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Popescu GDA, Scheau C, Badarau IA, Dumitrache MD, Caruntu A, Scheau AE, Costache DO, Costache RS, Constantin C, Neagu M, Caruntu C. The Effects of Capsaicin on Gastrointestinal Cancers. Molecules 2020; 26:molecules26010094. [PMID: 33379302 PMCID: PMC7794743 DOI: 10.3390/molecules26010094] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 12/11/2022] Open
Abstract
Gastrointestinal (GI) cancers are a group of diseases with very high positions in the ranking of cancer incidence and mortality. While they show common features regarding the molecular mechanisms involved in cancer development, organ-specific pathophysiological processes may trigger distinct signaling pathways and intricate interactions with inflammatory cells from the tumoral milieu and mediators involved in tumorigenesis. The treatment of GI cancers is a topic of increasing interest due to the severity of these diseases, their impact on the patients' survivability and quality of life, and the burden they set on the healthcare system. As the efficiency of existing drugs is hindered by chemoresistance and adverse reactions when administered in high doses, new therapies are sought, and emerging drugs, formulations, and substance synergies are the focus of a growing number of studies. A class of chemicals with great potential through anti-inflammatory, anti-oxidant, and anti-tumoral effects is phytochemicals, and capsaicin in particular is the subject of intensive research looking to validate its position in complementing cancer treatment. Our paper thoroughly reviews the available scientific evidence concerning the effects of capsaicin on major GI cancers and its interactions with the molecular pathways involved in the course of these diseases.
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Affiliation(s)
| | - Cristian Scheau
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (I.A.B.); (C.C.)
- Correspondence:
| | - Ioana Anca Badarau
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (I.A.B.); (C.C.)
| | - Mihai-Daniel Dumitrache
- Departament of Pneumology IV, “Marius Nasta” Institute of Pneumophtysiology, 050159 Bucharest, Romania;
| | - Ana Caruntu
- Department of Oral and Maxillofacial Surgery, “Carol Davila” Central Military Emergency Hospital, 010825 Bucharest, Romania;
- Department of Preclinical Sciences, Faculty of Medicine, “Titu Maiorescu” University, 031593 Bucharest, Romania
| | - Andreea-Elena Scheau
- Department of Radiology and Medical Imaging, Fundeni Clinical Institute, 022328 Bucharest, Romania;
| | - Daniel Octavian Costache
- Department of Dermatology, “Carol Davila” Central Military Emergency Hospital, 010825 Bucharest, Romania;
| | - Raluca Simona Costache
- Gastroenterology and Internal Medicine Clinic, “Carol Davila” Central Military Emergency Hospital, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania;
| | - Carolina Constantin
- Immunology Department, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania; (C.C.); (M.N.)
- Department of Pathology, Colentina University Hospital, 020125 Bucharest, Romania
| | - Monica Neagu
- Immunology Department, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania; (C.C.); (M.N.)
- Department of Pathology, Colentina University Hospital, 020125 Bucharest, Romania
- Faculty of Biology, University of Bucharest, 76201 Bucharest, Romania
| | - Constantin Caruntu
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania; (I.A.B.); (C.C.)
- Department of Dermatology, Prof. N.C. Paulescu National Institute of Diabetes, Nutrition and Metabolic Diseases, 011233 Bucharest, Romania
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Pearce LV, Ann J, Blumberg PM, Lee J. Combination of a Rapidly Penetrating Agonist and a Slowly Penetrating Antagonist Affords Agonist Action of Limited Duration at the Cellular Level. Biomol Ther (Seoul) 2019; 27:435-441. [PMID: 31302951 PMCID: PMC6720535 DOI: 10.4062/biomolther.2019.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/15/2019] [Accepted: 03/18/2019] [Indexed: 11/21/2022] Open
Abstract
The capsaicin receptor TRPV1 (transient receptor potential vanilloid 1) has been an object of intense interest for pharmacological development on account of its critical role in nociception. In the course of structure activity analysis, it has become apparent that TRPV1 ligands may vary dramatically in the rates at which they interact with TRPV1, presumably reflecting differences in their abilities to penetrate into the cell. Using a fast penetrating agonist together with an excess of a slower penetrating antagonist, we find that we can induce an agonist response of limited duration and, moreover, the duration of the agonist response remains largely independent of the absolute dose of agonist, as long as the ratio of antagonist to agonist is held constant. This general approach for limiting agonist duration under conditions in which absolute agonist dose is variable should have more general applicability.
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Affiliation(s)
- Larry V Pearce
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892-4255, USA
| | - Jihyae Ann
- Laboratory of Medicinal Chemistry, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892-4255, USA
| | - Jeewoo Lee
- Laboratory of Medicinal Chemistry, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
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3
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A Convenient Synthesis of 5′-Iodoresiniferatoxin (I-RTX). Nat Prod Commun 2019. [DOI: 10.1177/1934578x0600101215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Starting from resiniferonol orthophenylacetate (ROPA, 2) and commercial 5-iodovanillin (5a), a convenient synthesis of the ultrapotent vanilloid antagonist 5′-iodoresiniferatoxin (1a) was achieved, overcoming the problems involved in the direct iodination of either resiniferatoxin (1b) or homovanillic acid (3a).
