAMP signaling and CREB activity in DRGs can induce hyperalgesic priming, suggest that early, temporary, cAMP-induced transcriptional and translational mechanisms can induce nociceptor LTH that might last for long periods. The present results also raise the question of whether reactivation of primed signaling mechanisms by re-exposure to inflammatory mediators linked to cAMP synthesis during subsequent challenges to bodily integrity can "reconsolidate" nociceptor memory, extending the duration of persistent hyperexcitability.
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Affiliation(s)
- Alexis Bavencoffe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Michael Y. Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Sanjay V. Neerukonda
- Medical Scientist Training Program, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Kayla N. Johnson
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Carmen W. Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
| | - Edgar T. Walters
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
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Nakhleh-Francis Y, Awad-Igbaria Y, Sakas R, Bang S, Abu-Ata S, Palzur E, Lowenstein L, Bornstein J. Exploring Localized Provoked Vulvodynia: Insights from Animal Model Research. Int J Mol Sci 2024; 25:4261. [PMID: 38673846 PMCID: PMC11050705 DOI: 10.3390/ijms25084261] [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: 03/21/2024] [Revised: 04/07/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
Provoked vulvodynia represents a challenging chronic pain condition, characterized by its multifactorial origins. The inherent complexities of human-based studies have necessitated the use of animal models to enrich our understanding of vulvodynia's pathophysiology. This review aims to provide an exhaustive examination of the various animal models employed in this research domain. A comprehensive search was conducted on PubMed, utilizing keywords such as "vulvodynia", "chronic vulvar pain", "vulvodynia induction", and "animal models of vulvodynia" to identify pertinent studies. The search yielded three primary animal models for vulvodynia: inflammation-induced, allergy-induced, and hormone-induced. Additionally, six agents capable of triggering the condition through diverse pathways were identified, including factors contributing to hyperinnervation, mast cell proliferation, involvement of other immune cells, inflammatory cytokines, and neurotransmitters. This review systematically outlines the various animal models developed to study the pathogenesis of provoked vulvodynia. Understanding these models is crucial for the exploration of preventative measures, the development of novel treatments, and the overall advancement of research within the field.
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Affiliation(s)
- Yara Nakhleh-Francis
- Department of Obstetrics and Gynecology, Galilee Medical Center, Nahariya 2210001, Israel; (S.B.); (L.L.); (J.B.)
- Research Institute of Galilee Medical Center, Nahariya 2210001, Israel; (Y.A.-I.); (R.S.); (S.A.-A.); (E.P.)
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Yaseen Awad-Igbaria
- Research Institute of Galilee Medical Center, Nahariya 2210001, Israel; (Y.A.-I.); (R.S.); (S.A.-A.); (E.P.)
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Reem Sakas
- Research Institute of Galilee Medical Center, Nahariya 2210001, Israel; (Y.A.-I.); (R.S.); (S.A.-A.); (E.P.)
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Sarina Bang
- Department of Obstetrics and Gynecology, Galilee Medical Center, Nahariya 2210001, Israel; (S.B.); (L.L.); (J.B.)
- Research Institute of Galilee Medical Center, Nahariya 2210001, Israel; (Y.A.-I.); (R.S.); (S.A.-A.); (E.P.)
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Saher Abu-Ata
- Research Institute of Galilee Medical Center, Nahariya 2210001, Israel; (Y.A.-I.); (R.S.); (S.A.-A.); (E.P.)
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Eilam Palzur
- Research Institute of Galilee Medical Center, Nahariya 2210001, Israel; (Y.A.-I.); (R.S.); (S.A.-A.); (E.P.)
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Lior Lowenstein
- Department of Obstetrics and Gynecology, Galilee Medical Center, Nahariya 2210001, Israel; (S.B.); (L.L.); (J.B.)
- Research Institute of Galilee Medical Center, Nahariya 2210001, Israel; (Y.A.-I.); (R.S.); (S.A.-A.); (E.P.)
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Jacob Bornstein
- Department of Obstetrics and Gynecology, Galilee Medical Center, Nahariya 2210001, Israel; (S.B.); (L.L.); (J.B.)
- Research Institute of Galilee Medical Center, Nahariya 2210001, Israel; (Y.A.-I.); (R.S.); (S.A.-A.); (E.P.)
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
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Group II metabotropic glutamate receptor activation suppresses ATP currents in rat dorsal root ganglion neurons. Neuropharmacology 2023; 227:109443. [PMID: 36709909 DOI: 10.1016/j.neuropharm.2023.109443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 01/28/2023]
Abstract
P2X3 receptors and group II metabotropic glutamate receptors (mGluRs) have been found to be expressed in primary sensory neurons. P2X3 receptors participate in a variety of pain processes, while the activation of mGluRs has an analgesic effect. However, it's still unclear whether there is a link between them in pain. Herein, we reported that the group II mGluR activation inhibited the electrophysiological activity of P2X3 receptors in rat dorsal root ganglia (DRG) neurons. Group II mGluR agonist LY354740 concentration-dependently decreased P2X3 receptor-mediated and α,β-methylene-ATP (α,β-meATP)-evoked inward currents in DRG neurons. LY354740 significantly suppressed the maximum response of P2X3 receptor to α,β-meATP, but did not change their affinity. Inhibition of ATP currents by LY354740 was blocked by the group II mGluR antagonist LY341495, also prevented by the intracellular dialysis of either the Gi/o protein inhibitor pertussis toxin, the cAMP analog 8-Br-cAMP, or the protein kinase A (PKA) inhibitor H-89. Moreover, LY354740 decreased α,β-meATP-induced membrane potential depolarization and action potential bursts in DRG neurons. Finally, intraplantar injection of LY354740 also relieved α,β-meATP-induced spontaneous nociceptive behaviors and mechanical allodynia in rats by activating peripheral group Ⅱ mGluRs. These results indicated that peripheral group II mGluR activation inhibited the functional activity of P2X3 receptors via a Gi/o protein and cAMP/PKA signaling pathway in rat DRG neurons, which revealed a novel mechanism underlying analgesic effects of peripheral group II mGluRs. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
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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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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: 1.0] [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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Lei X, Zeng J, Yan Y, Liu X. Blockage of HCN Channels Inhibits the Function of P2X Receptors in Rat Dorsal Root Ganglion Neurons. Neurochem Res 2022; 47:1083-1096. [PMID: 35064517 DOI: 10.1007/s11064-021-03509-5] [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] [Received: 07/14/2021] [Revised: 12/06/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated channels and purinergic P2X receptors play critical roles in the nerve injury-induced pain hypersensitivity. Both HCN channels and P2XR are expressed in dorsal root ganglia sensory neurons. However, it is not clear whether the expression and function of P2X2 and P2X3 receptors can be modulated by HCN channel activity. For this reason, in rats with chronic constriction injury of sciatic nerve, we evaluated the effect of intrathecal administration of HCN channel blocker ZD7288 on nociceptive behavior and the expression of P2X2 and P2X3 in rat DRG. The mechanical withdrawal threshold was measured to evaluate pain behavior in rats. The protein expression of P2X2 and P2X3 receptor in rat DRG was observed by using Western Blot. The level of cAMP in rat DRG was measured by ELISA. As a result, decreased MWT was observed in CCI rats on 1 d after surgery, and the allodynia was sustained throughout the experimental period. In addition, CCI rats presented increased expression of P2X2 and P2X3 receptor in the ipsilateral DRG at 7 d and 14 d after CCI operation. Intrathecal injection of ZD7288 significantly reversed CCI-induced mechanical hyperalgesia, and attenuated the increased expression of P2X2 and P2X3 receptor in rat DRG, which open up the possibility that the expression of P2X2 and P2X3 receptor in DRG is down-regulated by HCN channel blocker ZD7288 in CCI rats. Furthermore, the level of cAMP in rat DRG significantly increased after nerve injury. Intrathecal administration of ZD7288 attenuated the increase of cAMP in DRG caused by nerve injury. Subsequently, effects of HCN channel activity on ATP-induced current (IATP) in rat DRG neurons were explored by using whole-cell patch-clamp techniques. ATP (100 μM) elicited three types of currents (fast, slow and mixed IATP) in cultured DRG neurons. Pretreatment with ZD7288 concentration-dependently inhibited three types of ATP-activated currents. On the other hand, pretreatment with 8-Br-cAMP (a cell-permeable cAMP analog, also known as an activator of PKA) significantly increased the amplitude of fast, slow and mixed IATP in DRG neurons. The enhanced effect of 8-Br-cAMP on ATP-activated currents could be reversed by ZD7288. In a summary, our observations suggest that the opening of HCN channels could enhance the expression and function of P2X2 and P2X3 receptor via the cAMP-PKA signaling pathway. This may be important for pathophysiological events occurring within the DRG, for where it is implicated in nerve injury-induced pain hypersensitivity.
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Affiliation(s)
- Xiaolu Lei
- Key Laboratory of Brain Science, Zunyi Medical University, Zunyi, 563000, China
| | - Junwei Zeng
- Department of Physiology, Zunyi Medical University, No. 6, Xuefu west road, Zunyi, 563000, Guizhou province, China
| | - Yan Yan
- Key Laboratory of Brain Science, Zunyi Medical University, Zunyi, 563000, China
| | - Xiaohong Liu
- Department of Physiology, Zunyi Medical University, No. 6, Xuefu west road, Zunyi, 563000, Guizhou province, China.
