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Morales P, Goya P, Jagerovic N, Hernandez-Folgado L. Allosteric Modulators of the CB 1 Cannabinoid Receptor: A Structural Update Review. Cannabis Cannabinoid Res 2016; 1:22-30. [PMID: 28861476 PMCID: PMC5576597 DOI: 10.1089/can.2015.0005] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In 2005, the first evidence of an allosteric binding site at the CB1R was provided by the identification of three indoles of the company Organon that were allosteric enhancers of agonist binding affinity and, functionally, allosteric inhibitors of agonist activity. Since then, structure–activity relationships of indoles as CB1R modulators have been reported. Targeting the allosteric site on CB1R, new families structurally based on urea and on 3-phenyltropane analogs of cocaine have been discovered as CB1R-negative allosteric modulators (NAMs), respectively, by Prosidion and by the Research Triangle Park. Endogenous allosteric ligands of different nature have been identified more recently. Thus, the therapeutic neuroprotection application of lipoxin A4, an arachidonic acid derivative, as an allosteric enhancer of CB1R activity has been confirmed in vivo. It was also the case of the steroid hormone, pregnenolone, whose negative allosteric effects on Δ9-tetrahydrocannabinol (Δ9-THC) were reproduced in vivo in a behavioral tetrad model and in food intake and memory impairment assays. Curiously, the peroxisome proliferator-activated receptor-γ agonist fenofibrate or polypeptides such as pepcan-12 have been shown to act on the endocannabinoid system through CB1R allosteric modulation. The mechanistic bases of the effects of the phytocannabinoid cannabidiol (CBD) are still not fully explained. However, there is evidence that CBD behaves as an NAM of Δ9-THC- and 2-AG. Allosteric modulation at CB1R offers new opportunities for therapeutic applications. Therefore, further understanding of the chemical features required for allosteric modulation as well as their orthosteric probe dependence may broaden novel approaches for fine-tuning the signaling pathways of the CB1R.
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Affiliation(s)
- Paula Morales
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Pilar Goya
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Nadine Jagerovic
- Instituto de Química Médica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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Kulkarni PM, Kulkarni AR, Korde A, Tichkule RB, Laprairie RB, Denovan-Wright EM, Zhou H, Janero DR, Zvonok N, Makriyannis A, Cascio MG, Pertwee RG, Thakur GA. Novel Electrophilic and Photoaffinity Covalent Probes for Mapping the Cannabinoid 1 Receptor Allosteric Site(s). J Med Chem 2015; 59:44-60. [PMID: 26529344 PMCID: PMC4716578 DOI: 10.1021/acs.jmedchem.5b01303] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
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Undesirable side effects associated
with orthosteric agonists/antagonists of cannabinoid 1 receptor (CB1R),
a tractable target for treating several pathologies affecting humans,
have greatly limited their translational potential. Recent discovery
of CB1R negative allosteric modulators (NAMs) has renewed interest
in CB1R by offering a potentially safer therapeutic avenue. To elucidate
the CB1R allosteric binding motif and thereby facilitate rational
drug discovery, we report the synthesis and biochemical characterization
of first covalent ligands designed to bind irreversibly to the CB1R
allosteric site. Either an electrophilic or a photoactivatable group
was introduced at key positions of two classical CB1R NAMs: Org27569
(1) and PSNCBAM-1 (2). Among these, 20 (GAT100) emerged as the most potent NAM in functional assays,
did not exhibit inverse agonism, and behaved as a robust positive
allosteric modulator of binding of orthosteric agonist CP55,940. This
novel covalent probe can serve as a useful tool for characterizing
CB1R allosteric ligand-binding motifs.
