1
|
Wang Y, Balvers MGJ, Esser D, Schutte S, Vincken JP, Afman LA, Witkamp RF, Meijerink J. Nutrient composition of different energy-restricted diets determines plasma endocannabinoid profiles and adipose tissue DAGL-α expression; a 12-week randomized controlled trial in subjects with abdominal obesity. J Nutr Biochem 2024; 128:109605. [PMID: 38401691 DOI: 10.1016/j.jnutbio.2024.109605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 02/14/2024] [Accepted: 02/19/2024] [Indexed: 02/26/2024]
Abstract
The endocannabinoid system (ECS) is dysregulated during obesity and metabolic disorders. Weight loss favours the re-establishment of ECS homeostatic conditions, but also the fatty acid composition of the diet can modulate endocannabinoid profiles. However, the combined impact of nutrient quality and energy restriction on the ECS remains unclear. In this 12 weeks randomized controlled trial, men and women (40-70 years) with obesity (BMI: 31.3 ± 3.5 kg/ m2) followed either a low nutrient quality 25% energy-restricted (ER) diet (n=39) high in saturated fats and fructose, or a high nutrient quality ER diet (n=34) amongst others enriched in n-3 polyunsaturated fatty acids (PUFAs) or kept their habitual diet (controls). Profiles of plasma- and adipose N-acylethanolamines and mono-acyl glycerol esters were quantified using LC-MS/MS. Gene expression of ECS-related enzymes and receptors was determined in adipose tissue. Measurements were performed under fasting conditions before and after 12 weeks. Our results showed that plasma level of the DHA-derived compound docosahexaenoylethanolamide (DHEA) was decreased in the low nutrient quality ER diet (P<0.001) compared with the high nutrient quality ER diet, whereas anandamide (AEA) and arachidonoylglycerol (2-AG) levels were unaltered. However, adipose tissue gene expression of the 2-AG synthesizing enzyme diacylglycerol lipase alpha (DAGL-α) was increased following the low nutrient quality ER diet (P<.009) and differed upon intervention with both other diets. Concluding, nutrient quality of the diet affects N-acylethanolamine profiles and gene expression of ECS-related enzymes and receptors even under conditions of high energy restriction in abdominally obese humans. ClinicalTrials.gov NCT02194504.
Collapse
Affiliation(s)
- Ya Wang
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands; The Laboratory of Food Chemistry, Wageningen University, Wageningen, The Netherlands
| | - Michiel G J Balvers
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Diederik Esser
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Sophie Schutte
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Jean-Paul Vincken
- The Laboratory of Food Chemistry, Wageningen University, Wageningen, The Netherlands
| | - Lydia A Afman
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Renger F Witkamp
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Jocelijn Meijerink
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands.
| |
Collapse
|
2
|
Manning JJ, Finlay DB, Glass M. GPCR kinase subtype requirements for arrestin-2 and -3 translocation to the cannabinoid CB 1 receptor and the consequences on G protein signalling. Biochem Pharmacol 2024; 224:116190. [PMID: 38604257 DOI: 10.1016/j.bcp.2024.116190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/13/2024]
Abstract
Arrestins are key negative regulators of G Protein-Coupled Receptors (GPCRs) through mediation of G protein desensitisation and receptor internalisation. Arrestins can also contribute to signal transduction by scaffolding downstream signalling effectors for activation. GPCR kinase (GRK) enzymes phosphorylate the intracellular C-terminal domain, or intracellular loop regions of GPCRs to promote arrestin interaction. There are seven different GRK subtypes, which may uniquely phosphorylate the C-terminal tail in a type of 'phosphorylation barcode,' potentially differentially contributing to arrestin translocation and arrestin-dependent signalling. Such contributions may be exploited to develop arrestin-biased ligands. Here, we examine the effect of different GRK subtypes on the ability to promote translocation of arrestin-2 and arrestin-3 to the cannabinoid CB1 receptor (CB1) with a range of ligands. We find that most GRK subtypes (including visual GRK1) can enhance arrestin-2 and -3 translocation to CB1, and that GRK-dependent changes in arrestin-2 and arrestin-3 translocation were broadly shared for most agonists tested. GRK2/3 generally enhanced arrestin translocation more than the other GRK subtypes, with some small differences between ligands. We also explore the interplay between G protein activity and GRK2/3-dependent arrestin translocation, highlighting that high-efficacy G protein agonists will cause GRK2/3 dependent arrestin translocation. This study supports the hypothesis that arrestin-biased ligands for CB1 must engage GRK5/6 rather than GRK2/3, and G protein-biased ligands must have inherently low efficacy.
Collapse
Affiliation(s)
- Jamie J Manning
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - David B Finlay
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
| |
Collapse
|
3
|
Pontearso M, Slepicka J, Bhattacharyya A, Spicarova D, Palecek J. Dual effect of anandamide on spinal nociceptive transmission in control and inflammatory conditions. Biomed Pharmacother 2024; 173:116369. [PMID: 38452657 DOI: 10.1016/j.biopha.2024.116369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/26/2024] [Accepted: 02/28/2024] [Indexed: 03/09/2024] Open
Abstract
Anandamide (AEA) is an important modulator of nociception in the spinal dorsal horn, acting presynaptically through Cannabinoid (CB1) and Transient receptor potential vanilloid (TRPV1) receptors. The role of AEA (1 µM, 10 µM, and 30 µM) application on the modulation of nociceptive synaptic transmission under control and inflammatory conditions was studied by recording miniature excitatory postsynaptic currents (mEPSCs) from neurons in spinal cord slices. Inhibition of the CB1 receptors by PF514273, TRPV1 by SB366791, and the fatty acid amide hydrolase (FAAH) by URB597 was used. Under naïve conditions, the AEA application did not affect the mEPSCs frequency (1.43±0.12 Hz) when all the recorded neurons were considered. The mEPSC frequency increased (180.0±39.2%) only when AEA (30 µM) was applied with PF514273 and URB597. Analysis showed that one sub-population of neurons had synaptic input inhibited (39.1% of neurons), the second excited (43.5%), whereas 8.7% showed a mixed effect and 8.7% did not respond to the AEA. With inflammation, the AEA effect was highly inhibitory (72.7%), while the excitation was negligible (9.1%), and 18.2% were not modulated. After inflammation, more neurons (45.0%) responded even to low AEA by mEPSC frequency increase with PF514273/URB597 present. AEA-induced dual (excitatory/inhibitory) effects at the 1st nociceptive synapse should be considered when developing analgesics targeting the endocannabinoid system. These findings contrast the clear inhibitory effects of the AEA precursor 20:4-NAPE application described previously and suggest that modulation of endogenous AEA production may be more favorable for analgesic treatments.
Collapse
Affiliation(s)
- Monica Pontearso
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jakub Slepicka
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Anirban Bhattacharyya
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Diana Spicarova
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jiri Palecek
- Laboratory of Pain Research, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
| |
Collapse
|
4
|
Brown C, Mitsch M, Blankenship K, Campbell C, Pelanne M, Sears J, Bell A, Olivier AK, Ross MK, Archer T, Kaplan BLF. Canine immune cells express high levels of CB 1 and CB 2 cannabinoid receptors and cannabinoid-mediated alteration of canine cytokine production is vehicle-dependent. Vet Immunol Immunopathol 2023; 265:110667. [PMID: 37931433 DOI: 10.1016/j.vetimm.2023.110667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 10/27/2023] [Indexed: 11/08/2023]
Abstract
With the increased popularity and societal acceptance of marijuana and cannabidiol (CBD) use in humans, there is an interest in using cannabinoids in veterinary medicine. There have been a few placebo-controlled clinical trials in dogs suggesting that cannabis-containing extracts are beneficial for dogs with inflammatory diseases such as osteoarthritis, and there is growing interest in their immunosuppressive potential for the treatment of immune-mediated diseases. Since cannabinoids exhibit anti-inflammatory and immunosuppressive effects in many species, the purpose of these studies was to examine whether the plant-derived cannabinoids, CBD and Δ9-tetrahydrocannabinol (THC), would also suppress immune function in canine peripheral blood mononuclear cells (PBMCs). Another goal was to characterize expression of the cannabinoid receptors, CB1 and CB2, in canine immune cells. We hypothesized that CBD and THC would suppress stimulated cytokine expression and that both cannabinoid receptors would be expressed in canine immune cells. Surprisingly, cannabinoid suppressive effects in canine PMBCs were quite modest, with the most robust effect occurring at early stimulation times and predominantly by THC. We further showed that cannabinoid-mediated suppression was dog- and vehicle-dependent with CBD and THC delivered in dimethyl sulfoxide (DMSO) producing more immune suppressive effects as compared to ethanol (ETOH). PCR, flow cytometry, and immunohistochemical staining demonstrated that both CB1 and CB2 are expressed in canine immune cells. Together these data show that canine immune cells are sensitive to suppression by cannabinoids, but more detailed studies are needed to further understand the mechanisms and broad effects of these compounds in the dog.