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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: 1.8] [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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10
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Neuro-immune-metabolism: The tripod system of homeostasis. Immunol Lett 2021; 240:77-97. [PMID: 34655659 DOI: 10.1016/j.imlet.2021.10.001] [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: 05/29/2021] [Revised: 09/30/2021] [Accepted: 10/08/2021] [Indexed: 11/20/2022]
Abstract
Homeostatic regulation of cellular and molecular processes is essential for the efficient physiological functioning of body organs. It requires an intricate balance of several networks throughout the body, most notable being the nervous, immune and metabolic systems. Several studies have reported the interactions between neuro-immune, immune-metabolic and neuro-metabolic pathways. Current review aims to integrate the information and show that neuro, immune and metabolic systems form the triumvirate of homeostasis. It focuses on the cellular and molecular interactions occurring in the extremities and intestine, which are innervated by the peripheral nervous system and for the intestine in particular the enteric nervous system. While the interdependence of neuro-immune-metabolic pathways provides a fallback mechanism in case of disruption of homeostasis, in chronic pathologies of continued disequilibrium, the collapse of one system spreads to the other interacting networks as well. Current review illustrates this domino-effect using diabetes as the main example. Together, this review attempts to provide a holistic picture of the integrated network of neuro-immune-metabolism and attempts to broaden the outlook when devising a scientific study or a treatment strategy.
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11
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Isensee J, van Cann M, Despang P, Araldi D, Moeller K, Petersen J, Schmidtko A, Matthes J, Levine JD, Hucho T. Depolarization induces nociceptor sensitization by CaV1.2-mediated PKA-II activation. J Cell Biol 2021; 220:212600. [PMID: 34431981 PMCID: PMC8404467 DOI: 10.1083/jcb.202002083] [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: 02/13/2020] [Revised: 06/14/2021] [Accepted: 08/05/2021] [Indexed: 01/20/2023] Open
Abstract
Depolarization drives neuronal plasticity. However, whether depolarization drives sensitization of peripheral nociceptive neurons remains elusive. By high-content screening (HCS) microscopy, we revealed that depolarization of cultured sensory neurons rapidly activates protein kinase A type II (PKA-II) in nociceptors by calcium influx through CaV1.2 channels. This effect was modulated by calpains but insensitive to inhibitors of cAMP formation, including opioids. In turn, PKA-II phosphorylated Ser1928 in the distal C terminus of CaV1.2, thereby increasing channel gating, whereas dephosphorylation of Ser1928 involved the phosphatase calcineurin. Patch-clamp and behavioral experiments confirmed that depolarization leads to calcium- and PKA-dependent sensitization of calcium currents ex vivo and local peripheral hyperalgesia in the skin in vivo. Our data suggest a local activity-driven feed-forward mechanism that selectively translates strong depolarization into further activity and thereby facilitates hypersensitivity of nociceptor terminals by a mechanism inaccessible to opioids.
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Affiliation(s)
- Jörg Isensee
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Marianne van Cann
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Patrick Despang
- Department of Pharmacology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Dioneia Araldi
- Division of Neuroscience, Departments of Medicine and Oral & Maxillofacial Surgery, University of California, San Francisco, San Francisco, CA
| | - Katharina Moeller
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Jonas Petersen
- Institute for Pharmacology and Clinical Pharmacy, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Achim Schmidtko
- Institute for Pharmacology and Clinical Pharmacy, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jan Matthes
- Department of Pharmacology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Jon D Levine
- Division of Neuroscience, Departments of Medicine and Oral & Maxillofacial Surgery, University of California, San Francisco, San Francisco, CA
| | - Tim Hucho
- Department of Anesthesiology and Intensive Care Medicine, Translational Pain Research, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
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12
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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: 1.0] [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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13
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Maba IK, Cruz JV, Zampronio AR. Change in prostaglandin signaling during sickness syndrome hyperalgesia after ovariectomy in female rats. Behav Brain Res 2021; 410:113368. [PMID: 34000337 DOI: 10.1016/j.bbr.2021.113368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 12/26/2022]
Abstract
The present study investigated hyperalgesia during sickness syndrome in female rats. Hyperalgesia was induced by an intraperitoneal injection of lipopolysaccharide (LPS) or an intracerebroventricular injection of prostaglandin E2 (PGE2). No differences were found in basal mechanical and thermal thresholds or in LPS-induced hyperalgesia in sham-operated animals in the diestrus or proestrus phase or in ovariectomized (OVX) animals. However, higher levels of PGE2 where found in the cerebrospinal fluid of OVX animals compared to sham-operated females. Intracerebroventricular injection of PGE2 produced rapid mechanical hyperalgesia in sham-operated rats while these responses were observed at later times in OVX animals. The protein kinase A (PKA) inhibitor H-89 reduced mechanical PGE2-induced hyperalgesia in OVX female rats, whereas no effect was observed in sham-operated animals. In contrast, the exchange protein activated by cyclic adenosine monophosphate (cAMP; Epac) inhibitor ESI-09 reduced mechanical PGE2-induced hyperalgesia, whereas no effect was observed in OVX animals. PGE2 also induced thermal hyperalgesia in sham-operated and OVX female rats and a similar effect of ESI-09 was observed. These results suggest that PGE2-induced hyperalgesia that is observed during sickness syndrome has different signaling mechanisms in cycling and OVX female rats involving the activation of the cAMP-Epac or cAMP-PKA pathways, respectively.
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Affiliation(s)
- I K Maba
- Department of Pharmacology, Biological Sciences Section, Federal University of Paraná, Curitiba, PR, Brazil
| | - J V Cruz
- Department of Pharmacology, Biological Sciences Section, Federal University of Paraná, Curitiba, PR, Brazil
| | - A R Zampronio
- Department of Pharmacology, Biological Sciences Section, Federal University of Paraná, Curitiba, PR, Brazil.
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14
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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: 44] [Impact Index Per Article: 8.8] [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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15
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Kanda H, Kobayashi K, Yamanaka H, Okubo M, Dai Y, Noguchi K. Localization of prostaglandin E2 synthases and E-prostanoid receptors in the spinal cord in a rat model of neuropathic pain. Brain Res 2020; 1750:147153. [PMID: 33049240 DOI: 10.1016/j.brainres.2020.147153] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/08/2020] [Accepted: 10/06/2020] [Indexed: 10/23/2022]
Abstract
Prostaglandin E2 (PGE2) is a lipid mediator which plays a role in the generation of inflammatory and neuropathic pain. In the peripheral nervous system, PGE2 sensitizes nociceptive afferent neurons through E-prostanoid (EP) receptors. In the central nervous system, PGE2 modulates pain sensitivity and contributes to the development of neuropathic pain. However, the distribution of PGE2 and EP receptors in the spinal cord remains unclear. In the present study, we examined the expression of PGE2 synthases (microsomal PGE synthase [mPGES]-1, mPGES-2, and cytosolic PGE synthase [cPGES]) and EP receptors (EP1-4) in a rat model of neuropathic pain. We identified that mPGES-1 mRNA was upregulated in spinal endothelial cells after nerve injury and exhibited co-localization with cyclooxygenase-2 (COX-2). We detected that mPGES-2 mRNA and cPGES mRNA were expressed in spinal neurons and noted that their expression level was not affected by nerve injury. With respect to EP receptors, EP2 mRNA and EP4 mRNA were expressed in spinal neurons in the dorsal horn. EP3 mRNA was expressed in motor neurons, whereas EP1 mRNA was not detected in the spinal cord. Intrathecal injection of tumor necrosis factor alpha (TNFα) upregulated mPGES-1 mRNA in blood vessels in the spinal cord. Intrathecal injection of a TNFα-neutralizing antibody partially inhibited the upregulation of mPGES-1 mRNA after nerve injury. These results indicate that PGE2 is synthesized by COX-2/mPGES-1 in spinal endothelial cells after nerve injury. These results suggest that in neuropathic pain condition, endothelial cell-derived PGE2 may act on EP2 and EP4 receptors on spinal neurons and modulate pain sensitivity.
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Affiliation(s)
- Hirosato Kanda
- Department of Pharmacology, Hyogo University of Health Sciences, Kobe, Hyogo 650-8530, Japan; Traditional Medicine Research Center, Chinese Medicine Confucius Institute at Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan; Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Kimiko Kobayashi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Hiroki Yamanaka
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Masamichi Okubo
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Yi Dai
- Department of Pharmacology, Hyogo University of Health Sciences, Kobe, Hyogo 650-8530, Japan; Traditional Medicine Research Center, Chinese Medicine Confucius Institute at Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan; Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Koichi Noguchi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan.
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16
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Abstract
A limited number of peripheral targets generate pain. Inflammatory mediators can sensitize these. The review addresses targets acting exclusively or predominantly on sensory neurons, mediators involved in inflammation targeting sensory neurons, and mediators involved in a more general inflammatory process, of which an analgesic effect secondary to an anti-inflammatory effect can be expected. Different approaches to address these systems are discussed, including scavenging proinflammatory mediators, applying anti-inflammatory mediators, and inhibiting proinflammatory or facilitating anti-inflammatory receptors. New approaches are contrasted to established ones; the current stage of progress is mentioned, in particular considering whether there is data from a molecular and cellular level, from animals, or from human trials, including an early stage after a market release. An overview of publication activity is presented, considering a IuPhar/BPS-curated list of targets with restriction to pain-related publications, which was also used to identify topics.
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Affiliation(s)
- Cosmin I Ciotu
- Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Michael J M Fischer
- Center of Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria.
