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Glenn NAK, Finlay DB, Carruthers ER, Mountjoy KG, Walker CS, Grimsey NL. RAMP and MRAP accessory proteins have selective effects on expression and signalling of the CB 1, CB 2, GPR18 and GPR55 cannabinoid receptors. Br J Pharmacol 2024; 181:2212-2231. [PMID: 37085333 DOI: 10.1111/bph.16095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 03/10/2023] [Accepted: 04/14/2023] [Indexed: 04/23/2023] Open
Abstract
BACKGROUND AND PURPOSE Receptor activity-modifying proteins (RAMPs) and melanocortin receptor accessory proteins (MRAPs) modulate expression and signalling of calcitonin and melanocortin GPCRs. Interactions with other GPCRs have also been reported. The cannabinoid receptors, CB1 and CB2, and two putative cannabinoid receptors, GPR18 and GPR55, exhibit substantial intracellular expression and there are discrepancies in ligand responsiveness between studies. We investigated whether interactions with RAMPs or MRAPs could explain these phenomena. EXPERIMENTAL APPROACH Receptors and accessory proteins were co-expressed in HEK-293 cells. Selected receptors were studied at basal expression levels and also with enhanced expression produced by incorporation of a preprolactin signal sequence/peptide (pplss). Cell surface and total expression of receptors and accessory proteins were quantified using immunocytochemistry. Signalling was measured using cAMP (CAMYEL) and G protein dissociation (TRUPATH Gα13) biosensors. KEY RESULTS MRAP2 enhanced surface and total expression of GPR18. Pplss-GPR18 increased detection of cell surface MRAP2. MRAP1α and MRAP2 reduced GPR55 surface and total expression, correlating with reduced constitutive, but not agonist-induced, signalling. GPR55, pplss-CB1 and CB2 reduced detection of MRAP1α at the cell surface. Pplss-CB1 agonist potency was reduced by MRAP2 in Gα13 but not cAMP assays, consistent with MRAP2 reducing pplss-CB1 expression. Some cannabinoid receptors increased RAMP2 or RAMP3 total expression without influencing surface expression. CONCLUSIONS AND IMPLICATIONS Mutual influences on expression and/or function for specific accessory protein-receptor pairings raises the strong potential for physiological and disease-relevant consequences. Sequestration and/or hetero-oligomerisation of cannabinoid receptors with accessory proteins is a possible novel mechanism for receptor crosstalk. LINKED ARTICLES This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
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MESH Headings
- Humans
- HEK293 Cells
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, Cannabinoid/metabolism
- Signal Transduction
- Receptor, Cannabinoid, CB1/metabolism
- Receptor Activity-Modifying Proteins/metabolism
- Receptor, Cannabinoid, CB2/metabolism
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/genetics
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Affiliation(s)
- Nathaniel A K Glenn
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - David B Finlay
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Emma R Carruthers
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Kathleen G Mountjoy
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Christopher S Walker
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
- School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
| | - Natasha L Grimsey
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
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Cooper ME, Nørregaard PK, Högberg T, Andersson G, Receveur JM, Linget JM, Elling CE. Efficacy in diet-induced obese mice of the hepatotropic, peripheral cannabinoid 1 receptor inverse agonist TM38837. Br J Pharmacol 2024. [PMID: 38886096 DOI: 10.1111/bph.16401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/26/2024] [Accepted: 03/19/2024] [Indexed: 06/20/2024] Open
Abstract
BACKGROUND AND PURPOSE The cannabinoid CB1 receptor has a well-established role in appetite regulation. Drugs antagonizing central CB1 receptors, most notably rimonabant, induced weight loss and improved the metabolic profile in obese individuals but were discontinued due to psychiatric side effects. However, metabolic benefits were only partially attributable to weight loss, implying a role for peripheral receptors, and peripherally restricted CB1 receptor antagonists have since been of interest. Herein, we describe the evaluation of the peripherally restricted potent CB1 receptor inverse agonists TM38837 and TM39875, with acidic functionality, which were administered daily to diet-induced obese (DIO) mice for 5 weeks at doses for which CNS-mediated effects were minimal. EXPERIMENTAL APPROACH Compounds were tested in dose-response in acute studies to compare efficacy (gastric transport) and extent of CNS exposure (hypothermia and satiety sequence) to demonstrate peripheral restriction and select doses for the subsequent chronic DIO study. KEY RESULTS TM38837 but not TM39875 produced considerable (26%) weight loss, linked to a sustained reduction in food intake, together with improvements in plasma markers of inflammation and glucose homeostasis. Pharmacokinetic analysis indicated high plasma and low brain levels for both compounds with high liver levels for TM38837 (but not TM39875) due to hepatic uptake. CONCLUSION AND IMPLICATIONS Weight loss and metabolic benefits of TM38837 are likely not CNS-mediated but could be linked to enhanced liver exposure, which implicates intracellular CB1 receptors in hepatocytes as a possible driver of obesity and co-morbidities.
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Fernández-Moncada I, Rodrigues RS, Fundazuri UB, Bellocchio L, Marsicano G. Type-1 cannabinoid receptors and their ever-expanding roles in brain energy processes. J Neurochem 2024; 168:693-703. [PMID: 37515372 DOI: 10.1111/jnc.15922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/06/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023]
Abstract
The brain requires large quantities of energy to sustain its functions. At the same time, the brain is isolated from the rest of the body, forcing this organ to develop strategies to control and fulfill its own energy needs. Likely based on these constraints, several brain-specific mechanisms emerged during evolution. For example, metabolically specialized cells are present in the brain, where intercellular metabolic cycles are organized to separate workload and optimize the use of energy. To orchestrate these strategies across time and space, several signaling pathways control the metabolism of brain cells. One of such controlling systems is the endocannabinoid system, whose main signaling hub in the brain is the type-1 cannabinoid (CB1) receptor. CB1 receptors govern a plethora of different processes in the brain, including cognitive function, emotional responses, or feeding behaviors. Classically, the mechanisms of action of CB1 receptors on brain function had been explained by its direct targeting of neuronal synaptic function. However, new discoveries have challenged this view. In this review, we will present and discuss recent data about how a small fraction of CB1 receptors associated to mitochondrial membranes (mtCB1), are able to exert a powerful control on brain functions and behavior. mtCB1 receptors impair mitochondrial functions both in neurons and astrocytes. In the latter cells, this effect is linked to an impairment of astrocyte glycolytic function, resulting in specific behavioral outputs. Finally, we will discuss the potential implications of (mt)CB1 expression on oligodendrocytes and microglia metabolic functions, with the aim to encourage interdisciplinary approaches to better understand the role of (mt)CB1 receptors in brain function and behavior.
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Affiliation(s)
| | - Rui S Rodrigues
- Université de Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France
| | - Unai B Fundazuri
- Université de Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France
| | - Luigi Bellocchio
- Université de Bordeaux, INSERM, Neurocentre Magendie, Bordeaux, France
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4
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Kallinen A, Mardon K, Lane S, Montgomery AP, Bhalla R, Stimson DHR, Ahamed M, Cowin GJ, Hibbs D, Werry EL, Fulton R, Connor M, Kassiou M. Synthesis and Preclinical Evaluation of Fluorinated 5-Azaindoles as CB2 PET Radioligands. ACS Chem Neurosci 2023; 14:2902-2921. [PMID: 37499194 DOI: 10.1021/acschemneuro.3c00345] [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] [Indexed: 07/29/2023] Open
Abstract
Several classes of cannabinoid receptor type 2 radioligands have been evaluated for imaging of neuroinflammation, with successful clinical translation yet to take place. Here we describe the synthesis of fluorinated 5-azaindoles and pharmacological characterization and in vivo evaluation of 18F-radiolabeled analogues. [18F]2 (hCB2 Ki = 96.5 nM) and [18F]9 (hCB2 Ki = 7.7 nM) were prepared using Cu-mediated 18F-fluorination with non-decay-corrected radiochemical yields of 15 ± 6% and 18 ± 2% over 85 and 80 min, respectively, with high radiochemical purities (>97%) and molar activities (140-416 GBq/μmol). In PET imaging studies in rats, both [18F]2 and [18F]9 demonstrated specific binding in CB2-rich spleen after pretreatment with CB2-specific GW405833. Moreover, [18F]9 exhibited higher brain uptake at later time points in a murine model of neuroinflammation compared with a healthy control group. The results suggest further evaluation of azaindole based CB2 radioligands is warranted in other neuroinflammation models.