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Affiliation(s)
| | | | | | | | - Robert B Laprairie
- Department of Pharmacology, Dalhousie University , Halifax NS Canada B3H 4R2
| | | | | | | | | | | | - Maria G Cascio
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen , Foresterhill, Aberdeen, AB25 2ZD, Scotland
| | - Roger G Pertwee
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen , Foresterhill, Aberdeen, AB25 2ZD, Scotland
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Stornaiuolo M, Bruno A, Botta L, La Regina G, Cosconati S, Silvestri R, Marinelli L, Novellino E. Endogenous vs Exogenous Allosteric Modulators in GPCRs: A dispute for shuttling CB1 among different membrane microenvironments. Sci Rep 2015; 5:15453. [PMID: 26482099 PMCID: PMC4612305 DOI: 10.1038/srep15453] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/21/2015] [Indexed: 11/26/2022] Open
Abstract
A Cannabinoid Receptor 1 (CB1) binding site for the selective allosteric modulator ORG27569 is here identified through an integrate approach of consensus pocket prediction, mutagenesis studies and Mass Spectrometry. This unprecedented ORG27569 pocket presents the structural features of a Cholesterol Consensus Motif, a cholesterol interacting region already found in other GPCRs. ORG27569 and cholesterol affects oppositely CB1 affinity for orthosteric ligands. Moreover, the rise in cholesterol intracellular level results in CB1 trafficking to the axonal region of neuronal cells, while, on the contrary, ORG27568 binding induces CB1 enrichment at the soma. This control of receptor migration among functionally different membrane regions of the cell further contributes to downstream signalling and adds a previously unknown mechanism underpinning CB1 modulation by ORG27569 , that goes beyond a mere control of receptor affinity for orthosteric ligands.
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Affiliation(s)
- Mariano Stornaiuolo
- Department of Pharmacy, University of Naples "Federico II", via D. Montesano 49, 80131 Naples, Italy
| | - Agostino Bruno
- Department of Pharmacy, University of Naples "Federico II", via D. Montesano 49, 80131 Naples, Italy
| | - Lorenzo Botta
- Department of Pharmacy, University of Naples "Federico II", via D. Montesano 49, 80131 Naples, Italy
| | - Giuseppe La Regina
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Sandro Cosconati
- DiSTABiF, Seconda Università di Napoli, Via Vivaldi 43, 81100 Caserta, Italy
| | - Romano Silvestri
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Luciana Marinelli
- Department of Pharmacy, University of Naples "Federico II", via D. Montesano 49, 80131 Naples, Italy
| | - Ettore Novellino
- Department of Pharmacy, University of Naples "Federico II", via D. Montesano 49, 80131 Naples, Italy
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54
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Straiker A, Mitjavila J, Yin D, Gibson A, Mackie K. Aiming for allosterism: Evaluation of allosteric modulators of CB1 in a neuronal model. Pharmacol Res 2015. [PMID: 26211948 DOI: 10.1016/j.phrs.2015.07.017] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cannabinoid pharmacology has proven nettlesome with issues of promiscuity a common theme among both agonists and antagonists. One recourse is to develop allosteric ligands to modulate cannabinoid receptor signaling. Cannabinoids have come late to the allosteric table. The 'first-generation' negative and positive allosteric modulators (NAMs and PAMs) represent an important first effort. However, most studies have relied on synthetic agonists, often tested in over-expression systems rather than a defined neuronal model system that utilizes endogenously synthesized and released cannabinoids. We have systematically examined first-generation NAMs and a PAM on endocannabinoid modulation of synaptic transmission in cultured autaptic hippocampal neurons. These neurons exhibit CB1 and 2-arachidonoyl glycerol (2-AG)-mediated depolarization induced suppression of excitation (DSE) and therefore serve as a model to test CB1 modulators in a neuronal model of endogenous cannabinoid signaling. We find ORG27569, PSNCBAM-1, and PEPCAN12 attenuate DSE and do not directly inhibit CB1 receptors. Of these PSNCBAM-1 is the most efficacious while PEPCAN12 has the distinction of being an endogenous NAM. The reported NAMs pregnenolone and hemopressin as well as the reported PAM lipoxin A4 are without effect in this model of endocannabinoid signaling. In summary, three of the allosteric modulators evaluated function in a manner consistent with allosterism in a neuronal 2-AG-based model of endogenous cannabinoid signaling.
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Affiliation(s)
- Alex Straiker
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, 1101 E, 10th St, Bloomington, IN 47405, United States.
