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Pagare PP, Flammia R, Zhang Y. IUPHAR review: Recent progress in the development of Mu opioid receptor modulators to treat opioid use disorders. Pharmacol Res 2024; 199:107023. [PMID: 38081336 DOI: 10.1016/j.phrs.2023.107023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/21/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024]
Abstract
Opioid Use Disorder (OUD) can be described as intense preoccupation with using or obtaining opioids despite the negative consequences associated with their use. As the number of OUD cases in the U.S. increase, so do the number of opioid-related overdose deaths. In 2022, opioid-related overdose became the No. 1 cause of death for individuals in the U.S. between the ages of 25 and 64 years of age. Because of the introduction of highly potent synthetic opioids (e.g. fentanyl) to the illicit drug market, there is an urgent need for therapeutics that successfully reduce the number of overdoses and can help OUD patients maintain sobriety. Most abused opioids stimulate the mu-opioid receptor (MOR) and activation of this receptor can lead to positive (e.g., euphoria) consequences. However, the negative side effects of MOR stimulation can be fatal (e.g., sedation, respiratory depression). Therefore, the MOR is an attractive target for developing medications to treat OUD. Current FDA drugs include MOR agonists that aid in detoxification and relapse prevention, and MOR antagonists that also serve as maintenance therapies or reverse overdose. These medications are limited by their abuse potential, adverse effects, or pharmacological profiles which leaves ample room for research into designing new chemical entities with optimal physiological effects. These includes, orthosteric ligands that target the primary binding site of the MOR, allosteric ligands that positively, negatively, or "silently" modulate receptor function, and lastly, bitopic ligands target both the orthosteric and allosteric sites simultaneously.
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Affiliation(s)
- Piyusha P Pagare
- Department of Medicinal Chemistry, Virginia Commonwealth University, 800 E. Leigh Street, Richmond, VA 23219, United States
| | - Rachael Flammia
- Department of Medicinal Chemistry, Virginia Commonwealth University, 800 E. Leigh Street, Richmond, VA 23219, United States
| | - Yan Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University, 800 E. Leigh Street, Richmond, VA 23219, United States; Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 North 12th Street, Richmond, VA 23298, United States; Institute for Drug and Alcohol Studies, 203 East Cary Street, Richmond, VA 23298, United States.
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2
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Funes M, Tosso RD, Machado ND, Fernández MA, Garro M, Díaz DD, Hikawczuk VJ, Enriz RD. Antinociceptive effect of cyclic and linear diterpenoids as new atypical agonists of κ-opioid receptors obtained from four species of the Baccharis genus, and vehiculated in nanometric niosomes. Fitoterapia 2023; 169:105622. [PMID: 37524126 DOI: 10.1016/j.fitote.2023.105622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 08/02/2023]
Abstract
New natural analgesic compounds that act in KORs are important alternatives for potential therapeutical use in medicine. In this work, we report and compare here the antinociceptive activity displayed by cyclic and linear diterpenes, obtained from the genus Baccharis. The antinociceptive activities determined were relatively strong, in comparison whit morphine. The antinociceptive mechanism of action was made through naloxone administration (a non-selective antagonist of opioid receptors). The more active compounds were vehiculized successfully in niosomes at nanometric scale. The observed antinociceptive activity for Bartemidiolide oxide (BARTO), obtain from Baccharis artemisioides, was greater than Flabeloic acid dimer (DACD), the first compound isolated from Baccharis flabellata that was reported possessing antinociceptive effects. We also conducted docking calculations and molecular dynamics simulations, which suggested that the newly identified diterpenes might share the molecular action mechanism reported for Salvinorin A (SalA). Molecular simulations have allowed us to appreciate some subtle differences between molecular interactions of these ligands stabilizing their respective complexes; such information might be useful for designing and searching for new inhibitors of KORs.
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Affiliation(s)
- Matías Funes
- Pharmacognosy, School of Chemistry, Biochemistry, and Pharmacy, National University of San Luis, Av. Ejército de los Andes 950, 5700 San Luis, Argentina; Multidisciplinary Institute for Biological Research (IMIBIO-CONICET), Av. Ejército de los Andes 950, 5700 San Luis, Argentina.
| | - Rodrigo D Tosso
- Multidisciplinary Institute for Biological Research (IMIBIO-CONICET), Av. Ejército de los Andes 950, 5700 San Luis, Argentina
| | - Noelia D Machado
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba X5000HUA, Argentina; Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada (IPQA-UNC-CONICET), Avda. Vélez Sársfield 1611, Córdoba X5016GCA, Argentina
| | - Mariana A Fernández
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba X5000HUA, Argentina; Instituto de Investigaciones en Físico-Química de Córdoba (INFIQC-CONICET), Ciudad Universitaria, Córdoba X5000HUA, Argentina
| | - María Garro
- Pharmacognosy, School of Chemistry, Biochemistry, and Pharmacy, National University of San Luis, Av. Ejército de los Andes 950, 5700 San Luis, Argentina
| | - David Díaz Díaz
- Departamento de Química Orgánica, Universidad de la Laguna, La Laguna, Spain; Instituto Universitario de Bio-Orgánica Antonio González, Universidad de la Laguna, La Laguna, Spain; Institute of Organic Chemistry, University of Regensburg, Universitätstr. 31, Regensburg 93053, Germany
| | - Virginia Juan Hikawczuk
- Organic Chemistry, School of Chemistry, Biochemistry, and Pharmacy, National University of San Luis, Av. Ejército de los Andes 950, 5700, San Luis, Argentina
| | - Ricardo D Enriz
- Pharmacognosy, School of Chemistry, Biochemistry, and Pharmacy, National University of San Luis, Av. Ejército de los Andes 950, 5700 San Luis, Argentina; Multidisciplinary Institute for Biological Research (IMIBIO-CONICET), Av. Ejército de los Andes 950, 5700 San Luis, Argentina.
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3
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Intercellular Communication in the Central Nervous System as Deduced by Chemical Neuroanatomy and Quantitative Analysis of Images: Impact on Neuropharmacology. Int J Mol Sci 2022; 23:ijms23105805. [PMID: 35628615 PMCID: PMC9145073 DOI: 10.3390/ijms23105805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 01/25/2023] Open
Abstract
In the last decades, new evidence on brain structure and function has been acquired by morphological investigations based on synergic interactions between biochemical anatomy approaches, new techniques in microscopy and brain imaging, and quantitative analysis of the obtained images. This effort produced an expanded view on brain architecture, illustrating the central nervous system as a huge network of cells and regions in which intercellular communication processes, involving not only neurons but also other cell populations, virtually determine all aspects of the integrative function performed by the system. The main features of these processes are described. They include the two basic modes of intercellular communication identified (i.e., wiring and volume transmission) and mechanisms modulating the intercellular signaling, such as cotransmission and allosteric receptor–receptor interactions. These features may also open new possibilities for the development of novel pharmacological approaches to address central nervous system diseases. This aspect, with a potential major impact on molecular medicine, will be also briefly discussed.