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Affiliation(s)
- Annukka Kallinen
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Karine Mardon
- ARC Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Samuel Lane
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | | | | | | | - Muneer Ahamed
- ARC Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Gary J Cowin
- ARC Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David Hibbs
- Sydney Pharmacy School, The University of Sydney, Sydney, NSW 2006, Australia
| | - Eryn L Werry
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Roger Fulton
- Faculty of Health Sciences, The University of Sydney, Sydney, NSW 2050, Australia
| | - Mark Connor
- Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
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Osorio-Perez RM, Rodríguez-Manzo G, Espinosa-Riquer ZP, Cruz SL, González-Espinosa C. Endocannabinoid modulation of allergic responses: Focus on the control of FcεRI-mediated mast cell activation. Eur J Cell Biol 2023; 102:151324. [PMID: 37236045 DOI: 10.1016/j.ejcb.2023.151324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/16/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
Allergic reactions are highly prevalent pathologies initiated by the production of IgE antibodies against harmless antigens (allergens) and the activation of the high-affinity IgE receptor (FcεRI) expressed in the surface of basophils and mast cells (MCs). Research on the mechanisms of negative control of those exacerbated inflammatory reactions has been intense in recent years. Endocannabinoids (eCBs) show important regulatory effects on MC-mediated immune responses, mainly inhibiting the production of pro-inflammatory mediators. However, the description of the molecular mechanisms involved in eCB control of MC activation is far from complete. In this review, we aim to summarize the available information regarding the role of eCBs in the modulation of FcεRI-dependent activation of that cell type, emphasizing the description of the eCB system and the existence of some of its elements in MCs. Unique characteristics of the eCB system and cannabinoid receptors (CBRs) localization and signaling in MCs are mentioned. The described and putative points of cross-talk between CBRs and FcεRI signaling cascades are also presented. Finally, we discuss some important considerations in the study of the effects of eCBs in MCs and the perspectives in the field.
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Affiliation(s)
- Rubi Monserrat Osorio-Perez
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Sede Sur, Calzada de los Tenorios No. 235, Col. Granjas Coapa, Tlalpan, CP 14330 Mexico City, Mexico
| | - Gabriela Rodríguez-Manzo
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Sede Sur, Calzada de los Tenorios No. 235, Col. Granjas Coapa, Tlalpan, CP 14330 Mexico City, Mexico
| | - Zyanya P Espinosa-Riquer
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Sede Sur, Calzada de los Tenorios No. 235, Col. Granjas Coapa, Tlalpan, CP 14330 Mexico City, Mexico
| | - Silvia L Cruz
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Sede Sur, Calzada de los Tenorios No. 235, Col. Granjas Coapa, Tlalpan, CP 14330 Mexico City, Mexico
| | - Claudia González-Espinosa
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Sede Sur, Calzada de los Tenorios No. 235, Col. Granjas Coapa, Tlalpan, CP 14330 Mexico City, Mexico.
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6
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Rokeby ACE, Natale BV, Natale DRC. Cannabinoids and the placenta: Receptors, signaling and outcomes. Placenta 2023; 135:51-61. [PMID: 36965349 DOI: 10.1016/j.placenta.2023.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/06/2023] [Accepted: 03/09/2023] [Indexed: 03/12/2023]
Abstract
Cannabis use during pregnancy is increasing. The improvement of pregnancy-related symptoms including morning sickness and management of mood and stress are among the most reported reasons for its use. Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) are the most abundant cannabinoids found within the cannabis flower. The concentration of these components has drastically increased in the past 20 years. Additionally, many edibles contain only one cannabinoid and are marketed to achieve a specific goal, meaning there are an increasing number of pregnancies that are exposed to isolated cannabinoids. Both Δ9-THC and CBD cross the placenta and can impact the fetus directly, but the receptors through which cannabinoids act are also expressed throughout the placenta, suggesting that the effects of in-utero cannabinoid exposure may include indirect effects from the placenta. In-utero cannabis research focuses on short and long-term fetal health and development; however, these studies include little to no placenta analysis. Prenatal cannabinoid exposure is linked to small for gestational age and fetal growth-restricted babies. Compromised placental development is also associated with fetal growth restriction and the few studies (clinical and animal models) that included placental analysis, identify changes in placental vasculature and function in these cannabinoid-exposed pregnancies. In vitro studies further support cannabinoid impact on cell function in the different populations that comprise the placenta. In this article, we aim to summarize how phytocannabinoids can impact placental development and function. Specifically, the cannabinoids and their actions at the different receptors are described, with receptor localization throughout the human and murine placenta discussed. Findings from studies that included placental analysis and how cannabinoid signaling may modulate critical developmental processing including cell proliferation, angiogenesis and migration are described. Considering the current research, prenatal cannabinoid exposure may significantly impact placental development, and, as such, identifying windows of placental vulnerability for each cannabinoid will be critical to elucidate the etiology of fetal outcome studies.
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Affiliation(s)
- Abbey C E Rokeby
- Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Bryony V Natale
- Department of Obstetrics and Gynaecology, Queen's University, Kingston, ON, Canada
| | - David R C Natale
- Department of Obstetrics and Gynaecology, Queen's University, Kingston, ON, Canada; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada.
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7
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Przybycień P, Gąsior-Perczak D, Placha W. Cannabinoids and PPAR Ligands: The Future in Treatment of Polycystic Ovary Syndrome Women with Obesity and Reduced Fertility. Cells 2022; 11:cells11162569. [PMID: 36010645 PMCID: PMC9406585 DOI: 10.3390/cells11162569] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 08/13/2022] [Accepted: 08/17/2022] [Indexed: 11/21/2022] Open
Abstract
Cannabinoids (CBs) are used to treat chronic pain, chemotherapy-induced nausea and vomiting, and multiple sclerosis spasticity. Recently, the medicinal use of CBs has attracted increasing interest as a new therapeutic in many diseases. Data indicate a correlation between CBs and PPARs via diverse mechanisms. Both the endocannabinoid system (ECS) and peroxisome proliferator-activated receptors (PPARs) may play a significant role in PCOS and PCOS related disorders, especially in disturbances of glucose-lipid metabolism as well as in obesity and fertility. Taking into consideration the ubiquity of PCOS in the human population, it seems indispensable to search for new potential therapeutic targets for this condition. The aim of this review is to examine the relationship between metabolic disturbances and obesity in PCOS pathology. We discuss current and future therapeutic interventions for PCOS and related disorders, with emphasis on the metabolic pathways related to PCOS pathophysiology. The link between the ECS and PPARs is a promising new target for PCOS, and we examine this relationship in depth.
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Affiliation(s)
- Piotr Przybycień
- Chair of Medical Biochemistry, Faculty of Medicine, Jagiellonian University Medical College, 31-034 Krakow, Poland
- Endocrinology Clinic, Holycross Cancer Centre, 25-734 Kielce, Poland
| | - Danuta Gąsior-Perczak
- Endocrinology Clinic, Holycross Cancer Centre, 25-734 Kielce, Poland
- Collegium Medicum, Jan Kochanowski University, 25-317 Kielce, Poland
| | - Wojciech Placha
- Chair of Medical Biochemistry, Faculty of Medicine, Jagiellonian University Medical College, 31-034 Krakow, Poland
- Correspondence: ; Tel.: +48-12-422-74-00
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8
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Lott J, Jutkiewicz EM, Puthenveedu MA. The Synthetic Cannabinoid WIN55,212-2 Can Disrupt the Golgi Apparatus Independent of Cannabinoid Receptor-1. Mol Pharmacol 2022; 101:371-380. [PMID: 35236771 PMCID: PMC9092469 DOI: 10.1124/molpharm.121.000377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 02/22/2022] [Indexed: 11/22/2022] Open
Abstract
The synthetic cannabinoid WIN55,212-2 (WIN) is widely used as a pharmacological tool to study the biologic activity of cannabinoid receptors. In contrast to many other cannabinoid agonists, however, WIN also causes broad effects outside of neurons, such as reducing inflammatory responses, causing cell cycle arrest, and reducing general protein expression. How exactly WIN causes these broad effects is not known. Here we show that WIN partially disrupts the Golgi apparatus at nanomolar concentrations and fully disperses the Golgi apparatus in neuronal and non-neuronal cells at micromolar concentrations. WIN55,212-3, the enantiomer of WIN; JWH-018, a related alkylindole; or 2-arachidonoylglycerol, an endocannabinoid, did not cause Golgi disruption, suggesting that the effect was specific to the chirality of WIN. WIN treatment also perturbed the microtubule network. Importantly, WIN disrupted the Golgi in primary cortical neurons derived from mice where cannabinoid receptor-1 (CB1) was genetically knocked out, indicating that the effects were independent of CB1 signaling. The Golgi dispersion could not be explained by WIN's action on peroxisome proliferator-activated receptors. Our results show that WIN can disrupt the Golgi apparatus independent of CB1 in cultured cells. These effects could contribute to the unique physiologic effects that WIN exhibits in neuronal behavior, as well as its role as an antiproliferative and anti-inflammatory agent. SIGNIFICANCE STATEMENT: The synthetic cannabinoid WIN55,212-2 (WIN), widely used to investigate the cannabinoid system, also shows unique broader effects at cellular and organismal levels compared to endogenous cannabinoids. Our study shows that WIN can disrupt the Golgi apparatus and the microtubule network in multiple cell types, independent of cannabinoid receptors. These results could explain how WIN reduces surface levels of proteins and contributes to the unique physiological effects observed with WIN.
