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Greco C, Basso L, Désormeaux C, Fournel A, Demuynck B, Lafendi L, Chapiro S, Lemoine A, Zhu YY, Knauf C, Cenac N, Boucheix C, Dietrich G. Endothelin-1 Exhibiting Pro-Nociceptive and Pro-Peristaltic Activities Is Increased in Peritoneal Carcinomatosis. FRONTIERS IN PAIN RESEARCH 2022; 2:613187. [PMID: 35295482 PMCID: PMC8915553 DOI: 10.3389/fpain.2021.613187] [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: 10/01/2020] [Accepted: 01/19/2021] [Indexed: 11/17/2022] Open
Abstract
Background: Peritoneal carcinomatosis often results in alterations in intestinal peristalsis and recurrent abdominal pain. Pain management in these patients is often unsatisfactory. This study aimed to investigate whether endothelin-1 (EDN1) was involved in pain mediation in peritoneal carcinomatosis, and thus whether the EDN1 pathway could be a new therapeutic target for peritoneal carcinomatosis-associated pain. Methods: EDN1 plasma levels and abdominal pain severity were assessed in patients with abdominal tumors, with or without peritoneal carcinomatosis, and in healthy donors. The effects of EDN1 on the visceromotor response to colorectal distension, and on colonic contractions were then examined in mice, and the mechanism of action of EDN1 was then investigated by measuring the impact of EDN1 exposure on calcium mobilization in cultured neurons. Inhibition studies were also performed to determine if the effects of EDN1 exposure could be reversed by EDN1-specific receptor antagonists. Results: A positive correlation between EDN1 plasma levels and abdominal pain was identified in patients with peritoneal carcinomatosis. EDN1 exposure increased visceral sensitivity and the amplitude of colonic contractions in mice and induced calcium mobilization by direct binding to its receptors on sensory neurons. The effects of EDN1 were inhibited by antagonists of the EDN1 receptors. Conclusions: This preliminary study, using data from patients with peritoneal carcinomatosis combined with data from experiments performed in mice, suggests that EDN1 may play a key role mediating pain in peritoneal carcinomatosis. Our findings suggest that antagonists of the EDN1 receptors might be beneficial in the management of pain in patients with peritoneal carcinomatosis.
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Affiliation(s)
- Céline Greco
- UMR-S935, INSERM, Univ. Paris-Sud, Université Paris Saclay, Villejuif, France.,Department of Pain Management and Palliative Care, Necker-Enfants Malades Hospital, AP-HP, Paris, France
| | - Lilian Basso
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Cléo Désormeaux
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Audren Fournel
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Benedicte Demuynck
- Department of Oncology, Montereau-Fault-Yonne Hospital, Montereau, France
| | - Leila Lafendi
- Department of Medical Biology and Physiology, Montereau-Fault-Yonne Hospital, Montereau, France
| | - Sylvie Chapiro
- Department of Palliative Care, Paul Brousse Hospital, AP-HP, Villejuif, France
| | - Antoinette Lemoine
- UMR-S1093, INSERM, Univ. Paris-Sud, Université Paris Saclay, Villejuif, France.,Department of Biochemistry, Paul Brousse Hospital, AP-HP, Villejuif, France
| | - Ying-Ying Zhu
- UMR-S935, INSERM, Univ. Paris-Sud, Université Paris Saclay, Villejuif, France
| | - Claude Knauf
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Nicolas Cenac
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Claude Boucheix
- UMR-S935, INSERM, Univ. Paris-Sud, Université Paris Saclay, Villejuif, France
| | - Gilles Dietrich
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
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Szöllősi AG, Oláh A, Lisztes E, Griger Z, Tóth BI. Pruritus: A Sensory Symptom Generated in Cutaneous Immuno-Neuronal Crosstalk. Front Pharmacol 2022; 13:745658. [PMID: 35321329 PMCID: PMC8937025 DOI: 10.3389/fphar.2022.745658] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 02/07/2022] [Indexed: 12/21/2022] Open
Abstract
Pruritus or itch generated in the skin is one of the most widespread symptoms associated with various dermatological and systemic (immunological) conditions. Although many details about the molecular mechanisms of the development of both acute and chronic itch were uncovered in the last 2 decades, our understanding is still incomplete and the clinical management of pruritic conditions is one of the biggest challenges in daily dermatological practice. Recent research revealed molecular interactions between pruriceptive sensory neurons and surrounding cutaneous cell types including keratinocytes, as well as resident and transient cells of innate and adaptive immunity. Especially in inflammatory conditions, these cutaneous cells can produce various mediators, which can contribute to the excitation of pruriceptive sensory fibers resulting in itch sensation. There also exists significant communication in the opposite direction: sensory neurons can release mediators that maintain an inflamed, pruritic tissue-environment. In this review, we summarize the current knowledge about the sensory transduction of pruritus detailing the local intercellular interactions that generate itch. We especially emphasize the role of various pruritic mediators in the bidirectional crosstalk between cutaneous non-neuronal cells and sensory fibers. We also list various dermatoses and immunological conditions associated with itch, and discuss the potential immune-neuronal interactions promoting the development of pruritus in the particular diseases. These data may unveil putative new targets for antipruritic pharmacological interventions.