Collapse
Affiliation(s)
- Clare Brown
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Matthew Mitsch
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Karis Blankenship
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Carly Campbell
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Mimi Pelanne
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Jaylan Sears
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Abigail Bell
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Alicia K Olivier
- Department of Pathobiology and Population Medicine, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Matthew K Ross
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Todd Archer
- Department of Clinical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA
| | - Barbara L F Kaplan
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, Mississippi State University College of Veterinary Medicine, Mississippi State, MS, USA.
| |
Collapse
|
5
|
Gioé-Gallo C, Ortigueira S, Brea J, Raïch I, Azuaje J, Paleo MR, Majellaro M, Loza MI, Salas CO, García-Mera X, Navarro G, Sotelo E. Pharmacological insights emerging from the characterization of a large collection of synthetic cannabinoid receptor agonists designer drugs. Biomed Pharmacother 2023; 164:114934. [PMID: 37236027 DOI: 10.1016/j.biopha.2023.114934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 04/01/2023] [Accepted: 05/22/2023] [Indexed: 05/28/2023] Open
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) constitute the largest and most defiant group of abuse designer drugs. These new psychoactive substances (NPS), developed as unregulated alternatives to cannabis, have potent cannabimimetic effects and their use is usually associated with episodes of psychosis, seizures, dependence, organ toxicity and death. Due to their ever-changing structure, very limited or nil structural, pharmacological, and toxicological information is available to the scientific community and the law enforcement offices. Here we report the synthesis and pharmacological evaluation (binding and functional) of the largest and most diverse collection of enantiopure SCRAs published to date. Our results revealed novel SCRAs that could be (or may currently be) used as illegal psychoactive substances. We also report, for the first time, the cannabimimetic data of 32 novel SCRAs containing an (R) configuration at the stereogenic center. The systematic pharmacological profiling of the library enabled the identification of emerging Structure-Activity Relationship (SAR) and Structure-Selectivity Relationship (SSR) trends, the detection of ligands exhibiting incipient cannabinoid receptor type 2 (CB2R) subtype selectivity and highlights the significant neurotoxicity of representative SCRAs on mouse primary neuronal cells. Several of the new emerging SCRAs are currently expected to have a rather limited potential for harm, as the evaluation of their pharmacological profiles revealed lower potencies and/or efficacies. Conceived as a resource to foster collaborative investigation of the physiological effects of SCRAs, the library obtained can contribute to addressing the challenge posed by recreational designer drugs.
Collapse
Affiliation(s)
- Claudia Gioé-Gallo
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain; Departamento de Química Orgánica, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Sandra Ortigueira
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain; Departamento de Química Orgánica, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - José Brea
- Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CiMUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain.
| | - Iu Raïch
- Department of Biochemistry and Physiology, School of Pharmacy and Food Science, Universitat de Barcelona, Barcelona 08028, Spain; Institute of Neurosciences (NeuroUB), Campus Mundet, University of Barcelona, Barcelona 08035, Spain
| | - Jhonny Azuaje
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain; Departamento de Química Orgánica, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - M Rita Paleo
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Maria Majellaro
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain; Departamento de Química Orgánica, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - María Isabel Loza
- Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CiMUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Cristian O Salas
- Department of Organic Chemistry, Faculty of Chemistry and Pharmacy, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Macul, Santiago 7820436, Chile
| | - Xerardo García-Mera
- Departamento de Química Orgánica, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Gemma Navarro
- Department of Biochemistry and Physiology, School of Pharmacy and Food Science, Universitat de Barcelona, Barcelona 08028, Spain; Institute of Neurosciences (NeuroUB), Campus Mundet, University of Barcelona, Barcelona 08035, Spain.
| | - Eddy Sotelo
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain; Departamento de Química Orgánica, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain.
| |
Collapse
|
6
|
Iyer V, Rangel-Barajas C, Woodward TJ, Kulkarni A, Cantwell L, Crystal JD, Mackie K, Rebec GV, Thakur GA, Hohmann AG. Negative allosteric modulation of CB 1 cannabinoid receptor signaling suppresses opioid-mediated reward. Pharmacol Res 2022; 185:106474. [PMID: 36179954 PMCID: PMC9948526 DOI: 10.1016/j.phrs.2022.106474] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/15/2022] [Accepted: 09/25/2022] [Indexed: 01/18/2023]
Abstract
Blockade of cannabinoid type 1 (CB1)-receptor signaling decreases the rewarding properties of many drugs of abuse and has been proposed as an anti-addiction strategy. However, psychiatric side-effects limit the clinical potential of orthosteric CB1 antagonists. Negative allosteric modulators (NAMs) represent a novel and indirect approach to attenuate CB1 signaling by decreasing affinity and/or efficacy of CB1 ligands. We hypothesized that a CB1-NAM would block opioid reward while avoiding the unwanted effects of orthosteric CB1 antagonists. GAT358, a CB1-NAM, failed to elicit cardinal signs of direct CB1 activation or inactivation when administered by itself. GAT358 decreased catalepsy and hypothermia but not antinociception produced by the orthosteric CB1 agonist CP55,940, suggesting that a CB1-NAM blocked cardinal signs of CB1 activation. Next, GAT358 was evaluated using in vivo assays of opioid-induced dopamine release and reward in male rodents. In the nucleus accumbens shell, a key component of the mesocorticolimbic reward pathway, morphine increased electrically-evoked dopamine efflux and this effect was blocked by a dose of GAT358 that lacked intrinsic effects on evoked dopamine efflux. Moreover, GAT358 blocked morphine-induced reward in a conditioned place preference (CPP) assay without producing reward or aversion alone. GAT358-induced blockade of morphine CPP was also occluded by GAT229, a CB1 positive allosteric modulator (CB1-PAM), and absent in CB1-knockout mice. Finally, GAT358 also reduced oral oxycodone (but not water) consumption in a two-bottle choice paradigm. Our results support the therapeutic potential of CB1-NAMs as novel drug candidates aimed at preventing opioid reward and treating opioid abuse while avoiding unwanted side-effects.
Collapse
Affiliation(s)
- Vishakh Iyer
- Program in Neuroscience, Indiana University, Bloomington, IN, USA,Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | | | - Taylor J. Woodward
- Program in Neuroscience, Indiana University, Bloomington, IN, USA,Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Abhijit Kulkarni
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Lucas Cantwell
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Jonathon D. Crystal
- Program in Neuroscience, Indiana University, Bloomington, IN, USA,Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Ken Mackie
- Program in Neuroscience, Indiana University, Bloomington, IN, USA,Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA,Gill Center for Biomolecular Science, Indiana University, Bloomington, IN, USA
| | - George V. Rebec
- Program in Neuroscience, Indiana University, Bloomington, IN, USA,Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Ganesh A. Thakur
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Andrea G. Hohmann
- Program in Neuroscience, Indiana University, Bloomington, IN, USA,Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA,Gill Center for Biomolecular Science, Indiana University, Bloomington, IN, USA,Corresponding Author: Andrea G. Hohmann, Psychological and Brain Sciences, Gill Center for Biomolecular Science, Indiana University, Bloomington, IN 47405-7007,
| |
Collapse
|
7
|
Abstract
The endocannabinoid (eCB) system is one of the most widespread neuromodulatory systems in the mammalian brain, with a multifaceted role in functions ranging from development to synaptic plasticity. Endocannabinoids are synthesized on demand from membrane lipid precursors, and act primarily on a single G-protein coupled receptor type, CB1, to carry out diverse functions. Despite the importance of the eCB system both in healthy brain function and in disease, critically important details of eCB signaling remained unknown. How eCBs are released from the membrane, how these lipid molecules are transported between cells, and how the distribution of their receptors is controlled, remained elusive. Recent advances in optical microscopy methods and biosensor engineering may open up new avenues for studying eCB signaling. We summarize applications of superresolution microscopy using single molecule localization to reveal distinct patterns of nanoscale CB1 distribution in neuronal axons and axon terminals. We review single particle tracking studies using quantum dots that allowed visualizing CB1 trajectories. We highlight the recent development of fluorescent eCB biosensors, that revealed spatiotemporally specific eCB release in live cells and live animals. Finally, we discuss future directions where method development may help to advance a precise understanding of eCB signaling.