| | - José Mitjavila
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, 1101 E, 10th St, Bloomington, IN 47405, United States
| | - Danielle Yin
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, 1101 E, 10th St, Bloomington, IN 47405, United States
| | - Anne Gibson
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, 1101 E, 10th St, Bloomington, IN 47405, United States
| | - Ken Mackie
- Department of Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, 1101 E, 10th St, Bloomington, IN 47405, United States
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55
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Cawston EE, Connor M, Di Marzo V, Silvestri R, Glass M. Distinct Temporal Fingerprint for Cyclic Adenosine Monophosphate (cAMP) Signaling of Indole-2-carboxamides as Allosteric Modulators of the Cannabinoid Receptors. J Med Chem 2015. [PMID: 26203658 DOI: 10.1021/acs.jmedchem.5b00579] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
ORG27569 (1) is an allosteric modulator of CB1. 1 produces a distinct cAMP temporal fingerprint with complex time-dependent modulation of agonist-mediated responses. The aim of this study was to characterize the cAMP signaling response of indole-2-carboxamides structurally correlated to 1 for both CB1 and CB2. We show that at CB1 1, 10, 13, and 18 display a delay in inhibiting CP55,940-mediated cAMP inhibition, whereas compounds 7, 14, 15, 16, 20, and 22 act immediately. To further characterize this, compounds 1, 10, 13, 14, 15, 18, and 20 were tested for their influence on CP55,940-mediated hyperpolarization in AtT20-hCB1 cells. Intriguingly, all compounds generated a response similar to that of 1, producing no decrease in CB1-mediated peak hyperpolarization at concentrations up to 10 μM but enhancing the rate at which the channel repolarizes. Additionally, we show that compounds 5, 10, and 20 indole-2-carboxamides modulate cAMP signaling through CB2.
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Affiliation(s)
- Erin E Cawston
- †Centre for Brain Research and Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Mark Connor
- ‡Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, 2 Technology Place, Sydney, NSW 2109, Australia
| | - Vincenzo Di Marzo
- §Istituto di Chemica Biomolecolare, Consiglio Nazionale delle Ricerche, Via Campi Flegrei 34, Comprensorio Olivetti, I-80078 Pozzuoli, Napoli, Italy
| | - Romano Silvestri
- ∥Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185, Rome, Italy
| | - Michelle Glass
- †Centre for Brain Research and Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
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56
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Structural dynamics and energetics underlying allosteric inactivation of the cannabinoid receptor CB1. Proc Natl Acad Sci U S A 2015; 112:8469-74. [PMID: 26100912 DOI: 10.1073/pnas.1500895112] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are surprisingly flexible molecules that can do much more than simply turn on G proteins. Some even exhibit biased signaling, wherein the same receptor preferentially activates different G-protein or arrestin signaling pathways depending on the type of ligand bound. Why this behavior occurs is still unclear, but it can happen with both traditional ligands and ligands that bind allosterically outside the orthosteric receptor binding pocket. Here, we looked for structural mechanisms underlying these phenomena in the marijuana receptor CB1. Our work focused on the allosteric ligand Org 27569, which has an unusual effect on CB1-it simultaneously increases agonist binding, decreases G--protein activation, and induces biased signaling. Using classical pharmacological binding studies, we find that Org 27569 binds to a unique allosteric site on CB1 and show that it can act alone (without need for agonist cobinding). Through mutagenesis studies, we find that the ability of Org 27569 to bind is related to how much receptor is in an active conformation that can couple with G protein. Using these data, we estimated the energy differences between the inactive and active states. Finally, site-directed fluorescence labeling studies show the CB1 structure stabilized by Org 27569 is different and unique from that stabilized by antagonist or agonist. Specifically, transmembrane helix 6 (TM6) movements associated with G-protein activation are blocked, but at the same time, helix 8/TM7 movements are enhanced, suggesting a possible mechanism for the ability of Org 27569 to induce biased signaling.
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57
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Feng Z, Hu G, Ma S, Xie XQ. Computational Advances for the Development of Allosteric Modulators and Bitopic Ligands in G Protein-Coupled Receptors. AAPS JOURNAL 2015; 17:1080-95. [PMID: 25940084 DOI: 10.1208/s12248-015-9776-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/21/2015] [Indexed: 12/14/2022]
Abstract
Allosteric modulators of G protein-coupled receptors (GPCRs), which target at allosteric sites, have significant advantages against the corresponding orthosteric compounds including higher selectivity, improved chemical tractability or physicochemical properties, and reduced risk of receptor oversensitization. Bitopic ligands of GPCRs target both orthosteric and allosteric sites. Bitopic ligands can improve binding affinity, enhance subtype selectivity, stabilize receptors, and reduce side effects. Discovering allosteric modulators or bitopic ligands for GPCRs has become an emerging research area, in which the design of allosteric modulators is a key step in the detection of bitopic ligands. Radioligand binding and functional assays ([(35)S]GTPγS and ERK1/2 phosphorylation) are used to test the effects for potential modulators or bitopic ligands. High-throughput screening (HTS) in combination with disulfide trapping and fragment-based screening are used to aid the discovery of the allosteric modulators or bitopic ligands of GPCRs. When used alone, these methods are costly and can often result in too many potential drug targets, including false positives. Alternatively, low-cost and efficient computational approaches are useful in drug discovery of novel allosteric modulators and bitopic ligands to help refine the number of targets and reduce the false-positive rates. This review summarizes the state-of-the-art computational methods for the discovery of modulators and bitopic ligands. The challenges and opportunities for future drug discovery are also discussed.