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Affiliation(s)
- Attila Gábor Szöllősi
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Attila Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Erika Lisztes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Griger
- Division of Clinical Immunology, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs István Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- *Correspondence: Balázs István Tóth,
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Kelemen B, Pinto S, Kim N, Lisztes E, Hanyicska M, Vládar A, Oláh A, Pénzes Z, Shu B, Vriens J, Bíró T, Rohács T, Voets T, Tóth BI. The TRPM3 ion channel mediates nociception but not itch evoked by endogenous pruritogenic mediators. Biochem Pharmacol 2021; 183:114310. [PMID: 33130130 PMCID: PMC8086171 DOI: 10.1016/j.bcp.2020.114310] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/22/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023]
Abstract
During the molecular transduction of itch, the stimulation of pruriceptors on sensory fibers leads to the activation or sensitization of ion channels, which results in a consequent depolarization of the neurons. These ion channels mostly belong to the transient receptor potential (TRP) channels, which are involved in nociception and thermosensation. In particular, TRPV1 and TRPA1 were described in the transduction of both thermal nociception as well as histaminergic and non-histaminergic itch. The thermosensitive TRPM3 plays an indispensable role in heat nociception together with TRPV1 and TRPA1. However, the role of TRPM3 in the development of pruritus has not been studied yet. Therefore, in this study we aimed at investigating the potential role of TRPM3 in the transduction of pruritus and pain by investigating itch- and nociception-related behavior of Trpm3+/+ and Trpm3-/- mice, and by studying the activation of somatosensory neurons isolated from trigeminal ganglia upon application of algogenic and pruritogenic substances. Activators of TRPM3 evoked only nocifensive responses, but not itch in Trpm3+/+ animals, and these nocifensive responses were abolished in the Trpm3-/- strain. Histamine and endogenous non-histaminergic pruritogens induced itch in both Trpm3+/+ and Trpm3-/- mice to a similar extent. Genetic deletion or pharmacological blockade diminished TRPM3 mediated Ca2+ responses of sensory neurons, but did not affect responses evoked by pruritogenic substances. Our results demonstrate that, in contrast to other thermosensitive TRP channels, TRPM3 selectively mediates nociception, but not itch sensation, and suggest that TRPM3 is a promising candidate to selectively target pain sensation.
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Affiliation(s)
- Balázs Kelemen
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Laboratory of Ion Channel Research (VIB-KU Leuven Center for Brain & Disease Research) Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Silvia Pinto
- Laboratory of Ion Channel Research (VIB-KU Leuven Center for Brain & Disease Research) Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Nawoo Kim
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Erika Lisztes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Martin Hanyicska
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Anita Vládar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Attila Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zsófia Pénzes
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Brian Shu
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Joris Vriens
- Laboratory of Endometrium, Endometriosis and Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Tamás Bíró
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tibor Rohács
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Thomas Voets
- Laboratory of Ion Channel Research (VIB-KU Leuven Center for Brain & Disease Research) Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Balázs István Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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4
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Lomba LA, Cruz JV, Coelho LCM, Leite-Avalca MCG, Correia D, Zampronio AR. Role of central endothelin-1 in hyperalgesia, anhedonia, and hypolocomotion induced by endotoxin in male rats. Exp Brain Res 2020; 239:267-277. [PMID: 33145614 DOI: 10.1007/s00221-020-05929-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/16/2020] [Indexed: 10/23/2022]
Abstract
Sickness syndrome is an adaptive response that can be distinguished by specific signs and symptoms, such as fever and generalized hyperalgesia. Endothelin-1 (ET-1) is produced by inflammatory stimuli, including lipopolysaccharide, and involved in the pathogenesis of inflammation and pain by acting through ETA and ETB receptors. ET-1 also induces fever by acting on the central nervous system. The present study investigated the role of ET-1 in sickness syndrome responses, including hyperalgesia, anhedonia, and hypolocomotion. Intracerebroventricular ET-1 administration induced mechanical and thermal hyperalgesia in rats, which was ameliorated by the ETA receptor antagonist BQ123 and exacerbated by the ETB receptor antagonist BQ788. A cyclooxygenase blocker did not alter hyperalgesia that was induced by ET-1. Lipopolysaccharide administration induced hyperalgesia, and both BQ123 and BQ788 abolished this mechanical hyperalgesia, but the thermal response was only partially blocked. The blockade of ETA receptors in the hypothalamus also abolished lipopolysaccharide-induced mechanical hyperalgesia, and the ETB receptor antagonist did not influence this response. Lipopolysaccharide also induced anhedonia, reflected by lower sucrose preference, and reduced locomotor activity. Both antagonists restored locomotor activity, but only BQ788 reversed the reduction of sucrose preference. These results indicate that ET-1 and both ETA and ETB receptors are involved in various responses that are related to sickness syndrome, including hyperalgesia, anhedonia, and hypolocomotion, that is induced by LPS. Hypothalamic ETA but not ETB receptors are involved in mechanical hyperalgesia that is observed during lipopolysaccharide-induced sickness syndrome.