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Pearce LV, Ann J, Jung A, Thorat SA, Herold BKA, Habtemichael AD, Blumberg PM, Lee J. Novel Radiolabeled Vanilloid with Enhanced Specificity for Human Transient Receptor Potential Vanilloid 1 (TRPV1). J Med Chem 2017; 60:8246-8252. [PMID: 28892388 DOI: 10.1021/acs.jmedchem.7b00859] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Transient receptor potential vanilloid 1 (TRPV1) has emerged as a promising therapeutic target. While radiolabeled resiniferatoxin (RTX) has provided a powerful tool for characterization of vanilloid binding to TRPV1, TRPV1 shows 20-fold weaker binding to the human TRPV1 than to the rodent TRPV1. We now describe a tritium radiolabeled synthetic vanilloid antagonist, 1-((2-(4-(methyl-[3H])piperidin-1-yl-4-[3H])-6-(trifluoromethyl)pyridin-3-yl)methyl)-3-(3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazin-8-yl)urea ([3H]MPOU), that embodies improved absolute affinity for human TRPV1 and improved synthetic accessibility.
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Affiliation(s)
- Larry V Pearce
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH , Bethesda, Maryland 20892-4255, United States
| | - Jihyae Ann
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 08826, Republic of Korea
| | - Aeran Jung
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 08826, Republic of Korea
| | - Shivaji A Thorat
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 08826, Republic of Korea
| | - Brienna K A Herold
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH , Bethesda, Maryland 20892-4255, United States
| | - Amelework D Habtemichael
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH , Bethesda, Maryland 20892-4255, United States
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH , Bethesda, Maryland 20892-4255, United States
| | - Jeewoo Lee
- Laboratory of Medicinal Chemistry, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University , Seoul 08826, Republic of Korea
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Pecze L, Viskolcz B, Oláh Z. Molecular Surgery Concept from Bench to Bedside: A Focus on TRPV1+ Pain-Sensing Neurons. Front Physiol 2017. [PMID: 28626428 PMCID: PMC5455100 DOI: 10.3389/fphys.2017.00378] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
"Molecular neurosurgery" is emerging as a new medical concept, and is the combination of two partners: (i) a molecular neurosurgery agent, and (ii) the cognate receptor whose activation results in the selective elimination of a specific subset of neurons in which this receptor is endogenously expressed. In general, a molecular surgery agent is a selective and potent ligand, and the target is a specific cell type whose elimination is desired through the molecular surgery procedure. These target cells have the highest innate sensitivity to the molecular surgery agent usually due to the highest receptor density being in their plasma membrane. The interaction between the ligand and its receptor evokes an overactivity of the receptor. If the receptor is a ligand-activated non-selective cation channel, the overactivity of receptor leads to excess Ca2+ and Na+ influx into the cell and finally cell death. One of the best known examples of such an interaction is the effect of ultrapotent vanilloids on TRPV1-expressing pain-sensing neurons. One intrathecal resiniferatoxin (RTX) dose allows for the receptor-mediated removal of TRPV1+ neurons from the peripheral nervous system. The TRPV1 receptor-mediated ion influx induces necrotic processes, but only in pain-sensing neurons, and usually within an hour. Besides that, target-specific apoptotic processes are also induced. Thus, as a nano-surgery scalpel, RTX removes the neurons responsible for generating pain and inflammation from the peripheral nervous system providing an option in clinical management for the treatment of morphine-insensitive pain conditions. In the future, the molecular surgery concept can also be exploited in cancer research for selectively targeting the specific tumor cell.
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Affiliation(s)
- László Pecze
- Unit of Anatomy, Department of Medicine, University of FribourgFribourg, Switzerland
| | - Béla Viskolcz
- Institute of Chemistry, Faculty of Materials Science and Engineering, University of MiskolcMiskolc, Hungary
| | - Zoltán Oláh
- Institute of Chemistry, Faculty of Materials Science and Engineering, University of MiskolcMiskolc, Hungary.,Acheuron Ltd.Szeged, Hungary
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Monastyrnaya M, Peigneur S, Zelepuga E, Sintsova O, Gladkikh I, Leychenko E, Isaeva M, Tytgat J, Kozlovskaya E. Kunitz-Type Peptide HCRG21 from the Sea Anemone Heteractis crispa Is a Full Antagonist of the TRPV1 Receptor. Mar Drugs 2016; 14:E229. [PMID: 27983679 PMCID: PMC5192466 DOI: 10.3390/md14120229] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/06/2016] [Accepted: 12/12/2016] [Indexed: 12/18/2022] Open
Abstract
Sea anemone venoms comprise multifarious peptides modulating biological targets such as ion channels or receptors. The sequence of a new Kunitz-type peptide, HCRG21, belonging to the Heteractis crispa RG (HCRG) peptide subfamily was deduced on the basis of the gene sequence obtained from the Heteractis crispa cDNA. HCRG21 shares high structural homology with Kunitz-type peptides APHC1-APHC3 from H. crispa, and clusters with the peptides from so named "analgesic cluster" of the HCGS peptide subfamily but forms a separate branch on the NJ-phylogenetic tree. Three unique point substitutions at the N-terminus of the molecule, Arg1, Gly2, and Ser5, distinguish HCRG21 from other peptides of this cluster. The trypsin inhibitory activity of recombinant HCRG21 (rHCRG21) was comparable with the activity of peptides from the same cluster. Inhibition constants for trypsin and α-chymotrypsin were 1.0 × 10-7 and 7.0 × 10-7 M, respectively. Electrophysiological experiments revealed that rHCRG21 inhibits 95% of the capsaicin-induced current through transient receptor potential family member vanilloid 1 (TRPV1) and has a half-maximal inhibitory concentration of 6.9 ± 0.4 μM. Moreover, rHCRG21 is the first full peptide TRPV1 inhibitor, although displaying lower affinity for its receptor in comparison with other known ligands. Macromolecular docking and full atom Molecular Dynamics (MD) simulations of the rHCRG21-TRPV1 complex allow hypothesizing the existence of two feasible, intra- and extracellular, molecular mechanisms of blocking. These data provide valuable insights in the structural and functional relationships and pharmacological potential of bifunctional Kunitz-type peptides.