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Affiliation(s)
- Zhiwei Feng
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, 3501 Terrace Street, 529 Salk Hall, Pittsburgh, Pennsylvania, 15261, USA
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58
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Nimczick M, Decker M. New Approaches in the Design and Development of Cannabinoid Receptor Ligands: Multifunctional and Bivalent Compounds. ChemMedChem 2015; 10:773-86. [DOI: 10.1002/cmdc.201500041] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Indexed: 12/22/2022]
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59
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Nguyen T, German N, Decker AM, Li JX, Wiley JL, Thomas BF, Kenakin TP, Zhang Y. Structure-activity relationships of substituted 1H-indole-2-carboxamides as CB1 receptor allosteric modulators. Bioorg Med Chem 2015; 23:2195-2203. [PMID: 25797163 DOI: 10.1016/j.bmc.2015.02.058] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/20/2015] [Accepted: 02/26/2015] [Indexed: 12/15/2022]
Abstract
A series of substituted 1H-indole-2-carboxamides structurally related to compounds Org27569 (1), Org29647 (2) and Org27759 (3) were synthesized and evaluated for CB1 allosteric modulating activity in calcium mobilization assays. Structure-activity relationship studies showed that the modulation potency of this series at the CB1 receptor was enhanced by the presence of a diethylamino group at the 4-position of the phenyl ring, a chloro or fluoro group at the C5 position and short alkyl groups at the C3 position on the indole ring. The most potent compound (45) had an IC₅₀ value of 79 nM which is ∼2.5 and 10 fold more potent than the parent compounds 3 and 1, respectively. These compounds appeared to be negative allosteric modulators at the CB1 receptor and dose-dependently reduced the Emax of agonist CP55,940. These analogs may provide the basis for further optimization and use of CB1 allosteric modulators.
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Affiliation(s)
- Thuy Nguyen
- Research Triangle Institute, Research Triangle Park, North Carolina 27709, United States
| | - Nadezhda German
- Research Triangle Institute, Research Triangle Park, North Carolina 27709, United States
| | - Ann M Decker
- Research Triangle Institute, Research Triangle Park, North Carolina 27709, United States
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, University at Buffalo, the State University of New York, Buffalo, New York 14214, United States
| | - Jenny L Wiley
- Research Triangle Institute, Research Triangle Park, North Carolina 27709, United States
| | - Brian F Thomas
- Research Triangle Institute, Research Triangle Park, North Carolina 27709, United States
| | - Terry P Kenakin
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Yanan Zhang
- Research Triangle Institute, Research Triangle Park, North Carolina 27709, United States
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60
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Priestley RS, Nickolls SA, Alexander SPH, Kendall DA. A potential role for cannabinoid receptors in the therapeutic action of fenofibrate. FASEB J 2014; 29:1446-55. [PMID: 25550466 DOI: 10.1096/fj.14-263053] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 12/01/2014] [Indexed: 01/26/2023]
Abstract
Cannabinoids are reported to have actions through peroxisome proliferator-activated receptors (PPARs), which led us to investigate PPAR agonists for activity at the cannabinoid receptors. Radio-ligand binding and functional assays were conducted using human recombinant cannabinoid type 1 (CB1) or cannabinoid type 2 (CB2) receptors, as well as the guinea pig isolated ileum, using the full agonist CP55940 as a positive control. The PPAR-α agonist fenofibrate exhibited submicromolar affinity for both receptors (pKi CB1, 6.3 ± 0.1; CB2, 7.7 ± 0.1). Functionally, fenofibrate acted as an agonist at the CB2 receptor (pEC50, 7.7 ± 0.1) and a partial agonist at the CB1 receptor, although with a decrease in functional response at higher concentrations, producing bell-shaped concentration-response curves. High concentrations of fenofibrate were able to increase the dissociation rate constant for [(3)H]-CP55940 at the CB1 receptor, (kfast without: 1.2 ± 0.2/min; with: 3.8 ± 0.1 × 10(-2)/min) and decrease the maximal response to CP55940 (Rmax, 86 ± 2%), which is consistent with a negative allosteric modulator. Fenofibrate also reduced electrically induced contractions in isolated guinea pig ileum via CB1 receptors (pEC50, 6.0 ± 0.4). Fenofibrate is thus identified as an example of a new class of cannabinoid receptor ligand and allosteric modulator, with the potential to interact therapeutically with cannabinoid receptors in addition to its primary PPAR target.