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17
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Jang Y, Kim M, Hwang SW. Molecular mechanisms underlying the actions of arachidonic acid-derived prostaglandins on peripheral nociception. J Neuroinflammation 2020; 17:30. [PMID: 31969159 PMCID: PMC6975075 DOI: 10.1186/s12974-020-1703-1] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 01/06/2020] [Indexed: 12/30/2022] Open
Abstract
Arachidonic acid-derived prostaglandins not only contribute to the development of inflammation as intercellular pro-inflammatory mediators, but also promote the excitability of the peripheral somatosensory system, contributing to pain exacerbation. Peripheral tissues undergo many forms of diseases that are frequently accompanied by inflammation. The somatosensory nerves innervating the inflamed areas experience heightened excitability and generate and transmit pain signals. Extensive studies have been carried out to elucidate how prostaglandins play their roles for such signaling at the cellular and molecular levels. Here, we briefly summarize the roles of arachidonic acid-derived prostaglandins, focusing on four prostaglandins and one thromboxane, particularly in terms of their actions on afferent nociceptors. We discuss the biosynthesis of the prostaglandins, their specific action sites, the pathological alteration of the expression levels of related proteins, the neuronal outcomes of receptor stimulation, their correlation with behavioral nociception, and the pharmacological efficacy of their regulators. This overview will help to a better understanding of the pathological roles that prostaglandins play in the somatosensory system and to a finding of critical molecular contributors to normalizing pain.
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Affiliation(s)
- Yongwoo Jang
- Department of Psychiatry and Program in Neuroscience, McLean Hospital, Harvard Medical School, Belmont, MA, 02478, USA.,Department of Biomedical Engineering, Hanyang University, Seoul, 04763, South Korea
| | - Minseok Kim
- Department of Biomedical Sciences, Korea University, Seoul, 02841, South Korea
| | - Sun Wook Hwang
- Department of Biomedical Sciences, Korea University, Seoul, 02841, South Korea. .,Department of Physiology, College of Medicine, Korea University, Seoul, 02841, South Korea.
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18
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PGE2/EP4 receptor and TRPV1 channel are involved in repeated restraint stress-induced prolongation of sensitization pain evoked by subsequent PGE2 challenge. Brain Res 2019; 1721:146335. [PMID: 31302096 DOI: 10.1016/j.brainres.2019.146335] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 06/21/2019] [Accepted: 07/10/2019] [Indexed: 01/09/2023]
Abstract
Prevalence of prior stressful experience is linked to high incidence of chronic pain. Stress, particularly repeated stress, is known to induce maladaptive neuroplasticity along peripheral and central pain transmission pathways. These maladaptive neuroplastic events facilitate sensitization of nociceptive neurons and transition from acute to chronic pain. Pro-inflammatory and pain mediators are involved in inducing neuroplasticity. Pain mediators such as prostaglandin E2 (PGE2), EP4 receptor and transient receptor potential vanilloid-1 (TRPV1) contribute to the genesis of chronic pain. In this study, we examined the role of PGE2/EP4 signaling and TRPV1 signaling in repeated restraint stress-induced prolongation of sensitization pain, a model for transition from acute to chronic pain, in both in vivo and in vitro models. We found that pre-exposure to single restraint stress induced analgesia that masked sensitization pain evoked by subsequent PGE2 challenge. However, pre-exposure to 3d consecutive restraint stress not only prolonged sensitization pain, but also increased stress hormone corticosterone (CORT) in serum, COX2 levels in paw skin, and EP4 and TRPV1 levels in dorsal root ganglion (DRG) and paw skin. Pre-exposure to CORT for 3d, not 1d, also prolonged sensitization pain evoked by PGE2. Co-injection of glucocorticoid receptor (GR) antagonist RU486, COX2 inhibitor NS-398, EP4 receptor antagonist L161,982 or TRPV1 antagonist capsazepine prevented 3d restraint stress prolonged sensitization pain evoked by PGE2. In DRG cultures, CORT increased EP4 and TRPV1 protein levels through GR activation. These data suggest that PGE2/EP4 signaling and TRPV1 signaling in peripheral pain pathway contribute to repeated stress-predisposed transition from acute to chronic pain.
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19
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Yang S, Xiao W, Wang S, Meng L, Zhou L, Wan A, Liu Y, Feng S, Wang T. Parecoxib Shortens the Duration of Acute Postoperative Pain After Laparoscopic-Assisted Vaginal Hysterectomy. Front Pharmacol 2019; 10:689. [PMID: 31275150 PMCID: PMC6591448 DOI: 10.3389/fphar.2019.00689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/27/2019] [Indexed: 11/20/2022] Open
Abstract
The effect of parecoxib sodium on the duration and severity of acute postoperative pain after laparoscopic-assisted vaginal hysterectomy has been inadequately studied. This randomized, controlled trial compared the effects of parecoxib, methylprednisolone, and placebo on the duration of acute postoperative pain after elective laparoscopic-assisted vaginal hysterectomy. Ninety-four eligible patients were randomized to three groups [parecoxib sodium 40 mg (Group P), methylprednisolone 1 mg/kg (Group M), and saline (Group S)]. The duration of pain during coughing [median (interquartile range)] was significantly lower in Group P than in Group M or Group S [26.0 (5.8–48.0) vs. 48.0 (30.0–55.5) vs. 48.0 (36.0–58.5) h; p = 0.025]. The duration of pain during rest was also significantly lower in Group P than in Group M or Group S [5.5 (3.8–21.0) vs. 24.0 (6.0–28.0) vs. 22.0 (5.8–36.0) h; p = 0.009]. Compared with those in Group M and Group S, the patients in Group P reported less intense visceral pain during coughing at 12 (p = 0.050) and 24 h (p = 0.009) as well as at rest at 12 h (p = 0.008). Compared with those in Group P and Group S, the patients in Group M showed lower serum C-reactive protein levels and higher blood glucose levels after surgery. No differences were noted in nausea, vomiting, length of hospital stay, wound infection, and delayed wound healing among the groups. Thus, parecoxib sodium reduces the duration and intensity of acute postoperative pain after laparoscopic-assisted vaginal hysterectomy.
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Affiliation(s)
- Shuyi Yang
- Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Wei Xiao
- Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Shijun Wang
- Department of Gynecology and Obstetrics, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Lingzhong Meng
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, United States
| | - Liane Zhou
- Department of Gynecology and Obstetrics, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Anxia Wan
- Department of Gynecology and Obstetrics, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yang Liu
- Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Shuai Feng
- Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Tianlong Wang
- Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, China.,National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing, China
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20
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Liang Y, Gu Y, Shi R, Li G, Chen Y, Huang LYM. Electroacupuncture downregulates P2X3 receptor expression in dorsal root ganglia of the spinal nerve-ligated rat. Mol Pain 2019; 15:1744806919847810. [PMID: 30983496 PMCID: PMC6537063 DOI: 10.1177/1744806919847810] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 03/30/2019] [Accepted: 03/31/2019] [Indexed: 12/18/2022] Open
Abstract
Electroacupuncture has been shown to effectively reduce chronic pain in patients with nerve injury. The underlying mechanisms are not well understood. Accumulated evidence suggests that purinergic P2X3 receptors (P2X3Rs) in dorsal root ganglion neurons play a major role in mediating chronic pain associated with nerve injury. The aim of this study is to determine if electroacupuncture stimulation alters P2X3R activity in dorsal root ganglia to produce analgesia under neuropathic pain condition. Peripheral neuropathy was produced by ligation of the left lumbar 5 (L5) spinal nerve in rats. Low-frequency (2 Hz) electrical stimulation was applied to ipsilateral ST36 and BL60 acupoints in rats. The P2X3R agonist (α,β-meATP)-induced flinch responses were reduced after electroacupuncture treatment. Western analyses showed that P2X3R expression was upregulated in nerve-uninjured lumbar 4 (L4) dorsal root ganglion neurons ipsilateral to the spinal nerve ligation. Electroacupuncture-stimulation reversed the upregulation. In nerve-injured L5 dorsal root ganglia, P2X3R expression was substantially reduced. Electroacupuncture had no effect on the reduction. We also determined the injury state of P2X3R expressing dorsal root ganglion neurons using the neuronal injury marker, activating transcription factor 3 (ATF3). Immunohistochemical assay showed that in L4 dorsal root ganglia, almost all P2X3Rs were expressed in uninjured (ATF3-) neurons. Spinal nerve ligation increased the expression of P2X3Rs. Electroacupuncture reduced the increase in P2X3R expression without affecting the percentage of ATF + neurons. In ipsilateral L5 dorsal root ganglion neurons, spinal nerve ligation reduced the percentage of P2X3R + neurons and markedly increased the percentage of ATF3 + cells. Almost all of P2X3Rs were expressed in damaged (ATF3+) neurons. Electroacupuncture had no effect on spinal nerve ligation-induced changes in the percentage of P2X3R or percentage of ATF3 + cells in L5 dorsal root ganglia. These observations led us to conclude that electroacupuncture effectively reduces injury-induced chronic pain by selectively reducing the expression of P2X3Rs in nerve-uninjured L4 dorsal root ganglion neurons.
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Affiliation(s)
- Yi Liang
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | - Yanping Gu
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | - Renyi Shi
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, Department of Neurobiology and Acupuncture Research, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Guangwen Li
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | - Yong Chen
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
| | - Li-Yen Mae Huang
- Department of Neuroscience, Cell Biology and Anatomy, University of Texas Medical Branch, Galveston, TX, USA
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21
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Abstract
Abstract Primary sensory neurons are responsible for transmitting sensory information from the peripheral to the central nervous system. Their responses to incoming stimulation become greatly enhanced and prolonged following inflammation, giving rise to exaggerated nociceptive responses and chronic pain. The inflammatory mediator, prostaglandin E2 (PGE2), released from the inflamed tissue surrounding the terminals of sensory neurons contributes to the abnormal pain responses. PGE2 acts on G protein-coupled EP receptors to activate adenylyl cyclase, which catalyzes the conversion of adenosine triphosphate to cyclic adenosine 3′,5′-monophosphate (cAMP). Under normal conditions, cAMP activates primarily protein kinase A. After inflammation, cAMP also activates the exchange proteins activated by cAMP (Epacs) to produce exaggerated PGE2-mediated hyperalgesia. The role of cAMP-Epac signaling in the generation of hypersensitivity is the topic of this review.