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Affiliation(s)
- Margarita Monastyrnaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, Leuven B-3000, Belgium.
| | - Elena Zelepuga
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Oksana Sintsova
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Irina Gladkikh
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Elena Leychenko
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Marina Isaeva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, Leuven B-3000, Belgium.
| | - Emma Kozlovskaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
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Hanson SM, Newstead S, Swartz KJ, Sansom MSP. Capsaicin interaction with TRPV1 channels in a lipid bilayer: molecular dynamics simulation. Biophys J 2016; 108:1425-1434. [PMID: 25809255 PMCID: PMC4375533 DOI: 10.1016/j.bpj.2015.02.013] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 01/29/2015] [Accepted: 02/03/2015] [Indexed: 12/18/2022] Open
Abstract
Transient receptor potential vanilloid subtype 1 (TRPV1) is a heat-sensitive ion channel also involved in pain sensation, and is the receptor for capsaicin, the active ingredient of hot chili peppers. The recent structures of TRPV1 revealed putative ligand density within the S1 to S4 voltage-sensor-like domain of the protein. However, questions remain regarding the dynamic role of the lipid bilayer in ligand binding to TRPV1. Molecular dynamics simulations were used to explore behavior of capsaicin in a 1-palmitoyl-2-oleoyl phosphatidylcholine bilayer and with the target S1–S4 transmembrane helices of TRPV1. Equilibrium simulations reveal a preferred interfacial localization for capsaicin. We also observed a capsaicin molecule flipping from the extracellular to the intracellular leaflet, and subsequently able to access the intracellular TRPV1 binding site. Calculation of the potential of mean force (i.e., free energy profile) of capsaicin along the bilayer normal confirms that it prefers an interfacial localization. The free energy profile indicates that there is a nontrivial but surmountable barrier to the flipping of capsaicin between opposing leaflets of the bilayer. Molecular dynamics of the S1–S4 transmembrane helices of the TRPV1 in a lipid bilayer confirm that Y511, known to be crucial to capsaicin binding, has a distribution along the bilayer normal similar to that of the aromatic group of capsaicin. Simulations were conducted of the TRPV1 S1–S4 transmembrane helices in the presence of capsaicin placed in the aqueous phase, in the lipid, or docked to the protein. No stable interaction between ligand and protein was seen for simulations initiated with capsaicin in the bilayer. However, interactions were seen between TRPV1 and capsaicin starting from the cytosolic aqueous phase, and capsaicin remained stable in the majority of simulations from the docked pose. We discuss the significance of capsaicin flipping from the extracellular to the intracellular leaflet and mechanisms of binding site access by capsaicin.
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Affiliation(s)
- Sonya M Hanson
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom; Computational Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York; Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Simon Newstead
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Kenton J Swartz
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
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Innovative polymeric system (IPS) for solvent-free lipophilic drug transdermal delivery via dissolving microneedles. J Control Release 2016; 223:118-125. [DOI: 10.1016/j.jconrel.2015.12.038] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/15/2015] [Accepted: 12/23/2015] [Indexed: 12/16/2022]
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Frank JA, Moroni M, Moshourab R, Sumser M, Lewin GR, Trauner D. Photoswitchable fatty acids enable optical control of TRPV1. Nat Commun 2015; 6:7118. [PMID: 25997690 PMCID: PMC4455067 DOI: 10.1038/ncomms8118] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 04/08/2015] [Indexed: 12/23/2022] Open
Abstract
Fatty acids (FAs) are not only essential components of cellular energy storage and structure, but play crucial roles in signalling. Here we present a toolkit of photoswitchable FA analogues (FAAzos) that incorporate an azobenzene photoswitch along the FA chain. By modifying the FAAzos to resemble capsaicin, we prepare a series of photolipids targeting the Vanilloid Receptor 1 (TRPV1), a non-selective cation channel known for its role in nociception. Several azo-capsaicin derivatives (AzCAs) emerge as photoswitchable agonists of TRPV1 that are relatively inactive in the dark and become active on irradiation with ultraviolet-A light. This effect can be rapidly reversed by irradiation with blue light and permits the robust optical control of dorsal root ganglion neurons and C-fibre nociceptors with precision timing and kinetics not available with any other technique. More generally, we expect that photolipids will find many applications in controlling biological pathways that rely on protein–lipid interactions. Fatty acids are ancient lipids with numerous functions, from metabolic processes as a source of energy to structural and signalling roles within cell membranes. Here, the authors present azobenzene-modified fatty acids and their application as photoswitchable agonists of the Vanilloid Receptor 1.