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Drakopoulos A, Moianos D, Prifti GM, Zoidis G, Decker M. Opioid ligands addressing unconventional binding sites and more than one opioid receptor subtype. ChemMedChem 2022; 17:e202200169. [PMID: 35560796 DOI: 10.1002/cmdc.202200169] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/11/2022] [Indexed: 11/10/2022]
Abstract
Opioid receptors (ORs) represent one of the most significant groups of G-protein coupled receptor (GPCR) drug targets and also act as prototypical models for GPCR function. In a constant effort to develop drugs with less side effects, and tools to explore the ORs nature and function, various (poly)pharmacological ligand design approaches have been performed. That is, besides classical ligands, a great number of bivalent ligands (i.e. aiming on two distinct OR subtypes), univalent heteromer-selective ligands and bitopic and allosteric ligands have been synthesized for the ORs. The scope of our review is to present the most important of the aforementioned ligands, highlight their properties and exhibit the current state-of-the-art pallet of promising drug candidates or useful molecular tools for the ORs.
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Affiliation(s)
- Antonios Drakopoulos
- University of Gothenburg: Goteborgs Universitet, Department of Chemistry and Molecular Biology, Kemigåden 4, 431 45, Göteborg, SWEDEN
| | - Dimitrios Moianos
- National and Kapodistrian University of Athens: Ethniko kai Kapodistriako Panepistemio Athenon, Department of Pharmacy, Panepistimiopolis-Zografou, 15771, Athens, GREECE
| | - Georgia-Myrto Prifti
- National and Kapodistrian University of Athens: Ethniko kai Kapodistriako Panepistemio Athenon, Department of Pharmacy, Panepistimiopolis-Zografou, 15771, Athens, GREECE
| | - Grigoris Zoidis
- National and Kapodistrian University of Athens, Department of Pharmaceutical Chemistry, Panepistimioupolis-Zografou, 15771, Athens, GREECE
| | - Michael Decker
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Institute of Pharmacy and Food Chemistry, Am Hubland, 97074, Würzburg, GERMANY
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Root-Bernstein R. Biased, Bitopic, Opioid–Adrenergic Tethered Compounds May Improve Specificity, Lower Dosage and Enhance Agonist or Antagonist Function with Reduced Risk of Tolerance and Addiction. Pharmaceuticals (Basel) 2022; 15:ph15020214. [PMID: 35215326 PMCID: PMC8876737 DOI: 10.3390/ph15020214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/02/2022] [Accepted: 02/07/2022] [Indexed: 01/03/2023] Open
Abstract
This paper proposes the design of combination opioid–adrenergic tethered compounds to enhance efficacy and specificity, lower dosage, increase duration of activity, decrease side effects, and reduce risk of developing tolerance and/or addiction. Combinations of adrenergic and opioid drugs are sometimes used to improve analgesia, decrease opioid doses required to achieve analgesia, and to prolong the duration of analgesia. Recent mechanistic research suggests that these enhanced functions result from an allosteric adrenergic binding site on opioid receptors and, conversely, an allosteric opioid binding site on adrenergic receptors. Dual occupancy of the receptors maintains the receptors in their high affinity, most active states; drops the concentration of ligand required for full activity; and prevents downregulation and internalization of the receptors, thus inhibiting tolerance to the drugs. Activation of both opioid and adrenergic receptors also enhances heterodimerization of the receptors, additionally improving each drug’s efficacy. Tethering adrenergic drugs to opioids could produce new drug candidates with highly desirable features. Constraints—such as the locations of the opioid binding sites on adrenergic receptors and adrenergic binding sites on opioid receptors, length of tethers that must govern the design of such novel compounds, and types of tethers—are described and examples of possible structures provided.
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Guidolin D, Tortorella C, Marcoli M, Cervetto C, Maura G, Agnati LF. Receptor-Receptor Interactions and Glial Cell Functions with a Special Focus on G Protein-Coupled Receptors. Int J Mol Sci 2021; 22:8656. [PMID: 34445362 PMCID: PMC8395429 DOI: 10.3390/ijms22168656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/30/2021] [Accepted: 08/11/2021] [Indexed: 12/18/2022] Open
Abstract
The discovery that receptors from all families can establish allosteric receptor-receptor interactions and variably associate to form receptor complexes operating as integrative input units endowed with a high functional and structural plasticity has expanded our understanding of intercellular communication. Regarding the nervous system, most research in the field has focused on neuronal populations and has led to the identification of many receptor complexes representing an important mechanism to fine-tune synaptic efficiency. Receptor-receptor interactions, however, also modulate glia-neuron and glia-glia intercellular communication, with significant consequences on synaptic activity and brain network plasticity. The research on this topic is probably still at the beginning and, here, available evidence will be reviewed and discussed. It may also be of potential interest from a pharmacological standpoint, opening the possibility to explore, inter alia, glia-based neuroprotective therapeutic strategies.
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Affiliation(s)
- Diego Guidolin
- Department of Neuroscience, Section of Anatomy, University of Padova, 35121 Padova, Italy;
| | - Cinzia Tortorella
- Department of Neuroscience, Section of Anatomy, University of Padova, 35121 Padova, Italy;
| | - Manuela Marcoli
- Department of Pharmacy, Center of Excellence for Biomedical Research, University of Genova, 16126 Genova, Italy; (M.M.); (C.C.); (G.M.)
| | - Chiara Cervetto
- Department of Pharmacy, Center of Excellence for Biomedical Research, University of Genova, 16126 Genova, Italy; (M.M.); (C.C.); (G.M.)
| | - Guido Maura
- Department of Pharmacy, Center of Excellence for Biomedical Research, University of Genova, 16126 Genova, Italy; (M.M.); (C.C.); (G.M.)
| | - Luigi F. Agnati
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy;
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Kuroda Y, Nonaka M, Kamikubo Y, Ogawa H, Murayama T, Kurebayashi N, Sakairi H, Miyano K, Komatsu A, Dodo T, Nakano-Ito K, Yamaguchi K, Sakurai T, Iseki M, Hayashida M, Uezono Y. Inhibition of endothelin A receptor by a novel, selective receptor antagonist enhances morphine-induced analgesia: Possible functional interaction of dimerized endothelin A and μ-opioid receptors. Biomed Pharmacother 2021; 141:111800. [PMID: 34175819 DOI: 10.1016/j.biopha.2021.111800] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/13/2021] [Accepted: 05/24/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The misuse of opioids has led to an epidemic in recent times. The endothelin A receptor (ETAR) has recently attracted attention as a novel therapeutic target to enhance opioid analgesia. We hypothesized that endothelin A receptors may affect pain mechanisms by heterodimerization with μ opioid receptors. We examined the mechanisms of ETAR-mediated pain and the potential therapeutic effects of an ETAR antagonist, Compound-E, as an agent for analgesia. METHODS Real-time in vitro effect of Compound-E on morphine response was assessed in HEK293 cells expressing both endothelin A and μ opioid receptors through CellKey™ and cADDis cAMP assays. Endothelin A/μ opioid receptor dimerization was assessed by immunoprecipitation and live cell imaging. The in vivo effect of Compound-E was evaluated using a morphine analgesia mouse model that observed escape response behavior, body temperature, and locomotor activity. RESULTS In CellKey™ and cAMP assays, pretreatment of cells with endothelin-1 attenuated morphine-induced responses. These responses were improved by Compound-E, but not by BQ-123 nor by bosentan, an ETAR and endothelin B receptor antagonist. Dimerization of ETARs and μ opioid receptors was confirmed by Western blot and total internal reflection fluorescence microscopy in live cells. In vivo, Compound-E potentiated and prolonged the analgesic effects of morphine, enhanced hypothermia, and increased locomotor activity compared to morphine alone. CONCLUSION The results suggest that attenuation by endothelin-1 of morphine analgesia may be caused by dimerization of Endothelin A/μ opioid receptors. The novel ETAR antagonist Compound-E could be an effective adjunct to reduce opioid use.