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Affiliation(s)
- Luís Alexandre Lomba
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
| | - Juliana Varella Cruz
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
| | | | | | - Diego Correia
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil
| | - Aleksander Roberto Zampronio
- Department of Pharmacology, Federal University of Paraná, Centro Politécnico, PO Box 19031, Curitiba, PR, 81531-980, Brazil.
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5
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Mason BN, Wattiez AS, Balcziak LK, Kuburas A, Kutschke WJ, Russo AF. Vascular actions of peripheral CGRP in migraine-like photophobia in mice. Cephalalgia 2020; 40:1585-1604. [PMID: 32811179 DOI: 10.1177/0333102420949173] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND Calcitonin gene-related peptide is recognized as a key player in migraine, yet the mechanisms and sites of calcitonin gene-related peptide action remain unknown. The efficacy of calcitonin gene-related peptide-blocking antibodies as preventative migraine drugs supports a peripheral site of action, such as the trigeminovasculature. Given the apparent disconnect between the importance of vasodilatory peptides in migraine and the prevailing opinion that vasodilation is an epiphenomenon, the goal of this study was to test whether vasodilation plays a role in calcitonin gene-related peptide-induced light aversive behavior in mice. METHODS Systemic mean arterial pressure and light aversive behavior were measured after intraperitoneal administration of calcitonin gene-related peptide and vasoactive intestinal peptide in wild-type CD1 mice. The functional significance of vasodilation was tested by co-administration of a vasoconstrictor (phenylephrine, endothelin-1, or caffeine) with calcitonin gene-related peptide to normalize blood pressure during the light aversion assay. RESULTS Both calcitonin gene-related peptide and vasoactive intestinal peptide induced light aversion that was associated with their effect on mean arterial pressure. Notably, vasoactive intestinal peptide caused relatively transient vasodilation and light aversion. Calcitonin gene-related peptide-induced light aversion was still observed even with normalized blood pressure. However, two of the agents, endothelin-1 and caffeine, did reduce the magnitude of light aversion. CONCLUSION We propose that perivascular calcitonin gene-related peptide causes light-aversive behavior in mice by both vasomotor and non-vasomotor mechanisms.
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Affiliation(s)
- Bianca N Mason
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.,Brain and Behavior Sciences, Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, USA
| | - Anne-Sophie Wattiez
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.,Center for the Prevention and Treatment of Visual Loss, Veterans Administration Health Center, Iowa City, IA, USA
| | - Louis K Balcziak
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.,Neuroscience Program, University of Iowa, Iowa City, IA, USA
| | - Adisa Kuburas
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - William J Kutschke
- Division of Cardiovascular Medicine, Department of Internal Medicine and Francois M Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA, USA
| | - Andrew F Russo
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.,Center for the Prevention and Treatment of Visual Loss, Veterans Administration Health Center, Iowa City, IA, USA.,Department of Neurology, University of Iowa, Iowa City, IA, USA
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6
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Kopruszinski CM, dos Reis RC, Rae GA, Chichorro JG. Blockade of peripheral endothelin receptors abolishes heat hyperalgesia and spontaneous nociceptive behavior in a rat model of facial cancer. Arch Oral Biol 2019; 97:231-237. [DOI: 10.1016/j.archoralbio.2018.10.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 10/30/2018] [Accepted: 10/31/2018] [Indexed: 12/27/2022]
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7
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Tai LW, Pan Z, Sun L, Li H, Gu P, Wong SSC, Chung SK, Cheung CW. Suppression of Pax2 Attenuates Allodynia and Hyperalgesia through ET-1-ETAR-NFAT5 Signaling in a Rat Model of Neuropathic Pain. Neuroscience 2018; 384:139-151. [PMID: 29847776 DOI: 10.1016/j.neuroscience.2018.05.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 01/16/2023]
Abstract
Endothelin-1 (ET-1) and its receptors (ETAR/ETBR) emerge to be a key signaling axis in neuropathic pain processing and are recognized as new therapeutic targets. Yet, little is known on the functional regulation of ET-1 axis during neuropathic pain. Bioinformatics analysis indicated that paired box gene 2 (Pax2) or nuclear factor of activated T-cells 5 (NFAT5), two transcription factors involved in the modulation of neurotransmission, may regulate ET-1. Therefore, we hypothesized that ET-1 axis may be regulated by Pax2 or NFAT5 in the development of neuropathic pain. After partial sciatic nerve ligation (pSNL), rats displayed allodynia and hyperalgesia, which was associated with increased mRNA and protein expressions of spinal Pax2, NFAT5, and mRNA levels of ET-1 and ETAR, but not ETBR. Knockdown of Pax2 or NFAT5 with siRNA, or inhibition of ETAR with BQ-123 attenuated pSNL-induced pain-like behaviors. At molecular level, Pax2 siRNA, but not NFAT5 siRNA, downregulated ET-1 and ETAR, while ETAR inhibitor reduced NFAT5, indicating Pax2 in the upstream of ET-1 axis with NFAT5 in the downstream. Further, suppression of Pax2 (inhibiting ET-1) or impairment of ET-1 signaling (inhibition of ETAR and/or decrease of NFAT5) deactivated mitogen-activated protein kinases (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways, supporting the significance of functional regulation of ET-1 axis in neuropathic pain signaling. These findings demonstrate that Pax2 targeting ET-1-ETAR-NFAT5 is a novel regulatory mechanism underlying neuropathic pain.