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Affiliation(s)
- James Allen Frank
- Department of Chemistry and Center for Integrated Protein Science, Ludwig Maximilians University Munich, Butenandtstrasse 5-13, Munich 81377, Germany
| | - Mirko Moroni
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany
| | - Rabih Moshourab
- 1] Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany [2] Department of Anesthesiology, Campus Charité Mitte und Virchow Klinikum, Charité Universitätsmedizin Berlin, Augustburgerplatz 1, Berlin 13353, Germany
| | - Martin Sumser
- Department of Chemistry and Center for Integrated Protein Science, Ludwig Maximilians University Munich, Butenandtstrasse 5-13, Munich 81377, Germany
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin 13125, Germany
| | - Dirk Trauner
- Department of Chemistry and Center for Integrated Protein Science, Ludwig Maximilians University Munich, Butenandtstrasse 5-13, Munich 81377, Germany
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Rudd JA, Nalivaiko E, Matsuki N, Wan C, Andrews PL. The involvement of TRPV1 in emesis and anti-emesis. Temperature (Austin) 2015; 2:258-76. [PMID: 27227028 PMCID: PMC4843889 DOI: 10.1080/23328940.2015.1043042] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/13/2015] [Accepted: 04/16/2015] [Indexed: 12/29/2022] Open
Abstract
Diverse transmitter systems (e.g. acetylcholine, dopamine, endocannabinoids, endorphins, glutamate, histamine, 5-hydroxytryptamine, substance P) have been implicated in the pathways by which nausea and vomiting are induced and are targets for anti-emetic drugs (e.g. 5-hydroxytryptamine3 and tachykinin NK1 antagonists). The involvement of TRPV1 in emesis was discovered in the early 1990s and may have been overlooked previously as TRPV1 pharmacology was studied in rodents (mice, rats) lacking an emetic reflex. Acute subcutaneous administration of resiniferatoxin in the ferret, dog and Suncus murinus revealed that it had “broad–spectrum” anti-emetic effects against stimuli acting via both central (vestibular system, area postrema) and peripheral (abdominal vagal afferents) inputs. One of several hypotheses discussed here is that the anti-emetic effect is due to acute depletion of substance P (or another peptide) at a critical site (e.g. nucleus tractus solitarius) in the central emetic pathway. Studies in Suncus murinus revealed a potential for a long lasting (one month) effect against the chemotherapeutic agent cisplatin. Subsequent studies using telemetry in the conscious ferret compared the anti-emetic, hypothermic and hypertensive effects of resiniferatoxin (pungent) and olvanil (non-pungent) and showed that the anti-emetic effect was present (but reduced) with olvanil which although inducing hypothermia it did not have the marked hypertensive effects of resiniferatoxin. The review concludes by discussing general insights into emetic pathways and their pharmacology revealed by these relatively overlooked studies with TRPV1 activators (pungent an non-pungent; high and low lipophilicity) and antagonists and the potential clinical utility of agents targeted at the TRPV1 system.
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Key Words
- 12-HPETE, 12-hydroperoxy-eicosatetraenoic acid
- 5-HT, 5-hydroxytryptamine
- 5-HT3, 5-hdroxytryptamine3
- 8-OH-DPAT, (±)-8-Hydroxy-2-dipropylaminotetralin
- AM404
- AM404, N-arachidonoylaminophenol
- AMT, anandamide membrane transporter
- AP, area postrema
- BBB, blood brain barrier
- CB1, cannabinoid1
- CGRP, calcitonin gene-related peptide
- CINV, chemotherapy-induced nausea and vomiting
- CP 99,994
- CTA, conditioned taste aversion
- CVO's, circumventricular organs
- D2, dopamine2
- DRG, dorsal root ganglia
- FAAH, fatty acid amide hydrolase
- H1, histamine1
- LTB4, leukotriene B4
- NADA, N-arachidonoyl-dopamine
- NK1, neurokinin1
- POAH, preoptic anterior hypothalamus
- RTX
- Suncus murinus
- TRPV1
- TRPV1, transient receptor potential vanilloid receptor1
- anti-emetic
- capsaicin
- ferret
- i.v., intravenous
- nausea
- olvanil
- thermoregulation
- vanilloid
- vomiting
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Affiliation(s)
- John A Rudd
- Brain and Mind Institute; Chinese University of Hong Kong; Shatin; New Territories, Hong Kong SAR; School of Biomedical Sciences; Faculty of Medicine; Chinese University of Hong Kong; Shatin; New Territories, Hong Kong SAR
| | - Eugene Nalivaiko
- School of Biomedical Sciences and Pharmacy; University of Newcastle ; Callaghan, NSW, Australia
| | - Norio Matsuki
- Laboratory of Chemical Pharmacology; Graduate School of Pharmaceutical Sciences; The University of Tokyo ; Tokyo, Japan
| | - Christina Wan
- School of Biomedical Sciences; Faculty of Medicine; Chinese University of Hong Kong ; Shatin; New Territories, Hong Kong SAR
| | - Paul Lr Andrews
- Division of Biomedical Sciences; St George's University of London ; London, UK
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De Petrocellis L, Schiano Moriello A, Fontana G, Sacchetti A, Passarella D, Appendino G, Di Marzo V. Effect of chirality and lipophilicity in the functional activity of evodiamine and its analogues at TRPV1 channels. Br J Pharmacol 2014; 171:2608-20. [PMID: 23902373 PMCID: PMC4009003 DOI: 10.1111/bph.12320] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 07/18/2013] [Accepted: 07/26/2013] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND AND PURPOSE Evodiamine, a racemic quinazolinocarboline alkaloid isolated from the traditional Chinese medicine Evodiae fructus, has been reported to act as an agonist of the transient receptor potential vanilloid type-1 (TRPV1) cation channel both in vitro and in vivo. Evodiamine is structurally different from all known TRPV1 activators, and has significant clinical potential as a thermogenic agent. Nevertheless, the molecular bases for its actions are still poorly understood. EXPERIMENTAL APPROACH To investigate the structure-activity relationships of evodiamine, the natural racemate was resolved, and a series of 23 synthetic analogues was prepared, using as the end point the intracellular Ca(2+) elevation in HEK-293 cells stably overexpressing either the human or the rat recombinant TRPV1. KEY RESULTS S-(+) evodiamine was more efficacious and potent than R-(-) evodiamine, and a new potent lead (Evo30) was identified, more potent than the reference TRPV1 agonist, capsaicin. In general, potency and efficacy correlated with the lipophilicity of the analogues. Like other TRPV1 agonists, several synthetic analogues could efficiently desensitize TRPV1 to activation by capsaicin. CONCLUSIONS AND IMPLICATIONS Evodiamine qualifies as structurally unique lead structure to develop new potent TRPV1 agonists/desensitizers.