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Affiliation(s)
- Joshua Lott
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Emily M Jutkiewicz
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan
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Kevin RC, Cairns EA, Boyd R, Arnold JC, Bowen MT, McGregor IS, Banister SD. Off-target pharmacological profiling of synthetic cannabinoid receptor agonists including AMB-FUBINACA, CUMYL-PINACA, PB-22, and XLR-11. Front Psychiatry 2022; 13:1048836. [PMID: 36590635 PMCID: PMC9798004 DOI: 10.3389/fpsyt.2022.1048836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022] Open
Abstract
INTRODUCTION Synthetic cannabinoid receptor agonists (SCRAs) are a diverse class of new psychoactive substances that have been associated with multiple instances and types of toxicity. Some SCRAs appear to carry a greater toxicological burden than others, or compared to the prototypical cannabis-derived agonist Δ9-tetrahydrocannabinol (Δ9-THC), despite a common primary mechanism of action via cannabinoid 1 (CB1) receptors. "Off-target" (i.e., non-CB1 receptor) effects could underpin this differential toxicity, although there are limited data around the activity of SCRAs at such targets. METHODS A selection of 7 SCRAs (AMB-FUBINACA, XLR11, PB-22, AKB-48, AB-CHMINICA, CUMYL-PINACA, and 4F-MDMB-BUTINACA), representing several distinct chemotypes and toxicological profiles, underwent a 30 μM single-point screen against 241 G protein-coupled receptor (GPCR) targets in antagonist and agonist mode using a cellular β-arrestin recruitment assay. Strong screening "hits" at specific GPCRs were followed up in detail using concentration-response assays with AMB-FUBINACA, a SCRA with a particularly notable history of toxicological liability. RESULTS The single-point screen yielded few hits in agonist mode for any compound aside from CB1 and CB2 receptors, but many hits in antagonist mode, including a range of chemokine receptors, the oxytocin receptor, and histamine receptors. Concentration-response experiments showed that AMB-FUBINACA inhibited most off-targets only at the highest 30 μM concentration, with inhibition of only a small subset of targets, including H1 histamine and α2B adrenergic receptors, at lower concentrations (≥1 μM). AMB-FUBINACA also produced concentration-dependent CB1 receptor signaling disruption at concentrations higher than 1 μM, but did not produce overt cytotoxicity beyond CP55,940 or Δ9-THC in CB1 expressing cells. DISCUSSION These results suggest that while some "off-targets" could possibly contribute to the SCRA toxidrome, particularly at high concentrations, CB1-mediated cellular dysfunction provides support for hypotheses concerning on-target, rather than off-target, toxicity. Further investigation of non-GPCR off-targets is warranted.
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Affiliation(s)
- Richard C Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown, NSW, Australia.,School of Pharmacy, The University of Sydney, Camperdown, NSW, Australia
| | - Elizabeth A Cairns
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown, NSW, Australia.,School of Psychology, The University of Sydney, Camperdown, NSW, Australia
| | - Rochelle Boyd
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown, NSW, Australia.,School of Psychology, The University of Sydney, Camperdown, NSW, Australia
| | - Jonathon C Arnold
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown, NSW, Australia.,School of Pharmacy, The University of Sydney, Camperdown, NSW, Australia
| | - Michael T Bowen
- School of Psychology, The University of Sydney, Camperdown, NSW, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Iain S McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown, NSW, Australia.,School of Psychology, The University of Sydney, Camperdown, NSW, Australia
| | - Samuel D Banister
- The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Camperdown, NSW, Australia.,School of Chemistry, The University of Sydney, Camperdown, NSW, Australia
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10
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Oyagawa CRM, Grimsey NL. Cannabinoid receptor CB 1 and CB 2 interacting proteins: Techniques, progress and perspectives. Methods Cell Biol 2021; 166:83-132. [PMID: 34752341 DOI: 10.1016/bs.mcb.2021.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cannabinoid receptors 1 and 2 (CB1 and CB2) are implicated in a range of physiological processes and have gained attention as promising therapeutic targets for a number of diseases. Protein-protein interactions play an integral role in modulating G protein-coupled receptor (GPCR) expression, subcellular distribution and signaling, and the identification and characterization of these will not only improve our understanding of GPCR function and biology, but may provide a novel avenue for therapeutic intervention. A variety of techniques are currently being used to investigate GPCR protein-protein interactions, including Förster/fluorescence and bioluminescence resonance energy transfer (FRET and BRET), proximity ligation assay (PLA), and bimolecular fluorescence complementation (BiFC). However, the reliable application of these methodologies is dependent on the use of appropriate controls and the consideration of the physiological context. Though not as extensively characterized as some other GPCRs, the investigation of CB1 and CB2 interacting proteins is a growing area of interest, and a range of interacting partners have been identified to date. This review summarizes the current state of the literature regarding the cannabinoid receptor interactome, provides commentary on the methodologies and techniques utilized, and discusses future perspectives.
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Affiliation(s)
- Caitlin R M Oyagawa
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Natasha L Grimsey
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.
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11
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Manning JJ, Green HM, Glass M, Finlay DB. Pharmacological selection of cannabinoid receptor effectors: Signalling, allosteric modulation and bias. Neuropharmacology 2021; 193:108611. [PMID: 34000272 DOI: 10.1016/j.neuropharm.2021.108611] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/26/2021] [Accepted: 05/10/2021] [Indexed: 12/14/2022]
Abstract
The type-1 cannabinoid receptor (CB1) is a promising drug target for a wide range of diseases. However, many existing and novel candidate ligands for CB1 have shown only limited therapeutic potential. Indeed, no ligands are currently approved for the clinic except formulations of the phytocannabinoids Δ9-THC and CBD and a small number of analogues. A key limitation of many promising CB1 ligands are their on-target adverse effects, notably including psychoactivity (agonists) and depression/suicidal ideation (inverse agonists). Recent drug development attempts have therefore focussed on altering CB1 signalling profiles in two ways. Firstly, with compounds that enhance or reduce the signalling of endogenous (endo-) cannabinoids, namely allosteric modulators. Secondly, with compounds that probe the capability of selectively targeting specific cellular signalling pathways that may mediate therapeutic effects using biased ligands. This review will summarise the current paradigm of CB1 signalling in terms of the intracellular transduction pathways acted on by the receptor. The development of compounds that selectively activate CB1 signalling pathways, whether allosterically or via orthosteric agonist bias, will also be addressed.
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Affiliation(s)
- Jamie J Manning
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand, PO Box 56, Dunedin, 9054, New Zealand
| | - Hayley M Green
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand, PO Box 56, Dunedin, 9054, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand, PO Box 56, Dunedin, 9054, New Zealand
| | - David B Finlay
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand, PO Box 56, Dunedin, 9054, New Zealand.