Collapse
Affiliation(s)
- Barna Dudok
- Department of Neurosurgery, Stanford University, Stanford, CA, USA.
| | - Ivan Soltesz
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
| |
Collapse
|
8
|
Mielnik CA, Lam VM, Ross RA. CB 1 allosteric modulators and their therapeutic potential in CNS disorders. Prog Neuropsychopharmacol Biol Psychiatry 2021; 106:110163. [PMID: 33152384 DOI: 10.1016/j.pnpbp.2020.110163] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/30/2020] [Accepted: 10/29/2020] [Indexed: 01/05/2023]
Abstract
CB1 is the most abundant GPCR found in the mammalian brain. It has garnered considerable attention as a potential therapeutic drug target. CB1 is involved in a wide range of physiological and psychiatric processes and has the potential to be targeted in a wide range of disease states. However, most of the selective and non-selective synthetic CB1 agonists and antagonists/inverse agonists developed to date are primarily used as research tools. No novel synthetic cannabinoids are currently in the clinic for use in psychiatric illness; synthetic analogues of the phytocannabinoid THC are on the market to treat nausea and vomiting caused by cancer chemotherapy, along with off-label use for pain. Novel strategies are being explored to target CB1, but with emphasis on the elimination or mitigation of the potential psychiatric adverse effects that are observed by central agonism/antagonism of CB1. New pharmacological options are being pursued that may avoid these adverse effects while preserving the potential therapeutic benefits of CB1 modulation. Allosteric modulation of CB1 is one such approach. In this review, we will summarize and critically analyze both the in vitro characterization and in vivo validation of CB1 allosteric modulators developed to date, with a focus on CNS therapeutic effects.
Collapse
Affiliation(s)
- Catharine A Mielnik
- Department of Pharmacology & Toxicology, University of Toronto, ON M5S 1A8, Canada
| | - Vincent M Lam
- Department of Pharmacology & Toxicology, University of Toronto, ON M5S 1A8, Canada
| | - Ruth A Ross
- Department of Pharmacology & Toxicology, University of Toronto, ON M5S 1A8, Canada.
| |
Collapse
|
9
|
Gamage TF, Barrus DG, Kevin RC, Finlay DB, Lefever TW, Patel PR, Grabenauer MA, Glass M, McGregor IS, Wiley JL, Thomas BF. In vitro and in vivo pharmacological evaluation of the synthetic cannabinoid receptor agonist EG-018. Pharmacol Biochem Behav 2020. [PMID: 32247816 DOI: 10.1016/j.pbb.2020.172918.in] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) possess high abuse liability and complex toxicological profiles, making them serious threats to public health. EG-018 is a SCRA that has been detected in both illicit products and human samples, but it has received little attention to date. The current studies investigated EG-018 at human CB1 and CB2 receptors expressed in HEK293 cells in [3H]CP55,940 competition binding, [35S]GTPγS binding and forskolin-stimulated cAMP production. EG-018 was also tested in vivo for its ability to produce cannabimimetic and abuse-related effects in the cannabinoid tetrad and THC drug discrimination, respectively. EG-018 exhibited high affinity at CB1 (21 nM) and at CB2 (7 nM), but in contrast to typical SCRAs, behaved as a weak partial agonist in [35S]GTPγS binding, exhibiting lower efficacy but greater potency, than that of THC at CB1 and similar potency and efficacy at CB2. EG-018 inhibited forskolin-stimulated cAMP with similar efficacy but lower potency, compared to THC, which was likely due to high receptor density facilitating saturation of this signaling pathway. In mice, EG-018 (100 mg/kg, 30 min) administered intraperitoneally (i.p.) did not produce effects in the tetrad or drug discrimination nor did it shift THC's ED50 value in drug discrimination when administered before THC, suggesting EG-018 has negligible occupancy of brain CB1 receptors following i.p. administration. Following intravenous (i.v.) administration, EG-018 (56 mg/kg) produced hypomotility, catalepsy, and hypothermia, but only catalepsy was blocked by the selective CB1 antagonist rimonabant (3 mg/kg, i.v.). Additional studies of EG-018 and its structural analogues could provide further insight into how cannabinoids exert efficacy through the cannabinoid receptors.
Collapse
MESH Headings
- Animals
- Behavior, Animal/drug effects
- Body Temperature/drug effects
- Cannabinoid Receptor Agonists/pharmacokinetics
- Cannabinoid Receptor Agonists/pharmacology
- Carbazoles/pharmacokinetics
- Carbazoles/pharmacology
- Cyclic AMP/metabolism
- Dronabinol/pharmacology
- HEK293 Cells
- Humans
- Liver/cytology
- Locomotion/drug effects
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred ICR
- Microsomes/drug effects
- Naphthalenes/pharmacokinetics
- Naphthalenes/pharmacology
- Rats
- Rats, Long-Evans
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/metabolism
- Signal Transduction/drug effects
- Synthetic Drugs/metabolism
- Synthetic Drugs/pharmacokinetics
Collapse
Affiliation(s)
- Thomas F Gamage
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Daniel G Barrus
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Richard C Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia; Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia
| | - David B Finlay
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Timothy W Lefever
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Purvi R Patel
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Megan A Grabenauer
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Michelle Glass
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Iain S McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia; Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jenny L Wiley
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA.
| | - Brian F Thomas
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| |
Collapse
|
10
|
Gamage TF, Barrus DG, Kevin RC, Finlay DB, Lefever TW, Patel PR, Grabenauer MA, Glass M, McGregor IS, Wiley JL, Thomas BF. In vitro and in vivo pharmacological evaluation of the synthetic cannabinoid receptor agonist EG-018. Pharmacol Biochem Behav 2020; 193:172918. [PMID: 32247816 DOI: 10.1016/j.pbb.2020.172918] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 03/26/2020] [Indexed: 01/08/2023]
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) possess high abuse liability and complex toxicological profiles, making them serious threats to public health. EG-018 is a SCRA that has been detected in both illicit products and human samples, but it has received little attention to date. The current studies investigated EG-018 at human CB1 and CB2 receptors expressed in HEK293 cells in [3H]CP55,940 competition binding, [35S]GTPγS binding and forskolin-stimulated cAMP production. EG-018 was also tested in vivo for its ability to produce cannabimimetic and abuse-related effects in the cannabinoid tetrad and THC drug discrimination, respectively. EG-018 exhibited high affinity at CB1 (21 nM) and at CB2 (7 nM), but in contrast to typical SCRAs, behaved as a weak partial agonist in [35S]GTPγS binding, exhibiting lower efficacy but greater potency, than that of THC at CB1 and similar potency and efficacy at CB2. EG-018 inhibited forskolin-stimulated cAMP with similar efficacy but lower potency, compared to THC, which was likely due to high receptor density facilitating saturation of this signaling pathway. In mice, EG-018 (100 mg/kg, 30 min) administered intraperitoneally (i.p.) did not produce effects in the tetrad or drug discrimination nor did it shift THC's ED50 value in drug discrimination when administered before THC, suggesting EG-018 has negligible occupancy of brain CB1 receptors following i.p. administration. Following intravenous (i.v.) administration, EG-018 (56 mg/kg) produced hypomotility, catalepsy, and hypothermia, but only catalepsy was blocked by the selective CB1 antagonist rimonabant (3 mg/kg, i.v.). Additional studies of EG-018 and its structural analogues could provide further insight into how cannabinoids exert efficacy through the cannabinoid receptors.