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Affiliation(s)
- Yui Kuroda
- Department of Anesthesiology and Pain Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; Department of Pain Control Research, The Jikei University School of Medicine, Tokyo, Japan
| | - Miki Nonaka
- Department of Pain Control Research, The Jikei University School of Medicine, Tokyo, Japan
| | - Yuji Kamikubo
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Haruo Ogawa
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hakushun Sakairi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kanako Miyano
- Department of Pain Control Research, The Jikei University School of Medicine, Tokyo, Japan; Division of Cancer Pathophysiology, National Cancer Center Research Institute, Tokyo, Japan
| | - Akane Komatsu
- Department of Anesthesiology and Pain Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; Department of Pain Control Research, The Jikei University School of Medicine, Tokyo, Japan
| | - Tetsushi Dodo
- Strategy Planning & Operations, Medicine Development Center, Eisai Co., Ltd., Ibaraki, Japan
| | - Kyoko Nakano-Ito
- Global Drug Safety, Medicine Development Center, Eisai Co., Ltd., Ibaraki, Japan
| | - Keisuke Yamaguchi
- Department of Pain Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Masako Iseki
- Department of Anesthesiology and Pain Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; Department of Pain Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Masakazu Hayashida
- Department of Anesthesiology and Pain Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; Department of Pain Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yasuhito Uezono
- Department of Pain Control Research, The Jikei University School of Medicine, Tokyo, Japan; Department of Pain Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan; Supportive and Palliative Care Research Support Office, National Center Hospital East, Chiba, Japan; Project for Supportive Care Research, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Tokyo, Japan.
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8
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Obeng S, Hiranita T, León F, McMahon LR, McCurdy CR. Novel Approaches, Drug Candidates, and Targets in Pain Drug Discovery. J Med Chem 2021; 64:6523-6548. [PMID: 33956427 DOI: 10.1021/acs.jmedchem.1c00028] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Because of the problems associated with opioids, drug discovery efforts have been employed to develop opioids with reduced side effects using approaches such as biased opioid agonism, multifunctional opioids, and allosteric modulation of opioid receptors. Receptor targets such as adrenergic, cannabinoid, P2X3 and P2X7, NMDA, serotonin, and sigma, as well as ion channels like the voltage-gated sodium channels Nav1.7 and Nav1.8 have been targeted to develop novel analgesics. Several enzymes, such as soluble epoxide hydrolase, sepiapterin reductase, and MAGL/FAAH, have also been targeted to develop novel analgesics. In this review, old and recent targets involved in pain signaling and compounds acting at these targets are summarized. In addition, strategies employed to reduce side effects, increase potency, and efficacy of opioids are also elaborated. This review should aid in propelling drug discovery efforts to discover novel analgesics.
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Affiliation(s)
- Samuel Obeng
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States.,Department Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Takato Hiranita
- Department Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Francisco León
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia 29208, United States
| | - Lance R McMahon
- Department Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Christopher R McCurdy
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States.,Translational Drug Development Core, Clinical and Translational Sciences Institute, University of Florida, Gainesville, Florida 32610, United States
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9
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de Moura FB, Bergman J. Enhancement of Opioid Antinociception by Nicotinic Ligands. J Pharmacol Exp Ther 2021; 377:100-107. [PMID: 33441370 DOI: 10.1124/jpet.120.000423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/11/2021] [Indexed: 11/22/2022] Open
Abstract
Nicotine has previously been shown to augment the antinociceptive effects of μ-opioid agonists in squirrel monkeys without producing a concomitant increase in behavioral disruption. The present studies were conducted to extend these findings by determining the ability of the nicotinic acetylcholine receptor (nAChR) agonist epibatidine and partial α4β2 nAChR agonist varenicline to selectively augment the antinociceptive effects of the μ-opioid receptor (MOR) full agonist fentanyl, the MOR partial agonist nalbuphine, and the κ-opioid receptor (KOR) agonist U69,593 in male squirrel monkeys. Results indicate that both nAChR ligands selectively increased the antinociceptive effects of nalbuphine and that epibatidine increased the antinociceptive effects of U69,593 without altering effects on operant behavior. However, neither epibatidine nor varenicline enhanced the antinociceptive effects of fentanyl, perhaps due to its high efficacy. The enhancement of nalbuphine's antinociceptive effects by epibatidine, but not varenicline, could be antagonized by either mecamylamine or dihydro-β-erythroidine, consistent with α4β2 mediation of epibatidine's effects but suggesting the involvement of non-nAChR mechanisms in the effects of varenicline. The present results support previous findings showing that an nAChR agonist can serve as an adjuvant for MOR antinociception and, based on results with U69,593, further indicate that the adjuvant effects of nAChR drugs may also apply to antinociception produced by KOR. Our findings support the further evaluation of nAChR agonists as adjuvants of opioid pharmacotherapy for pain management and point out the need for further investigation into the mechanisms by which they produce opioid-adjuvant effects. SIGNIFICANCE STATEMENT: Nicotine has been shown to augment the antinociceptive effects of μ-opioid receptor analgesics without exacerbating their effects on operant performance. The present study demonstrates that the nicotinic acetylcholine receptor (nAChR) agonist epibatidine and partial α4β2 nAChR agonist varenicline can also augment the antinociceptive effects of nalbuphine, as well as those of a κ-opioid receptor agonist, without concomitantly exacerbating their behaviorally disruptive effects. These findings support the view that nAChR agonists and partial agonists may have potential as adjuvant therapies for opioid-based analgesics.
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Affiliation(s)
- Fernando B de Moura
- Behavioral Biology Program, McLean Hospital, Belmont, Massachusetts and Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Jack Bergman
- Behavioral Biology Program, McLean Hospital, Belmont, Massachusetts and Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
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10
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Wei F, Zhao L, Jing Y. Hemoglobin-derived peptides and mood regulation. Peptides 2020; 127:170268. [PMID: 32070683 DOI: 10.1016/j.peptides.2020.170268] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 02/02/2020] [Accepted: 02/04/2020] [Indexed: 12/12/2022]
Abstract
Evidence accumulated over the past decades has revealed that red blood cells and hemoglobin (Hb) in the blood play important roles in modulating moods and emotions. The number of red blood cells affects the mood. Hb is the principal content in the red blood cells besides water. Denatured Hb is hydrolyzed to produce bioactive peptides. RVD-hemopressin α (RVD-Hpα), which is a fragment of α-chain (95-103) in Hb, functions as a negative allosteric modulator of cannabinoid receptor 1 and a positive allosteric modulator of cannabinoid receptor 2. Hemorphins, which are fragments of β-chain in Hb, exert their effects on opioid receptors. Two hemorphins, namely, LVV-hemorphin-6 and LVV-hemorphin-7, could induce anxiolytic-like effects. The use of Hb-derived bioactive peptides for the treatment of mood disorders is desirable due to cannabinoid-opioid cross modulation and the critical roles of the two systems in physiological processes, such as memory, mood and emotion.