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Affiliation(s)
| | - Yanping Gu
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch Galveston, TX 77555-1069, USA
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22
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Bernier L, Ase AR, Séguéla P. P2X receptor channels in chronic pain pathways. Br J Pharmacol 2018; 175:2219-2230. [PMID: 28728214 PMCID: PMC5980614 DOI: 10.1111/bph.13957] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/05/2017] [Accepted: 07/10/2017] [Indexed: 12/18/2022] Open
Abstract
Chronic pain is a highly prevalent debilitating condition for which treatment options remain limited for many patients. Ionotropic ATP signalling through excitatory and calcium-permeable P2X receptor channels is now rightfully considered as a critical player in pathological pain generation and maintenance; therefore, their selective targeting represents a therapeutic opportunity with promising yet untapped potential. Recent advances in the structural, functional and pharmacological characterization of rodent and human ATP-gated P2X receptor channels have shed brighter light on the role of specific subtypes in the pathophysiology of chronic inflammatory, neuropathic or cancer pain. Here, we will review the contribution of P2X3, P2X4 and P2X7 receptors to chronic pain and discuss the opportunities and challenges associated with the pharmacological manipulation of their function. LINKED ARTICLES This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.
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Affiliation(s)
- Louis‐Philippe Bernier
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Ariel R Ase
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Alan Edwards Centre for Research on PainMcGill UniversityMontréalQCCanada
| | - Philippe Séguéla
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, Alan Edwards Centre for Research on PainMcGill UniversityMontréalQCCanada
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23
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Abstract
Protein kinase C alpha plays a major role in mediating Epac-dependent enhancement of purinergic P2X3R activity in dorsal root ganglion neurons after inflammation. Sensitization of purinergic P2X3 receptors (P2X3Rs) is a major mechanism contributing to injury-induced exaggerated pain responses. We showed in a previous study that cyclic adenosine monophosphate (cAMP)–dependent guanine nucleotide exchange factor 1 (Epac1) in rat sensory dorsal root ganglia (DRGs) is upregulated after inflammatory injury, and it plays a critical role in P2X3R sensitization by activating protein kinase C epsilon (PKCε) inside the cells. protein kinase C epsilon has been established as the major PKC isoform mediating injury-induced hyperalgesic responses. On the other hand, the role of PKCα in receptor sensitization was seldom considered. Here, we studied the participation of PKCα in Epac signaling in P2X3R-mediated hyperalgesia. The expression of both Epac1 and Epac2 and the level of cAMP in DRGs are greatly enhanced after complete Freund adjuvant (CFA)–induced inflammation. The expression of phosphorylated PKCα is also upregulated. Complete Freund adjuvant (CFA)–induced P2X3R-mediated hyperalgesia is not only blocked by Epac antagonists but also by the classical PKC isoform inhibitors, Go6976, and PKCα-siRNA. These CFA effects are mimicked by the application of the Epac agonist, 8-(4-chlorophenylthio)-2 -O-methyl-cAMP (CPT), in control rats, further confirming the involvement of Epacs. Because the application of Go6976 prior to CPT still reduces CPT-induced hyperalgesia, PKCα is downstream of Epacs to mediate the enhancement of P2X3R responses in DRGs. The pattern of translocation of PKCα inside DRG neurons in response to CPT or CFA stimulation is distinct from that of PKCε. Thus, in contrast to prevalent view, PKCα also plays an essential role in producing complex inflammation-induced receptor-mediated hyperalgesia.
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24
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Wang L, Wang K, Chu X, Li T, Shen N, Fan C, Niu Z, Zhang X, Hu L. Intra-articular injection of Botulinum toxin A reduces neurogenic inflammation in CFA-induced arthritic rat model. Toxicon 2017; 126:70-78. [DOI: 10.1016/j.toxicon.2016.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 11/03/2016] [Accepted: 11/08/2016] [Indexed: 12/21/2022]
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EP3 activation facilitates bladder excitability via HCN channels on ICCs. Biochem Biophys Res Commun 2017; 485:535-541. [PMID: 28131828 DOI: 10.1016/j.bbrc.2017.01.131] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 01/23/2017] [Indexed: 12/20/2022]
Abstract
EP3 is a receptor for prostaglandin E2 (PGE2), and although its effect on bladder excitability has attracted considerable attention, the underlying mechanism remains unclear. To investigate whether the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in the interstitial cells of Cajal (ICCs) of the bladder are involved in the effect of EP3 activation on bladder excitability, wild-type mice, HCN1 knockout (HCN1-/-) mice and rats were used in our study. Double immunofluorescence staining and immunoprecipitation assays demonstrated the interaction between EP3 and the HCN channels. Sulprostone is a selective agonist of EP3. The current density of HCN channels was enhanced by sulprostone or PGE2 using whole-cell patch clamping. Western blot analyses showed that the expression levels of HCN1 and HCN4 were higher in bladders that had undergone intravesical instillation with sulprostone than in bladders treated with normal saline (NS). Both PGE2 and sulprostone increased the calcium concentration of the ICCs, and their effects were inhibited by ZD7288 (antagonist of HCN channels) treatment. In bladder detrusor strip testing, both PGE2 and sulprostone enhanced the amplitude of the bladder detrusor in HCN1-/- mice; however, these effects were less than those in the wild-type mice. Furthermore, the effects of PGE2 and sulprostone were inhibited by ZD7288. Taken together, our results indicate that EP3 is expressed in bladder ICCs and facilitates bladder excitability via HCN channels. This study provides more comprehensive insights into the mechanism between inflammation and bladder excitability and highlights methods that can resolve bladder hyperactivity.
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Gu Y, Wang C, Li G, Huang LYM. EXPRESS: F-actin links Epac-PKC signaling to purinergic P2X3 receptors sensitization in dorsal root ganglia following inflammation. Mol Pain 2016; 12:12/0/1744806916660557. [PMID: 27385722 PMCID: PMC4955968 DOI: 10.1177/1744806916660557] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Sensitization of purinergic P2X3 receptors (P2X3Rs) contributes to the production of exaggerated nociceptive responses following inflammatory injury. We showed previously that prostaglandin E2 (PGE2) potentiates P2X3R-mediated ATP currents in dorsal root ganglion neurons isolated from both control and complete Freund’s adjuvant-induced inflamed rats. PGE2 potentiation of ATP currents depends only on PKA signaling in control neurons, but it depends on both PKA and PKC signaling in inflamed neurons. We further found that inflammation evokes an increase in exchange proteins directly activated by cAMP (Epacs) in dorsal root ganglions. This increase promotes the activation of PKC to produce a much enhanced PGE2 effect on ATP currents and to elicit Epac-dependent flinch nocifensive behavioral responses in complete Freund’s adjuvant rats. The link between Epac-PKC signaling and P2X3R sensitization remains unexplored. Here, we show that the activation of Epacs promotes the expression of phosphorylated PKC and leads to an increase in the cytoskeleton, F-actin, expression at the cell perimeter. Depolymerization of F-actin blocks PGE2-enhanced ATP currents and inhibits P2X3R-mediated nocifensive responses after inflammation. Thus, F-actin is dynamically involved in the Epac-PKC-dependent P2X3R sensitization. Furthermore, Epacs induce a PKC-dependent increase in the membrane expression of P2X3Rs. This increase is abolished by F-actin depolymerization, suggesting that F-actin mediates Epac-PKC signaling of P2X3R membrane expression. Thus, after inflammation, an Epac-PKC dependent increase in F-actin in dorsal root ganglion neurons enhances the membrane expression of P2X3Rs to bring about sensitization of P2X3Rs and abnormal pain behaviors.
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Affiliation(s)
- Yanping Gu
- University of Texas Medical Branch at Galveston
| | - Congying Wang
- University of Texas Medical Branch at GalvestonUniversity of Texas Medical Branch at Galveston
| | - Guangwen Li
- University of Texas Medical Branch at Galveston
| | - Li-Yen Mae Huang
- University of Texas Medical Branch at GalvestonUniversity of Texas Medical Branch at Galveston
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St-Jacques B, Ma W. Preferred recycling pathway by internalized PGE2 EP4 receptor following agonist stimulation in cultured dorsal root ganglion neurons contributes to enhanced EP4 receptor sensitivity. Neuroscience 2016; 326:56-68. [PMID: 27060485 DOI: 10.1016/j.neuroscience.2016.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 10/22/2022]
Abstract
Prostaglandin E2 (PGE2), a well-known pain mediator abundantly produced in injured tissues, sensitizes nociceptive dorsal root ganglion (DRG) neurons (nociceptors) through its four EP receptors (EP1-4). Our prior study showed that PGE2 or EP4 agonist stimulates EP4 externalization and this event was not only suppressed by the inhibitor of anterograde export, but also by the recycling inhibitor (St-Jacques and Ma, 2013). These data suggest that EP4 recycling also contributes to agonist-enhanced EP4 surface abundance. In the current study, we tested this hypothesis using antibody-feeding-based internalization assay, recycling assay and FITC-PGE2 binding assay. We observed that selective EP4 agonist 1-hydroxy-PGE1 (1-OH-PGE1) or CAY10850 time- and concentration-dependently increased EP4 internalization in cultured DRG neuron. Internalized EP4 was predominantly localized in the early endosomes and recycling endosomes, but rarely in the late endosomes and lysosomes. These observations were confirmed by FITC-PGE2 binding assay. We further revealed that 1-OH-PGE1 or CAY10850 time- and concentration-dependently increased EP4 recycling. Double exposures to 1-OH-PGE1 induced a greater increase in calcitonin gene-related peptide (CGRP) release than a single exposure or vehicle exposure, an event blocked by pre-treatment with the recycling inhibitor monensin. Our data suggest that EP4 recycling contributes to agonist-induced cell surface abundance and consequently enhanced receptor sensitivity. Facilitating EP4 externalization and recycling is a novel mechanism underlying PGE2-induced nociceptor sensitization.