Collapse
Affiliation(s)
- Thomas F Gamage
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Daniel G Barrus
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Richard C Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia; Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia
| | - David B Finlay
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Timothy W Lefever
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Purvi R Patel
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Megan A Grabenauer
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - Michelle Glass
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Iain S McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia; Faculty of Science, School of Psychology, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jenny L Wiley
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA.
| | - Brian F Thomas
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
| |
Collapse
|
11
|
Rock EM, Limebeer CL, Aliasi-Sinai L, Parker LA. The ventral pallidum as a critical region for fatty acid amide hydrolase inhibition of nausea-induced conditioned gaping in male Sprague-Dawley rats. Neuropharmacology 2019; 155:142-149. [PMID: 31145905 DOI: 10.1016/j.neuropharm.2019.05.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/15/2019] [Accepted: 05/23/2019] [Indexed: 12/21/2022]
Abstract
Here we investigate the involvement of the ventral pallidum (VP) in the anti-nausea effect of fatty acid amide hydrolase (FAAH) inhibition with PF-3845, and examine the pharmacological mechanism of such an effect. We explored the potential of intra-VP PF-3845 to reduce the establishment of lithium chloride (LiCl)-induced conditioned gaping (a model of acute nausea) in male Sprague-Dawley rats. As well, the role of the cannabinoid 1 (CB1) receptors and the peroxisome proliferator-activated receptors-α (PPARα) in the anti-nausea effect of PF-3845 was examined. Finally, the potential of intra-VP GW7647, a PPARα agonist, to reduce acute nausea was also evaluated. Intra-VP PF-3845 dose-dependently reduced acute nausea by a PPARα mechanism (and not a CB1 receptor mechanism). Intra-VP administration of GW7647, similarly attenuated acute nausea. These findings suggest that the anti-nausea action of FAAH inhibition may occur in the VP, and may involve activation of PPARα to suppress acute nausea.
Collapse
Affiliation(s)
- Erin M Rock
- Department of Psychology and Neuroscience Graduate Program, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Cheryl L Limebeer
- Department of Psychology and Neuroscience Graduate Program, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Lital Aliasi-Sinai
- Department of Psychology and Neuroscience Graduate Program, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Linda A Parker
- Department of Psychology and Neuroscience Graduate Program, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada.
| |
Collapse
|
12
|
Nealon CM, Henderson-Redmond AN, Hale DE, Morgan DJ. Tolerance to WIN55,212-2 is delayed in desensitization-resistant S426A/S430A mice. Neuropharmacology 2019; 148:151-159. [PMID: 30629988 PMCID: PMC6535342 DOI: 10.1016/j.neuropharm.2018.12.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 12/05/2018] [Accepted: 12/21/2018] [Indexed: 02/08/2023]
Abstract
Tolerance to cannabinoid agonists can develop through desensitization of the cannabinoid receptor 1 (CB1) following prolonged administration. Desensitization results from phosphorylation of CB1 by a G protein-coupled receptor kinase (GRK), and subsequent association of the receptor with arrestin. Mice expressing a mutant form of CB1, in which the serine residues at two putative phosphorylation sites necessary for desensitization have been replaced by non-phosphorylatable alanines (S426A/S430A), display reduced tolerance to Δ9-tetrahydrocannabinol (Δ9-THC). Tolerance to the antinociceptive effects of WIN55,212-2 was delayed in S426A/S430A mutants using the tail-flick and formalin tests. However, tolerance to the antinociceptive effects of once daily CP55,940 injections was not significantly delayed in S426A/S430A mutant mice using either of these tests. Interestingly, the dose response curve shifts for the hypothermic and antinociceptive effects of CP55,940 that were induced by chronic treatment with this agonist in wild-type mice were blocked in S426A/S430A mutant mice. Assessment of mechanical allodynia in mice exhibiting chronic cisplatin-evoked neuropathic pain found that tolerance to the anti-allodynic effects WIN55,212-2 but not CP55,940 was delayed in S426A/S430A mice compared to wild-type littermates. Despite these deficits in tolerance, S426A/S430A mutant mice eventually developed tolerance to both WIN55,212-2 and CP55,940 for all pain assays that were examined, suggesting that other mechanisms likely contribute to tolerance for these cannabinoid agonists. These findings suggest that GRK- and βarrestin2-mediated desensitization of CB1 may strongly contribute to the rate of tolerance to the antinociceptive effects of WIN55,212-2, and raises the possibility of agonist-specific mechanisms of cannabinoid tolerance.
Collapse
Affiliation(s)
- Caitlin M Nealon
- Department of Anesthesiology and Perioperative Medicine, Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - Angela N Henderson-Redmond
- Department of Anesthesiology and Perioperative Medicine, Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - David E Hale
- Department of Anesthesiology and Perioperative Medicine, Penn State University College of Medicine, Hershey, PA, 17033, USA
| | - Daniel J Morgan
- Department of Anesthesiology and Perioperative Medicine, Penn State University College of Medicine, Hershey, PA, 17033, USA; Department of Pharmacology, Penn State University College of Medicine, Hershey, PA, 17033, USA; Department of Neural and Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, 17033, USA.
| |
Collapse
|
13
|
Vuolo F, Abreu SC, Michels M, Xisto DG, Blanco NG, Hallak JE, Zuardi AW, Crippa JA, Reis C, Bahl M, Pizzichinni E, Maurici R, Pizzichinni MMM, Rocco PRM, Dal-Pizzol F. Cannabidiol reduces airway inflammation and fibrosis in experimental allergic asthma. Eur J Pharmacol 2018; 843:251-259. [PMID: 30481497 DOI: 10.1016/j.ejphar.2018.11.029] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 11/16/2018] [Accepted: 11/21/2018] [Indexed: 10/27/2022]
Abstract
Asthma is characterized by chronic lung inflammation and airway hyperresponsiveness. Asthma remains a major public health problem and, at present, there are no effective interventions capable of reversing airway remodelling. Cannabidiol (CBD) is known to exert immunomodulatory effects through the activation of cannabinoid-1 and - 2 (CB1 and CB2) receptors located in the central nervous system and immune cells, respectively. However, as the role of CBD on airway remodelling and the mechanisms of CB1 and CB2 aren't fully elucidated, this study was designed to evaluate the effects of cannabidiol in this scenario. Allergic asthma was induced in Balb/c mice exposed to ovalbumin, and respiratory mechanics, collagen fibre content in airway and alveolar septa, cytokine levels, and CB1 and CB2 expression were determined. Moreover, expressions of CB1 and CB2 in induced sputum of asthmatic individuals and their correlation with airway inflammation and lung function were also evaluated. CBD treatment, regardless of dosage, decreased airway hyperresponsiveness, whereas static lung elastance only reduced with high dose. These outcomes were accompanied by decreases in collagen fibre content in both airway and alveolar septa and the expression of markers associated with inflammation in the bronchoalveolar lavage fluid and lung homogenate. There was a significant and inverse correlation between CB1 levels and lung function in asthmatic patients. CBD treatment decreased the inflammatory and remodelling processes in the model of allergic asthma. The mechanisms of action appear to be mediated by CB1/CB2 signalling, but these receptors may act differently on lung inflammation and remodelling.
