1
|
Gavryushov S, Bashilov A, Cherashev-Tumanov KV, Kuzmich NN, Burykina TI, Izotov BN. Interaction of Synthetic Cannabinoid Receptor Agonists with Cannabinoid Receptor I: Insights into Activation Molecular Mechanism. Int J Mol Sci 2023; 24:14874. [PMID: 37834323 PMCID: PMC10574015 DOI: 10.3390/ijms241914874] [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: 08/31/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) have become a wide group of new psychoactive substances since the 2010s. For the last few years, the X-ray structures of the complexes of cannabinoid receptor I (CB1) with SCRAs as well as the complexes of CB1 with its antagonist have been published. Based on those data, SCRA-CB1 interactions are analyzed in detail, using molecular modeling and molecular dynamics simulations. The molecular mechanism of the conformational transformation of the transmembrane domain of CB1 caused by its interaction with SCRA is studied. These conformational changes allosterically modulate the CB1-Gi complex, providing activation of the Gi protein. Based on the X-ray-determined structures of the CB1-ligand complexes, a stable apo conformation of inactive CB1 with a relatively low potential barrier of receptor activation was modeled. For that model, molecular dynamic simulations of SCRA binding to CB1 led to the active state of CB1, which allowed us to explore the key features of this activation and the molecular mechanism of the receptor's structural transformation. The simulated CB1 activation is in accordance with the previously published experimental data for the activation at protein mutations or structural changes of ligands. The key feature of the suggested activation mechanism is the determination of the stiff core of the CB1 transmembrane domain and the statement that the entire conformational transformation of the receptor to the active state is caused by a shift of alpha helix TM7 relative to this core. The shift itself is caused by protein-ligand interactions. It was verified via steered molecular dynamics simulations of the X-ray-determined structures of the inactive receptor, which resulted in the active conformation of CB1 irrespective of the placement of agonist ligand in the receptor's active site.
Collapse
Affiliation(s)
- Sergei Gavryushov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova Str. 32, Moscow 119991, Russia
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 2-4 Bolshaya Pirogovskaya Str., Moscow 119991, Russia; (A.B.); (K.V.C.-T.); (T.I.B.); (B.N.I.)
| | - Anton Bashilov
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 2-4 Bolshaya Pirogovskaya Str., Moscow 119991, Russia; (A.B.); (K.V.C.-T.); (T.I.B.); (B.N.I.)
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, Moscow 121205, Russia
| | - Konstantin V. Cherashev-Tumanov
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 2-4 Bolshaya Pirogovskaya Str., Moscow 119991, Russia; (A.B.); (K.V.C.-T.); (T.I.B.); (B.N.I.)
| | - Nikolay N. Kuzmich
- The Maurice and Vivienne Wohl Institute for Drug Discovery, Weizmann Institute of Science, Rehovot 7610001, Israel;
| | - Tatyana I. Burykina
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 2-4 Bolshaya Pirogovskaya Str., Moscow 119991, Russia; (A.B.); (K.V.C.-T.); (T.I.B.); (B.N.I.)
| | - Boris N. Izotov
- Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 2-4 Bolshaya Pirogovskaya Str., Moscow 119991, Russia; (A.B.); (K.V.C.-T.); (T.I.B.); (B.N.I.)
| |
Collapse
|
2
|
Morales P, Reggio PH. An Update on Non-CB 1, Non-CB 2 Cannabinoid Related G-Protein-Coupled Receptors. Cannabis Cannabinoid Res 2017; 2:265-273. [PMID: 29098189 PMCID: PMC5665501 DOI: 10.1089/can.2017.0036] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The endocannabinoid system (ECS) has been shown to be of great importance in the regulation of numerous physiological and pathological processes. To date, two Class A G-protein-coupled receptors (GPCRs) have been discovered and validated as the main therapeutic targets of this system: the cannabinoid receptor type 1 (CB1), which is the most abundant neuromodulatory receptor in the brain, and the cannabinoid receptor type 2 (CB2), predominantly found in the immune system among other organs and tissues. Endogenous cannabinoid receptor ligands (endocannabinoids) and the enzymes involved in their synthesis, cell uptake, and degradation have also been identified as part of the ECS. However, its complex pharmacology suggests that other GPCRs may also play physiologically relevant roles in this therapeutically promising system. In the last years, GPCRs such as GPR18 and GPR55 have emerged as possible missing members of the cannabinoid family. This categorization still stimulates strong debate due to the lack of pharmacological tools to validate it. Because of their close phylogenetic relationship, the Class A orphan GPCRs, GPR3, GPR6, and GPR12, have also been associated with the cannabinoids. Moreover, certain endo-, phyto-, and synthetic cannabinoid ligands have displayed activity at other well-established GPCRs, including the opioid, adenosine, serotonin, and dopamine receptor families. In addition, the cannabinoid receptors have also been shown to form dimers with other GPCRs triggering cross-talk signaling under specific conditions. In this mini review, we aim to provide insight into the non-CB1, non-CB2 cannabinoid-related GPCRs that have been reported thus far. We consider the physiological relevance of these molecular targets in modulating the ECS.