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Affiliation(s)
- Bruno St-Jacques
- Douglas Mental Health University Institute, McGill University, Montréal, Québec H4H 1R3, Canada
| | - Weiya Ma
- Douglas Mental Health University Institute, McGill University, Montréal, Québec H4H 1R3, Canada; Department of Psychiatry, McGill University, Montréal, Québec H4H 1R3, Canada.
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Sugimoto M, Toda Y, Hori M, Mitani A, Ichihara T, Sekine S, Hirose T, Endo H, Futaki N, Kaku S, Otsuka N, Matsumoto H. Analgesic Effect of the Newly Developed S(+)-Flurbiprofen Plaster on Inflammatory Pain in a Rat Adjuvant-Induced Arthritis Model. Drug Dev Res 2016; 77:20-8. [PMID: 26763139 PMCID: PMC4819712 DOI: 10.1002/ddr.21288] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 12/10/2015] [Indexed: 12/21/2022]
Abstract
Preclinical Research This article describes the properties of a novel topical NSAID (Nonsteroidal anti-inflammatory drug) patch, SFPP (S(+)-flurbiprofen plaster), containing the potent cyclooxygenase (COX) inhibitor, S(+)-flurbiprofen (SFP). The present studies were conducted to confirm human COX inhibition and absorption of SFP and to evaluate the analgesic efficacy of SFPP in a rat adjuvant-induced arthritis (AIA) model. COX inhibition by SFP, ketoprofen and loxoprofen was evaluated using human recombinant COX proteins. Absorption of SFPP, ketoprofen and loxoprofen from patches through rat skin was assessed 24 h after application. The AIA model was induced by injecting Mycobacterium tuberculosis followed 20 days later by the evaluation of the prostaglandin PGE2 content of the inflamed paw and the pain threshold. SFP exhibited more potent inhibitory activity against COX-1 (IC50 = 8.97 nM) and COX-2 (IC50 = 2.94 nM) than the other NSAIDs evaluated. Absorption of SFP was 92.9%, greater than that of ketoprofen and loxoprofen from their respective patches. Application of SFPP decreased PGE2 content from 15 min to 6 h and reduced paw hyperalgesia compared with the control, ketoprofen and loxoprofen patches. SFPP showed analgesic efficacy, and was superior to the ketoprofen and loxoprofen patches, which could be through the potent COX inhibitory activity of SFP and greater skin absorption. The results suggested SFPP can be expected to exert analgesic effect clinically.
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Affiliation(s)
| | - Yoshihisa Toda
- Research HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Miyuki Hori
- Research HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Akiko Mitani
- Research HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | | | - Shingo Sekine
- Research HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Takuya Hirose
- Development HeadquartersTaisho Pharmaceutical Co., Ltd.TokyoJapan
| | - Hiromi Endo
- Research HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Nobuko Futaki
- Product Management DivisionTaisho Toyama Pharmaceutical Co., Ltd.TokyoJapan
| | - Shinsuke Kaku
- Research HeadquartersTaisho Pharmaceutical Co., Ltd.SaitamaJapan
| | - Noboru Otsuka
- Development HeadquartersTaisho Pharmaceutical Co., Ltd.TokyoJapan
| | - Hideo Matsumoto
- Institute for Integrated Sports Medicine, Keio University School of MedicineTokyoJapan
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Wang S, Zhu HY, Jin Y, Zhou Y, Hu S, Liu T, Jiang X, Xu GY. Adrenergic signaling mediates mechanical hyperalgesia through activation of P2X3 receptors in primary sensory neurons of rats with chronic pancreatitis. Am J Physiol Gastrointest Liver Physiol 2015; 308:G710-9. [PMID: 25634810 DOI: 10.1152/ajpgi.00395.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/24/2015] [Indexed: 02/08/2023]
Abstract
The mechanism of pain in chronic pancreatitis (CP) is poorly understood. The aim of this study was designed to investigate roles of norepinephrine (NE) and P2X receptor (P2XR) signaling pathway in the pathogenesis of hyperalgesia in a rat model of CP. CP was induced in male adult rats by intraductal injection of trinitrobenzene sulfonic acid (TNBS). Mechanical hyperalgesia was assessed by referred somatic behaviors to mechanical stimulation of rat abdomen. P2XR-mediated responses of pancreatic dorsal root ganglion (DRG) neurons were measured utilizing calcium imaging and whole cell patch-clamp-recording techniques. Western blot analysis and immunofluorescence were performed to examine protein expression. TNBS injection produced a significant upregulation of P2X3R expression and an increase in ATP-evoked responses of pancreatic DRG neurons. The sensitization of P2X3Rs was reversed by administration of β-adrenergic receptor antagonist propranolol. Incubation of DRG neurons with NE significantly enhanced ATP-induced intracellular calcium signals, which were abolished by propranolol, and partially blocked by protein kinase A inhibitor H-89. Interestingly, TNBS injection led to a significant elevation of NE concentration in DRGs and the pancreas, an upregulation of β2-adrenergic receptor expression in DRGs, and amplification of the NE-induced potentiation of ATP responses. Importantly, pancreatic hyperalgesia was markedly attenuated by administration of purinergic receptor antagonist suramin or A317491 or β2-adrenergic receptor antagonist butoxamine. Sensitization of P2X3Rs, which was likely mediated by adrenergic signaling in primary sensory neurons, contributes to pancreatic pain, thus identifying a potential target for treating pancreatic pain caused by inflammation.
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Affiliation(s)
- Shusheng Wang
- The Affiliated Zhangjiagang Hospital of Soochow University, Suzhou, China
| | - Hong-Yan Zhu
- The Affiliated Zhangjiagang Hospital of Soochow University, Suzhou, China; Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Yi Jin
- Department of Anesthesiology, Nanjing Jinling Hospital, Nanjing, China
| | - Youlang Zhou
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Shufen Hu
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Tong Liu
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Xinghong Jiang
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Soochow University, Suzhou, China
| | - Guang-Yin Xu
- The Affiliated Zhangjiagang Hospital of Soochow University, Suzhou, China; Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Soochow University, Suzhou, China;
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Schiavuzzo JG, Teixeira JM, Melo B, da Silva dos Santos DF, Jorge CO, Oliveira-Fusaro MCG, Parada CA. Muscle hyperalgesia induced by peripheral P2X3 receptors is modulated by inflammatory mediators. Neuroscience 2014; 285:24-33. [PMID: 25446353 DOI: 10.1016/j.neuroscience.2014.11.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/06/2014] [Accepted: 11/11/2014] [Indexed: 11/25/2022]
Abstract
ATP, via activation of P2X3 receptors, has been highlighted as a key target in inflammatory hyperalgesia. Therefore, the aim of this study was to confirm whether the activation of P2X3 receptors in the gastrocnemius muscle of rats induces mechanical muscle hyperalgesia and, if so, to analyze the involvement of the classical inflammatory mediators (bradykinin, prostaglandins, sympathetic amines, pro-inflammatory cytokines and neutrophil migration) in this response. Intramuscular administration of the non-selective P2X3 receptor agonist α,β-meATP in the gastrocnemius muscle of rats induced mechanical muscle hyperalgesia, which, in turn, was prevented by the selective P2X3 and P2X2/3 receptors antagonist A-317491, the selective bradykinin B1-receptor antagonist Des-Arg9-[Leu8]-BK (DALBK), the cyclooxygenase inhibitor indomethacin, the β1- or β2-adrenoceptor antagonist atenolol and ICI 118,551, respectively. Also, the nonspecific selectin inhibitor fucoidan. α,β-meATP induced increases in the local concentration of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin 1β (IL-1β), which were reduced by bradykinin antagonist. Finally, α,β-meATP also induced neutrophil migration. Together, these findings suggest that α,β-meATP induced mechanical hyperalgesia in the gastrocnemius muscle of rats via activation of peripheral P2X3 receptors, which involves bradykinin, prostaglandins, sympathetic amines, pro-inflammatory cytokines release and neutrophil migration. It is also indicated that bradykinin is the key modulator of the mechanical muscle hyperalgesia induced by P2X3 receptors. Therefore, we suggest that P2X3 receptors are important targets to control muscle inflammatory pain.
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Affiliation(s)
- J G Schiavuzzo
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil; Department of Structural and Functional Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil
| | - J M Teixeira
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil
| | - B Melo
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil
| | - D F da Silva dos Santos
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil
| | - C O Jorge
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil
| | - M C G Oliveira-Fusaro
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil.
| | - C A Parada
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil
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St-Jacques B, Ma W. Peripheral prostaglandin E2 prolongs the sensitization of nociceptive dorsal root ganglion neurons possibly by facilitating the synthesis and anterograde axonal trafficking of EP4 receptors. Exp Neurol 2014; 261:354-66. [DOI: 10.1016/j.expneurol.2014.05.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/09/2014] [Accepted: 05/30/2014] [Indexed: 12/21/2022]
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Su YS, Sun WH, Chen CC. Molecular mechanism of inflammatory pain. World J Anesthesiol 2014; 3:71-81. [DOI: 10.5313/wja.v3.i1.71] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Revised: 09/20/2013] [Accepted: 11/03/2013] [Indexed: 02/07/2023] Open
Abstract
Chronic inflammatory pain resulting from arthritis, nerve injury and tumor growth is a serious public health issue. One of the major challenges in chronic inflammatory pain research is to develop new pharmacologic treatments with long-term efficacy and few side effects. The mediators released from inflamed sites induce complex changes in peripheral and central processing by directly acting on transducer receptors located on primary sensory neurons to transmit pain signals or indirectly modulating pain signals by activating receptors coupled with G-proteins and second messengers. High local proton concentration (acidosis) is thought to be a decisive factor in inflammatory pain and other mediators such as prostaglandin, bradykinin, and serotonin enhance proton-induced pain. Proton-sensing ion channels [transient receptor potential V1 (TRPV1) and the acid-sensing ion channel (ASIC) family] are major receptors for direct excitation of nociceptive sensory neurons in response to acidosis or inflammation. G-protein-coupled receptors activated by prostaglandin, bradykinin, serotonin, and proton modulate functions of TRPV1, ASICs or other ion channels, thus leading to inflammation- or acidosis-linked hyperalgesia. Although detailed mechanisms remain unsolved, clearly different types of pain or hyperalgesia could be due to complex interactions between a distinct subset of inflammatory mediator receptors expressed in a subset of nociceptors. This review describes new directions for the development of novel therapeutic treatments in pain.