Collapse
Affiliation(s)
- Francieli Vuolo
- Laboratory of Experimental Pathophysiology, Extreme University South of Santa Catarina, Criciúma, Brazil
| | - Soraia C Abreu
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Monique Michels
- Laboratory of Experimental Pathophysiology, Extreme University South of Santa Catarina, Criciúma, Brazil
| | - Débora G Xisto
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Natália G Blanco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jaime Ec Hallak
- Department of Neuroscience and Behavior, Faculty of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Antonio W Zuardi
- Department of Pneumology, Asthma Research Centre, Federal University of Santa Catarina, Florianópolis, Brazil
| | - José A Crippa
- Department of Neuroscience and Behavior, Faculty of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | - Cardine Reis
- Department of Pneumology, Asthma Research Centre, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Marina Bahl
- Department of Pneumology, Asthma Research Centre, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Emílio Pizzichinni
- Department of Pneumology, Asthma Research Centre, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Rosemeri Maurici
- Department of Pneumology, Asthma Research Centre, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Marcia M M Pizzichinni
- Department of Pneumology, Asthma Research Centre, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Patricia R M Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Felipe Dal-Pizzol
- Laboratory of Experimental Pathophysiology, Extreme University South of Santa Catarina, Criciúma, Brazil; Department of Pneumology, Asthma Research Centre, Federal University of Santa Catarina, Florianópolis, Brazil.
| |
Collapse
|
14
|
Khurana L, Mackie K, Piomelli D, Kendall DA. Modulation of CB1 cannabinoid receptor by allosteric ligands: Pharmacology and therapeutic opportunities. Neuropharmacology 2017; 124:3-12. [PMID: 28527758 PMCID: PMC5540789 DOI: 10.1016/j.neuropharm.2017.05.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/12/2017] [Accepted: 05/16/2017] [Indexed: 02/03/2023]
Abstract
Cannabinoid pharmacology has been intensely studied because of cannabis' pervasive medicinal and non-medicinal uses as well as for the therapeutic potential of cannabinoid-based drugs for the treatment of pain, anxiety, substance abuse, obesity, cancer and neurodegenerative disorders. The identification of allosteric modulators of the cannabinoid receptor 1 (CB1) has given a new direction to the development of cannabinoid-based therapeutics due to the many advantages offered by targeting allosteric site(s). Allosteric receptor modulators hold potential to develop subtype-specific and pathway-specific therapeutics. Here we briefly discuss the first-generation of allosteric modulators of CB1 receptor, their structure-activity relationships, signaling pathways and the allosteric binding site(s) on the CB1 receptor. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
Collapse
Affiliation(s)
- Leepakshi Khurana
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, United States
| | - Ken Mackie
- Gill Center and Departmental of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, United States
| | - Daniele Piomelli
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697, United States; Department of Biological Chemistry, University of California, Irvine, CA 92697, United States
| | - Debra A Kendall
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, United States.
| |
Collapse
|
15
|
Bagher AM, Laprairie RB, Toguri JT, Kelly MEM, Denovan-Wright EM. Bidirectional allosteric interactions between cannabinoid receptor 1 (CB 1) and dopamine receptor 2 long (D 2L) heterotetramers. Eur J Pharmacol 2017; 813:66-83. [PMID: 28734930 DOI: 10.1016/j.ejphar.2017.07.034] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 01/22/2023]
Abstract
Type 1 cannabinoid (CB1) and dopamine 2 long form (D2L) receptors can physically interact to form heteromers that display unique pharmacology in vitro compared to homomeric complexes. Co-expression of CB1 and D2L and co-application of CB1 and D2 agonists increases cAMP levels while administration of either agonist alone decreases cAMP levels. To understand the observed co-agonist response, our first goal of the current study was to define the stoichiometry of CB1/D2L/Gα protein complexes. Using bioluminescence resonance energy transfer 2 (BRET2), we confirmed that, CB1 homodimers, D2L homodimers, and CB1/D2L heteromers are formed. By using sequential resonance energy transfer 2 (SRET2) combined with bimolecular fluorescence complementation (BiFC), we were able to demonstrate that CB1/D2L form heterotetramers consisting of CB1 and D2L homodimers. We demonstrated that CB1/D2L heterotetramers are coupled to at least two Gα proteins. The second aim of the study was to investigate allosteric effects of a D2L agonist (quinpirole) on CB1 receptor function and to investigate the effects of a CB1 agonist [arachidonyl-2-chloroethylamide (ACEA)] on D2L receptor function within CB1/D2L heterotetramers. Treating cells co-expressing CB1 and D2L with both ACEA and quinpirole switched CB1 and D2L receptor coupling and signaling from Gαi to Gαs proteins, enhanced β-arrestin1 recruitment and receptor co-internalization. The concept of bidirectional allosteric interaction within CB1/D2 heterotetramers has important implications for understanding the activity of receptor complexes in native tissues and under pathological conditions.
Collapse
|
16
|
Abstract
The human cannabinoid receptor, CB1, has been difficult to purify in a functional form, hampering structural and biophysical studies. Here, we present our approaches for obtaining pure, detergent solubilized, functional CB1. We also discuss our site-directed fluorescence labeling (SDFL) methods for identifying different structural changes that CB1 can undergo upon binding different cannabinoid ligands. To identify optimal CB1 constructs for these studies (those with the best expression levels, solubility in detergent and function), we first screened various CB1-green fluorescent protein chimeras in a mammalian expression system. Once identified, we then tagged the best candidates with the 1D4 epitope (the C-terminus of rhodopsin) and purified them using a single-step immunoaffinity process. The resulting, highly pure proteins retain their ability to activate G-protein, and are ~85% functional, as assessed by radioligand binding studies. The SDFL studies involve introducing single cysteine residues at key places in the receptor, then labeling them with a small fluorophore, bimane. The spectral properties of the bimane probe are then monitored before and after addition of cannabinoid ligands. Changes in fluorescence of the attached probe indicate regions of the receptor undergoing conformational changes upon ligand binding. Together, these approaches set the stage for a deeper understanding of the structure and function of CB1. Access to pure, functional CB1 makes subsequent structural studies possible (such as crystallography and single-particle EM analysis), and the SDFL studies enable a better structural and mechanistic understanding of this key receptor and the dynamic changes it undergoes during activation and attenuation.
Collapse
|
17
|
Ho JM, Bergeon Burns CM, Rendon NM, Rosvall KA, Bradshaw HB, Ketterson ED, Demas GE. Lipid signaling and fat storage in the dark-eyed junco. Gen Comp Endocrinol 2017; 247:166-173. [PMID: 28161439 PMCID: PMC5410188 DOI: 10.1016/j.ygcen.2017.01.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 12/13/2016] [Accepted: 01/28/2017] [Indexed: 12/11/2022]
Abstract
Seasonal hyperphagia and fattening promote survivorship in migratory and wintering birds, but reduced adiposity may be more advantageous during the breeding season. Factors such as photoperiod, temperature, and food predictability are known environmental determinants of fat storage, but the underlying neuroendocrine mechanisms are less clear. Endocannabinoids and other lipid signaling molecules regulate multiple aspects of energy balance including appetite and lipid metabolism. However, these functions have been established primarily in mammals; thus the role of lipid signals in avian fat storage remains largely undefined. Here we examined relationships between endocannabinoid signaling and individual variation in fat storage in captive white-winged juncos (Junco hyemalis aikeni) following a transition to long-day photoperiods. We report that levels of the endocannabinoid 2-arachidonoylglycerol (2-AG), but not anandamide (AEA), in furcular and abdominal fat depots correlate negatively with fat mass. Hindbrain mRNA expression of CB1 endocannabinoid receptors also correlates negatively with levels of fat, demonstrating that fatter animals experience less central and peripheral endocannabinoid signaling when in breeding condition. Concentrations of the anorexigenic lipid, oleoylethanolamide (OEA), also inversely relate to adiposity. These findings demonstrate unique and significant relationships between adiposity and lipid signaling molecules in the brain and periphery, thereby suggesting a potential role for lipid signals in mediating adaptive levels of fat storage.