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Affiliation(s)
- Lydia Wai Tai
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China; Laboratory and Clinical Research Institute for Pain, The University of Hong Kong, Hong Kong, China
| | - Zhiqiang Pan
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China; Laboratory and Clinical Research Institute for Pain, The University of Hong Kong, Hong Kong, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China
| | - Liting Sun
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China; Laboratory and Clinical Research Institute for Pain, The University of Hong Kong, Hong Kong, China
| | - Haobo Li
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China
| | - Pan Gu
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China; Laboratory and Clinical Research Institute for Pain, The University of Hong Kong, Hong Kong, China
| | - Stanley Sau Ching Wong
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China; Laboratory and Clinical Research Institute for Pain, The University of Hong Kong, Hong Kong, China
| | - Sookja K Chung
- Laboratory and Clinical Research Institute for Pain, The University of Hong Kong, Hong Kong, China; School of Biomedical Sciences, Hormone and Healthy Aging, The University of Hong Kong, Hong Kong, China; Research Center of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong, Hong Kong, China
| | - Chi Wai Cheung
- Department of Anaesthesiology, The University of Hong Kong, Hong Kong, China; Laboratory and Clinical Research Institute for Pain, The University of Hong Kong, Hong Kong, China.
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Blockade of endothelin receptors reduces tumor-induced ongoing pain and evoked hypersensitivity in a rat model of facial carcinoma induced pain. Eur J Pharmacol 2018; 818:132-140. [DOI: 10.1016/j.ejphar.2017.10.045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 12/11/2022]
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9
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Mule NK, Singh JN, Shah KU, Gulati A, Sharma SS. Endothelin-1 Decreases Excitability of the Dorsal Root Ganglion Neurons via ET B Receptor. Mol Neurobiol 2017. [PMID: 28623618 DOI: 10.1007/s12035-017-0640-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Endothelin-1 (ET-1) has been demonstrated to be a pro-nociceptive as well as an anti-nociceptive agent. However, underlying molecular mechanisms for these pain modulatory actions remain unclear. In the present study, we evaluated the ability of ET-1 to alter the nociceptor excitability using a patch clamp technique in acutely dissociated rat dorsal root ganglion (DRG) neurons. ET-1 produced an increase in threshold current to evoke an action potential (I threshold) and hyperpolarization of resting membrane potential (RMP) indicating decreased excitability of DRG neurons. I threshold increased from 0.25 ± 0.08 to 0.33 ± 0.07 nA and hyperpolarized RMP from -57.51 ± 1.70 to -67.41 ± 2.92 mV by ET-1 (100 nM). The hyperpolarizing effect of ET-1 appears to be orchestrated via modulation of membrane conductances, namely voltage-gated sodium current (I Na) and outward transient potassium current (I KT). ET-1, 30 and 100 nM, decreased the peak I Na by 41.3 ± 6.8 and 74 ± 15.2%, respectively. Additionally, ET-1 (100 nM) significantly potentiated the transient component (I KT) of the potassium currents. ET-1-induced effects were largely attenuated by BQ-788, a selective ETBR blocker. However, a selective ETAR blocker BQ-123 did not alter the effects of ET-1. A selective ETBR agonist, IRL-1620, mimicked the effect of ET-1 on I Na in a concentration-dependent manner (IC50 159.5 ± 92.6 μM). In conclusion, our results demonstrate that ET-1 hyperpolarizes nociceptors by blocking I Na and potentiating I KT through selective activation of ETBR, which may represent one of the underlying mechanisms for reported anti-nociceptive effects of ET-1.
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Affiliation(s)
- Nandkishor K Mule
- Electrophysiology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab, 160062, India
| | - Jitendra N Singh
- Electrophysiology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab, 160062, India.
| | - Kunal U Shah
- Electrophysiology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab, 160062, India
| | - Anil Gulati
- Department of Pharmaceutical Sciences, Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, 60515, USA
| | - Shyam S Sharma
- Electrophysiology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab, 160062, India.