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12
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Heimann AS, Dale CS, Guimarães FS, Reis RAM, Navon A, Shmuelov MA, Rioli V, Gomes I, Devi LL, Ferro ES. Hemopressin as a breakthrough for the cannabinoid field. Neuropharmacology 2021; 183:108406. [PMID: 33212113 PMCID: PMC8609950 DOI: 10.1016/j.neuropharm.2020.108406] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 11/06/2020] [Accepted: 11/11/2020] [Indexed: 12/14/2022]
Abstract
Hemopressin (PVNFKFLSH in rats, and PVNFKLLSH in humans and mice), a fragment derived from the α-chain of hemoglobin, was the first peptide described to have type 1 cannabinoid receptor activity. While hemopressin was shown to have inverse agonist/antagonistic activity, extended forms of hemopressin (i.e. RVD-hemopressin, also called pepcan-12) exhibit type 1 and type 2 cannabinoid receptor agonistic/allosteric activity, and recent studies suggest that they can activate intracellular mitochondrial cannabinoid receptors. Therefore, hemopressin and hemopressin-related peptides could have location-specific and biased pharmacological action, which would increase the possibilities for fine-tunning and broadening cannabinoid receptor signal transduction. Consistent with this, hemopressins were shown to play a role in a number of physiological processes including antinociceptive and anti-inflammatory activity, regulation of food intake, learning and memory. The shortest active hemopressin fragment, NFKF, delays the first seizure induced by pilocarpine, and prevents neurodegeneration in an experimental model of autoimmune encephalomyelitis. These functions of hemopressins could be due to engagement of both cannabinoid and non-cannabinoid receptor systems. Self-assembled nanofibrils of hemopressin have pH-sensitive switchable surface-active properties, and show potential as inflammation and cancer targeted drug-delivery systems. Upon disruption of the self-assembled hemopressin nanofibril emulsion, the intrinsic analgesic and anti-inflammatory properties of hemopressin could help bolster the therapeutic effect of anti-inflammatory or anti-cancer formulations. In this article, we briefly review the molecular and behavioral pharmacological properties of hemopressins, and summarize studies on the intricate and unique mode of generation and binding of these peptides to cannabinoid receptors. Thus, the review provides a window into the current status of hemopressins in expanding the repertoire of signaling and activity by the endocannabinoid system, in addition to their new potential for pharmaceutic formulations.
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Affiliation(s)
| | - Camila S Dale
- Department of Anatomy, Biomedical Science Institute, University of São Paulo, 05508-000, São Paulo, SP, Brazil
| | - Francisco S Guimarães
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, 14025-600, Ribeirão Preto, SP, Brazil; Department of Neuroscience and Behavior, Ribeirão Preto Medical School, University of São Paulo, 14025-600, Ribeirão Preto, SP, Brazil
| | - Ricardo A M Reis
- Laboratory of Neurochemistry, Institute of Biophysics Carlos Chagas Filho, Rio de Janeiro, Federal University, 21949-900, Rio de Janeiro, RJ, Brazil
| | - Ami Navon
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Michal A Shmuelov
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Vanessa Rioli
- Special Laboratory of Applied Toxinology (LETA), Center of Toxins, Immune Response and Cell Signaling (CETICS), Butantan Institute, São Paulo, 05503-900, Brazil
| | - Ivone Gomes
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, 10029, New York, NY, United States
| | - Lakshmi L Devi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, 10029, New York, NY, United States
| | - Emer S Ferro
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, 7610001, Israel; Department of Pharmacology, Biomedical Science Institute, University of São Paulo, 05508-000, São Paulo, SP, Brazil.
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13
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Moir M, Lane S, Montgomery AP, Hibbs D, Connor M, Kassiou M. The discovery of a potent and selective pyrazolo-[2,3-e]-[1,2,4]-triazine cannabinoid type 2 receptor agonist. Eur J Med Chem 2020; 210:113087. [PMID: 33321261 DOI: 10.1016/j.ejmech.2020.113087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 11/26/2022]
Abstract
The development of selective CB2 receptor agonists is a promising therapeutic approach for the treatment of inflammatory diseases, without CB1 receptor mediated psychoactive side effects. Preliminary structure-activity relationship studies on pyrazoylidene benzamide agonists revealed the -ylidene benzamide moiety was crucial for functional activity at the CB2 receptor. A small library of compounds with varying linkage moieties between the pyrazole and substituted phenyl group has culminated in the discovery of a potent and selective pyrazolo-[2,3-e]-[1,2,4]-triazine agonist 19 (CB2R EC50 = 19 nM, CB1R EC50 > 10 μM). Docking studies have revealed key structural features of the linkage group that are important for potent functional activity.
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Affiliation(s)
- Michael Moir
- School of Chemistry, The University of Sydney, NSW, 2006, Australia
| | - Samuel Lane
- Faculty of Health Sciences, The University of Sydney, NSW, 2006, Australia
| | | | - David Hibbs
- Sydney Pharmacy School, The University of Sydney, NSW, 2006, Australia
| | - Mark Connor
- Department of Biomedical Sciences, Macquarie University, NSW, 2109, Australia
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, NSW, 2006, Australia.
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14
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Robson H, Braund R, Glass M, Ashton J, Tatley M. Synthetic cannabis: adverse events reported to the New Zealand Pharmacovigilance Centre. Clin Toxicol (Phila) 2020; 59:472-479. [DOI: 10.1080/15563650.2020.1828592] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Hunter Robson
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Rhiannon Braund
- New Zealand Pharmacovigilance Centre, University of Otago, Dunedin, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Janelle Ashton
- New Zealand Pharmacovigilance Centre, University of Otago, Dunedin, New Zealand
| | - Michael Tatley
- New Zealand Pharmacovigilance Centre, University of Otago, Dunedin, New Zealand
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15
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Fletcher-Jones A, Hildick KL, Evans AJ, Nakamura Y, Henley JM, Wilkinson KA. Protein Interactors and Trafficking Pathways That Regulate the Cannabinoid Type 1 Receptor (CB1R). Front Mol Neurosci 2020; 13:108. [PMID: 32595453 PMCID: PMC7304349 DOI: 10.3389/fnmol.2020.00108] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 05/20/2020] [Indexed: 12/29/2022] Open
Abstract
The endocannabinoid system (ECS) acts as a negative feedback mechanism to suppress synaptic transmission and plays a major role in a diverse range of brain functions including, for example, the regulation of mood, energy balance, and learning and memory. The function and dysfunction of the ECS are strongly implicated in multiple psychiatric, neurological, and neurodegenerative diseases. Cannabinoid type 1 receptor (CB1R) is the most abundant G protein-coupled receptor (GPCR) expressed in the brain and, as for any synaptic receptor, CB1R needs to be in the right place at the right time to respond appropriately to changing synaptic circumstances. While CB1R is found intracellularly throughout neurons, its surface expression is highly polarized to the axonal membrane, consistent with its functional expression at presynaptic sites. Surprisingly, despite the importance of CB1R, the interacting proteins and molecular mechanisms that regulate the highly polarized distribution and function of CB1R remain relatively poorly understood. Here we set out what is currently known about the trafficking pathways and protein interactions that underpin the surface expression and axonal polarity of CB1R, and highlight key questions that still need to be addressed.
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Affiliation(s)
- Alexandra Fletcher-Jones
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Keri L Hildick
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Ashley J Evans
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Yasuko Nakamura
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Jeremy M Henley
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Kevin A Wilkinson
- Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, Bristol, United Kingdom
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16
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Patel M, Manning JJ, Finlay DB, Javitch JA, Banister SD, Grimsey NL, Glass M. Signalling profiles of a structurally diverse panel of synthetic cannabinoid receptor agonists. Biochem Pharmacol 2020; 175:113871. [PMID: 32088263 DOI: 10.1016/j.bcp.2020.113871] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/18/2020] [Indexed: 12/11/2022]
Abstract
Synthetic cannabinoid receptor agonists (SCRAs) represent the most rapidly proliferating class of "designer drugs" or "new psychoactive substances". SCRAs offer unregulated alternatives to cannabis that evade routine drug tests, but their use is increasingly associated with severe toxicity and death worldwide. Little is currently known about SCRA molecular pharmacology, or the mechanisms underpinning their toxicity, although the effects are believed to be primarily mediated by the type 1 cannabinoid receptor (CB1). In this study, we aimed to characterise the signalling profiles of a structurally diverse panel of novel SCRAs at CB1. We compare SCRAs to traditional reference cannabinoids CP55,940, WIN55,212-2, and THC. The activity of the SCRAs was assessed in key receptor signalling and regulatory pathways, including cAMP production, translocation of β-arrestin 1 and 2, and receptor internalisation. The activity profiles of the ligands were also evaluated using operational analysis to identify ligand bias. Results revealed that SCRAs activities were relatively balanced in the pathways evaluated (compared to WIN55,212-2), although 5F-CUMYL-P7AICA and XLR-11 possessed partial efficacy in cAMP stimulation and β-arrestin translocation. Notably, the SCRAs showed distinct potency and efficacy profiles compared to THC. In particular, while the majority of SCRAs demonstrated robust β-arrestin translocation, cAMP stimulation, and internalisation, THC failed to elicit high efficacy responses in any of these assays. Further study is required to delineate if these pathways could contribute to SCRA toxicity in humans.