Collapse
Affiliation(s)
- Jacqueline M Ho
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA.
| | - Christine M Bergeon Burns
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| | - Nikki M Rendon
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| | - Kimberly A Rosvall
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA; Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
| | - Heather B Bradshaw
- Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA; Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA; Department of Psychological & Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - Ellen D Ketterson
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| | - Gregory E Demas
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA; Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
| |
Collapse
|
18
|
Stanley CP, Hind WH, Tufarelli C, O'Sullivan SE. The endocannabinoid anandamide causes endothelium-dependent vasorelaxation in human mesenteric arteries. Pharmacol Res 2016; 113:356-363. [PMID: 27633407 PMCID: PMC5113919 DOI: 10.1016/j.phrs.2016.08.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 07/14/2016] [Accepted: 08/27/2016] [Indexed: 12/12/2022]
Abstract
The endocannabinoid anandamide (AEA) causes vasorelaxation in animal studies. Although circulating AEA levels are increased in many pathologies, little is known about its vascular effects in humans. The aim of this work was to characterise the effects of AEA in human arteries. Ethical approval was granted to obtain mesenteric arteries from patients (n = 31) undergoing bowel resection. Wire myography was used to probe the effects and mechanisms of action of AEA. RT‐PCR was used to confirm the presence of receptor mRNA in human aortic endothelial cells (HAECs) and intracellular signalling proteins were measured using multiplex technology. AEA caused vasorelaxation of precontracted human mesenteric arteries with an Rmax of ∼30%. A synthetic CB1 agonist (CP55940) caused greater vasorelaxation (Rmax ∼60%) while a CB2 receptor agonist (HU308) had no effect on vascular tone. AEA-induced vasorelaxation was inhibited by removing the endothelium, inhibition of nitric oxide (NO) synthase, antagonising the CB1 receptor and antagonising the proposed novel endothelial cannabinoid receptor (CBe). AEA‐induced vasorelaxation was not affected by CB2 antagonism, by depleting sensory neurotransmitters, or inhibiting cyclooxygenase activity. RT‐PCR showed CB1 but not CB2 receptors were present in HAECs, and AEA and CP55940 had similar profiles in HAECs (increased phosphorylation of JNK, NFκB, ERK, Akt, p70s6K, STAT3 and STAT5). Post hoc analysis of the data set showed that overweight patients and those taking paracetamol had reduced vasorelaxant responses to AEA. These data show that AEA causes moderate endothelium-dependent, NO-dependent vasorelaxation in human mesenteric arteries via activation of CB1 receptors.
Collapse
Affiliation(s)
- Christopher P Stanley
- School of Medicine, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK
| | - William H Hind
- School of Medicine, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK
| | - Christina Tufarelli
- School of Medicine, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK
| | - Saoirse E O'Sullivan
- School of Medicine, University of Nottingham, Royal Derby Hospital, Derby, DE22 3DT, UK.
| |
Collapse
|
19
|
Murataeva N, Dhopeshwarkar A, Yin D, Mitjavila J, Bradshaw H, Straiker A, Mackie K. Where's my entourage? The curious case of 2-oleoylglycerol, 2-linolenoylglycerol, and 2-palmitoylglycerol. Pharmacol Res 2016; 110:173-180. [PMID: 27117667 DOI: 10.1016/j.phrs.2016.04.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/18/2016] [Accepted: 04/19/2016] [Indexed: 10/21/2022]
Abstract
2-Arachidonoylglycerol (2-AG) is the most abundant endogenous cannabinoid in the brain and an agonist at two cannabinoid receptors (CB1 and CB2). The synthesis, degradation and signaling of 2-AG have been investigated in detail but its relationship to other endogenous monoacylglycerols has not been fully explored. Three congeners that have been isolated from the CNS are 2-linoleoylglycerol (2-LG), 2-oleoylglycerol (2-OG), and 2-palmitoylglycerol (2-PG). These lipids do not orthosterically bind to cannabinoid receptors but are reported to potentiate the activity of 2-AG, possibly through inhibition of 2-AG degradation. This phenomenon has been dubbed the 'entourage effect' and has been proposed to regulate synaptic activity of 2-AG. To clarify the activity of these congeners of 2-AG we tested them in neuronal and cell-based signaling assays. The signaling profile for these compounds is inconsistent with an entourage effect. None of the compounds inhibited neurotransmission via CB1 in autaptic neurons. Interestingly, each failed to potentiate 2-AG-mediated depolarization-induced suppression of excitation (DSE), behaving instead as antagonists. Examining other signaling pathways we found that 2-OG interferes with agonist-induced CB1 internalization while 2-PG modestly internalizes CB1 receptors. However in tests of pERK, cAMP and arrestin recruitment, none of the acylglycerols altered CB1 signaling. Our results suggest 1) that these compounds do not serve as entourage compounds under the conditions examined, and 2) that they may instead serve as functional antagonists. Our results suggest that the relationship between 2-AG and its congeners is more nuanced than previously appreciated.
Collapse
Affiliation(s)
- Natalia Murataeva
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - Amey Dhopeshwarkar
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - Danielle Yin
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - José Mitjavila
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - Heather Bradshaw
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - Alex Straiker
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA.
| | - Ken Mackie
- The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| |
Collapse
|
20
|
Henderson-Redmond AN, Guindon J, Morgan DJ. Roles for the endocannabinoid system in ethanol-motivated behavior. Prog Neuropsychopharmacol Biol Psychiatry 2016; 65:330-9. [PMID: 26123153 PMCID: PMC4679600 DOI: 10.1016/j.pnpbp.2015.06.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 06/15/2015] [Accepted: 06/22/2015] [Indexed: 12/19/2022]
Abstract
Alcohol use disorder represents a significant human health problem that leads to substantial loss of human life and financial cost to society. Currently available treatment options do not adequately address this human health problem, and thus, additional therapies are desperately needed. The endocannabinoid system has been shown, using animal models, to modulate ethanol-motivated behavior, and it has also been demonstrated that chronic ethanol exposure can have potentially long-lasting effects on the endocannabinoid system. For example, chronic exposure to ethanol, in either cell culture or preclinical rodent models, causes an increase in endocannabinoid levels that results in down-regulation of the cannabinoid receptor 1 (CB1) and uncoupling of this receptor from downstream G protein signaling pathways. Using positron emission tomography (PET), similar down-regulation of CB1 has been noted in multiple regions of the brain in human alcoholic patients. In rodents, treatment with the CB1 inverse agonist SR141716A (Rimonabant), or genetic deletion of CB1 leads to a reduction in voluntary ethanol drinking, ethanol-stimulated dopamine release in the nucleus accumbens, operant self-administration of ethanol, sensitization to the locomotor effects of ethanol, and reinstatement/relapse of ethanol-motivated behavior. Although the clinical utility of Rimonabant or other antagonists/inverse agonists for CB1 is limited due to negative neuropsychiatric side effects, negative allosteric modulators of CB1 and inhibitors of endocannabinoid catabolism represent therapeutic targets worthy of additional examination.
Collapse
Affiliation(s)
| | - Josée Guindon
- Department of Pharmacology and Neuroscience, Texas Tech University Health Science Center, Lubbock, TX, 79430
| | - Daniel J Morgan
- Department of Anesthesiology, Penn State University College of Medicine, Hershey, PA 17033, United States; Department of Pharmacology, Penn State University College of Medicine, Hershey, PA 17033, United States.
| |
Collapse
|
21
|
Mazier W, Saucisse N, Gatta-Cherifi B, Cota D. The Endocannabinoid System: Pivotal Orchestrator of Obesity and Metabolic Disease. Trends Endocrinol Metab 2015; 26:524-537. [PMID: 26412154 DOI: 10.1016/j.tem.2015.07.007] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 01/10/2023]
Abstract
The endocannabinoid system (ECS) functions to adjust behavior and metabolism according to environmental changes in food availability. Its actions range from the regulation of sensory responses to the development of preference for the consumption of calorically-rich food and control of its metabolic handling. ECS activity is beneficial when access to food is scarce or unpredictable. However, when food is plentiful, the ECS favors obesity and metabolic disease. We review recent advances in understanding the roles of the ECS in energy balance, and discuss newly identified mechanisms of action that, after the withdrawal of first generation cannabinoid type 1 (CB1) receptor antagonists for the treatment of obesity, have made the ECS once again an attractive target for therapy.