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10
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Akiyama T, Nagamine M, Davoodi A, Iodi Carstens M, Cevikbas F, Steinhoff M, Carstens E. Intradermal endothelin-1 excites bombesin-responsive superficial dorsal horn neurons in the mouse. J Neurophysiol 2015; 114:2528-34. [PMID: 26311187 DOI: 10.1152/jn.00723.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 08/24/2015] [Indexed: 01/21/2023] Open
Abstract
Endothelin-1 (ET-1) has been implicated in nonhistaminergic itch. Here we used electrophysiological methods to investigate whether mouse superficial dorsal horn neurons respond to intradermal (id) injection of ET-1 and whether ET-1-sensitive neurons additionally respond to other pruritic and algesic stimuli or spinal superfusion of bombesin, a homolog of gastrin-releasing peptide (GRP) that excites spinal itch-signaling neurons. Single-unit recordings were made from lumbar dorsal horn neurons in pentobarbital-anesthetized C57BL/6 mice. We searched for units that exhibited elevated firing after id injection of ET-1 (1 μg/μl). Responsive units were further tested with mechanical stimuli, bombesin (spinal superfusion, 200 μg·ml(-1)·min(-1)), heating, cooling, and additional chemicals [histamine, chloroquine, allyl isothiocyanate (AITC), capsaicin]. Of 40 ET-1-responsive units, 48% responded to brush and pinch [wide dynamic range (WDR)] and 52% to pinch only [high threshold (HT)]. Ninety-three percent responded to noxious heat, 50% to cooling, and >70% to histamine, chloroquine, AITC, and capsaicin. Fifty-seven percent responded to bombesin, suggesting that they participate in spinal itch transmission. That most ET-1-sensitive spinal neurons also responded to pruritic and algesic stimuli is consistent with previous studies of pruritogen-responsive dorsal horn neurons. We previously hypothesized that pruritogen-sensitive neurons signal itch. The observation that ET-1 activates nociceptive neurons suggests that both itch and pain signals may be generated by ET-1 to result in simultaneous sensations of itch and pain, consistent with observations that ET-1 elicits both itch- and pain-related behaviors in animals and burning itch sensations in humans.
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Affiliation(s)
- T Akiyama
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | - M Nagamine
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | - A Davoodi
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | - M Iodi Carstens
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California
| | - F Cevikbas
- Departments of Dermatology and Surgery, University of California, San Francisco, California; and
| | - M Steinhoff
- Department of Dermatology and Charles Institute for Translational Dermatology, University College Dublin, Dublin, Ireland
| | - E Carstens
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California;
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11
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12
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Kim YO, Kim IJ, Yoon MH. Antiallodynic effect through spinal endothelin-B receptor antagonism in rat models of complex regional pain syndrome. Neurosci Lett 2014; 584:45-9. [PMID: 25451723 DOI: 10.1016/j.neulet.2014.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Revised: 09/21/2014] [Accepted: 10/06/2014] [Indexed: 10/24/2022]
Abstract
Complex regional pain syndrome (CRPS) is a very complicated chronic pain disorder that has been classified into two types (I and II). Endothelin (ET) receptors are involved in pain conditions at the spinal level. We investigated the role of spinal ET receptors in CRPS. Chronic post-ischemia pain (CPIP) was induced in male Sprague-Dawley rats as a model for CRPS-I by placing a tourniquet (O-ring) at the ankle joint for 3h, and removing it to allow reperfusion. Ligation of L5 and L6 spinal nerves to induce neuropathic pain was performed as a model for CRPS-II. After O-ring application and spinal nerve ligation, the paw withdrawal threshold was significantly decreased at injured sites. Intrathecal administration of the selective ET-B receptor antagonist BQ 788 dose-dependently increased the withdrawal threshold in both CRPS-I and CRPS-II. In contrast, ET-A receptor antagonist BQ 123 did not affect the withdrawal threshold in either CRPS type. The ET-1 levels of plasma and spinal cord increased in both CRPS types. Intrathecal BQ 788 decreased the spinal ET-1 level. These results suggest that ET-1 is involved in the development of mechanical allodynia in CRPS. Furthermore, the ET-B receptor appears to be involved in spinal cord-related CRPS.
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Affiliation(s)
- Yeo Ok Kim
- Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, South Korea
| | - In Ji Kim
- Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, South Korea
| | - Myung Ha Yoon
- Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, South Korea; Center for Creative Biomedical Scientists at Chonnam National University, Gwangju, South Korea.
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Hung VK, Tai LW, Qiu Q, Luo X, Wong K, Chung SK, Cheung C. Over-expression of astrocytic ET-1 attenuates neuropathic pain by inhibition of ERK1/2 and Akt(s) via activation of ETA receptor. Mol Cell Neurosci 2014; 60:26-35. [DOI: 10.1016/j.mcn.2014.02.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 01/28/2014] [Accepted: 02/21/2014] [Indexed: 12/13/2022] Open
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Abstract
The global burden of cancer pain is enormous and opioids, despite their side effects, remain the primary therapeutic approach. The cause of cancer pain is unknown. Mechanisms driving cancer pain differ from those mechanisms responsible for inflammatory and neuropathic pain. The prevailing hypothesis put forward to explain cancer pain posits that cancers generate and secrete mediators which sensitize and activate primary afferent nociceptors in the cancer microenvironment. Moreover, cancers induce neurochemical reorganization of the spinal cord, which contributes to spontaneous activity and enhanced responsiveness. The purpose of this review, which covers clinical and preclinical studies, is to highlight those peripheral and central mechanisms responsible for cancer pain. The challenges facing neuroscientists and clinicians studying and ultimately treating cancer pain are discussed.