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Affiliation(s)
- Monica Patel
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand; Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | - Jamie J Manning
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - David B Finlay
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Jonathan A Javitch
- Department of Psychiatry and Pharmacology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, United States
| | - Samuel D Banister
- Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, University of Sydney, NSW, Australia; School of Chemistry, Faculty of Science, University of Sydney, NSW, Australia
| | - Natasha L Grimsey
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand.
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Zhu X, Finlay DB, Glass M, Duffull SB. Model-free and kinetic modelling approaches for characterising non-equilibrium pharmacological pathway activity: Internalisation of cannabinoid CB 1 receptors. Br J Pharmacol 2019; 176:2593-2607. [PMID: 30945265 PMCID: PMC6592866 DOI: 10.1111/bph.14684] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/13/2019] [Accepted: 03/22/2019] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Receptor internalisation is by nature kinetic. Application of a standard equilibrium dose response model to describe the properties of a ligand inducing internalisation, while commonly used, are therefore problematic. Here, we propose two quantitative approaches to address this issue-(a) a model-free method and (b) a kinetic modelling approach-and systematically evaluate the performance of these methods against traditional equilibrium methods to characterise the internalisation profiles of cannabinoid CB1 receptor agonists. EXPERIMENTAL APPROACH Kinetic internalisation assays were conducted using a concentration series of six CB1 receptor ligands. Internalisation rate analysis and snapshot equilibrium analysis were performed. A model-free method was developed based on the mean residence time of internalisation. A kinetic internalisation model was developed under the quasi-steady state assumption. KEY RESULTS Rates of receptor internalisation depended on both agonist and concentration. Agonist potencies from snapshot equilibrium analysis increased with stimulation time, and there was no single time point at which internalisation profiles could infer agonist properties in a comparative manner. The model-free method yielded a time-invariant measure of potency/efficacy for internalisation. The kinetic model adequately described the internalisation of CB1 receptors over time and provided robust estimates of both potency and efficacy. CONCLUSION AND IMPLICATIONS Applying equilibrium analysis to a non-equilibrium pathway cannot provide a reliable estimate of agonist potency. Both the model-free and kinetic modelling approaches characterised the internalisation profiles of CB1 receptor agonists. The kinetic model provides additional advantages as a method to capture changes in receptor number during other functional assays.
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Affiliation(s)
- Xiao Zhu
- Otago Pharmacometrics Group, School of PharmacyUniversity of OtagoDunedinNew Zealand
| | - David B. Finlay
- Department of Pharmacology and ToxicologyUniversity of OtagoDunedinNew Zealand
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand
| | - Michelle Glass
- Department of Pharmacology and ToxicologyUniversity of OtagoDunedinNew Zealand
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand
| | - Stephen B. Duffull
- Otago Pharmacometrics Group, School of PharmacyUniversity of OtagoDunedinNew Zealand
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18
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Weinberg ZY, Puthenveedu MA. Regulation of G protein-coupled receptor signaling by plasma membrane organization and endocytosis. Traffic 2019; 20:121-129. [PMID: 30536564 PMCID: PMC6415975 DOI: 10.1111/tra.12628] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 11/27/2018] [Accepted: 12/05/2018] [Indexed: 12/11/2022]
Abstract
The trafficking of G protein coupled-receptors (GPCRs) is one of the most exciting areas in cell biology because of recent advances demonstrating that GPCR signaling is spatially encoded. GPCRs, acting in a diverse array of physiological systems, can have differential signaling consequences depending on their subcellular localization. At the plasma membrane, GPCR organization could fine-tune the initial stages of receptor signaling by determining the magnitude of signaling and the type of effectors to which receptors can couple. This organization is mediated by the lipid composition of the plasma membrane, receptor-receptor interactions, and receptor interactions with intracellular scaffolding proteins. GPCR organization is subsequently changed by ligand binding and the regulated endocytosis of these receptors. Activated GPCRs can modulate the dynamics of their own endocytosis through changing clathrin-coated pit dynamics, and through the scaffolding adaptor protein β-arrestin. This endocytic regulation has signaling consequences, predominantly through modulation of the MAPK cascade. This review explores what is known about receptor sorting at the plasma membrane, protein partners that control receptor endocytosis, and the ways in which receptor sorting at the plasma membrane regulates downstream trafficking and signaling.
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Affiliation(s)
- Zara Y Weinberg
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan
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19
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Long-term application of cannabinoids leads to dissociation between changes in cAMP and modulation of GABA A receptors of mouse trigeminal sensory neurons. Neurochem Int 2019; 126:74-85. [PMID: 30633953 DOI: 10.1016/j.neuint.2019.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/20/2018] [Accepted: 01/07/2019] [Indexed: 12/11/2022]
Abstract
Antinociception caused by cannabinoids may have a partial peripheral origin in addition to its central site of action. In fact, we have observed that anandamide selectively and reversibly inhibits GABAA receptors of putative nociceptive neurons of mouse trigeminal sensory ganglia via CB1 receptor activation to inhibit adenylyl cyclase and decrease cAMP with downstream posttranslational alterations. Since cannabinoids are often used chronically, we studied changes in cAMP levels and GABA-mediated currents of trigeminal neurons following 24 h application of anandamide (0.5 μM) or the synthetic cannabinoid WIN 55,212-2 (5 μM). With this protocol GABA responses were similar to control despite persistent fall in cAMP levels. Inhibition by WIN 55,212-2 of GABA effects recovered after 30 min washout and was not associated with changes in CB1 receptor expression, indicating lack of CB1 receptor inactivation and transient loss of negative coupling between CB1 receptors and GABAA receptors. The phosphodiesterase inhibitor rolipram (100 μM; 24 h) enhanced cAMP levels and GABA-mediated currents, suggesting GABAA receptors were sensitive to persistent upregulation via cAMP. While the adenylyl cyclase activator forskolin (1-20 μM) facilitated cAMP levels and GABA currents following 30 min application, this action was lost after 24 h in line with the drug limited lifespan. The PKA inhibitor PKI 14-22 (10 μM) increased cAMP without changing GABA currents. These data indicate that modulation of GABAA receptors by intracellular cAMP could be lost following persistent application of cannabinoids. Thus, these observations provide an insight into the waning antinociceptive effects of these compounds.
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20
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Wickert M, Hildick KL, Baillie GL, Jelinek R, Aparisi Rey A, Monory K, Schneider M, Ross RA, Henley JM, Lutz B. The F238L Point Mutation in the Cannabinoid Type 1 Receptor Enhances Basal Endocytosis via Lipid Rafts. Front Mol Neurosci 2018; 11:230. [PMID: 30026687 PMCID: PMC6041392 DOI: 10.3389/fnmol.2018.00230] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/12/2018] [Indexed: 11/22/2022] Open
Abstract
Defining functional domains and amino acid residues in G protein coupled receptors (GPCRs) represent an important way to improve rational drug design for this major class of drug targets. The cannabinoid type 1 (CB1) receptor is one of the most abundant GPCRs in the central nervous system and is involved in many physiological and pathophysiological processes. Interestingly, cannabinoid type 1 receptor with a phenylalanine 238 to leucine mutation (CB1F238L) has been already linked to a number of both in vitro and in vivo alterations. While CB1F238L causes significantly reduced presynaptic neurotransmitter release at the cellular level, behaviorally this mutation induces increased risk taking, social play behavior and reward sensitivity in rats. However, the molecular mechanisms underlying these changes are not fully understood. In this study, we tested whether the F238L mutation affects trafficking and axonal/presynaptic polarization of the CB1 receptor in vitro. Steady state or ligand modulated surface expression and lipid raft association was analyzed in human embryonic kidney 293 (HEK293) cells stably expressing either wild-type cannabinoid type 1 receptor (CB1wt) or CB1F238L receptor. Axonal/presynaptic polarization of the CB1F238L receptor was assessed in transfected primary hippocampal neurons. We show that in vitro the CB1F238L receptor displays increased association with lipid rafts, which coincides with increased lipid raft mediated constitutive endocytosis, leading to a reduction in steady state surface expression of the CB1F238L receptor. Furthermore, the CB1F238L receptor showed increased axonal polarization in primary hippocampal neurons. These data demonstrate that endocytosis of the CB1 receptor is an important mediator of axonal/presynaptic polarization and that phenylalanine 238 plays a key role in CB1 receptor trafficking and axonal polarization.