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Gregory NS, Sluka KA. Anatomical and physiological factors contributing to chronic muscle pain. Curr Top Behav Neurosci 2014; 20:327-48. [PMID: 24633937 PMCID: PMC4294469 DOI: 10.1007/7854_2014_294] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Chronic muscle pain remains a significant source of suffering and disability despite the adoption of pharmacologic and physical therapies. Muscle pain is mediated by free nerve endings distributed through the muscle along arteries. These nerves project to the superficial dorsal horn and are transmitted primarily through the spinothalamic tract to several cortical and subcortical structures, some of which are more active during the processing of muscle pain than other painful conditions. Mechanical forces, ischemia, and inflammation are the primary stimuli for muscle pain, which is reflected in the array of peripheral receptors contributing to muscle pain-ASIC, P2X, and TRP channels. Sensitization of peripheral receptors and of central pain processing structures are both critical for the development and maintenance of chronic muscle pain. Further, variations in peripheral receptors and central structures contribute to the significantly greater prevalence of chronic muscle pain in females.
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Affiliation(s)
- Nicholas S Gregory
- Neuroscience Graduate Program, University of Iowa, 3144 Med Labs, Iowa City, IA, 52246, USA,
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Ma W, Quirion R. Targeting cell surface trafficking of pain-facilitating receptors to treat chronic pain conditions. Expert Opin Ther Targets 2014; 18:459-72. [DOI: 10.1517/14728222.2014.887683] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Isensee J, Diskar M, Waldherr S, Buschow R, Hasenauer J, Prinz A, Allgöwer F, Herberg FW, Hucho T. Pain modulators regulate the dynamics of PKA-RII phosphorylation in subgroups of sensory neurons. J Cell Sci 2013; 127:216-29. [PMID: 24190886 DOI: 10.1242/jcs.136580] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Knowledge about the molecular structure of protein kinase A (PKA) isoforms is substantial. In contrast, the dynamics of PKA isoform activity in living primary cells has not been investigated in detail. Using a high content screening microscopy approach, we identified the RIIβ subunit of PKA-II to be predominantly expressed in a subgroup of sensory neurons. The RIIβ-positive subgroup included most neurons expressing nociceptive markers (TRPV1, NaV1.8, CGRP, IB4) and responded to pain-eliciting capsaicin with calcium influx. Isoform-specific PKA reporters showed in sensory-neuron-derived F11 cells that the inflammatory mediator PGE₂ specifically activated PKA-II but not PKA-I. Accordingly, pain-sensitizing inflammatory mediators and activators of PKA increased the phosphorylation of RII subunits (pRII) in subgroups of primary sensory neurons. Detailed analyses revealed basal pRII to be regulated by the phosphatase PP2A. Increase of pRII was followed by phosphorylation of CREB in a PKA-dependent manner. Thus, we propose RII phosphorylation to represent an isoform-specific readout for endogenous PKA-II activity in vivo, suggest RIIβ as a novel nociceptive subgroup marker, and extend the current model of PKA-II activation by introducing a PP2A-dependent basal state.
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Affiliation(s)
- Joerg Isensee
- University Hospital Cologne, Department of Anesthesiology and Intensive Care Medicine, Experimental Anesthesiology and Pain Research, Robert Koch Str. 10, 50931 Cologne, Germany
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Hendrich J, Alvarez P, Joseph EK, Chen X, Bogen O, Levine JD. Electrophysiological correlates of hyperalgesic priming in vitro and in vivo. Pain 2013; 154:2207-2215. [PMID: 23831864 DOI: 10.1016/j.pain.2013.07.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 06/04/2013] [Accepted: 07/02/2013] [Indexed: 11/29/2022]
Abstract
We have modeled the transition from acute to chronic pain in the rat. In this model (termed hyperalgesic priming) a chronic state develops after a prior inflammatory process or exposure to an inflammatory mediator, in which response to subsequent exposure to prostaglandin E2 (PGE2) is characterized by a protein kinase Cε-dependent marked prolongation of mechanical hyperalgesia. To assess the effect of priming on the function of the nociceptor, we have performed in vitro patch clamp and in vivo single-fiber electrophysiology studies using tumor necrosis factor α to induce priming. In vitro, the only change observed in nociceptors cultured from primed animals was a marked hyperpolarization in resting membrane potential (RMP); prolonged sensitization, measured at 60 minutes, could not be tested in vitro. However, complimentary with behavioral findings, in vivo baseline mechanical nociceptive threshold was significantly elevated compared to controls. Thirty minutes after injection of PGE2 into the peripheral receptive field, both primed and control nociceptors showed enhanced response to mechanical stimulation. However, 60 minutes after PGE2 administration, the response to mechanical stimulation was further increased in primed but not in control nociceptors. Thus, at the level of the primary afferent nociceptor, it is possible to demonstrate both altered function at baseline and prolonged PGE2-induced sensitization. Intrathecal antisense (AS) to Kv7.2, which contributes to RMP in sensory neurons, reversibly prevented the expression of priming in both behavioral and single-fiber electrophysiology experiments, implicating these channels in the expression of hyperalgesic priming.
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Affiliation(s)
- Jan Hendrich
- Department of Oral and Maxillofacial Surgery, University of California at San Francisco, CA, USA Division of Neuroscience, University of California at San Francisco, CA, USA Department of Medicine, University of California at San Francisco, CA, USA
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Masterson CG, Durham PL. DHE repression of ATP-mediated sensitization of trigeminal ganglion neurons. Headache 2013; 50:1424-39. [PMID: 20561068 DOI: 10.1111/j.1526-4610.2010.01714.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE To investigate the mechanism by which adenosine triphosphate (ATP) causes sensitization of trigeminal neurons and how dihydroergotamine (DHE) represses this modulatory effect. BACKGROUND Dihydroergotamine is an effective treatment of migraine. The cellular mechanisms of action of DHE in treating migraine attacks remain unclear. METHODS In this study, neonatal rat trigeminal ganglia cultures were used to investigate effects of ATP, alpha, beta-methyl ATP (α,β-meATP), and DHE on intracellular calcium levels and calcitonin gene-related peptide (CGRP) secretion. RESULTS Pretreatment with ATP or α,β-meATP caused sensitization of neurons, via P2X(3) receptors, such that a subthreshold amount of potassium chloride (KCl) significantly increased intracellular calcium levels and CGRP secretion. Pretreatment with DHE repressed increases in calcium and CGRP secretion in response to ATP-KCl or α,β-meATP-KCl treatment. Importantly, these inhibitory effects of DHE were blocked with an α(2) -adrenoceptor antagonist and unaffected by a 5HT(1B/D) receptor antagonist. DHE also decreased neuronal membrane expression of the P2X(3) receptor. CONCLUSIONS Our findings provide evidence for a novel mechanism of action for DHE that involves blocking ATP-mediated sensitization of trigeminal neurons, repressing stimulated CGRP release, and decreasing P2X(3) membrane expression via activation of α(2) -adrenoceptors.
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Affiliation(s)
- Caleb G Masterson
- Center for Biomedical and Life Sciences, Missouri State University, Springfield, MO 65806, USA
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Mo G, Peleshok JC, Cao CQ, Ribeiro-da-Silva A, Séguéla P. Control of P2X3 channel function by metabotropic P2Y2 utp receptors in primary sensory neurons. Mol Pharmacol 2013; 83:640-7. [PMID: 23249537 DOI: 10.1124/mol.112.082099] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purinergic signaling contributes significantly to pain mechanisms, and the nociceptor-specific P2X3 ATP receptor channel is considered a target in pain therapeutics. Recent findings suggesting the coexpression of metabotropic P2Y receptors with P2X3 implies that ATP release triggers the activation of both ionotropic and metabotropic purinoceptors, with strong potential for functional interaction. Modulation of native P2X3 function by P2Y receptor activation was investigated in rat dorsal root ganglia (DRG) neurons using whole cell patch-clamp recordings. Application of the selective P2Y receptor agonist UTP decreased peak amplitudes of α,β-meATP-evoked homomeric P2X3-mediated currents, but had no effect on heteromeric P2X2/3-mediated currents. Treatment with phospholipase C inhibitor U73122 significantly reversed P2X3 current inhibition induced by UTP-sensitive P2Y receptor activation. We previously reported the modulation of P2X receptors by phospholipids in DRG neurons and injection of exogenous phosphatidylinositol-4,5-bisphosphate (PIP(2)) fully reverses UTP-mediated regulation of P2X3 channel activity. Pharmacological as well as functional screening of P2Y receptor subtypes indicates the predominant involvement of P2Y2 receptor in P2X3 inhibition, and immunolocalization confirms a significant cellular coexpression of P2X3 and P2Y2 in rat DRG neurons. In summary, the function of P2X3 ATP receptor can be inhibited by P2Y2-mediated depletion of PIP(2). We propose that expression of P2Y2 purinoceptor in nociceptive sensory neurons provides an homeostatic mechanism to prevent excessive ATP signaling through P2X3 receptor channels.