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Affiliation(s)
- Luciano De Petrocellis
- Istituto di Cibernetica, Endocannabinoid Research Group, Consiglio Nazionale delle RicerchePozzuoli, Italy
| | - Aniello Schiano Moriello
- Istituto di Chimica Biomolecolare, Endocannabinoid Research Group, Consiglio Nazionale delle RicerchePozzuoli, Italy
| | | | | | - Daniele Passarella
- Dipartimento di Chimica, Materiali ed Ingegneria Chimica ‘G. Natta’, Politecnico di MilanoMilano, Italy
| | - Giovanni Appendino
- Dipartimento di Scienze Chimiche, Alimentari, Farmaceutiche e Farmacologiche, Università del Piemonte OrientaleNovara, Italy
| | - Vincenzo Di Marzo
- Istituto di Chimica Biomolecolare, Endocannabinoid Research Group, Consiglio Nazionale delle RicerchePozzuoli, Italy
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Zelepuga EA, Tabakmakher VM, Chausova VE, monastyrnaia MM, Isaeva MP, Kozlovskaia ÉP. [Interaction of sea amemone Heteractis crispa Kunitz type polypeptides with pain vanilloid receptor TRPV1: in silico investigation]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2012; 38:185-98. [PMID: 22792722 DOI: 10.1134/s106816201202015x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Using methods of molecular biology we defined the structures of the 31 sea anemone Heteractis crispa genes encoding polypeptides which are structurally homologous to the Kunitz proteinase inhibitor family. Identified amino acid sequences have point residue substitutions, high degree of homology with sequences of known H. crispa Kunitz family members, and represent a combinatorial library of polypeptides. We generated their three-dimensional structures by homologous modeling methods. Analysis of their molecular electrostatic potential enabled us to divide given polypeptides into three clusters. One of them includes polypeptides APHC1, APHC2 and APHC3, which were earlier shown to possess a unique property of inhibiting of the pain vanilloid receptor TRPV1 in vitro and providing the analgesic effects in vivo in addition to their trypsin inhibitory activity. Molecular docking made possible establishing the spatial structure of the complexes, the nature of the polypeptides binding with TRPV1, as well as functionally important structural elements involved in the complex formation. Structural models have enabled us to propose a hypothesis contributing to understanding the APHC1-3 impact mechanism for the pain signals transduction by TRPV1: apparently, there is an increase of the receptor relaxation time resulted in binding of its two chains with the polypeptide molecule, which disrupt the functioning of the TRPV1 and leads to partial inhibition of signal transduction in electrophysiological experiments.
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Blumberg PM, Pearce LV, Lee J. TRPV1 activation is not an all-or-none event: TRPV1 partial agonism/antagonism and its regulatory modulation. Curr Top Med Chem 2012; 11:2151-8. [PMID: 21671879 DOI: 10.2174/156802611796904825] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 10/18/2010] [Indexed: 12/26/2022]
Abstract
TRPV1 has emerged as a promising therapeutic target for pain as well as a broad range of other conditions such as asthma or urge incontinence. The identification of resiniferatoxin as an ultrapotent ligand partially able to dissect the acute activation of TRPV1 from subsequent desensitization and the subsequent intense efforts in medicinal chemistry have revealed that TRPV1 affords a dramatic landscape of opportunities for pharmacological manipulation. While agonism and antagonism have represented the primary directions for drug development, the pharmacological complexity of TRPV1 affords additional opportunities. Partial agonism/partial antagonism, its modulation by signaling pathways, variable desensitization, and slow kinetics of action can all be exploited through drug design.
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Affiliation(s)
- Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892-4255, USA.