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Affiliation(s)
- Fengmei Wei
- Department of Physiology and Psychology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Long Zhao
- Department of Orthopaedics, Lanzhou University First Affiliated Hospital, Lanzhou, Gansu, 730000, PR China
| | - Yuhong Jing
- Institute of Anatomy and Histology & Embryology, Neuroscience, School of Basic Medical Sciences, Lanzhou University, Lanzhou, Gansu, 730000, PR China; Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, Gansu, 730000, PR China.
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11
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Reinecke BA, Wang H, Zhang Y. Recent Advances in the Drug Discovery and Development of Dualsteric/ Bitopic Activators of G Protein-Coupled Receptors. Curr Top Med Chem 2019; 19:2378-2392. [PMID: 31833462 DOI: 10.2174/1568026619666191009164609] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/26/2019] [Accepted: 09/05/2019] [Indexed: 01/20/2023]
Abstract
G protein-coupled receptors (GPCRs) represent the largest family of proteins targeted by drug design and discovery efforts. Of these efforts, the development of GPCR agonists is highly desirable, due to their therapeutic robust utility in treating diseases caused by deficient receptor signaling. One of the challenges in designing potent and selective GPCR agonists lies in the inability to achieve combined high binding affinity and subtype selectivity, due to the high homology between orthosteric sites among GPCR subtypes. To combat this difficulty, researchers have begun to explore the utility of targeting topographically distinct and less conserved binding sites, namely "allosteric" sites. Pursuing these sites offers the benefit of achieving high subtype selectivity, however, it also can result in a decreased binding affinity and potency as compared to orthosteric agonists. Therefore, bitopic ligands comprised of an orthosteric agonist and an allosteric modulator connected by a spacer and allowing binding with both the orthosteric and allosteric sites within one receptor, have been developed. It may combine the high subtype selectivity of an allosteric modulator with the high binding affinity of an orthosteric agonist and provides desired advantages over orthosteric agonists or allosteric modulators alone. Herein, we review the recent advances in the development of bitopic agonists/activators for various GPCR targets and their novel therapeutic potentials.
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Affiliation(s)
- Bethany A Reinecke
- Department of Medicinal Chemistry, Virginia Commonwealth University, 800 East Leigh Street, Richmond, VA 23298, United States
| | - Huiqun Wang
- Department of Medicinal Chemistry, Virginia Commonwealth University, 800 East Leigh Street, Richmond, VA 23298, United States
| | - Yan Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University, 800 East Leigh Street, Richmond, VA 23298, United States
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12
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Ma H, Obeng S, Wang H, Zheng Y, Li M, Jali AM, Stevens DL, Dewey WL, Selley DE, Zhang Y. Application of Bivalent Bioisostere Concept on Design and Discovery of Potent Opioid Receptor Modulators. J Med Chem 2019; 62:11399-11415. [PMID: 31782922 DOI: 10.1021/acs.jmedchem.9b01767] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Here, we described the structural modification of previously identified μ opioid receptor (MOR) antagonist NAN, a 6α-N-7'-indolyl substituted naltrexamine derivative, and its 6β-N-2'-indolyl substituted analogue INTA by adopting the concept of "bivalent bioisostere". Three newly prepared opioid ligands, 25 (NBF), 31, and 38, were identified as potent MOR antagonists both in vitro and in vivo. Moreover, these three compounds significantly antagonized DAMGO-induced intracellular calcium flux and displayed varying degrees of inhibition on cAMP production. Furthermore, NBF produced much less significant withdrawal effects than naloxone in morphine-pelleted mice. Molecular modeling studies revealed that these bivalent bioisosteres may adopt similar binding modes in the MOR and the "address" portions of them may have negative or positive allosteric modulation effects on the function of their "message" portions compared with NAN and INTA. Collectively, our successful application of the "bivalent bioisostere concept" identified a promising lead to develop novel therapeutic agents toward opioid use disorder treatments.
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Affiliation(s)
- Hongguang Ma
- Department of Medicinal Chemistry, School of Pharmacy , Virginia Commonwealth University , 800 E Leigh Street , Richmond , Virginia 23298 , United States
| | - Samuel Obeng
- Department of Medicinal Chemistry, School of Pharmacy , Virginia Commonwealth University , 800 E Leigh Street , Richmond , Virginia 23298 , United States
| | - Huiqun Wang
- Department of Medicinal Chemistry, School of Pharmacy , Virginia Commonwealth University , 800 E Leigh Street , Richmond , Virginia 23298 , United States
| | - Yi Zheng
- Department of Medicinal Chemistry, School of Pharmacy , Virginia Commonwealth University , 800 E Leigh Street , Richmond , Virginia 23298 , United States
| | - Mengchu Li
- Department of Medicinal Chemistry, School of Pharmacy , Virginia Commonwealth University , 800 E Leigh Street , Richmond , Virginia 23298 , United States
| | - Abdulmajeed M Jali
- Department of Pharmacology and Toxicology , Virginia Commonwealth University , 410 North 12th Street , Richmond , Virginia 23298 , United States
| | - David L Stevens
- Department of Pharmacology and Toxicology , Virginia Commonwealth University , 410 North 12th Street , Richmond , Virginia 23298 , United States
| | - William L Dewey
- Department of Pharmacology and Toxicology , Virginia Commonwealth University , 410 North 12th Street , Richmond , Virginia 23298 , United States
| | - Dana E Selley
- Department of Pharmacology and Toxicology , Virginia Commonwealth University , 410 North 12th Street , Richmond , Virginia 23298 , United States
| | - Yan Zhang
- Department of Medicinal Chemistry, School of Pharmacy , Virginia Commonwealth University , 800 E Leigh Street , Richmond , Virginia 23298 , United States
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13
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Obeng S, Wang H, Jali A, Stevens DL, Akbarali HI, Dewey WL, Selley DE, Zhang Y. Structure-Activity Relationship Studies of 6α- and 6β-Indolylacetamidonaltrexamine Derivatives as Bitopic Mu Opioid Receptor Modulators and Elaboration of the "Message-Address Concept" To Comprehend Their Functional Conversion. ACS Chem Neurosci 2019; 10:1075-1090. [PMID: 30156823 PMCID: PMC6405326 DOI: 10.1021/acschemneuro.8b00349] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Structure-activity relationship (SAR) studies of numerous opioid ligands have shown that introduction of a methyl or ethyl group on the tertiary amino group at position 17 of the epoxymorphinan skeleton generally results in a mu opioid receptor (MOR) agonist while introduction of a cyclopropylmethyl group typically leads to an antagonist. Furthermore, it has been shown that introduction of heterocyclic ring systems at position 6 can favor antagonism. However, it was reported that 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(2'-indolyl)acetamido]morphinan (INTA), which bears a cyclopropylmethyl group at position 17 and an indole ring at position 6, acted as a MOR agonist. We herein report a SAR study on INTA with a series of its complementary derivatives to understand how introduction of an indole moiety with α or β linkage at position 6 of the epoxymorphinan skeleton may influence ligand function. Interestingly, one of INTA derivatives, compound 15 (NAN) was identified as a MOR antagonist both in vitro and in vivo. Molecular modeling studies revealed that INTA and NAN may interact with different domains of the MOR allosteric binding site. In addition, INTA may interact with W293 and N150 residues found in the orthosteric site to stabilize MOR activation conformation while NAN does not. These results suggest that INTA and NAN may be bitopic ligands and the type of allosteric interactions with the MOR influence their functional activity. These insights along with our enriched comprehension of the "message-address" concept will to benefit future ligand design.