Collapse
Affiliation(s)
- Paula Morales
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, North Carolina
| | - Patricia H. Reggio
- Chemistry and Biochemistry Department, UNC Greensboro, Greensboro, North Carolina
| |
Collapse
|
3
|
Mollica A, Pelliccia S, Famiglini V, Stefanucci A, Macedonio G, Chiavaroli A, Orlando G, Brunetti L, Ferrante C, Pieretti S, Novellino E, Benyhe S, Zador F, Erdei A, Szucs E, Samavati R, Dvrorasko S, Tomboly C, Ragno R, Patsilinakos A, Silvestri R. Exploring the first Rimonabant analog-opioid peptide hybrid compound, as bivalent ligand for CB1 and opioid receptors. J Enzyme Inhib Med Chem 2017; 32:444-451. [PMID: 28097916 PMCID: PMC6009935 DOI: 10.1080/14756366.2016.1260565] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Cannabinoid (CB) and opioid systems are both involved in analgesia, food intake, mood and behavior. Due to the co-localization of µ-opioid (MOR) and CB1 receptors in various regions of the central nervous system (CNS) and their ability to form heterodimers, bivalent ligands targeting to both these systems may be good candidates to investigate the existence of possible cross-talking or synergistic effects, also at sub-effective doses. In this work, we selected from a small series of new Rimonabant analogs one CB1R reverse agonist to be conjugated to the opioid fragment Tyr-D-Ala-Gly-Phe-NH2. The bivalent compound (9) has been used for in vitro binding assays, for in vivo antinociception models and in vitro hypothalamic perfusion test, to evaluate the neurotransmitters release.
Collapse
Affiliation(s)
- Adriano Mollica
- a Dipartimento di Farmacia , Università di Chieti-Pescara "G. d'Annunzio" , Chieti , Italy
| | - Sveva Pelliccia
- b Dipartimento di Chimica e Tecnologie del Farmaco , Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma , Roma , Italy
| | - Valeria Famiglini
- b Dipartimento di Chimica e Tecnologie del Farmaco , Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma , Roma , Italy
| | - Azzurra Stefanucci
- a Dipartimento di Farmacia , Università di Chieti-Pescara "G. d'Annunzio" , Chieti , Italy
| | - Giorgia Macedonio
- a Dipartimento di Farmacia , Università di Chieti-Pescara "G. d'Annunzio" , Chieti , Italy
| | - Annalisa Chiavaroli
- a Dipartimento di Farmacia , Università di Chieti-Pescara "G. d'Annunzio" , Chieti , Italy
| | - Giustino Orlando
- a Dipartimento di Farmacia , Università di Chieti-Pescara "G. d'Annunzio" , Chieti , Italy
| | - Luigi Brunetti
- a Dipartimento di Farmacia , Università di Chieti-Pescara "G. d'Annunzio" , Chieti , Italy
| | - Claudio Ferrante
- a Dipartimento di Farmacia , Università di Chieti-Pescara "G. d'Annunzio" , Chieti , Italy
| | - Stefano Pieretti
- c Dipartimento del Farmaco , Istituto Superiore di Sanità , Rome , Italy
| | - Ettore Novellino
- d Dipartimento di Farmacia , Università di Napoli "Federico II" , Naples , Italy
| | - Sandor Benyhe
- e Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences , Szeged , Hungary
| | - Ferenc Zador
- e Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences , Szeged , Hungary
| | - Anna Erdei
- e Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences , Szeged , Hungary
| | - Edina Szucs
- e Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences , Szeged , Hungary
| | - Reza Samavati
- e Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences , Szeged , Hungary
| | - Szalbolch Dvrorasko
- e Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences , Szeged , Hungary
| | - Csaba Tomboly
- e Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences , Szeged , Hungary
| | - Rino Ragno
- f Dipartimento di Chimica e Tecnologie del Farmaco , Rome Center for Molecular Design, Sapienza Università di Roma , Roma , Italy.,g Alchemical Dynamics s.r.l , Roma , Italy
| | - Alexandros Patsilinakos
- f Dipartimento di Chimica e Tecnologie del Farmaco , Rome Center for Molecular Design, Sapienza Università di Roma , Roma , Italy.,g Alchemical Dynamics s.r.l , Roma , Italy
| | - Romano Silvestri
- b Dipartimento di Chimica e Tecnologie del Farmaco , Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma , Roma , Italy
| |
Collapse
|
4
|
Low dosage of rimonabant leads to anxiolytic-like behavior via inhibiting expression levels and G-protein activity of kappa opioid receptors in a cannabinoid receptor independent manner. Neuropharmacology 2015; 89:298-307. [DOI: 10.1016/j.neuropharm.2014.10.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/19/2014] [Accepted: 10/04/2014] [Indexed: 12/15/2022]
|
5
|
Abstract
The cannabinoid receptors are G protein-coupled receptors activated by endocannabinoids or exogenous agonist such as tetrahydrocannabinol. Upon agonist binding, cannabinoid receptors will activate G proteins of the Gi family, which in turn inhibits adenylyl cyclase. Recently, inverse agonists and neutral antagonist for cannabinoid receptors have been discovered, demonstrating constitutive activity of the cannabinoid receptors. This chapter will discuss the current state of the art and provide a framework for evaluating constitutive receptor activity and distinguishing constitutive receptor activity from constitutive endogenous agonist tone.