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Gal N, Kolusheva S, Kedei N, Telek A, Naeem TA, Lewin NE, Lim L, Mannan P, Garfield SH, El Kazzouli S, Sigano DM, Marquez VE, Blumberg PM, Jelinek R. N-Methyl-Substituted Fluorescent DAG-Indololactone Isomers Exhibit Dramatic Differences in Membrane Interactions and Biological Activity. Chembiochem 2011; 12:2331-40. [DOI: 10.1002/cbic.201100246] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Abstract
This chapter reviews the evidence for "specific" pharmacokinetics playing a role in currently marketed drugs intended to treat lower urinary tract (LUT) symptoms. Principles of drug targeting include intrinsic properties of drugs or organs as well as drug formulations to modify drug release or to create confinement of drug presence. Prodrugs and specific formulations to deliver high drug concentrations at the site(s) of action as well as other ways to manipulate drug distribution to achieve enrichment in target tissues are considered. In overactive bladder (OAB), specific formulations for oxybutynin have been introduced to reduce the level of side effects of the active drug. Extended release tablet formulations and a topical gel formulation have been introduced, with efficacy similar to immediate release (IR) tablets, but with a reduction in anticholinergic adverse effects. However, these modifications have not led to outstanding performance parameters compared to other anticholinergic drugs marketed as IR formulations. Urinary excretion is discussed as potential mechanism for targeting LUT symptoms, but no strong indications appear to exist that this mechanism would contribute for currently available drugs. Intravesical administration of drugs is not a preferred option and only considered for drugs like botulinum toxin, where the inconvenient application compensates for a reasonable degree of long-term efficacy in severe refractory OAB. Alpha acid glycoprotein binding is discussed as a potential factor to influence drug tissue distribution, and it is concluded that there is reasonable evidence that for tamsulosin this mechanism is responsible for the difference in free fraction of the drug observed in plasma and prostate, which could contribute to its relative absence of blood pressure effects in patients with LUT symptoms related to benign prostate hyperplasia (LUTS-BPH). The principle of irreversible inhibition of type II 5α-reductase as a tool to develop drugs to reduce prostatic levels of dihydrotestosterone is employed by both dutasteride and finasteride for treatment of LUTS-BPH. Of the mechanisms discussed, the principles employed for the 5α-reductase blockers and tamsulosin in this respect can be considered relatively specific for its urological indication.
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Tóth BI, Dobrosi N, Dajnoki A, Czifra G, Oláh A, Szöllosi AG, Juhász I, Sugawara K, Paus R, Bíró T. Endocannabinoids modulate human epidermal keratinocyte proliferation and survival via the sequential engagement of cannabinoid receptor-1 and transient receptor potential vanilloid-1. J Invest Dermatol 2011; 131:1095-104. [PMID: 21248768 DOI: 10.1038/jid.2010.421] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have recently shown that lipid mediators of the emerging endocannabinoid system (ECS) are key players of growth control of the human pilosebaceous unit. In this study, we asked whether the prototypic endocannabinoid anandamide (N-arachidonoylethanolamine, AEA) has a role in growth and survival of epidermal keratinocytes (KCs). Using human cultured KCs and skin organ-culture models, and by employing combined pharmacological and molecular approaches, we provide early evidence that AEA markedly suppresses KC proliferation and induces cell death, both in vitro and in situ. Moreover, we present that these cellular actions are mediated by a most probably constitutively active signaling mechanism that involves the activation of the metabotropic cannabinoid receptor CB(1) and a sequential engagement of the "ionotropic cannabinoid receptor" transient receptor potential vanilloid-1 (TRPV1). Finally, we demonstrate that the cellular effects of AEA are most probably due to a Ca(2+) influx via the non-selective, highly Ca(2+)-permeable ion channel TRPV1, and the concomitant elevation of intracellular Ca(2+) concentration. The data reported here may encourage one to explore whether the targeted manipulation of the above signaling pathway of the cutaneous ECS could become a useful adjunct treatment strategy for hyperproliferative human dermatoses such as psoriasis or KC-derived skin tumors.
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Affiliation(s)
- Balázs I Tóth
- Department of Physiology, Medical and Health Science Center, Research Center for Molecular Medicine, University of Debrecen, Debrecen, Hungary
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De Petrocellis L, Guida F, Moriello AS, De Chiaro M, Piscitelli F, de Novellis V, Maione S, Di Marzo V. N-palmitoyl-vanillamide (palvanil) is a non-pungent analogue of capsaicin with stronger desensitizing capability against the TRPV1 receptor and anti-hyperalgesic activity. Pharmacol Res 2011; 63:294-9. [PMID: 21215315 DOI: 10.1016/j.phrs.2010.12.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 12/31/2010] [Accepted: 12/31/2010] [Indexed: 01/22/2023]
Abstract
N-acyl-vanillamide (NAVAM) analogues of the natural pungent principle of capsicum, capsaicin, were developed several years ago as potential non-pungent analgesic compounds. N-oleoyl-vanillamide (olvanil) and N-arachidonoy-vanillamide (arvanil), in particular, were described in several publications and patents to behave as potent anti-hyperalgesic compounds in experimental models of chronic and inflammatory pain, and to activate both "capsaicin receptors", i.e. the transient receptor potential of vanilloid type-1 (TRPV1) channel, and, either directly or indirectly, cannabinoid receptors of type-1. Here we report the biochemical and pharmacological characterization of a so far neglected NAVAM, N-palmitoyl-vanillamide (palvanil), and propose its possible use instead of capsaicin, as a possible topical analgesic. Palvanil exhibited a kinetics of activation of human recombinant TRPV1-mediated intracellular calcium elevation significantly slower than that of capsaicin (t(1/2)=21s and 8s, respectively at 1μM). Slow kinetics of TRPV1 agonists were previously found to be associated with stronger potencies as TRPV1 desensitizing agents, which in turn are usually associated with lower pungency and stronger anti-hyperalgesic activity. Accordingly, palvanil desensitized the human recombinant TRPV1 to the effect of capsaicin (10nM) with significantly higher potency than capsaicin (IC(50)=0.8nM and 3.8nM, respectively), this effect reaching its maximum more rapidly (50 and 250min, respectively). Palvanil was also more potent than capsaicin at desensitizing the stimulatory effect of TRPV1 by low pH together with anandamide, which mimics conditions occurring during inflammation. In the eye-wiping assay carried out in mice, palvanil was not pungent and instead caused a strong and long-lasting inhibition of capsaicin-induced eye-wiping. Finally, intraplantar palvanil inhibited the second phase of the nociceptive response to formalin in mice. In conclusion, palvanil appears to be a non-pungent analogue of capsaicin with stronger desensitizing effects on TRPV1 and hence potentially higher anti-hyperalgesic activity.