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Affiliation(s)
- Brian L Schmidt
- Department of Oral Maxillofacial Surgery, New York University College of Dentistry, New York, NY, USA Department of Neuroscience & Physiology, New York University School of Medicine, New York, NY, USA Bluestone Center for Clinical Research, New York University, NY, USA
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15
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He L, Üçeyler N, Krämer HH, Colaço MN, Lu B, Birklein F, Sommer C. Methylprednisolone prevents nerve injury-induced hyperalgesia in neprilysin knockout mice. Pain 2013; 155:574-580. [PMID: 24333776 DOI: 10.1016/j.pain.2013.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 11/16/2013] [Accepted: 12/04/2013] [Indexed: 10/25/2022]
Abstract
The pathophysiology of the complex regional pain syndrome involves enhanced neurogenic inflammation mediated by neuropeptides. Neutral endopeptidase (neprilysin, NEP) is a key enzyme in neuropeptide catabolism. Our previous work revealed that NEP knock out (ko) mice develop more severe hypersensitivity to thermal and mechanical stimuli after chronic constriction injury (CCI) of the sciatic nerve than wild-type (wt) mice. Because treatment with glucocorticoids is effective in early complex regional pain syndrome, we investigated whether methylprednisolone (MP) reduces pain and sciatic nerve neuropeptide content in NEP ko and wt mice with nerve injury. After CCI, NEP ko mice developed more severe thermal and mechanical hypersensitivity and hind paw edema than wt mice, confirming previous findings. Hypersensitivity was prevented by MP treatment in NEP ko but not in wt mice. MP treatment had no effect on protein levels of calcitonin-gene related peptide, substance P, and bradykinin in sciatic nerves of NEP ko mice. Endothelin-1 (ET-1) levels were higher in naïve and nerve-injured NEP ko than in wt mice, without an effect of MP treatment. Gene expression of the ET-1 receptors ETAR and ETBR was not different between genotypes and was not altered after CCI, but was increased after additional MP treatment. The ETBR agonist IRL-1620 was analgesic in NEP ko mice after CCI, and the ETBR antagonist BQ-788 showed a trend to reduce the analgesic effect of MP. The results provide evidence that MP reduces CCI-induced hyperalgesia in NEP ko mice, and that this may be related to ET-1 via analgesic actions of ETBR.
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Affiliation(s)
- Lan He
- Department of Neurology, University Hospital of Würzburg, Würzburg, Germany Department of Neurology, Johannes Gutenberg University Mainz, Mainz, Germany Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
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16
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Effects of repeated central administration of endothelin type A receptor antagonist on the development of neuropathic pain in rats. BIOMED RESEARCH INTERNATIONAL 2013; 2013:529871. [PMID: 24073407 PMCID: PMC3773389 DOI: 10.1155/2013/529871] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/13/2013] [Accepted: 07/26/2013] [Indexed: 11/18/2022]
Abstract
Endothelin-1 (ET-1) predominates in the endothelin family effectively in vascular tone control, mitogenesis, and neuromodulation. Its receptors are widespread in the central nervous system (CNS) associated with endogenous pain control, suggesting an important role of ET-1 in central pain processing. This study aimed to evaluate the effect of central ET-1 on the development of neuropathic pain behaviour by repeated intrathecal administration of endothelin type A receptor (ETAR) antagonist (BQ-123) in a sciatic nerve ligation (SNL) animal model. BQ-123 was administered intrathecally to rats at dosages 15 μg, 20 μg, 25 μg, and 30 μg, daily for 3 days. Mechanical allodynia was assessed daily 30 minutes before/after injection, 1 hour after injection of BQ-123 from post-SNL day 4 to day 6, and once on day 7 (without BQ-123 administration) before rats were sacrificed. Increasing trends of mechanical threshold were observed, and they reached significance at all dosages on post-SNL day 7 (P < 0.05 at dosage 15 μg and P < 0.001 at dosages 20 μg, 25 μg, and 30 μg) in comparison to control group. BQ-123 at dosage 30 μg showed the most stable and significant mechanical threshold rise. Repeated central administration of BQ-123 alleviated mechanical allodynia after SNL. Our results provide insight into the therapeutic strategies, including timing, against neuropathic pain development with ETAR antagonist.