Collapse
|
6
|
Zádor F, Kocsis D, Borsodi A, Benyhe S. Micromolar concentrations of rimonabant directly inhibits delta opioid receptor specific ligand binding and agonist-induced G-protein activity. Neurochem Int 2014; 67:14-22. [PMID: 24508403 DOI: 10.1016/j.neuint.2013.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 11/26/2013] [Accepted: 12/17/2013] [Indexed: 12/16/2022]
Abstract
WHAT IS KNOWN There is a growing number of evidence showing, that the cannabinoid receptor 1 (CB1) antagonist rimonabant has many non-cannabimimetic actions, such as affecting the opioid system. The direct effect of rimonabant on opioid receptors has been studied so far mainly on μ-opioid receptors. However recently the δ-opioid receptor (DOR) receives much more attention as before, due to its potential therapeutic applications, such as nociception or treatment for psychiatric disorders. OBJECTIVES To investigate the direct effect of rimonabant on DOR specific ligand binding and on the DOR mediated G-protein activation. RESULTS Micromolar concentrations of rimonabant directly inhibited the DOR specific agonist binding in radioligand competition binding experiments using Chinese hamster ovary cells stably transfected with mouse DOR (CHO-mDOR). However the inhibition occurred also in the subnanomolar range during DOR specific antagonist binding in similar experimental conditions. In functional [(35)S]GTPγS binding assays rimonabant significantly decreased the basal receptor activity in CHO-mDOR but also in parental CHO cell membranes. During DOR agonist stimulation, micromolar concentration of rimonabant attenuated the DOR G-protein activation and the potency of the activator ligand in [(35)S]GTPγS binding assays performed in CHO-mDOR, in wild type and also in CB1/CB2 double knock-out mouse forebrain membranes. Yet again this inhibitory action was DOR specific, since it did not occur during other specific GPCR agonist mediated G-protein activation. CONCLUSION Rimonabant directly inhibited DOR function in the micromolar concentrations. The inhibitory actions indicate an antagonistic behavior towards DOR which was established by the followings: (i) rimonabant inhibited DOR antagonist binding more effectively than agonist binding, (ii) the inverse agonistic, agonistic effect of the compound can be excluded, and (iii) additionally according to previous findings the allosteric mechanism can also be foreclosed.
Collapse
MESH Headings
- Animals
- CHO Cells
- Cricetinae
- Cricetulus
- GTP-Binding Proteins/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Ligands
- Mice
- Piperidines/pharmacology
- Protein Binding
- Pyrazoles/pharmacology
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB2/genetics
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Rimonabant
Collapse
Affiliation(s)
- Ferenc Zádor
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary.