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Affiliation(s)
- Luciano De Petrocellis
- Endocannabinoid Research Group, Institute of Cybernetics - CNR, Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
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Pungency of TRPV1 agonists is directly correlated with kinetics of receptor activation and lipophilicity. Eur J Pharmacol 2010; 641:114-22. [DOI: 10.1016/j.ejphar.2010.05.029] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 04/19/2010] [Accepted: 05/23/2010] [Indexed: 12/11/2022]
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Long DJ, Devantier HR, Brennan FX, Bryant RW, Salemme FR, Palmer RK. Pharmacologic antagonism of the oral aversive taste-directed response to capsaicin in a mouse brief access taste aversion assay. J Pharmacol Exp Ther 2009; 332:525-30. [PMID: 19903834 DOI: 10.1124/jpet.109.155416] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Chemosensory signaling by the tongue is a primary determinant of ingestive behavior and is mediated by specific interactions between tastant molecules and G protein-coupled and ion channel receptors. The functional relationship between tastant and receptor should be amenable to pharmacologic methods and manipulation. We have performed a pharmacologic characterization of the taste-directed licking of mice presented with solutions of capsaicin and other transient receptor potential vanilloid-1 (TRPV1) agonists using a brief access taste aversion assay. Dose-response functions for lick-rate suppression were established for capsaicin (EC(50) = 0.5 microM), piperine (EC(50) = 2 muM), and resiniferatoxin (EC(50) = 0.02 microM). Little or no effect on lick rate was observed in response to the full TRPV1 agonist olvanil. Capsaicin lick rates of wild-type and transient receptor potential melastatin-5 (TRPM5) knockout mice were equivalent, indicating that TRPM5, a critical component of aversive signaling for many bitter tastants, did not contribute to the capsaicin taste response. The selective TRPV1 antagonists N-(4-tertiarybutylphenyl)-4-(3-chloropyridin-2-yl)tetrahydropyrazine-1(2H)-carbox-amide (10 microM) and (E)-3-(4-t-butylphenyl)-N-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)acrylamide (AMG9810) (10 microM) effectively blocked capsaicin- and piperine-mediated lick suppression. However, (E)-3-(4-chlorophenyl)-N-(3-methoxyphenyl)-N-phenylprop-2-enamide (SB 366791) and capsazepine, also TRPV1 antagonists, were without effect at test concentrations of up to 30 and 100 microM, respectively. Our results demonstrate that TRPV1-mediated oral aversiveness presents a pharmacologic profile differing from what has been reported previously for TRPV1 pain signaling and, furthermore, that aversive tastes can be evaluated and controlled pharmacologically.
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Affiliation(s)
- Daniel J Long
- Discovery Research, RedPoint Bio Corporation, Ewing, New Jersey, USA
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Role of endocannabinoids and endovanilloids in Ca2+ signalling. Cell Calcium 2009; 45:611-24. [DOI: 10.1016/j.ceca.2009.03.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 03/03/2009] [Accepted: 03/11/2009] [Indexed: 12/14/2022]
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Lázár J, Gharat L, Khairathkar-Joshi N, Blumberg PM, Szallasi A. Screening TRPV1 antagonists for the treatment of pain: lessons learned over a decade. Expert Opin Drug Discov 2009; 4:159-80. [DOI: 10.1517/17460440802681300] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Kissin I. Vanilloid-induced conduction analgesia: selective, dose-dependent, long-lasting, with a low level of potential neurotoxicity. Anesth Analg 2008; 107:271-81. [PMID: 18635498 DOI: 10.1213/ane.0b013e318162cfa3] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Vanilloid agonists (capsaicin, resiniferatoxin, [RTX]) applied to the peripheral nerves provide conduction blockade. In contrast to the analgesic component of conduction anesthesia produced by local anesthetics, vanilloid agonists provide conduction analgesia not associated with suppression of motor or sensory functions not related to pain. Vanilloid agonists provide conduction analgesia selectively because their effect on the nerve trunks is limited to C- and ADelta-fibers. RTX is much more potent than capsaicin and has a wider therapeutic window. In rat experiments, perineural RTX produced a long-lasting thermal and mechanical hypoalgesia with a very wide separation between effective concentrations (from 0.00003% to 0.001%) providing an effect lasting from several hours to several weeks. A nerve block with RTX prevented the development of thermal and mechanical hyperalgesia as well as pain behavior in a model of incisional pain. RTX-induced conduction blockade has an inherent drawback of TRPV1 agonists, the initial excitation (pain); therefore, a local anesthetic should be injected to prevent it. When RTX was applied to the rat's sciatic nerve in doses necessary to provide conduction analgesia, the frequency of unmyelinated fiber degeneration was more than an order of magnitude lower than that with the therapeutic concentration of lidocaine. These promising results should be confirmed by experiments in species other than rodents (pigs, sheep). Taken together, the data indicate possible clinical applicability of vanilloid-induced conduction analgesia.