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MESH Headings
- Allosteric Regulation/drug effects
- Allosteric Regulation/physiology
- Analgesics, Opioid/chemistry
- Analgesics, Opioid/pharmacology
- Animals
- CHO Cells
- Cricetinae
- Cricetulus
- Dose-Response Relationship, Drug
- Male
- Mice
- Narcotic Antagonists/chemistry
- Narcotic Antagonists/pharmacology
- Protein Binding/drug effects
- Protein Binding/physiology
- Protein Structure, Secondary
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/physiology
- Structure-Activity Relationship
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Affiliation(s)
- Samuel Obeng
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, 800 E Leigh Street, Richmond, Virginia 23298, United States
| | - Huiqun Wang
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, 800 E Leigh Street, Richmond, Virginia 23298, United States
| | - Abdulmajeed Jali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 North 12th Street, Richmond, Virginia 23298, United States
| | - David L. Stevens
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 North 12th Street, Richmond, Virginia 23298, United States
| | - Hamid I. Akbarali
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 North 12th Street, Richmond, Virginia 23298, United States
| | - William L. Dewey
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 North 12th Street, Richmond, Virginia 23298, United States
| | - Dana E. Selley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, 410 North 12th Street, Richmond, Virginia 23298, United States
| | - Yan Zhang
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, 800 E Leigh Street, Richmond, Virginia 23298, United States
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14
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Zjawiony JK, Machado AS, Menegatti R, Ghedini PC, Costa EA, Pedrino GR, Lukas SE, Franco OL, Silva ON, Fajemiroye JO. Cutting-Edge Search for Safer Opioid Pain Relief: Retrospective Review of Salvinorin A and Its Analogs. Front Psychiatry 2019; 10:157. [PMID: 30971961 PMCID: PMC6445891 DOI: 10.3389/fpsyt.2019.00157] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 03/04/2019] [Indexed: 12/21/2022] Open
Abstract
Over the years, pain has contributed to low life quality, poor health, and economic loss. Opioids are very effective analgesic drugs for treating mild, moderate, or severe pain. Therapeutic application of opioids has been limited by short and long-term side effects. These side effects and opioid-overuse crisis has intensified interest in the search for new molecular targets and drugs. The present review focuses on salvinorin A and its analogs with the aim of exploring their structural and pharmacological profiles as clues for the development of safer analgesics. Ethnopharmacological reports and growing preclinical data have demonstrated the antinociceptive effect of salvinorin A and some of its analogs. The pharmacology of analogs modified at C-2 dominates the literature when compared to the ones from other positions. The distinctive binding affinity of these analogs seems to correlate with their chemical structure and in vivo antinociceptive effects. The high susceptibility of salvinorin A to chemical modification makes it an important pharmacological tool for cellular probing and developing analogs with promising analgesic effects. Additional research is still needed to draw reliable conclusions on the therapeutic potential of salvinorin A and its analogs.
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Affiliation(s)
- Jordan K Zjawiony
- Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi, University, MS, United States
| | - Antônio S Machado
- Laboratory of Medicinal Pharmaceutical Chemistry, Faculty of Pharmacy, Universidade Federal de Goiás, Goiânia, Brazil
| | - Ricardo Menegatti
- Laboratory of Medicinal Pharmaceutical Chemistry, Faculty of Pharmacy, Universidade Federal de Goiás, Goiânia, Brazil
| | - Paulo C Ghedini
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Goiás, Goiânia, Brazil
| | - Elson A Costa
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Goiás, Goiânia, Brazil
| | - Gustavo R Pedrino
- Department of Physiology, Universidade Federal de Goiás, Goiânia, Brazil
| | - Scott E Lukas
- McLean Imaging Center, Harvard Medical School, McLean Hospital, Belmont, MA, United States
| | - Octávio L Franco
- S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil.,Centro de Análises Proteômicas e Bioquímicas, Pós-graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil.,Programa de Pós-graduação em Patologia Molecular, Universidade de Brasília, Brasília, Brazil
| | - Osmar N Silva
- S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil
| | - James O Fajemiroye
- Department of Physiology, Universidade Federal de Goiás, Goiânia, Brazil.,Centro Universitário de Anápolis, Unievangélica, Anápolis, Brazil
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15
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Guidolin D, Marcoli M, Tortorella C, Maura G, Agnati LF. Receptor-Receptor Interactions as a Widespread Phenomenon: Novel Targets for Drug Development? Front Endocrinol (Lausanne) 2019; 10:53. [PMID: 30833931 PMCID: PMC6387912 DOI: 10.3389/fendo.2019.00053] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 01/21/2019] [Indexed: 12/19/2022] Open
Abstract
The discovery of receptor-receptor interactions (RRI) has expanded our understanding of the role that G protein-coupled receptors (GPCRs) play in intercellular communication. The finding that GPCRs can operate as receptor complexes, and not only as monomers, suggests that several different incoming signals could already be integrated at the plasma membrane level via direct allosteric interactions between the protomers that form the complex. Most research in this field has focused on neuronal populations and has led to the identification of a large number of RRI. However, RRI have been seen to occur not only in neurons but also in astrocytes and, outside the central nervous system, in cells of the cardiovascular and endocrine systems and in cancer cells. Furthermore, RRI involving the formation of macromolecular complexes are not limited to GPCRs, being also observed in other families of receptors. Thus, RRI appear as a widespread phenomenon and oligomerization as a common mechanism for receptor function and regulation. The discovery of these macromolecular assemblies may well have a major impact on pharmacology. Indeed, the formation of receptor complexes significantly broadens the spectrum of mechanisms available to receptors for recognition and signaling, which may be implemented through modulation of the binding sites of the adjacent protomers and of their signal transduction features. In this context, the possible appearance of novel allosteric sites in the receptor complex structure may be of particular relevance. Thus, the existence of RRI offers the possibility of new therapeutic approaches, and novel pharmacological strategies for disease treatment have already been proposed. Several challenges, however, remain. These include the accurate characterization of the role that the receptor complexes identified so far play in pathological conditions and the development of ligands specific to given receptor complexes, in order to efficiently exploit the pharmacological properties of these complexes.