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Affiliation(s)
- Richard S Priestley
- *School of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom; and Neusentis-Pfizer Limited, Great Abington, Cambridge, United Kingdom
| | - Sarah A Nickolls
- *School of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom; and Neusentis-Pfizer Limited, Great Abington, Cambridge, United Kingdom
| | - Stephen P H Alexander
- *School of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom; and Neusentis-Pfizer Limited, Great Abington, Cambridge, United Kingdom
| | - David A Kendall
- *School of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom; and Neusentis-Pfizer Limited, Great Abington, Cambridge, United Kingdom
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61
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Jing L, Qiu Y, Zhang Y, Li JX. Effects of the cannabinoid CB₁ receptor allosteric modulator ORG 27569 on reinstatement of cocaine- and methamphetamine-seeking behavior in rats. Drug Alcohol Depend 2014; 143:251-6. [PMID: 25169627 PMCID: PMC4161648 DOI: 10.1016/j.drugalcdep.2014.08.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 07/31/2014] [Accepted: 08/02/2014] [Indexed: 12/25/2022]
Abstract
BACKGROUND Cannabinoid CB1 receptors play an essential role in drug addiction. Given the side effect profiles of orthosteric CB1 antagonism, new strategies have been attempted to modulate this target, such as CB1 receptor allosteric modulation. However, the effect of CB1 allosteric modulation in drug addiction is unknown. The present study examined the effects of the CB1 receptor allosteric modulator ORG27569 on the reinstatement of cocaine- and methamphetamine-seeking behavior in rats. METHODS Rats were trained to self-administer 0.75 mg/kg cocaine or 0.05 mg/kg methamphetamine in 2-h daily sessions for 14 days which was followed by 7 days of extinction sessions in which rats responded on the levers with no programmed consequences. On reinstatement test sessions, rats were administered ORG27569 (1.0, 3.2, 5.6 mg/kg, i.p.) or SR141716A (3.2 mg/kg, i.p.) 10 min prior to re-exposure to cocaine- or methamphetamine-paired cues or a priming injection of cocaine (10mg/kg, i.p.) or methamphetamine (1mg/kg, i.p.). RESULTS Both cues and a priming injection of cocaine or methamphetamine significantly reinstated the extinguished active lever responding. Pretreatment with ORG27569 resulted in a dose-related attenuation of both cue- and drug-induced reinstatement of cocaine- and methamphetamine-seeking behavior. SR141716A also exhibited similar inhibitory action on reinstatement of drug-seeking behavior. CONCLUSION Negative allosteric modulation of CB1 receptors can produce similar functional antagonism as orthosteric CB1 receptor antagonists on reinstatement of drug-seeking behavior. Thus, ORG27569 or other negative allosteric modulators deserve further study as potentially effective pharmacotherapy for drug addiction.
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Affiliation(s)
- Li Jing
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York, USA
,Department of Physiology and Pathophysiology, Tianjin Medical University, Tianjin, China
| | - Yanyan Qiu
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York, USA
| | - Yanan Zhang
- Research Triangle Institute, Research Triangle Park, North Carolina, USA
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, NY, USA.