| | - Dóra Kocsis
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Anna Borsodi
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Sándor Benyhe
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
| |
Collapse
|
7
|
Baur R, Gertsch J, Sigel E. The cannabinoid CB1 receptor antagonists rimonabant (SR141716) and AM251 directly potentiate GABA(A) receptors. Br J Pharmacol 2012; 165:2479-84. [PMID: 21470203 DOI: 10.1111/j.1476-5381.2011.01405.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Rimonabant (SR141716) and the structurally related AM251 are widely used in pharmacological experiments as selective cannabinoid receptor CB(1) antagonists / inverse agonists. Concentrations of 0.5-10 µM are usually applied in in vitro experiments. We intended to show that these drugs did not act at GABA(A) receptors but found a significant positive allosteric modulation instead. EXPERIMENTAL APPROACH Recombinant GABA(A) receptors were expressed in Xenopus oocytes. Receptors were exposed to AM251 or rimonabant in the absence and presence of GABA. Standard electrophysiological techniques were used to monitor the elicited ionic currents. KEY RESULTS AM251 dose-dependently potentiated responses to 0.5 µM GABA at the recombinant α(1) β(2) γ(2) GABA(A) receptor with an EC(50) below 1 µM and a maximal potentiation of about eightfold. The Hill coefficient indicated that more than one binding site for AM251 was located in this receptor. Rimonabant had a lower affinity, but a fourfold higher efficacy. AM251 potentiated also currents mediated by α(1) β(2) , α(x) β(2) γ(2) (x = 2,3,5,6), α(1) β(3) γ(2) and α(4) β(2) δ GABA(A) receptors, but not those mediated by α(1) β(1) γ(2) . Interestingly, the CB(1) receptor antagonists LY320135 and O-2050 did not significantly affect α(1) β(2) γ(2) GABA(A) receptor-mediated currents at concentrations of 1 µM. CONCLUSIONS AND IMPLICATIONS This study identified rimonabant and AM251 as positive allosteric modulators of GABA(A) receptors. Thus, potential GABAergic effects of commonly used concentrations of these compounds should be considered in in vitro experiments, especially at extrasynaptic sites where GABA concentrations are low. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7.
Collapse
Affiliation(s)
- R Baur
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstr, Bern, Switzerland
| | | | | |
Collapse
|
8
|
Strack AM, Nicolich S, Faidley T, Achanfuo-Yeboah J, Cunningham PK, Hora D, Thompson D, Hickey G, Johnson-Levonas AO, Fong TM, Heymsfield SB. Cannabinoid-1 receptor inhibition prevents the reduction of 24-hour energy expenditure with weight loss. Metabolism 2012; 61:546-53. [PMID: 22001334 DOI: 10.1016/j.metabol.2011.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 08/15/2011] [Accepted: 09/06/2011] [Indexed: 11/15/2022]
Abstract
Pharmacologic inhibition of the cannabinoid-1 receptor (CB1R) in rodent models leads to weight loss and time-dependent changes in energy balance. This study evaluated the effects of CB1R inhibition on weight loss, energy expenditure (EE), and food intake (FI) in an obese canine model following 4 weeks of treatment. Eighteen maintenance-fed obese beagles were evenly and randomly allocated to a CB1R inverse agonist (AM251) (2 mg/kg), a 70% food-restricted (FR) diet, or a control group (C). Evaluations included body weight and composition (dual-energy x-ray absorptiometry scan), EE (doubly labeled water), and FI. Change in body mass at week 4 was significantly greater (P < .050) in the AM251 (-1476.7 g) and FR groups (-1100.0 g) than in the C group (-228.3 g). Food intake was decreased from week 2 onward in the FR and AM251 groups (P < .05). Absolute and lean mass-adjusted EEs were decreased only in the FR group (P < .01); EE in the AM251 group was greater (P < .05) than that in the FR group. Pharmacologic inhibition of CB1R in a canine model led to sustained effects on FI and EE. Weight loss was greater with AM251 than could be accounted for by food restriction (∼25%), an effect likely mediated by the EE response to CB1R inhibition.
Collapse
|
9
|
Pertwee RG, Howlett AC, Abood ME, Alexander SPH, Di Marzo V, Elphick MR, Greasley PJ, Hansen HS, Kunos G, Mackie K, Mechoulam R, Ross RA. International Union of Basic and Clinical Pharmacology. LXXIX. Cannabinoid receptors and their ligands: beyond CB₁ and CB₂. Pharmacol Rev 2011; 62:588-631. [PMID: 21079038 DOI: 10.1124/pr.110.003004] [Citation(s) in RCA: 1166] [Impact Index Per Article: 89.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
There are at least two types of cannabinoid receptors (CB(1) and CB(2)). Ligands activating these G protein-coupled receptors (GPCRs) include the phytocannabinoid Δ(9)-tetrahydrocannabinol, numerous synthetic compounds, and endogenous compounds known as endocannabinoids. Cannabinoid receptor antagonists have also been developed. Some of these ligands activate or block one type of cannabinoid receptor more potently than the other type. This review summarizes current data indicating the extent to which cannabinoid receptor ligands undergo orthosteric or allosteric interactions with non-CB(1), non-CB(2) established GPCRs, deorphanized receptors such as GPR55, ligand-gated ion channels, transient receptor potential (TRP) channels, and other ion channels or peroxisome proliferator-activated nuclear receptors. From these data, it is clear that some ligands that interact similarly with CB(1) and/or CB(2) receptors are likely to display significantly different pharmacological profiles. The review also lists some criteria that any novel "CB(3)" cannabinoid receptor or channel should fulfil and concludes that these criteria are not currently met by any non-CB(1), non-CB(2) pharmacological receptor or channel. However, it does identify certain pharmacological targets that should be investigated further as potential CB(3) receptors or channels. These include TRP vanilloid 1, which possibly functions as an ionotropic cannabinoid receptor under physiological and/or pathological conditions, and some deorphanized GPCRs. Also discussed are 1) the ability of CB(1) receptors to form heteromeric complexes with certain other GPCRs, 2) phylogenetic relationships that exist between CB(1)/CB(2) receptors and other GPCRs, 3) evidence for the existence of several as-yet-uncharacterized non-CB(1), non-CB(2) cannabinoid receptors; and 4) current cannabinoid receptor nomenclature.