Collapse
Affiliation(s)
- Wilfrid Mazier
- Institut National de la Santé et de la Recherche Médicale (INSERM), Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Unité 862, 33000 Bordeaux, France; University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Unité 862, 33000 Bordeaux, France
| | - Nicolas Saucisse
- Institut National de la Santé et de la Recherche Médicale (INSERM), Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Unité 862, 33000 Bordeaux, France; University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Unité 862, 33000 Bordeaux, France
| | - Blandine Gatta-Cherifi
- Institut National de la Santé et de la Recherche Médicale (INSERM), Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Unité 862, 33000 Bordeaux, France; University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Unité 862, 33000 Bordeaux, France; Endocrinology Department, Haut-Lévêque Hospital, 33604 Pessac, France
| | - Daniela Cota
- Institut National de la Santé et de la Recherche Médicale (INSERM), Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Unité 862, 33000 Bordeaux, France; University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Unité 862, 33000 Bordeaux, France.
| |
Collapse
|
22
|
Huang G, Pemp D, Stadtmüller P, Nimczick M, Heilmann J, Decker M. Design, synthesis and in vitro evaluation of novel uni- and bivalent ligands for the cannabinoid receptor type 1 with variation of spacer length and structure. Bioorg Med Chem Lett 2014; 24:4209-14. [PMID: 25096297 DOI: 10.1016/j.bmcl.2014.07.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/13/2014] [Accepted: 07/14/2014] [Indexed: 10/25/2022]
Abstract
Using rimonabant, a potent inverse agonist for cannabinoid receptor type 1 (CB1R), as parent ligand, a series of novel univalent and bivalent ligands were designed by variation of spacer length and its chemical structure. The ligands synthesized were evaluated for affinity and selectivity by radioligand displacement and a functional steady-state GTPase assay. The results showed the nature of the spacer influences the biological readout. Albeit all compounds show significantly lower affinities than rimonabant, this fact could be used to demonstrate that affinities and selectivity are influenced by the chemical structure and length of the spacer and might be helpful for designing bivalent probes for other GPCR receptors.
Collapse
Affiliation(s)
- Guozheng Huang
- Pharmazeutische und Medizinische Chemie, Institut für Pharmazie und Lebensmittelchemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany; Lehrstuhl für Pharmazeutische Chemie I, Institut für Pharmazie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Daniela Pemp
- Lehrstuhl für Pharmazeutische Biologie, Institut für Pharmazie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Patricia Stadtmüller
- Pharmazeutische und Medizinische Chemie, Institut für Pharmazie und Lebensmittelchemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Martin Nimczick
- Pharmazeutische und Medizinische Chemie, Institut für Pharmazie und Lebensmittelchemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany; Lehrstuhl für Pharmazeutische Chemie I, Institut für Pharmazie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Jörg Heilmann
- Lehrstuhl für Pharmazeutische Biologie, Institut für Pharmazie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Michael Decker
- Pharmazeutische und Medizinische Chemie, Institut für Pharmazie und Lebensmittelchemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany; Lehrstuhl für Pharmazeutische Biologie, Institut für Pharmazie, Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.
| |
Collapse
|
23
|
Riaño Barros DA, McGinnity CJ, Rosso L, Heckemann RA, Howes OD, Brooks DJ, Duncan JS, Turkheimer FE, Koepp MJ, Hammers A. Test-retest reproducibility of cannabinoid-receptor type 1 availability quantified with the PET ligand [¹¹C]MePPEP. Neuroimage 2014; 97:151-62. [PMID: 24736184 PMCID: PMC4283194 DOI: 10.1016/j.neuroimage.2014.04.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/19/2014] [Accepted: 04/07/2014] [Indexed: 11/30/2022] Open
Abstract
Background Endocannabinoids are involved in normal cognition, and dysfunction in cannabinoid-receptor-mediated neurotransmission has been suggested in a variety of neurological and psychiatric pathologies. The type 1 cannabinoid receptor (CB1) is widely expressed in the human central nervous system. The objective of this study was to quantify the test–retest reproducibility of measures of the PET ligand [11C]MePPEP in order to assess the stability of CB1-receptor quantification in humans in vivo. Methods Fifteen healthy subjects (eight females; median age 32 years, range 25 to 65 years) had a 90-minute PET scan on two occasions after injection of a median dose of [11C]MePPEP of 364 MBq. Metabolite-corrected arterial plasma input functions were obtained for all scans. Eight ROIs, reflecting different levels of receptor densities/concentrations, were defined automatically: hippocampus, anterior cingulate gyrus, inferior frontal gyrus, caudate nucleus, globus pallidus, nucleus accumbens, thalamus, and pons. We used seven quantification methods: reversible compartmental models with one and two tissue classes, two and four rate constants, and a variable blood volume term (2kbv; 4kbv); model-free (spectral) analyses with and without regularisation, including one with voxel-wise quantification; the simplified reference tissue model (SRTM) with pons as a pseudo-reference region; and modified standard uptake values (mSUVs) calculated for the period of ~ 30–60 min after injection. Percentage test–retest change and between-subject variability were both assessed, and test–retest reliability was quantified by the intraclass correlation coefficient (ICC). The ratio of binding estimates pallidum:pons served as an indicator of a method's ability to reflect binding heterogeneity. Results Neither the SRTM nor the 4kbv model produced reliable measures, with ICCs around zero. Very good (> 0.75) or excellent (> 0.80) ICCs were obtained with the other methods. The most reliable were spectral analysis parametric maps (average across regions ± standard deviation 0.83 ± 0.03), rank shaping regularised spectral analysis (0.82 ± 0.05), and the 2kbv model (0.82 ± 0.09), but mSUVs were also reliable for most regions (0.79 ± 0.13). Mean test–retest changes among the five well-performing methods ranged from 12 ± 10% for mSUVs to 16% for 2kbv. Intersubject variability was high, with mean between-subject coefficients of variation ranging from 32 ± 13% for mSUVs to 45% for 2kbv. The highest pallidum:pons ratios of binding estimates were achieved by mSUV (4.2), spectral analysis-derived parametric maps (3.6), and 2kbv (3.6). Conclusion Quantification of CB1 receptor availability using [11C]MePPEP shows good to excellent reproducibility with several kinetic models and model-free analyses, whether applied on a region-of-interest or voxelwise basis. Simple mSUV measures were also reliable for most regions, but do not allow fully quantitative interpretation. [11C]MePPEP PET is well placed as a tool to investigate CB1-receptor mediated neurotransmission in health and disease. [11C]MePPEP is a PET tracer for cannabinoid receptors (CB1R). Extensive evaluation of [11C]MePPEP data quantification strategies in large sample We highlight successful methods to quantify CB1R in regions of interest. Highly reliable parametric maps (ICC 0.83 ± 0.03) allow whole-brain surveys. Modified standard uptake values also reliable, without arterial input functions
Collapse
Affiliation(s)
- Daniela A Riaño Barros
- Centre for Neuroscience, Department of Medicine, Imperial College London, London, UK; MRC Clinical Sciences Centre Hammersmith Hospital, London, UK
| | - Colm J McGinnity
- Centre for Neuroscience, Department of Medicine, Imperial College London, London, UK; MRC Clinical Sciences Centre Hammersmith Hospital, London, UK
| | - Lula Rosso
- Centre for Neuroscience, Department of Medicine, Imperial College London, London, UK
| | - Rolf A Heckemann
- Centre for Neuroscience, Department of Medicine, Imperial College London, London, UK; Neurodis Foundation, CERMEP, Imagerie du Vivant, Lyon. France
| | - Oliver D Howes
- Centre for Neuroscience, Department of Medicine, Imperial College London, London, UK; MRC Clinical Sciences Centre Hammersmith Hospital, London, UK
| | - David J Brooks
- Centre for Neuroscience, Department of Medicine, Imperial College London, London, UK; Institute of Clinical Medicine, Aarhus University, Denmark
| | - John S Duncan
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, UK; Epilepsy Society, Chalfont St Peter, UK
| | | | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, UK; Epilepsy Society, Chalfont St Peter, UK
| | - Alexander Hammers
- Centre for Neuroscience, Department of Medicine, Imperial College London, London, UK; MRC Clinical Sciences Centre Hammersmith Hospital, London, UK; Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, UK; Epilepsy Society, Chalfont St Peter, UK; Neurodis Foundation, CERMEP, Imagerie du Vivant, Lyon. France.