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62
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German N, Decker AM, Gilmour BP, Gay EA, Wiley JL, Thomas BF, Zhang Y. Diarylureas as allosteric modulators of the cannabinoid CB1 receptor: structure-activity relationship studies on 1-(4-chlorophenyl)-3-{3-[6-(pyrrolidin-1-yl)pyridin-2-yl]phenyl}urea (PSNCBAM-1). J Med Chem 2014; 57:7758-69. [PMID: 25162172 PMCID: PMC4175001 DOI: 10.1021/jm501042u] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Indexed: 12/22/2022]
Abstract
The recent discovery of allosteric modulators of the CB1 receptor including PSNCBAM-1 (4) has generated significant interest in CB1 receptor allosteric modulation. Here in the first SAR study on 4, we have designed and synthesized a series of analogs focusing on modifications at two positions. Pharmacological evaluation in calcium mobilization and binding assays revealed the importance of alkyl substitution at the 2-aminopyridine moiety and electron deficient aromatic groups at the 4-chlorophenyl position for activity at the CB1 receptor, resulting in several analogs with comparable potency to 4. These compounds increased the specific binding of [(3)H]CP55,940, in agreement with previous reports. Importantly, 4 and two analogs dose-dependently reduced the Emax of the agonist curve in the CB1 calcium mobilization assays, confirming their negative allosteric modulator characteristics. Given the side effects associated with CB1 receptor orthosteric antagonists, negative allosteric modulators provide an alternative approach to modulate the pharmacologically important CB1 receptor.
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Affiliation(s)
- Nadezhda German
- Research Triangle Institute, Research
Triangle Park, North Carolina 27709, United States
| | - Ann M. Decker
- Research Triangle Institute, Research
Triangle Park, North Carolina 27709, United States
| | - Brian P. Gilmour
- Research Triangle Institute, Research
Triangle Park, North Carolina 27709, United States
| | - Elaine A. Gay
- Research Triangle Institute, Research
Triangle Park, North Carolina 27709, United States
| | - Jenny L. Wiley
- Research Triangle Institute, Research
Triangle Park, North Carolina 27709, United States
| | - Brian F. Thomas
- Research Triangle Institute, Research
Triangle Park, North Carolina 27709, United States
| | - Yanan Zhang
- Research Triangle Institute, Research
Triangle Park, North Carolina 27709, United States
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63
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Ding Y, Qiu Y, Jing L, Thorn DA, Zhang Y, Li JX. Behavioral effects of the cannabinoid CB1 receptor allosteric modulator ORG27569 in rats. Pharmacol Res Perspect 2014; 2:e00069. [PMID: 25431655 PMCID: PMC4186448 DOI: 10.1002/prp2.69] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 07/15/2014] [Indexed: 01/03/2023] Open
Abstract
The cannabinoid CB1 receptor system is involved in feeding behaviors and the CB1 receptor antagonist SR141716A is an effective antiobesity drug. However, SR141716A also has serious side effects, which prompted the exploration of alternative strategies to modulate this important drug target. Recently a CB1 receptor allosteric modulating site has been discovered and the allosteric modulating activity of several modulators including ORG27569 has been characterized in vitro. Yet, little is known of the in vivo pharmacological effects of ORG27569. This study examined the behavioral pharmacology of ORG27569 in rats. ORG27569 (3.2–10 mg/kg, i.p.) selectively attenuated the hypothermic effects of CB1 receptor agonists CP55940 (0.1–1 mg/kg) and anandamide (3.2–32 mg/kg). In contrast, SR141716A only attenuated the hypothermic effects of CP55940 but not anandamide. SR141716A but not ORG27569 blocked CP55940-induced catalepsy and antinociception. In addition, ORG27569 did not modify SR141716A-elicited grooming and scratching behaviors. In feeding studies, ORG27569 decreased palatable and plain food intake which was partially blocked by CP55940. The hypophagic effect of ORG27569 developed tolerance after 4 days of daily 5.6 mg/kg treatment; however, the effect on body weight gain outlasted the drug treatment for 10 days. These data suggest that ORG27569 may not function as a CB1 receptor allosteric modulator in vivo, although its hypophagic activity still has potential therapeutic utility.
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Affiliation(s)
- Yuanyuan Ding
- Department of Pharmacology and Toxicology, University at Buffalo Buffalo, New York
| | - Yanyan Qiu
- Department of Pharmacology and Toxicology, University at Buffalo Buffalo, New York
| | - Li Jing
- Department of Pharmacology and Toxicology, University at Buffalo Buffalo, New York ; Department of Physiology and Pathophysiology, Tianjin Medical University Tianjin, China
| | - David A Thorn
- Department of Pharmacology and Toxicology, University at Buffalo Buffalo, New York
| | - Yanan Zhang
- Research Triangle Institute Research Triangle Park, North Carolina
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, University at Buffalo Buffalo, New York
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