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Affiliation(s)
- Melanie Wickert
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Keri L Hildick
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Gemma L Baillie
- Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Ruth Jelinek
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Alejandro Aparisi Rey
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Krisztina Monory
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Miriam Schneider
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Department of Psychology, University of Heidelberg, Heidelberg, Germany
| | - Ruth A Ross
- Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Jeremy M Henley
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.,German Resilience Center (DRZ), University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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21
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Cannabinoid Receptors and the Endocannabinoid System: Signaling and Function in the Central Nervous System. Int J Mol Sci 2018. [PMID: 29533978 PMCID: PMC5877694 DOI: 10.3390/ijms19030833] [Citation(s) in RCA: 653] [Impact Index Per Article: 108.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The biological effects of cannabinoids, the major constituents of the ancient medicinal plant Cannabis sativa (marijuana) are mediated by two members of the G-protein coupled receptor family, cannabinoid receptors 1 (CB1R) and 2. The CB1R is the prominent subtype in the central nervous system (CNS) and has drawn great attention as a potential therapeutic avenue in several pathological conditions, including neuropsychological disorders and neurodegenerative diseases. Furthermore, cannabinoids also modulate signal transduction pathways and exert profound effects at peripheral sites. Although cannabinoids have therapeutic potential, their psychoactive effects have largely limited their use in clinical practice. In this review, we briefly summarized our knowledge of cannabinoids and the endocannabinoid system, focusing on the CB1R and the CNS, with emphasis on recent breakthroughs in the field. We aim to define several potential roles of cannabinoid receptors in the modulation of signaling pathways and in association with several pathophysiological conditions. We believe that the therapeutic significance of cannabinoids is masked by the adverse effects and here alternative strategies are discussed to take therapeutic advantage of cannabinoids.
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22
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Siddiqui SS, Springer SA, Verhagen A, Sundaramurthy V, Alisson-Silva F, Jiang W, Ghosh P, Varki A. The Alzheimer's disease-protective CD33 splice variant mediates adaptive loss of function via diversion to an intracellular pool. J Biol Chem 2017; 292:15312-15320. [PMID: 28747436 DOI: 10.1074/jbc.m117.799346] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 07/20/2017] [Indexed: 12/25/2022] Open
Abstract
The immunomodulatory receptor Siglec-3/CD33 influences risk for late-onset Alzheimer's disease (LOAD), an apparently human-specific post-reproductive disease. CD33 generates two splice variants: a full-length CD33M transcript produced primarily by the "LOAD-risk" allele and a shorter CD33m isoform lacking the sialic acid-binding domain produced primarily from the "LOAD-protective" allele. An SNP that modulates CD33 splicing to favor CD33m is associated with enhanced microglial activity. Individuals expressing more protective isoform accumulate less brain β-amyloid and have a lower LOAD risk. How the CD33m isoform increases β-amyloid clearance remains unknown. We report that the protection by the CD33m isoform may not be conferred by what it does but, rather, from what it cannot do. Analysis of blood neutrophils and monocytes and a microglial cell line revealed that unlike CD33M, the CD33m isoform does not localize to cell surfaces; instead, it accumulates in peroxisomes. Cell stimulation and activation did not mobilize CD33m to the surface. Thus, the CD33m isoform may neither interact directly with amyloid plaques nor engage in cell-surface signaling. Rather, production and localization of CD33m in peroxisomes is a way of diminishing the amount of CD33M and enhancing β-amyloid clearance. We confirmed intracellular localization by generating a CD33m-specific monoclonal antibody. Of note, CD33 is the only Siglec with a peroxisome-targeting sequence, and this motif emerged by convergent evolution in toothed whales, the only other mammals with a prolonged post-reproductive lifespan. The CD33 allele that protects post-reproductive individuals from LOAD may have evolved by adaptive loss-of-function, an example of the less-is-more hypothesis.
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Affiliation(s)
- Shoib S Siddiqui
- From the Center for Academic Research and Training in Anthropogeny (CARTA) and Glycobiology Research and Training Center (GRTC) and.,Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093 and
| | - Stevan A Springer
- From the Center for Academic Research and Training in Anthropogeny (CARTA) and Glycobiology Research and Training Center (GRTC) and.,Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093 and
| | - Andrea Verhagen
- From the Center for Academic Research and Training in Anthropogeny (CARTA) and Glycobiology Research and Training Center (GRTC) and.,Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093 and
| | - Venkatasubramaniam Sundaramurthy
- From the Center for Academic Research and Training in Anthropogeny (CARTA) and Glycobiology Research and Training Center (GRTC) and
| | - Frederico Alisson-Silva
- From the Center for Academic Research and Training in Anthropogeny (CARTA) and Glycobiology Research and Training Center (GRTC) and.,Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093 and
| | | | - Pradipta Ghosh
- Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093 and
| | - Ajit Varki
- From the Center for Academic Research and Training in Anthropogeny (CARTA) and Glycobiology Research and Training Center (GRTC) and .,Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093 and
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23
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Mascia F, Klotz L, Lerch J, Ahmed MH, Zhang Y, Enz R. CRIP1a inhibits endocytosis of G-protein coupled receptors activated by endocannabinoids and glutamate by a common molecular mechanism. J Neurochem 2017; 141:577-591. [PMID: 28295323 DOI: 10.1111/jnc.14021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/17/2017] [Accepted: 03/10/2017] [Indexed: 01/20/2023]
Abstract
The excitability of the central nervous system depends largely on the surface density of neurotransmitter receptors. The endocannabinoid receptor 1 (CB1 R) and the metabotropic glutamate receptor mGlu8 R are expressed pre-synaptically where they reduce glutamate release into the synaptic cleft. Recently, the CB1 R interacting protein cannabinoid receptor interacting protein 1a (CRIP1a) was identified and characterized to regulate CB1 R activity in neurons. However, underlying molecular mechanisms are largely unknown. Here, we identified a common mechanism used by CRIP1a to regulate the cell surface density of two different types of G-protein coupled receptors, CB1 R and mGlu8a R. Five amino acids within the CB1 R C-terminus were required and sufficient to reduce constitutive CB1 R endocytosis by about 72% in the presence of CRIP1a. Interestingly, a similar sequence is present in mGlu8a R and consistently, endocytosis of mGlu8a R depended on CRIP1a, as well. Docking analysis and molecular dynamics simulations identified a conserved serine in CB1 R (S468) and mGlu8a R (S894) that forms a hydrogen bond with the peptide backbone of CRIP1a at position R82. In contrast to mGlu8a R, the closely related mGlu8b R splice-variant carries a lysine (K894) at this position, and indeed, mGlu8b R endocytosis was not affected by CRIP1a. Chimeric constructs between CB1 R, mGlu8a R, and mGlu8b R underline the role of the identified five CRIP1a sensitive amino acids. In summary, we suggest that CRIP1a negatively regulates endocytosis of two different G-protein coupled receptor types, CB1 R and mGlu8a R.
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Affiliation(s)
- Fabrizio Mascia
- Institut für Biochemie (Emil-Fischer-Zentrum), Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Lisa Klotz
- Institut für Biochemie (Emil-Fischer-Zentrum), Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Judith Lerch
- Institut für Biochemie (Emil-Fischer-Zentrum), Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Mostafa H Ahmed
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Yan Zhang
- Department of Medicinal Chemistry, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ralf Enz
- Institut für Biochemie (Emil-Fischer-Zentrum), Universität Erlangen-Nürnberg, Erlangen, Germany
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24
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Abstract
An agonist that acts through a single receptor can activate numerous signaling pathways. Recent studies have suggested that different ligands can differentially activate these pathways by stabilizing a limited range of receptor conformations, which in turn preferentially drive different downstream signaling cascades. This concept, termed "biased signaling" represents an exciting therapeutic opportunity to target specific pathways that elicit only desired effects, while avoiding undesired effects mediated by different signaling cascades. The cannabinoid receptors CB1 and CB2 each activate multiple pathways, and evidence is emerging for bias within these pathways. This review will summarize the current evidence for biased signaling through cannabinoid receptor subtypes CB1 and CB2.