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Yamamoto T, Ono K, Hitomi S, Harano N, Sago T, Yoshida M, Nunomaki M, Shiiba S, Watanabe S, Nakanishi O, Inenaga K. Endothelin receptor-mediated responses in trigeminal ganglion neurons. J Dent Res 2013; 92:335-9. [PMID: 23396520 DOI: 10.1177/0022034513478428] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Recent evidence implicates endothelin in nociception, but it is unclear how endothelin activates trigeminal ganglion (TRG) neurons. In the present study, we investigated the expression of the endothelin receptors ETA and ETB and endothelin-induced responses in rat TRG neurons. Double-immunofluorescence studies demonstrated that ETA and ETB were expressed in TRG neurons and that 26% of ETA- or ETB-expressing neurons expressed both receptors. During whole-cell patch-clamp recording, endothelin-1 enhanced an induced current in response to capsaicin, a TRPV1 agonist, in approximately 20% of dissociated neurons. The enhancement was blocked by the PKC inhibitor chelerythrine and by the ETA antagonist BQ-123, but not by the ETB antagonist BQ-788. Ca(2+)-imaging showed that endothelin-1 increased the intracellular Ca(2+) concentration in more than 20% of the dissociated neurons. Importantly, unlike the effect of endothelin-1 on capsaicin-induced current, the Ca(2+) response was largely suppressed by BQ-788 but not by BQ-123. These results suggest that ETA-mediated TRPV1 hyperactivation via PKC activation and ETB-mediated Ca(2+) mobilization occurs in different subsets of TRG neurons. These endothelin-induced responses may contribute to the induction of orofacial pain. The ETB-mediated function in TRG neurons is a special feature in the trigeminal system because of no ETB expression in dorsal root ganglion neurons.
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Affiliation(s)
- T Yamamoto
- Division of Physiology, Kokurakitaku, Kitakyushu, Japan
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18
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Chen G, Tanabe K, Yanagidate F, Kawasaki Y, Zhang L, Dohi S, Iida H. Intrathecal endothelin-1 has antinociceptive effects in rat model of postoperative pain. Eur J Pharmacol 2012; 697:40-6. [DOI: 10.1016/j.ejphar.2012.09.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Revised: 09/10/2012] [Accepted: 09/22/2012] [Indexed: 01/19/2023]
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19
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Over-expression of endothelin-1 in astrocytes, but not endothelial cells, ameliorates inflammatory pain response after formalin injection. Life Sci 2012; 91:618-22. [DOI: 10.1016/j.lfs.2012.06.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 06/24/2012] [Accepted: 06/28/2012] [Indexed: 10/28/2022]
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20
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Joseph EK, Levine JD. Sexual dimorphism in endothelin-1 induced mechanical hyperalgesia in the rat. Exp Neurol 2011; 233:505-12. [PMID: 22155617 DOI: 10.1016/j.expneurol.2011.11.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Revised: 10/26/2011] [Accepted: 11/22/2011] [Indexed: 01/20/2023]
Abstract
While the onset of mechanical hyperalgesia induced by endothelin-1 was delayed in female rats, compared to males, the duration was much longer. Given that the repeated test stimulus used to assess nociceptive threshold enhances hyperalgesia, a phenomenon we have referred to as stimulus-induced enhancement of hyperalgesia, we also evaluated for sexual dimorphism in the impact of repeated application of the mechanical test stimulus on endothelin-1 hyperalgesia. In male and female rats, endothelin-1 induced hyperalgesia is already maximal at 30 min. At this time stimulus-induced enhancement of hyperalgesia, which is observed only in male rats, persisted for 3-4h. In contrast, in females, it develops only after a very long (15 day) delay, and is still present, without attenuation, at 45 days. Ovariectomy eliminated these differences between male and female rats. These findings suggest marked, ovarian-dependent sexual dimorphism in endothelin-1 induced mechanical hyperalgesia and its enhancement by repeated mechanical stimulation.
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Affiliation(s)
- Elizabeth K Joseph
- Department of Medicine and Oral and Maxillofacial Surgery, University of California, San Francisco, CA 94143-0440, USA
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21
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Pourtau L, Leemburg S, Roux P, Leste-Lasserre T, Costaglioli P, Garbay B, Drutel G, Konsman JP. Hormonal, hypothalamic and striatal responses to reduced body weight gain are attenuated in anorectic rats bearing small tumors. Brain Behav Immun 2011; 25:777-86. [PMID: 21334429 DOI: 10.1016/j.bbi.2011.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 02/01/2011] [Accepted: 02/09/2011] [Indexed: 01/23/2023] Open
Abstract
Lack of compensatory or even reduced food intake is frequently observed in weight-losing cancer patients and contributes to increased morbidity and mortality. Our previous work has shown increased transcription factor expression in the hypothalamus and ventral striatum of anorectic rats bearing small tumors. mRNA expression of molecules known to be involved in pathways regulating appetite in these structures was therefore assessed in this study. Given that pain, pro-inflammatory cytokines and metabolic hormones can modify food intake, spinal cord cellular activation patterns and plasma concentrations of cytokines and hormones were also studied. Morris hepatoma 7777 cells injected subcutaneously in Buffalo rats provoked a 10% lower body weight and 15% reduction in food intake compared to free-feeding tumor-free animals 4 weeks later when the tumor represented 1-2% of body mass. No differences in spinal cord activation patterns or plasma concentration of pro-inflammatory cytokines were observed between groups. However, the changes in plasma ghrelin and leptin concentrations found in food-restricted weight-matched rats in comparison to ad libitum-fed animals did not occur in anorectic tumor-bearing animals. Real-time PCR showed that tumor-bearing rats did not display the increase in hypothalamic agouti-related peptide mRNA observed in food-restricted weight-matched animals. In addition, microarray analysis and real-time PCR revealed increased ventral striatal prostaglandin D synthase expression in food-restricted animals compared to anorectic tumor-bearing rats. These findings indicate that blunted hypothalamic AgRP mRNA expression, probably as a consequence of relatively high leptin and low ghrelin concentrations, and reduced ventral striatal prostaglandin D synthesis play a role in maintaining cancer-associated anorexia.