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Affiliation(s)
- Diego Guidolin
- Department of Neuroscience, University of Padova, Padova, Italy
- *Correspondence: Diego Guidolin
| | - Manuela Marcoli
- Department of Pharmacy and Center of Excellence for Biomedical Research, University of Genova, Genoa, Italy
| | | | - Guido Maura
- Department of Pharmacy and Center of Excellence for Biomedical Research, University of Genova, Genoa, Italy
| | - Luigi F. Agnati
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Modena, Italy
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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16
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Machelska H, Celik MÖ. Advances in Achieving Opioid Analgesia Without Side Effects. Front Pharmacol 2018; 9:1388. [PMID: 30555325 PMCID: PMC6282113 DOI: 10.3389/fphar.2018.01388] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/12/2018] [Indexed: 12/12/2022] Open
Abstract
Opioids are the most effective drugs for the treatment of severe pain, but they also cause addiction and overdose deaths, which have led to a worldwide opioid crisis. Therefore, the development of safer opioids is urgently needed. In this article, we provide a critical overview of emerging opioid-based strategies aimed at effective pain relief and improved side effect profiles. These approaches comprise biased agonism, the targeting of (i) opioid receptors in peripheral inflamed tissue (by reducing agonist access to the brain, the use of nanocarriers, or low pH-sensitive agonists); (ii) heteromers or multiple receptors (by monovalent, bivalent, and multifunctional ligands); (iii) receptor splice variants; and (iv) endogenous opioid peptides (by preventing their degradation or enhancing their production by gene transfer). Substantial advancements are underscored by pharmaceutical development of new opioids such as peripheral κ-receptor agonists, and by treatments augmenting the action of endogenous opioids, which have entered clinical trials. Additionally, there are several promising novel opioids comprehensively examined in preclinical studies, but also strategies such as biased agonism, which might require careful rethinking.
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Affiliation(s)
- Halina Machelska
- Department of Experimental Anesthesiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Melih Ö Celik
- Department of Experimental Anesthesiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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17
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Cataldo G, Lunzer MM, Olson JK, Akgün E, Belcher JD, Vercellotti GM, Portoghese PS, Simone DA. Bivalent ligand MCC22 potently attenuates nociception in a murine model of sickle cell disease. Pain 2018; 159:1382-1391. [PMID: 29578946 PMCID: PMC6008209 DOI: 10.1097/j.pain.0000000000001225] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Sickle cell disease (SCD) is a chronic inflammatory disorder accompanied by chronic pain. In addition to ongoing pain and hyperalgesia, vaso-occlusive crises-induced pain can be chronic or episodic. Because analgesics typically used to treat pain are not very effective in SCD, opioids, including morphine, are a primary treatment for managing pain in SCD but are associated with many serious side effects, including constipation, tolerance, addiction, and respiratory depression. Thus, there is a need for the development of novel treatments for pain in SCD. In this study, we used the Townes transgenic mouse model of SCD to investigate the antinociceptive efficacy of the bivalent ligand, MCC22, and compared its effectiveness with morphine. MCC22 consists of a mu-opioid receptor agonist and a chemokine receptor-5 (CCR5) antagonist that are linked through a 22-atom spacer. Our results show that intraperitoneal administration of MCC22 produced exceptionally potent dose-dependent antihyperalgesia as compared to morphine, dramatically decreased evoked responses of nociceptive dorsal horn neurons, and decreased expression of proinflammatory cytokines in the spinal cord. Moreover, tolerance did not develop to its analgesic effects after repeated administration. In view of the extraordinary potency of MCC22 without tolerance, MCC22 and similar compounds may vastly improve the management of pain associated with SCD.
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Affiliation(s)
- Giuseppe Cataldo
- Department of Diagnostic & Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN
| | - Mary M. Lunzer
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN
| | - Julie K. Olson
- Department of Diagnostic & Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN
| | - Eyup Akgün
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN
| | - John D. Belcher
- Department of Medicine, Vascular Biology Center, Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN
| | - Gregory M. Vercellotti
- Department of Medicine, Vascular Biology Center, Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN
| | - Philip S. Portoghese
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN
| | - Donald A. Simone
- Department of Diagnostic & Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN
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18
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Lensing CJ, Freeman KT, Schnell SM, Speth RC, Zarth AT, Haskell-Luevano C. Developing a Biased Unmatched Bivalent Ligand (BUmBL) Design Strategy to Target the GPCR Homodimer Allosteric Signaling (cAMP over β-Arrestin 2 Recruitment) Within the Melanocortin Receptors. J Med Chem 2018; 62:144-158. [PMID: 29669202 DOI: 10.1021/acs.jmedchem.8b00238] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Understanding the functional relevance of G protein-coupled receptor (GPCR) homodimerization has been limited by the insufficient tools to assess asymmetric signaling occurring within dimers comprised of the same receptor type. We present unmatched bivalent ligands (UmBLs) to study the asymmetric function of melanocortin homodimers. UmBLs contain one agonist and one antagonist pharmacophore designed to target a melanocortin homodimer such that one receptor is occupied by an agonist and the other receptor by an antagonist pharmacophore. First-in-class biased UmBLs (BUmBLs) targeting the human melanocortin-4 receptor (hMC4R) were discovered. The BUmBLs displayed biased agonism by potently stimulating cAMP signaling (EC50 ∼ 2-6 nM) but minimally activating the β-arrestin recruitment pathway (≤55% maximum signal at 10 μM). To our knowledge, we report the first single-compound strategy to pharmacologically target melanocortin receptor allosteric signaling that occurs between homodimers that can be applied straightforwardly in vitro and in vivo to other GPCR systems.
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Affiliation(s)
- Cody J Lensing
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States
| | - Katie T Freeman
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States
| | - Sathya M Schnell
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States
| | - Robert C Speth
- College of Pharmacy , Nova Southeastern University , Fort Lauderdale , Florida 33328-2018 , United States.,Department of Pharmacology and Physiology , Georgetown University , Washington, D.C. 20057 , United States
| | - Adam T Zarth
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States.,Masonic Cancer Center , University of Minnesota , 2231 Sixth Street SE, 2-210 CCRB , Minneapolis , Minnesota 55455 , United States
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience , University of Minnesota , 308 Harvard Street SE , Minneapolis , Minnesota 55455 , United States
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19
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Dothel G, Barbaro MR, Raschi E, Barbara G, De Ponti F. Advancements in drug development for diarrhea-predominant irritable bowel syndrome. Expert Opin Investig Drugs 2018; 27:251-263. [PMID: 29451407 DOI: 10.1080/13543784.2018.1442434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Diarrhea-predominant irritable bowel syndrome (IBS-D) is a common disorder characterized by a complex pathophysiology hampering optimal targeted drug development. Recent advances in our understanding of key underlying mechanisms prompted novel therapeutics including novel pharmacological approaches. AREAS COVERED This review summarizes the latest advancements in the pipeline of IBS-D drugs focusing on new pharmacological targets, efficacy and safety of medicinal products considering the recent harmonization of regulatory requirements by the FDA and the EMA. EXPERT OPINION The new 5-HT3 receptor antagonist ramosetron appears a promising therapeutic approach devoid of significant adverse events, although it is presently unavailable in Western countries, most likely because of the precautionary approach taken by regulatory agencies with this drug class. New pharmacological concepts on full agonists/antagonists, mixed-receptor activity and novel drug targets may streamline the present drug pipeline along with the adherence on new regulatory guidelines on outcome measures. Eluxadoline can be taken as an example of this paradigm shift. It has now been granted marketing authorization for IBS-D on both sides of the Atlantic, but it is still considered as a second-line agent by the NICE. There is still much work to be done to fully cover clinical needs of patients with IBS-D.