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Affiliation(s)
- Mikkel Søes Ibsen
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Mark Connor
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, New South Wales, Australia
| | - Michelle Glass
- Department of Pharmacology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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25
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Soethoudt M, Grether U, Fingerle J, Grim TW, Fezza F, de Petrocellis L, Ullmer C, Rothenhäusler B, Perret C, van Gils N, Finlay D, MacDonald C, Chicca A, Gens MD, Stuart J, de Vries H, Mastrangelo N, Xia L, Alachouzos G, Baggelaar MP, Martella A, Mock ED, Deng H, Heitman LH, Connor M, Di Marzo V, Gertsch J, Lichtman AH, Maccarrone M, Pacher P, Glass M, van der Stelt M. Cannabinoid CB 2 receptor ligand profiling reveals biased signalling and off-target activity. Nat Commun 2017; 8:13958. [PMID: 28045021 PMCID: PMC5216056 DOI: 10.1038/ncomms13958] [Citation(s) in RCA: 224] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 11/15/2016] [Indexed: 01/01/2023] Open
Abstract
The cannabinoid CB2 receptor (CB2R) represents a promising therapeutic target for various forms of tissue injury and inflammatory diseases. Although numerous compounds have been developed and widely used to target CB2R, their selectivity, molecular mode of action and pharmacokinetic properties have been poorly characterized. Here we report the most extensive characterization of the molecular pharmacology of the most widely used CB2R ligands to date. In a collaborative effort between multiple academic and industry laboratories, we identify marked differences in the ability of certain agonists to activate distinct signalling pathways and to cause off-target effects. We reach a consensus that HU910, HU308 and JWH133 are the recommended selective CB2R agonists to study the role of CB2R in biological and disease processes. We believe that our unique approach would be highly suitable for the characterization of other therapeutic targets in drug discovery research.
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Affiliation(s)
- Marjolein Soethoudt
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
- Department of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Uwe Grether
- Roche Innovation Center Basel, F. Hoffman-La Roche Ltd., Grenzachterstrasse 124, Basel 4070, Switzerland
| | - Jürgen Fingerle
- Department of Biochemistry, NMI, University Tübingen, Markwiesenstrasse 55, Reutlingen 72770, Germany
| | - Travis W. Grim
- Department of Pharmacology and Toxicology, 1220 East Broad Street, PO Box 980613, Richmond, Virginia 23298-0613, USA
| | - Filomena Fezza
- Department of Experimental Medicine and Surgery, Tor Vergata University of Rome, Via Montpellier 1, Rome 00133, Italy
- European Center for Brain Research/IRCCS Santa Lucia Foundation, via del Fosso del Fiorano 65, Rome 00143, Italy
| | - Luciano de Petrocellis
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, C.N.R., Via Campi Flegrei 34, Comprensorio Olivetti, Pozzuoli 80078, Italy
| | - Christoph Ullmer
- Roche Innovation Center Basel, F. Hoffman-La Roche Ltd., Grenzachterstrasse 124, Basel 4070, Switzerland
| | - Benno Rothenhäusler
- Roche Innovation Center Basel, F. Hoffman-La Roche Ltd., Grenzachterstrasse 124, Basel 4070, Switzerland
| | - Camille Perret
- Roche Innovation Center Basel, F. Hoffman-La Roche Ltd., Grenzachterstrasse 124, Basel 4070, Switzerland
| | - Noortje van Gils
- Department of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - David Finlay
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park road, Grafton, Auckland 1023, New Zealand
| | - Christa MacDonald
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park road, Grafton, Auckland 1023, New Zealand
| | - Andrea Chicca
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, Bern CH-3012, Switzerland
| | - Marianela Dalghi Gens
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, Bern CH-3012, Switzerland
| | - Jordyn Stuart
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia
| | - Henk de Vries
- Department of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Nicolina Mastrangelo
- Department of Medicine, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 21, Rome 00128, Italy
| | - Lizi Xia
- Department of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Georgios Alachouzos
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Marc P. Baggelaar
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Andrea Martella
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
- Department of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Elliot D. Mock
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Hui Deng
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Laura H. Heitman
- Department of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Mark Connor
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia
| | - Vincenzo Di Marzo
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry, C.N.R., Via Campi Flegrei 34, Comprensorio Olivetti, Pozzuoli 80078, Italy
| | - Jürg Gertsch
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, Bern CH-3012, Switzerland
| | - Aron H. Lichtman
- Department of Pharmacology and Toxicology, 1220 East Broad Street, PO Box 980613, Richmond, Virginia 23298-0613, USA
| | - Mauro Maccarrone
- European Center for Brain Research/IRCCS Santa Lucia Foundation, via del Fosso del Fiorano 65, Rome 00143, Italy
- Department of Medicine, Campus Bio-Medico University of Rome, Via Alvaro del Portillo 21, Rome 00128, Italy
| | - Pal Pacher
- Laboratory of Cardiovascular Physiology and Tissue Injury, National Institute of Health/NIAAA, 5625 Fishers Lane, Rockville, Maryland 20852, USA
| | - Michelle Glass
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park road, Grafton, Auckland 1023, New Zealand
| | - Mario van der Stelt
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
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26
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Jansson D, Scotter EL, Rustenhoven J, Coppieters N, Smyth LCD, Oldfield RL, Bergin PS, Mee EW, Graham ES, Faull RLM, Dragunow M. Interferon-γ blocks signalling through PDGFRβ in human brain pericytes. J Neuroinflammation 2016; 13:249. [PMID: 27654972 PMCID: PMC5031293 DOI: 10.1186/s12974-016-0722-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/13/2016] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Neuroinflammation and blood-brain barrier (BBB) disruption are common features of many brain disorders, including Alzheimer's disease, epilepsy, and motor neuron disease. Inflammation is thought to be a driver of BBB breakdown, but the underlying mechanisms for this are unclear. Brain pericytes are critical cells for maintaining the BBB and are immunologically active. We sought to test the hypothesis that inflammation regulates the BBB by altering pericyte biology. METHODS We exposed primary adult human brain pericytes to chronic interferon-gamma (IFNγ) for 4 days and measured associated functional aspects of pericyte biology. Specifically, we examined the influence of inflammation on platelet-derived growth factor receptor-beta (PDGFRβ) expression and signalling, as well as pericyte proliferation and migration by qRT-PCR, immunocytochemistry, flow cytometry, and western blotting. RESULTS Chronic IFNγ treatment had marked effects on pericyte biology most notably through the PDGFRβ, by enhancing agonist (PDGF-BB)-induced receptor phosphorylation, internalization, and subsequent degradation. Functionally, chronic IFNγ prevented PDGF-BB-mediated pericyte proliferation and migration. CONCLUSIONS Because PDGFRβ is critical for pericyte function and its removal leads to BBB leakage, our results pinpoint a mechanism linking chronic brain inflammation to BBB dysfunction.
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Affiliation(s)
- Deidre Jansson
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Gravida National Centre for Growth and Development, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Emma L Scotter
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Justin Rustenhoven
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Natacha Coppieters
- Department of Anatomy and Medical Imaging, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Leon C D Smyth
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | | | - Peter S Bergin
- Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand.,Auckland City Hospital, 1023, Auckland, New Zealand
| | - Edward W Mee
- Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand.,Auckland City Hospital, 1023, Auckland, New Zealand
| | - E Scott Graham
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Richard L M Faull
- Department of Anatomy and Medical Imaging, The University of Auckland, 1023, Auckland, New Zealand.,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand
| | - Mike Dragunow
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, 1023, Auckland, New Zealand. .,Gravida National Centre for Growth and Development, The University of Auckland, 1023, Auckland, New Zealand. .,Centre for Brain Research, The University of Auckland, 1023, Auckland, New Zealand. .,Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Private Bag 92019, 1142, Auckland, New Zealand.