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Affiliation(s)
- Line Pourtau
- CNRS UMR 5226-INRA 1286, Université de Bordeaux, France
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Abstract
Over two decades of research have demonstrated that the peptide hormone endothelin-1 (ET-1) plays multiple, complex roles in cardiovascular, neural, pulmonary, reproductive, and renal physiology. Differential and tissue-specific production of ET-1 must be tightly regulated in order to preserve these biologically diverse actions. The primary mechanism thought to control ET-1 bioavailability is the rate of transcription from the ET-1 gene (edn1). Studies conducted on a variety of cell types have identified key transcription factors that govern edn1 expression. With few exceptions, the cis-acting elements bound by these factors have been mapped in the edn1 regulatory region. Recent evidence has revealed new roles for some factors originally believed to regulate edn1 in a tissue or hormone-specific manner. In addition, other mechanisms involved in epigenetic regulation and mRNA stability have emerged as important processes for regulated edn1 expression. The goal of this review is to provide a comprehensive overview of the specific factors and signaling systems that govern edn1 activity at the molecular level.
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Affiliation(s)
- Lisa R Stow
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA
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Hoffmann RR, Yurgel LS, Campos MM. Endothelins and their receptors as biological markers for oral cancer. Oral Oncol 2010; 46:644-7. [PMID: 20656542 DOI: 10.1016/j.oraloncology.2010.06.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 06/24/2010] [Accepted: 06/25/2010] [Indexed: 12/20/2022]
Abstract
Oral squamous cell carcinoma (OSCC) is one of the most common malignancies recognized nowadays, and represents a public health problem. Its early detection is the better alternative to provide a good quality of life for the patients. During the last years, several studies have identified potential biomarkers of OSCC progression and prognosis. Endothelins and their receptors are involved in several pathophysiological conditions and in various cancer types. The present review article discusses whether the endothelin system would represent a biomarker for OSCC.
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Affiliation(s)
- Renata R Hoffmann
- Postgraduate Program of Dental College, PUCRS, Pontifícia Universidade Católica do Rio Grande do Sul, Partenon, Porto Alegre, Brazil
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Fu LW, Guo ZL, Longhurst JC. Endogenous endothelin stimulates cardiac sympathetic afferents during ischaemia. J Physiol 2010; 588:2473-86. [PMID: 20442267 DOI: 10.1113/jphysiol.2010.188730] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Myocardial ischaemia activates cardiac sympathetic afferents leading to chest pain and reflex cardiovascular responses. Previous studies have shown that a brief period of myocardial ischaemia increases endothelin in cardiac venous plasma draining ischaemic myocardium and that exogenous endothelin excites cutaneous group III and IV sensory nerve fibres. The present study tested the hypothesis that endogenous endothelin stimulates cardiac afferents during ischaemia through direct activation of endothelin A receptors (ET(A)Rs). Nerve activity of single unit cardiac sympathetic afferents was recorded from the left sympathetic chain or rami communicates (T(2)-T(5)) in anaesthetized cats. Single fields of 38 afferents (CV = 0.25-3.86 m s(-1)) were identified in the left or right ventricle with a stimulating electrode. Five minutes of myocardial ischaemia stimulated all 38 cardiac afferents (8 Adelta, 30 C-fibres) and the responses of these 38 afferents to chemical stimuli were further studied in the following protocols. In the first protocol, injection of endothelin 1 (ET-1, 1, 2 and 4 microg) into the left atrium (LA) stimulated seven ischaemically sensitive cardiac afferents in a dose-dependent manner. Second, BQ-123, a selective ET(A)R antagonist, abolished the responses of nine afferents to 2 microg of ET-1 injected into the left atrium and attenuated the ischaemia-related increase in activity of eight other afferents by 51%. In contrast, blockade of ET(B) receptors caused inconsistent responses to exogenous ET-1 as well as to ischaemia. Furthermore, in the absence of ET(A)R blockade, cardiac afferents responded consistently to repeated administration of ET-1 (n = 7) and to recurrent myocardial ischaemia (n = 7). Finally, using an immunocytochemical staining approach, we observed that ET(A) receptors were expressed in cardiac sensory neurons in thoracic dorsal root ganglia. Taken together, these data indicate that endogenous endothelin contributes to activation of cardiac afferents during myocardial ischaemia through direct stimulation of ET(A) receptors likely to be located in the cardiac sensory nervous system.
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Affiliation(s)
- Liang-Wu Fu
- Department of Medicine, School of Medicine, University of California, Irvine, CA 92697, USA.
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Yaksh TL. The Pain State Arising From the Laminitic Horse: Insights Into Future Analgesic Therapies. J Equine Vet Sci 2010. [DOI: 10.1016/j.jevs.2010.01.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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