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Affiliation(s)
- Giovanni Dothel
- a Department of Medical and Surgical Sciences , University of Bologna , Bologna , Italy
| | | | - Emanuel Raschi
- a Department of Medical and Surgical Sciences , University of Bologna , Bologna , Italy
| | - Giovanni Barbara
- a Department of Medical and Surgical Sciences , University of Bologna , Bologna , Italy
| | - Fabrizio De Ponti
- a Department of Medical and Surgical Sciences , University of Bologna , Bologna , Italy
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20
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Guidolin D, Marcoli M, Tortorella C, Maura G, Agnati LF. G protein-coupled receptor-receptor interactions give integrative dynamics to intercellular communication. Rev Neurosci 2018; 29:703-726. [DOI: 10.1515/revneuro-2017-0087] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 01/01/2018] [Indexed: 01/14/2023]
Abstract
Abstract
The proposal of receptor-receptor interactions (RRIs) in the early 1980s broadened the view on the role of G protein-coupled receptors (GPCR) in the dynamics of the intercellular communication. RRIs, indeed, allow GPCR to operate not only as monomers but also as receptor complexes, in which the integration of the incoming signals depends on the number, spatial arrangement, and order of activation of the protomers forming the complex. The main biochemical mechanisms controlling the functional interplay of GPCR in the receptor complexes are direct allosteric interactions between protomer domains. The formation of these macromolecular assemblies has several physiologic implications in terms of the modulation of the signaling pathways and interaction with other membrane proteins. It also impacts on the emerging field of connectomics, as it contributes to set and tune the synaptic strength. Furthermore, recent evidence suggests that the transfer of GPCR and GPCR complexes between cells via the exosome pathway could enable the target cells to recognize/decode transmitters and/or modulators for which they did not express the pertinent receptors. Thus, this process may also open the possibility of a new type of redeployment of neural circuits. The fundamental aspects of GPCR complex formation and function are the focus of the present review article.
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Affiliation(s)
- Diego Guidolin
- Department of Neuroscience , University of Padova, via Gabelli 65 , I-35121 Padova , Italy
| | - Manuela Marcoli
- Department of Pharmacy and Center of Excellence for Biomedical Research , University of Genova , I-16126 Genova , Italy
| | - Cinzia Tortorella
- Department of Neuroscience , University of Padova, via Gabelli 65 , I-35121 Padova , Italy
| | - Guido Maura
- Department of Pharmacy and Center of Excellence for Biomedical Research , University of Genova , I-16126 Genova , Italy
| | - Luigi F. Agnati
- Department of Biomedical Sciences , University of Modena and Reggio Emilia , I-41121 Modena , Italy
- Department of Neuroscience , Karolinska Institutet , S-17177 Stockholm , Sweden
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21
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22
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Abstract
Opioids are the most effective drugs for the treatment of severe pain, but they also cause addiction and overdose deaths, which have led to a worldwide opioid crisis. Therefore, the development of safer opioids is urgently needed. In this article, we provide a critical overview of emerging opioid-based strategies aimed at effective pain relief and improved side effect profiles. These approaches comprise biased agonism, the targeting of (i) opioid receptors in peripheral inflamed tissue (by reducing agonist access to the brain, the use of nanocarriers, or low pH-sensitive agonists); (ii) heteromers or multiple receptors (by monovalent, bivalent, and multifunctional ligands); (iii) receptor splice variants; and (iv) endogenous opioid peptides (by preventing their degradation or enhancing their production by gene transfer). Substantial advancements are underscored by pharmaceutical development of new opioids such as peripheral κ-receptor agonists, and by treatments augmenting the action of endogenous opioids, which have entered clinical trials. Additionally, there are several promising novel opioids comprehensively examined in preclinical studies, but also strategies such as biased agonism, which might require careful rethinking.
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Affiliation(s)
- Halina Machelska
- Department of Experimental Anesthesiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Melih Ö Celik
- Department of Experimental Anesthesiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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23
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Olson KM, Lei W, Keresztes A, LaVigne J, Streicher JM. Novel Molecular Strategies and Targets for Opioid Drug Discovery for the Treatment of Chronic Pain. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2017; 90:97-110. [PMID: 28356897 PMCID: PMC5369049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Opioid drugs like morphine and fentanyl are the gold standard for treating moderate to severe acute and chronic pain. However, opioid drug use can be limited by serious side effects, including constipation, tolerance, respiratory suppression, and addiction. For more than 100 years, we have tried to develop opioids that decrease or eliminate these liabilities, with little success. Recent advances in understanding opioid receptor signal transduction have suggested new possibilities to activate the opioid receptors to cause analgesia, while reducing or eliminating unwanted side effects. These new approaches include designing functionally selective ligands, which activate desired signaling cascades while avoiding signaling cascades that are thought to provoke side effects. It may also be possible to directly modulate downstream signaling through the use of selective activators and inhibitors. Separate from downstream signal transduction, it has also been found that when the opioid system is stimulated, various negative feedback systems are upregulated to compensate, which can drive side effects. This has led to the development of multi-functional molecules that simultaneously activate the opioid receptor while blocking various negative feedback receptor systems including cholecystokinin and neurokinin-1. Other novel approaches include targeting heterodimers of the opioid and other receptor systems which may drive side effects, and making endogenous opioid peptides druggable, which may also reduce opioid mediated side effects. Taken together, these advances in our molecular understanding provide a path forward to break the barrier in producing an opioid with reduced or eliminated side effects, especially addiction, which may provide relief for millions of patients.
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Affiliation(s)
- Keith M. Olson
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ,Department of Chemistry and Biochemistry, College of Science, University of Arizona, Tucson, AZ
| | - Wei Lei
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ
| | - Attila Keresztes
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ
| | - Justin LaVigne
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ
| | - John M. Streicher
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ,To whom all correspondence should be addressed: John M. Streicher, Ph.D., University of Arizona, College of Medicine, Department of Pharmacology, Life Sciences North 563, Box 245050, 1501 N. Campbell Ave., Tucson, AZ 85724, 520-626-7495,
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24
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Gaitonde SA, González-Maeso J. Contribution of heteromerization to G protein-coupled receptor function. Curr Opin Pharmacol 2016; 32:23-31. [PMID: 27835800 DOI: 10.1016/j.coph.2016.10.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/22/2016] [Accepted: 10/24/2016] [Indexed: 12/22/2022]
Abstract
G protein-coupled receptors (GPCRs) are a remarkably multifaceted family of transmembrane proteins that exert a variety of physiological effects. Although family A GPCRs are able to operate as monomers, there is increasing evidence that heteromerization represents a fundamental aspect of receptor function, trafficking and pharmacology. Most recently, it has been suggested that GPCR heteromers may play a crucial role as new molecular targets of heteromer-selective and bivalent ligands. The current review summarizes key recent developments in these topics.
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Affiliation(s)
- Supriya A Gaitonde
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, United States
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, United States.