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Affiliation(s)
- Igor Kissin
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
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Differential modulation of agonist and antagonist structure activity relations for rat TRPV1 by cyclosporin A and other protein phosphatase inhibitors. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2008; 377:149-57. [PMID: 18259730 DOI: 10.1007/s00210-007-0258-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2006] [Accepted: 12/21/2007] [Indexed: 10/22/2022]
Abstract
The transient receptor potential V1 channel (vanilloid receptor, TRPV1) represents a promising therapeutic target for inflammatory pain and other conditions involving C-fiber sensory afferent neurons. Sensitivity of TRPV1 is known to be subject to modulation by numerous signaling pathways, in particular by phosphorylation, and we wished to determine whether TRPV1 structure activity relations could be differentially affected. We demonstrate here that the structure activity relations of TRPV1, as determined by (45)Ca(2) uptake, were substantially altered by treatment of the cells with cyclosporin A, an inhibitor of protein phosphatase 2B. Whereas the potency of resiniferatoxin for stimulation of (45)Ca(2) was not altered by cyclosporin A treatment, the potencies of some other agonists were increased up to 8-fold. Among the antagonists examined, potencies were reduced to a lesser extent, ranging from 1- to 2.5-fold. Finally, the efficacy of partial agonists was increased. In contrast to cyclosporin A, okadaic acid, an inhibitor of protein phosphatases 1 and 2A, had little effect on agonist potencies, and calyculin A, an inhibitor of protein phosphatases 1 and 2A but with somewhat different selectivity from that of okadaic acid, caused changes in structure activity relations distinct from those induced by cyclosporin A. Because phosphatase activity differentially modulates the structure activity relations of TRPV1 agonists and antagonists, our findings predict that it may be possible to design agonists and antagonists selective for TRPV1 in a specific regulatory environment. A further implication is that it may be desirable to tailor screening approaches for drug discovery to reflect the desired regulatory state of the targeted TRPV1.
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Appendino G, Bacchiega S, Minassi A, Cascio M, De Petrocellis L, Di Marzo V. The 1,2,3-Triazole Ring as a Peptido- and Olefinomimetic Element: Discovery of Click Vanilloids and Cannabinoids. Angew Chem Int Ed Engl 2007; 46:9312-5. [DOI: 10.1002/anie.200703590] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Appendino G, Bacchiega S, Minassi A, Cascio M, De Petrocellis L, Di Marzo V. The 1,2,3-Triazole Ring as a Peptido- and Olefinomimetic Element: Discovery of Click Vanilloids and Cannabinoids. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200703590] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Helyes Z, Pozsgai G, Börzsei R, Németh J, Bagoly T, Márk L, Pintér E, Tóth G, Elekes K, Szolcsányi J, Reglodi D. Inhibitory effect of PACAP-38 on acute neurogenic and non-neurogenic inflammatory processes in the rat. Peptides 2007; 28:1847-55. [PMID: 17698245 DOI: 10.1016/j.peptides.2007.07.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 06/22/2007] [Accepted: 07/02/2007] [Indexed: 11/25/2022]
Abstract
Inhibitory actions of pituitary adenylate cyclase activating polypeptide (PACAP) have been described on cellular/vascular inflammatory components, but there are few data concerning its role in neurogenic inflammation. In this study we measured PACAP-like immunoreactivity with radioimmunoassay in the rat plasma and showed a two-fold elevation in response to systemic stimulation of capsaicin-sensitive sensory nerves by resiniferatoxin, but not after local excitation of cutaneous afferents. Neurogenic plasma extravasation in the plantar skin induced by intraplantar capsaicin or resiniferatoxin, as well as carrageenan-induced paw edema were significantly diminished by intraperitoneal PACAP-38. In summary, these results demonstrate that PACAP is released from activated capsaicin-sensitive afferents into the systemic circulation. It diminishes acute pure neurogenic and mixed-type inflammatory reactions via inhibiting pro-inflammatory mediator release and/or by acting at post-junctional targets on the vascular endothelium.
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Affiliation(s)
- Z Helyes
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Pécs, Hungary
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Abstract
Omega-3 (n-3) fatty acids are essential for proper neuronal function, and they possess prominent analgesic properties, yet their underlying signalling mechanisms are unclear. Here we show that n-3 fatty acids interact directly with TRPV1, an ion channel expressed in nociceptive neurones and brain. These fatty acids activate TRPV1 in a phosphorylation-dependent manner, enhance responses to extracellular protons, and displace binding of the ultrapotent TRPV1 ligand [3H]resiniferatoxin. In contrast to their agonistic properties, n-3 fatty acids competitively inhibit the responses of vanilloid agonists. These actions occur in mammalian cells in the physiological concentration range of 1-10 mum. Significantly, docosahexaenoic acid exhibits the greatest efficacy as an agonist, whereas eicosapentaenoic acid and linolenic acid are markedly more effective inhibitors. Similarly, eicosapentaenoic acid but not docosahexaenoic acid profoundly reduces capsaicin-evoked pain-related behaviour in mice. These effects are independent of alterations in membrane elasticity because the micelle-forming detergent Triton X-100 only minimally affects TRPV1 properties. Thus, n-3 fatty acids differentially regulate TRPV1 and this form of signalling may contribute to their biological effects. Further, these results suggest that dietary supplementation with selective n-3 fatty acids would be most beneficial for the treatment of pain.
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Affiliation(s)
- José A Matta
- Department of Pharmacology, Georgetown University, Washington, DC 20007, USA
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