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Affiliation(s)
- Gary Mo
- Alan Edwards Research Centre on Pain, Montreal, Quebec, Canada
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St-Jacques B, Ma W. Prostaglandin E2/EP4 signalling facilitates EP4 receptor externalization in primary sensory neurons in vitro and in vivo. Pain 2013; 154:313-323. [DOI: 10.1016/j.pain.2012.11.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 08/28/2012] [Accepted: 11/14/2012] [Indexed: 12/21/2022]
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Petho G, Reeh PW. Sensory and signaling mechanisms of bradykinin, eicosanoids, platelet-activating factor, and nitric oxide in peripheral nociceptors. Physiol Rev 2013; 92:1699-775. [PMID: 23073630 DOI: 10.1152/physrev.00048.2010] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Peripheral mediators can contribute to the development and maintenance of inflammatory and neuropathic pain and its concomitants (hyperalgesia and allodynia) via two mechanisms. Activation or excitation by these substances of nociceptive nerve endings or fibers implicates generation of action potentials which then travel to the central nervous system and may induce pain sensation. Sensitization of nociceptors refers to their increased responsiveness to either thermal, mechanical, or chemical stimuli that may be translated to corresponding hyperalgesias. This review aims to give an account of the excitatory and sensitizing actions of inflammatory mediators including bradykinin, prostaglandins, thromboxanes, leukotrienes, platelet-activating factor, and nitric oxide on nociceptive primary afferent neurons. Manifestations, receptor molecules, and intracellular signaling mechanisms of the effects of these mediators are discussed in detail. With regard to signaling, most data reported have been obtained from transfected nonneuronal cells and somata of cultured sensory neurons as these structures are more accessible to direct study of sensory and signal transduction. The peripheral processes of sensory neurons, where painful stimuli actually affect the nociceptors in vivo, show marked differences with respect to biophysics, ultrastructure, and equipment with receptors and ion channels compared with cellular models. Therefore, an effort was made to highlight signaling mechanisms for which supporting data from molecular, cellular, and behavioral models are consistent with findings that reflect properties of peripheral nociceptive nerve endings. Identified molecular elements of these signaling pathways may serve as validated targets for development of novel types of analgesic drugs.
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Affiliation(s)
- Gábor Petho
- Pharmacodynamics Unit, Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Pécs, Pécs, Hungary
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Petrushenko YA. P2X Receptors: Peculiarities of the Structure and Modulation of the Functions. NEUROPHYSIOLOGY+ 2012. [DOI: 10.1007/s11062-012-9284-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Wang S, Dai Y, Kobayashi K, Zhu W, Kogure Y, Yamanaka H, Wan Y, Zhang W, Noguchi K. Potentiation of the P2X3 ATP receptor by PAR-2 in rat dorsal root ganglia neurons, through protein kinase-dependent mechanisms, contributes to inflammatory pain. Eur J Neurosci 2012; 36:2293-301. [PMID: 22616675 DOI: 10.1111/j.1460-9568.2012.08142.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Proinflammatory agents trypsin and mast cell tryptase cleave and activate protease-activated receptor-2 (PAR-2), which is expressed on sensory nerves and causes neurogenic inflammation. P2X3 is a subtype of the ionotropic receptors for adenosine 5'-triphosphate (ATP), and is mainly localized on nociceptors. Here, we show that a functional interaction of the PAR-2 and P2X3 in primary sensory neurons could contribute to inflammatory pain. PAR-2 activation increased the P2X3 currents evoked by α, β, methylene ATP in dorsal root ganglia (DRG) neurons. Application of inhibitors of either protein kinase C (PKC) or protein kinase A (PKA) suppressed this potentiation. Consistent with this, a PKC or PKA activator mimicked the PAR-2-mediated potentiation of P2X3 currents. In the in vitro phosphorylation experiments, application of a PAR-2 agonist failed to establish phosphorylation of the P2X3 either on the serine or the threonine site. In contrast, application of a PAR-2 agonist induced trafficking of the P2X3 from the cytoplasm to the plasma membrane. These findings indicate that PAR-2 agonists may potentiate the P2X3, and the mechanism of this potentiation is likely to be a result of translocation, but not phosphorylation. The functional interaction between P2X3 and PAR-2 was also confirmed by detection of the α, β, methylene-ATP-evoked extracellular signal-regulated kinases (ERK) activation, a marker of neuronal signal transduction in DRG neurons, and pain behavior. These results demonstrate a functional interaction of the protease signal with the ATP signal, and a novel mechanism through which protease released in response to tissue inflammation might trigger the sensation to pain through P2X3 activation.
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Affiliation(s)
- Shenglan Wang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100088, China
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Wu JX, Xu MY, Miao XR, Lu ZJ, Yuan XM, Li XQ, Yu WF. Functional up-regulation of P2X3 receptors in dorsal root ganglion in a rat model of bone cancer pain. Eur J Pain 2012; 16:1378-88. [PMID: 22528605 DOI: 10.1002/j.1532-2149.2012.00149.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2012] [Indexed: 12/30/2022]
Abstract
BACKGROUND Cancer-induced bone pain remains a clinical challenge due to the poor understanding of the mechanisms. Recent study revealed extracellular adenosine triphosphate (ATP) and P2X receptors may be implicated in nociceptive signalling under cancer pain state. Therefore, here we investigated the potential role of P2X(3) receptor in a rat model of bone cancer pain. METHODS Walker 256 tumour cells were inoculated into the left tibia of Wistar rats. The model was verified by X-ray imaging, pathology and behaviour examinations. The expression of P2X(3) receptors in dorsal root ganglia (DRG) was examined. Functional significance of altered P2X(3) receptors was investigated by measuring influx upon α,β-meATP stimulation in acutely dissociated DRG neurons. Moreover, A-317491, an antagonist of P2X(3) receptors, was administrated intrathecally or locally to evaluate its analgesia effect in the cancer pain animals. RESULTS The P2X(3) receptor was up-regulated for about 50% in DRG neurons in rats with bone cancer at both protein and mRNA levels and correlated with the pain behaviour in bone cancer rats. A 51.9% increase of α,β-me ATP (10 μM, for 4 s) evoked transient response currents and a higher percentage of neurons responsive to the application of α,β-me ATP was detected in bone cancer rats. Intrathecal or local injection of A-317491 significantly attenuated pain behaviour induced by bone cancer. CONCLUSIONS These results suggest that the P2X(3) receptor is functionally up-regulated in DRG in cancer rats. P2X(3) receptor is a promising target for therapeutic intervention in cancer patients for pain management.
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Affiliation(s)
- J X Wu
- Department of Anesthesiology, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
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Xu J, Chu KL, Brederson JD, Jarvis MF, McGaraughty S. Spontaneous firing and evoked responses of spinal nociceptive neurons are attenuated by blockade of P2X3 and P2X2/3 receptors in inflamed rats. J Neurosci Res 2012; 90:1597-606. [PMID: 22422599 DOI: 10.1002/jnr.23042] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 01/04/2012] [Accepted: 01/15/2012] [Indexed: 11/11/2022]
Abstract
P2X3 and P2X2/3 receptors are selectively expressed on primary afferent nociceptors and have been implicated in modulating nociception in different models of pathological pain, including inflammatory pain. In an effort to delineate further the role of P2X3 receptors (homomeric and heteromeric) in the modulation of nociceptive transmission after a chronic inflammation injury, A-317491, a potent and selective P2X3-P2X2/3 antagonist, was administered to CFA-inflamed rats in order to examine its effects on responses of spinal dorsal horn neurons to mechanical and thermal stimulation. Systemic injection of A-317491 (30 μmol/kg, i.v.) reduced the responses of wide-dynamic-range (WDR) and nociceptive specific (NS) neurons to both high-intensity mechanical (pinch) and heat (49°C) stimulation. A-317491 also decreased low-intensity (10 g von Frey hair) mechanically evoked activity of WDR neurons but did not alter WDR neuronal responses to cold stimulation (5°C). Spontaneous firing of WDR neurons in CFA-inflamed rats was also significantly attenuated by A-317491 injection. By using immunohistochemistry, P2X3 receptors were demonstrated to be enhanced in lamina II of the spinal dorsal horn after inflammation. In summary, blockade of P2X3 and P2X2/3 receptors dampens mechanical- and heat-related signaling, as well as nonevoked activity of key classes of spinal nociceptive neurons in inflamed animals. These data suggest that P2X3 and/or P2X2/3 receptors have a broad contribution to somatosensory/nociceptive transmission in rats with a chronic inflammatory injury and are consistent with previous behavioral data demonstrating antiallodynic and antihyperalgesic effects of receptor antagonists.
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Affiliation(s)
- Jun Xu
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois 60064-6118, USA
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Abstract
Prostaglandin E(2) (PGE(2)), a cyclooxygenase (COX) product, is the best known lipid mediator that contributes to inflammatory pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), inhibitors of COX-1 and/or COX-2, suppress inflammatory pain by reducing generation of prostanoids, mainly PGE(2), while they exhibit gastrointestinal, renal and cardiovascular toxicities. Selective inhibitors of microsomal PGE synthase-1 and subtype-selective antagonists of PGE(2) receptors, particularly EP(1) and EP(4), may be useful as analgesics with minimized side-effects. Protein kinase C (PKC) and PKA downstream of EP(1) and EP(4), respectively, sensitize/activate multiple molecules including transient receptor potential vanilloid-1 (TRPV1) channels, purinergic P2X3 receptors, and voltage-gated calcium or sodium channels in nociceptors, leading to hyperalgesia. PGE(2) is also implicated in neuropathic and visceral pain and in migraine. Thus, PGE(2) has a great impact on pain signals, and pharmacological intervention in upstream and downstream signals of PGE(2) may serve as novel therapeutic strategies for the treatment of intractable pain.