Collapse
Affiliation(s)
- R G Pertwee
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, UK.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Measurement of inverse agonism of the cannabinoid receptors. Methods Enzymol 2011. [PMID: 21050915 DOI: 10.1016/b978-0-12-381296-4.00008-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The cannabinoid receptors are G protein-coupled receptors that are activated by endocannabinoids or exogenous agonists such as tetrahydrocannabinol. Upon agonist binding, cannabinoid receptors will activate Gi which in turn inhibits adenylyl cyclase. Recently, inverse agonists for the cannabinoid receptors have been identified, demonstrating constitutive activity of the cannabinoid receptors. Several methods have been used to measure inverse agonist activity of ligands for the cannabinoid receptors, including Gi-cAMP second messenger assay, GTPγS binding assay, and electrophysiological assays. Each assay has its advantages and limitations, and the Gi-cAMP second messenger assay appears to provide the best overall measurement of inverse agonism in a cellular environment.
Collapse
|
11
|
Bolognini D, Costa B, Maione S, Comelli F, Marini P, Di Marzo V, Parolaro D, Ross RA, Gauson LA, Cascio MG, Pertwee RG. The plant cannabinoid Delta9-tetrahydrocannabivarin can decrease signs of inflammation and inflammatory pain in mice. Br J Pharmacol 2010; 160:677-87. [PMID: 20590571 DOI: 10.1111/j.1476-5381.2010.00756.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE The phytocannabinoid, Delta(9)-tetrahydrocannabivarin (THCV), can block cannabinoid CB(1) receptors. This investigation explored its ability to activate CB(2) receptors, there being evidence that combined CB(2) activation/CB(1) blockade would ameliorate certain disorders. EXPERIMENTAL APPROACH We tested the ability of THCV to activate CB(2) receptors by determining whether: (i) it inhibited forskolin-stimulated cyclic AMP production by Chinese hamster ovary (CHO) cells transfected with human CB(2) (hCB(2)) receptors; (ii) it stimulated [(35)S]GTPgammaS binding to hCB(2) CHO cell and mouse spleen membranes; (iii) it attenuated signs of inflammation/hyperalgesia induced in mouse hind paws by intraplantar injection of carrageenan or formalin; and (iv) any such anti-inflammatory or anti-hyperalgesic effects were blocked by a CB(1) or CB(2) receptor antagonist. KEY RESULTS THCV inhibited cyclic AMP production by hCB(2) CHO cells (EC(50)= 38 nM), but not by hCB(1) or untransfected CHO cells or by hCB(2) CHO cells pre-incubated with pertussis toxin (100 ng.mL(-1)) and stimulated [(35)S]GTPgammaS binding to hCB(2) CHO and mouse spleen membranes. THCV (0.3 or 1 mg.kg(-1) i.p.) decreased carrageenan-induced oedema in a manner that seemed to be CB(2) receptor-mediated and suppressed carrageenan-induced hyperalgesia. THCV (i.p.) also decreased pain behaviour in phase 2 of the formalin test at 1 mg.kg(-1), and in both phases of this test at 5 mg.kg(-1); these effects of THCV appeared to be CB(1) and CB(2) receptor mediated. CONCLUSIONS AND IMPLICATIONS THCV can activate CB(2) receptors in vitro and decrease signs of inflammation and inflammatory pain in mice partly via CB(1) and/or CB(2) receptor activation.
Collapse
|
12
|
Fong TM, Addy C, Erondu N, Heymsfield SB. CB1 receptor inverse agonist pharmacotherapy for metabolic disorders. Drug Dev Res 2009. [DOI: 10.1002/ddr.20335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|