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Abstract
Chronic pain is one of the most ubiquitous diseases in the world, but treatment is difficult with conventional methods, due to undesirable side effects of treatments and unknown mechanisms of pathological pain states. The endogenous peptide, dynorphin A has long been established as a target for the treatment of pain. Interestingly, this unique peptide has both inhibitory (opioid in nature) and excitatory activities (nonopioid) in the CNS. Both of these effects have been found to play a role in pain and much work has been done to develop therapeutics to enhance the inhibitory effects. Here we will review the dynorphin A compounds that have been designed for the modulation of pain and will discuss where the field stands today.
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Abstract
This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, United States.
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Schembri LS, Stoddart LA, Briddon SJ, Kellam B, Canals M, Graham B, Scammells PJ. Synthesis, Biological Evaluation, and Utility of Fluorescent Ligands Targeting the μ-Opioid Receptor. J Med Chem 2015; 58:9754-67. [DOI: 10.1021/acs.jmedchem.5b01664] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
| | - Leigh A. Stoddart
- Cell
Signaling Research Group, School of Life Sciences, Queen’s
Medical Centre, University of Nottingham, Nottingham NG7 2UH, U.K
| | - Stephen J. Briddon
- Cell
Signaling Research Group, School of Life Sciences, Queen’s
Medical Centre, University of Nottingham, Nottingham NG7 2UH, U.K
| | - Barrie Kellam
- School
of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, U.K
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28
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Abstract
G protein-coupled receptors (GPCRs) remain a major domain of pharmaceutical discovery. The identification of GPCR lead compounds and their optimization are now structure-based, thanks to advances in X-ray crystallography, molecular modeling, protein engineering and biophysical techniques. In silico screening provides useful hit molecules. New pharmacological approaches to tuning the pleotropic action of GPCRs include: allosteric modulators, biased ligands, GPCR heterodimer-targeted compounds, manipulation of polypharmacology, receptor antibodies and tailoring of drug molecules to fit GPCR pharmacogenomics. Measurements of kinetics and drug efficacy are factors influencing clinical success. With the exception of inhibitors of GPCR kinases, targeting of intracellular GPCR signaling or receptor cycling for therapeutic purposes remains a futuristic concept. New assay approaches are more efficient and multidimensional: cell-based, label-free, fluorescence-based assays, and biosensors. Tailoring GPCR drugs to a patient's genetic background is now being considered. Chemoinformatic tools can predict ADME-tox properties. New imaging technology visualizes drug action in vivo. Thus, there is reason to be optimistic that new technology for GPCR ligand discovery will help reverse the current narrowing of the pharmaceutical pipeline.
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Affiliation(s)
- Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bldg. 8A, Rm. B1A-19, Bethesda, Maryland 20892, USA.
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Váradi A, Marrone GF, Eans SO, Ganno ML, Subrath JJ, Le Rouzic V, Hunkele A, Pasternak GW, McLaughlin JP, Majumdar S. Synthesis and characterization of a dual kappa-delta opioid receptor agonist analgesic blocking cocaine reward behavior. ACS Chem Neurosci 2015; 6:1813-24. [PMID: 26325040 DOI: 10.1021/acschemneuro.5b00153] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
3-Iodobenzoyl naltrexamine (IBNtxA) is a potent analgesic belonging to the pharmacologically diverse 6β-amidoepoxymorphinan group of opioids. We present the synthesis and pharmacological evaluation of five analogs of IBNtxA. The scaffold of IBNtxA was modified by removing the 14-hydroxy group, incorporating a 7,8 double bond and various N-17 alkyl substituents. The structural modifications resulted in analogs with picomolar affinities for opioid receptors. The lead compound (MP1104) was found to exhibit approximately 15-fold greater antinociceptive potency (ED50 = 0.33 mg/kg) compared with morphine, mediated through the activation of kappa- and delta-opioid receptors. Despite its kappa agonism, this lead derivative did not cause place aversion or preference in mice in a place-conditioning assay, even at doses 3 times the analgesic ED50. However, pretreatment with the lead compound prevented the reward behavior associated with cocaine in a conditioned place preference assay. Together, these results suggest the promise of dual acting kappa- and delta-opioid receptor agonists as analgesics and treatments for cocaine addiction.
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Affiliation(s)
- András Váradi
- Molecular
Pharmacology and Chemistry Program, Department of Neurology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Gina F. Marrone
- Molecular
Pharmacology and Chemistry Program, Department of Neurology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Shainnel O. Eans
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, Florida 34987, United States
| | - Michelle L. Ganno
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, Florida 34987, United States
| | - Joan J. Subrath
- Molecular
Pharmacology and Chemistry Program, Department of Neurology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Valerie Le Rouzic
- Molecular
Pharmacology and Chemistry Program, Department of Neurology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Amanda Hunkele
- Molecular
Pharmacology and Chemistry Program, Department of Neurology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Gavril W. Pasternak
- Molecular
Pharmacology and Chemistry Program, Department of Neurology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
| | - Jay P. McLaughlin
- Torrey Pines Institute for Molecular Studies, 11350 SW Village Parkway, Port St. Lucie, Florida 34987, United States
| | - Susruta Majumdar
- Molecular
Pharmacology and Chemistry Program, Department of Neurology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States
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30
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Pugsley MK, Saint DA, Hayes ES, Abraham S, Walker MJ. An examination of the cardiac actions of PD117,302, a κ-opioid receptor agonist. Eur J Pharmacol 2015; 761:330-40. [DOI: 10.1016/j.ejphar.2015.06.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 06/09/2015] [Accepted: 06/10/2015] [Indexed: 11/16/2022]
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31
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Facile synthesis and biological evaluation of assorted indolyl-3-amides and esters from a single, stable carbonyl nitrile intermediate. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.02.090] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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32
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Guidolin D, Agnati LF, Marcoli M, Borroto-Escuela DO, Fuxe K. G-protein-coupled receptor type A heteromers as an emerging therapeutic target. Expert Opin Ther Targets 2014; 19:265-83. [PMID: 25381716 DOI: 10.1517/14728222.2014.981155] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The discovery of receptor-receptor interactions (RRIs) in the early 1980s provided evidence that G-protein-coupled receptors (GPCRs) operate not only as monomers but also as heteromers, in which integration of the incoming signals takes place already at the plasma membrane level through allosteric RRIs. These integrative mechanisms give sophisticated dynamics to the structure and function of these receptor assemblies in terms of modulation of recognition, G-protein signaling and selectivity and switching to β-arrestin signaling. AREAS COVERED The present review briefly describes the concept of direct RRI and the available data on the mechanisms of oligomer formation. Further, pharmacological data concerning the best characterized heteromers involving type A GPCRs will be analyzed to evaluate their profile as possible targets for the treatment of various diseases, in particular of impacting diseases of the CNS. EXPERT OPINION GPCR heteromers have the potential to open a completely new field for pharmacology with likely a major impact in molecular medicine. Novel pharmacological strategies for the treatment of several pathologies have already been proposed. However, several challenges still exist to accurately characterize the role of the identified heteroreceptor complexes in pathology and to develop heteromer-specific ligands capable of efficiently exploiting their pharmacological features.
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Affiliation(s)
- Diego Guidolin
- University of Padova, Department of Molecular Medicine , via Gabelli 65, 35121 Padova , Italy +39 049 8272316 ; +39 049 8272319 ;
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