| |
Collapse
|
24
|
Bagher AM, Laprairie RB, Kelly MEM, Denovan-Wright EM. Co-expression of the human cannabinoid receptor coding region splice variants (hCB₁) affects the function of hCB₁ receptor complexes. Eur J Pharmacol 2013; 721:341-54. [PMID: 24091169 DOI: 10.1016/j.ejphar.2013.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 08/26/2013] [Accepted: 09/04/2013] [Indexed: 10/26/2022]
Abstract
The human type 1 cannabinoid (hCB1) receptor is expressed at high levels in the central nervous system. mRNA variants of the coding region of this receptor, human cannabinoid hCB1a and hCB1b receptors, have been identified, their biological function remains unclear. The present study demonstrated that the three human cannabinoid hCB1 coding region variants are expressed in the human and monkey (Macaca fascicularis) brain. Western blot analyses of homogenates from different regions of the monkey brain demonstrated that proteins with the expected molecular weights of the cannabinoid CB1, CB1a and CB1b receptors were co-expressed throughout the brain. Given the co-localization of these receptors, we hypothesized that physical interactions between the three splice variants may affect cannabinoid pharmacology. The human cannabinoid hCB1, hCB1a, and hCB1b receptors formed homodimers and heterodimers, as determined by BRET in transiently transfected HEK 293A cells. We found that the co-expression of the human cannabinoid hCB1 and each of the splice variants increased cell surface expression of the human cannabinoid hCB1 receptor and increased Gi/o-dependent ERK phosphorylation in response to cannabinoid agonists. Therefore, the human cannabinoid hCB1 coding region splice variants play an important physiological role in the activity of the endocannabinoid system.
Collapse
Affiliation(s)
- Amina M Bagher
- Department of Pharmacology, Dalhousie University, 6E Sir Charles Tupper Medical Bldg., 5850 College St., Halifax, NS, Canada B3H 4R2
| | | | | | | |
Collapse
|
25
|
Laricchiuta D, Centonze D, Petrosini L. Effects of endocannabinoid and endovanilloid systems on aversive memory extinction. Behav Brain Res 2013; 256:101-7. [PMID: 23948212 DOI: 10.1016/j.bbr.2013.08.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 08/01/2013] [Accepted: 08/05/2013] [Indexed: 01/23/2023]
Abstract
In contextual fear conditioning animals have to integrate various elemental stimuli into a coherent representation of the condition and then associate context representation with punishment. Although several studies indicated the modulating role of endocannabinoid system (ECS) on the associative learning, ECS effect on contextual fear conditioning requires further investigations. The present study assessed the effects of the increased endocannabinoid anandamide (AEA) tone on acquisition, retrieval and extinction of the contextual fear conditioning. Given that AEA may bind to cannabinoid type 1 (CB1) receptors as well as to postsynaptic ionotropic Transient Receptor Potential Vanilloid type 1 (TRPV1) channels, particular attention was paid in determining how the increased AEA tone influenced fear responses. Furthermore, it was investigated how the ECS modulated the effects of stress-sensitization on fear response. Thus, mice submitted or not to a social defeat stress protocol were treated with drugs acting on ECS, CB1 receptors or TRPV1 channels and tested in a contextual fear conditioning whose conditioning, retrieval and extinction phases were analyzed. ECS activation influenced the extinction process and contrasted the stress effects on fear memory. Furthermore, CB1 receptor antagonist blocked and TRPV1 channel antagonist promoted short- and long-term extinction. The present study indicates that ECS controls the extinction of aversive memories in the contextual fear conditioning.
Collapse
Affiliation(s)
- Daniela Laricchiuta
- I.R.C.C.S. Santa Lucia Foundation, Via del Fosso di Fiorano 64, 00143, Rome, Italy; Department of Psychology, Faculty of Medicine and Psychology, University "Sapienza" of Rome, via dei Marsi 78, 00185, Rome, Italy.
| | | | | |
Collapse
|
26
|
Salazar M, Lorente M, García-Taboada E, Hernández-Tiedra S, Davila D, Francis SE, Guzmán M, Kiss-Toth E, Velasco G. The pseudokinase tribbles homologue-3 plays a crucial role in cannabinoid anticancer action. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1573-8. [PMID: 23567453 DOI: 10.1016/j.bbalip.2013.03.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 03/27/2013] [Indexed: 01/16/2023]
Abstract
Δ(9)-Tetrahydrocannabinol (THC), the major active ingredient of marijuana, and other cannabinoids inhibit tumor growth in animal models of cancer. This effect relies, at least in part, on the up-regulation of several endoplasmic reticulum stress-related proteins including the pseudokinase tribbles homologue-3 (TRIB3), which leads in turn to the inhibition of the AKT/mTORC1 axis and the subsequent stimulation of autophagy-mediated apoptosis in tumor cells. Here, we took advantage of the use of cells derived from Trib3-deficient mice to investigate the precise mechanisms by which TRIB3 regulates the anti-cancer action of THC. Our data show that RasV(12)/E1A-transformed embryonic fibroblasts derived from Trib3-deficient mice are resistant to THC-induced cell death. We also show that genetic inactivation of this protein abolishes the ability of THC to inhibit the phosphorylation of AKT and several of its downstream targets, including those involved in the regulation of the AKT/mammalian target of rapamycin complex 1 (mTORC1) axis. Our data support the idea that THC-induced TRIB3 up-regulation inhibits AKT phosphorylation by regulating the accessibility of AKT to its upstream activatory kinase (the mammalian target of rapamycin complex 2; mTORC2). Finally, we found that tumors generated by inoculation of Trib3-deficient cells in nude mice are resistant to THC anticancer action. Altogether, the observations presented here strongly support that TRIB3 plays a crucial role on THC anti-neoplastic activity. This article is part of a Special Issue entitled Lipid Metabolism in Cancer.
Collapse
|
27
|
Lee TTY, Hill MN. Age of stress exposure modulates the immediate and sustained effects of repeated stress on corticolimbic cannabinoid CB₁ receptor binding in male rats. Neuroscience 2012. [PMID: 23200786 DOI: 10.1016/j.neuroscience.2012.11.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Chronic stress is known to modulate cannabinoid CB1 receptor binding densities in corticolimbic structures, in a region-dependent manner; however, the ontogeny of these changes and the degree to which they recover following exposure to stress have yet to be determined. To this extent, we examined both the immediate and sustained effects (following a 40-day recovery period) of a repeated restraint stress paradigm (30-min restraint/day for 10 days) on CB1 receptor binding in the prefrontal cortex (PFC), hippocampus and amygdala in both adolescent (stress onset at post-natal day [PND] 35) and adult (stress onset at PND 75) male Sprague-Dawley rats. Consistent with previous reports, we found that repeated stress in adult rats resulted in an increase in CB1 receptor binding in the PFC, a reduction in CB1 receptor binding in the hippocampus and no effect in the amygdala. Interestingly, adolescent rats exposed to repeated restraint stress did not show any change in hippocampal CB1 receptor density, but exhibited an upregulation of CB1 receptor binding in both the PFC and amygdala. In adults, a 40-day recovery period resulted in a normalization of CB1 receptor binding in the PFC, and surprisingly a pronounced upregulation of CB1 receptor binding in the hippocampus, possibly indicative of a rebound effect. Adolescents similarly exhibited this rebound increase in hippocampal CB1 receptor binding, despite a lack in immediate downregulation following repeated restraint. Of particular interest, adolescents exposed to stress were found to have a sustained downregulation of prefrontocortical CB1 receptors in adulthood, which may relate to some of the reported sustained behavioral effects of stress in adolescence. Collectively, these data indicate that the effects of chronic stress on cannabinoid CB1 receptor binding are modulated by the age of stress exposure and period of recovery following the cessation of stress.
Collapse
Affiliation(s)
- T T Y Lee
- Hotchkiss Brain Institute, Department of Cell Biology, University of Calgary, Calgary, AB, Canada
| | | |
Collapse
|