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Affiliation(s)
- Atsufumi Kawabata
- Division of Pharmacology and Pathophysiology, School of Pharmacy, Kinki University, Higashi-Osaka 577–8502, Japan.
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Zhao H, Kinch DC, Simasko SM. Pharmacological investigations of the cellular transduction pathways used by cholecystokinin to activate nodose neurons. Auton Neurosci 2011; 164:20-6. [PMID: 21664195 DOI: 10.1016/j.autneu.2011.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 05/18/2011] [Accepted: 05/19/2011] [Indexed: 11/25/2022]
Abstract
Cholecystokinin (CCK) directly activates vagal afferent neurons resulting in coordinated gastrointestinal functions and satiation. In vitro, the effects of CCK on dissociated vagal afferent neurons are mediated via activation of the vanilloid family of transient receptor potential (TRPV) cation channels leading to membrane depolarization and an increase in cytosolic calcium. However, the cellular transduction pathway(s) involved in this process between CCK receptors and channel opening have not been identified. To address this question, we monitored CCK-induced cytosolic calcium responses in dissociated nodose neurons from rat in the presence or absence of reagents that interact with various intracellular signaling pathways. We found that the phospholipase C (PLC) inhibitor U-73122 significantly attenuated CCK-induced responses, whereas the inactive analog U-73433 had no effect. Responses to CCK were also cross-desensitized by a brief pretreatment with m-3M3FBS, a PLC stimulator. Together these observations strongly support the participation of PLC in the effects of CCK on vagal afferent neurons. In contrast, pharmacological antagonism of phospholipase A(2), protein kinase A, and phosphatidylinositol 3-kinase revealed that they are not critical in the CCK-induced calcium response in nodose neurons. Further investigations of the cellular pathways downstream of PLC showed that neither protein kinase C (PKC) nor generation of diacylglycerol (DAG) or release of calcium from intracellular stores participates in the response to CCK. These results suggest that alteration of membrane phosphatidylinositol 4,5-bisphosphate (PIP(2)) content by PLC activity mediates CCK-induced calcium response and that this pathway may underlie the vagally-mediated actions of CCK to induce satiation and alter gastrointestinal functions.
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Affiliation(s)
- Huan Zhao
- Program in Neuroscience, Dept of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, Washington State University, Pullman, WA 99164, USA.
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Jin J, Morales-Ramos Á, Eidam P, Mecom J, Li Y, Brooks C, Hilfiker M, Zhang D, Wang N, Shi D, Tseng PS, Wheless K, Budzik B, Evans K, Jaworski JP, Jugus J, Leon L, Wu C, Pullen M, Karamshi B, Rao P, Ward E, Laping N, Evans C, Leach C, Holt D, Su X, Morrow D, Fries H, Thorneloe K, Edwards R. Novel 3-Oxazolidinedione-6-aryl-pyridinones as Potent, Selective, and Orally Active EP3 Receptor Antagonists. ACS Med Chem Lett 2010; 1:316-20. [PMID: 24900213 DOI: 10.1021/ml100077x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 05/06/2010] [Indexed: 12/24/2022] Open
Abstract
High-throughput screening and subsequent optimization led to the discovery of novel 3-oxazolidinedione-6-aryl-pyridinones exemplified by compound 2 as potent and selective EP3 antagonists with excellent pharmacokinetic properties. Compound 2 was orally active and showed robust in vivo activities in overactive bladder models. To address potential bioactivation liabilities of compound 2, further optimization resulted in compounds 9 and 10, which maintained excellent potency, selectivity, and pharmacokinetic properties and showed no bioactivation liability in glutathione trapping studies. These highly potent, selective, and orally active EP3 antagonists are excellent tool compounds for investigating and validating potential therapeutic benefits from selectively inhibiting the EP3 receptor.
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Affiliation(s)
- Jian Jin
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | | | - Patrick Eidam
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - John Mecom
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Yue Li
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Carl Brooks
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Mark Hilfiker
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - David Zhang
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Ning Wang
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Dongchuan Shi
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Pei-San Tseng
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Karen Wheless
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Brian Budzik
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Karen Evans
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Jon-Paul Jaworski
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Jack Jugus
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Lisa Leon
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Charlene Wu
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Mark Pullen
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Bhumika Karamshi
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Parvathi Rao
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Emma Ward
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Nicholas Laping
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Christopher Evans
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Colin Leach
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Dennis Holt
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Xin Su
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Dwight Morrow
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Harvey Fries
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Kevin Thorneloe
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
| | - Richard Edwards
- GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406
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Okubo M, Yamanaka H, Kobayashi K, Fukuoka T, Dai Y, Noguchi K. Expression of leukotriene receptors in the rat dorsal root ganglion and the effects on pain behaviors. Mol Pain 2010; 6:57. [PMID: 20846451 PMCID: PMC2949724 DOI: 10.1186/1744-8069-6-57] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 09/17/2010] [Indexed: 01/08/2023] Open
Abstract
Background Leukotrienes (LTs) belong to the large family of lipid mediators implicated in various inflammatory conditions such as asthma and rheumatoid arthritis. Four distinct types (BLT1, BLT2, CysLT1 and CysLT2) of G-protein-coupled receptors for LTs have been identified. Several studies have reported that LTs are involved in inflammatory pain, but the mechanism and the expression of LT receptors in the nociceptive pathway are unknown. Results We investigated the precise expression of these four types of LT receptors in the adult rat dorsal root ganglion (DRG) using reverse transcription-polymerase reaction (RT-PCR) and radioisotope-labeled in situ hybridization histochemistry (ISHH). We detected mRNAs for BLT1 and CysLT2 in the DRG, but not for BLT2 and CysLT1. CysLT2 mRNA was preferentially expressed by small sized DRG neurons (about 36% of total neurons), whereas BLT1 mRNA was expressed by non-neuronal cells. Double labeling analysis of CysLT2 with NF-200, calcitonin gene-related peptide (CGRP), isolectin B4 (IB4), transient receptor potential vanilloid subfamily 1 (TRPV1) and P2X3 receptor revealed that many CysLT2-labeled neurons were localized with unmyelinated and non-peptidergic neurons, and interestingly, CysLT2 mRNA heavily co-localized with TRPV1 and P2X3-positive neurons. Intraplantar injection of LTC4, a CysLT2 receptor agonist, itself did not induce the thermal hyperalgesia, spontaneous pain behaviors or swelling of hind paw. However, pretreatment of LTC4 remarkably enhanced the painful behaviors produced by alpha, beta-methylene adenosine 5'-triphosphate (αβ-me-ATP), a P2X3 receptor agonist. Conclusions These data suggests that CysLT2 expressed in DRG neurons may play a role as a modulator of P2X3, and contribute to a potentiation of the neuronal activity following peripheral inflammation.
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Affiliation(s)
- Masamichi Okubo
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
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Cyclooxygenase inhibitors suppress the expression of P2X3 receptors in the DRG and attenuate hyperalgesia following chronic constriction injury in rats. Neurosci Lett 2010; 478:77-81. [DOI: 10.1016/j.neulet.2010.04.069] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2010] [Revised: 04/26/2010] [Accepted: 04/27/2010] [Indexed: 01/27/2023]
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De Roo M, Boué-Grabot E, Schlichter R. Selective potentiation of homomeric P2X2 ionotropic ATP receptors by a fast non-genomic action of progesterone. Neuropharmacology 2009; 58:569-77. [PMID: 20004677 DOI: 10.1016/j.neuropharm.2009.12.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 11/06/2009] [Accepted: 12/02/2009] [Indexed: 01/05/2023]
Abstract
P2X receptors are ligand-gated ion channels activated by ATP that are widely expressed in the organism and regulate many physiological functions. We have studied the effect of progesterone (PROG) on native P2X receptors present in rat dorsal root ganglion (DRG) neurons and on recombinant P2X receptors expressed in HEK293 cells or Xenopus laevis oocytes. The effects of PROG were observed and already maximal during the first coapplication with ATP and did not need any preincubation of the cells with PROG, indicating a fast mechanism of action. In DRG neurons, PROG rapidly and reversibly potentiated submaximal but not saturating plateau-like currents evoked by ATP, but had no effect on the currents activated by alpha,beta-methylene ATP, an agonist of homomeric or heteromeric receptors containing P2X1 or P2X3 subunits. In cells expressing homomeric P2X2 receptors, responses to submaximal ATP, were systematically potentiated by PROG in a dose-dependent manner with a threshold between 1 and 10 nM. PROG had no effect on ATP currents carried by homomeric P2X1, P2X3, and P2X4 receptors or by heteromeric P2X1/5 and P2X2/3 receptors. We conclude that PROG selectively potentiates homomeric P2X2 receptors and, in contrast with dehydroepiandrosterone (DHEA), discriminates between homomeric and heteromeric P2X2-containing receptors. This might have important physiological implications since the P2X2 subunit is the most widely distributed P2X subunit in the organism. Moreover, DHEA and PROG might be useful tools to clarify the distribution and the role of native homo- and heteromeric P2X2 receptors.
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Affiliation(s)
- Mathias De Roo
- Institut des Neurosciences Cellulaires et Intégratives, UPR 3212 Centre National de la Recherche Scientifique, Université de Strasbourg, Département Nociception et Douleur, 21 rue René Descartes, F-67084 Strasbourg cedex, France
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