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27
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Longworth M, Banister SD, Mack JBC, Glass M, Connor M, Kassiou M. The 2-alkyl-2 H-indazole regioisomers of synthetic cannabinoids AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA are possible manufacturing impurities with cannabimimetic activities. Forensic Toxicol 2016; 34:286-303. [PMID: 27547266 PMCID: PMC4971050 DOI: 10.1007/s11419-016-0316-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/01/2016] [Indexed: 01/14/2023]
Abstract
Indazole-derived synthetic cannabinoids (SCs) featuring an alkyl substituent at the 1-position and l-valinamide at the 3-carboxamide position (e.g., AB-CHMINACA) have been identified by forensic chemists around the world, and are associated with serious adverse health effects. Regioisomerism is possible for indazole SCs, with the 2-alkyl-2H-indazole regioisomer of AB-CHMINACA recently identified in SC products in Japan. It is unknown whether this regiosiomer represents a manufacturing impurity arising as a synthetic byproduct, or was intentionally synthesized as a cannabimimetic agent. This study reports the synthesis, analytical characterization, and pharmacological evaluation of commonly encountered indazole SCs AB-CHMINACA, AB-FUBINACA, AB-PINACA, 5F-AB-PINACA and their corresponding 2-alkyl-2H-indazole regioisomers. Both regioisomers of each SC were prepared from a common precursor, and the physical properties, 1H and 13C nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry, and ultraviolet-visible spectroscopy of all SC compounds are described. Additionally, AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA were found to act as high potency agonists at CB1 (EC50 = 2.1-11.6 nM) and CB2 (EC50 = 5.6-21.1 nM) receptors in fluorometric assays, while the corresponding 2-alkyl-2H-indazole regioisomers demonstrated low potency (micromolar) agonist activities at both receptors. Taken together, these data suggest that 2-alkyl-2H-indazole regioisomers of AB-CHMINACA, AB-FUBINACA, AB-PINACA, and 5F-AB-PINACA are likely to be encountered by forensic chemists and toxicologists as the result of improper purification during the clandestine synthesis of 1-alkyl-1H-indazole regioisomers, and can be distinguished by differences in gas chromatography-mass spectrometry fragmentation pattern.
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Affiliation(s)
- Mitchell Longworth
- School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia
| | - Samuel D Banister
- School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia.,Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA USA
| | - James B C Mack
- Department of Chemistry, Stanford University, Stanford, CA USA
| | - Michelle Glass
- School of Medical Sciences, The University of Auckland, Auckland, New Zealand
| | - Mark Connor
- Department of Biomedical Sciences, Macquarie University, Sydney, Australia
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia.,Faculty of Health Sciences, The University of Sydney, Sydney, Australia
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28
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Finlay DB, Joseph WR, Grimsey NL, Glass M. GPR18 undergoes a high degree of constitutive trafficking but is unresponsive to N-Arachidonoyl Glycine. PeerJ 2016; 4:e1835. [PMID: 27018161 PMCID: PMC4806671 DOI: 10.7717/peerj.1835] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 03/01/2016] [Indexed: 01/11/2023] Open
Abstract
The orphan receptor GPR18 has become a research target following the discovery of a putative endogenous agonist, N-arachidonoyl glycine (NAGly). Chemical similarity between NAGly and the endocannabinoid anandamide suggested the hypothesis that GPR18 is a third cannabinoid receptor. GPR18-mediated cellular signalling through inhibition of cyclic adenosine monophosphate (cAMP) and phosphorylation of extracellular signal-regulated kinase (ERK), in addition to physiological consequences such as regulation of cellular migration and proliferation/apoptosis have been described in response to both NAGly and anandamide. However, discordant findings have also been reported. Here we sought to describe the functional consequences of GPR18 activation in heterologously-expressing HEK cells. GPR18 expression was predominantly intracellular in stably transfected cell lines, but moderate cell surface expression could be achieved in transiently transfected cells which also had higher overall expression. Assays were employed to characterise the ability of NAGly or anandamide to inhibit cAMP or induce ERK phosphorylation through GPR18, or induce receptor trafficking. Positive control experiments, which utilised cells expressing hCB1 receptors (hCB1R), were performed to validate assay design and performance. While these functional pathways in GPR18-expressing cells were not modified on treatment with a panel of putative GPR18 ligands, a constitutive phenotype was discovered for this receptor. Our data reveal that GPR18 undergoes rapid constitutive receptor membrane trafficking-several-fold faster than hCB1R, a highly constitutively active receptor. To enhance the likelihood of detecting agonist-mediated receptor signalling responses, we increased GPR18 protein expression (by tagging with a preprolactin signal sequence) and generated a putative constitutively inactive receptor by mutating the hGPR18 gene at amino acid site 108 (alanine to asparagine). This A108N mutant did cause an increase in surface receptor expression (which may argue for reduced constitutive activity), but no ligand-mediated effects were detected. Two glioblastoma multiforme cell lines (which endogenously express GPR18) were assayed for NAGly-induced pERK phosphorylation, with negative results. Despite a lack of ligand-mediated responses in all assays, the constitutive trafficking of GPR18 remains an interesting facet of receptor function and will have consequences for understanding the role of GPR18 in physiology.
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Affiliation(s)
- David B Finlay
- Centre for Brain Research and Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Wayne R Joseph
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Natasha L Grimsey
- Centre for Brain Research and Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Michelle Glass
- Centre for Brain Research and Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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29
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Redmond WJ, Cawston EE, Grimsey NL, Stuart J, Edington AR, Glass M, Connor M. Identification of N-arachidonoyl dopamine as a highly biased ligand at cannabinoid CB1 receptors. Br J Pharmacol 2016; 173:115-27. [PMID: 26398720 PMCID: PMC4813372 DOI: 10.1111/bph.13341] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 09/13/2015] [Accepted: 09/17/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE N-arachidonyl dopamine (NADA) has been identified as a putative endocannabinoid, but there is little information about which signalling pathways it activates. The purpose of this study was to identify the signalling pathways activated by NADA in vitro. EXPERIMENTAL APPROACH Human or rat cannabinoid CB1 receptors were expressed in AtT20, CHO or HEK 293 cells. NADA displacement of radiolabelled cannabinoids, and CB1 receptor mediated activation of K channels or ERK phosphorylation, release of intracellular calcium ([Ca]i ) and modulation of adenylyl cyclase were measured in addition to NADA effects on CB1 receptor trafficking. KEY RESULTS At concentrations up to 30 μM, NADA failed to activate any signalling pathways via CB1 receptors, with the exception of mobilization of [Ca]i . The elevations of [Ca]i were insensitive to pertussis toxin, and reduced or abolished by blockers of Gq /11 -dependent processes including U73122, thapsigargin and a peptide antagonist of Gq /11 activation. Prolonged NADA incubation produced modest loss of cell surface CB1 receptors. The prototypical cannabinoid agonist CP55940 signalled as expected in all assays. CONCLUSIONS AND IMPLICATIONS NADA is an ineffective agonist at most canonical cannabinoid receptor signalling pathways, but did promote mobilization of [Ca]i via Gq -dependent processes and some CB1 receptor trafficking. This signalling profile is distinct from that of any known cannabinoid, and suggests that NADA may have a unique spectrum of effects in vivo. Our results also indicate that it may be possible to identify highly biased CB1 receptor ligands displaying a subset of the pharmacological or therapeutic effects usually attributed to CB1 ligands.
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Affiliation(s)
- William J. Redmond
- Department of Biomedical Sciences, Faculty of Medicine and Health SciencesMacquarie UniversityNSW2109Australia
| | - Erin E. Cawston
- Department of Pharmacology and Clinical Pharmacology, and Centre for Brain ResearchUniversity of AucklandAucklandNew Zealand
| | - Natasha L. Grimsey
- Department of Pharmacology and Clinical Pharmacology, and Centre for Brain ResearchUniversity of AucklandAucklandNew Zealand
| | - Jordyn Stuart
- Department of Biomedical Sciences, Faculty of Medicine and Health SciencesMacquarie UniversityNSW2109Australia
| | - Amelia R. Edington
- Department of Biomedical Sciences, Faculty of Medicine and Health SciencesMacquarie UniversityNSW2109Australia
| | - Michelle Glass
- Department of Pharmacology and Clinical Pharmacology, and Centre for Brain ResearchUniversity of AucklandAucklandNew Zealand
| | - Mark Connor
- Department of Biomedical Sciences, Faculty of Medicine and Health SciencesMacquarie UniversityNSW2109Australia
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30
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G-protein inhibition profile of the reported Gq/11 inhibitor UBO-QIC. Biochem Biophys Res Commun 2015; 469:101-107. [PMID: 26614908 DOI: 10.1016/j.bbrc.2015.11.078] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 11/18/2015] [Indexed: 11/22/2022]
Abstract
UBO-QIC (FR900359) is the only currently available Gq/11 protein inhibitor. However, its characterization has not been published, and we thus set out to do this. Gi, Gs and Gq protein-mediated responses were assessed utilizing endogenous or heterologously expressed receptors in Chinese hamster ovary cells. UBO-QIC, at 1 μM, was an effective inhibitor of the Gq-mediated responses, but was inactive at Gi- and Gs-mediated responses. Gq/11 and G16 responses were additionally compared in HEL92.1.7 cells, showing inhibition of Gq/11 responses. However, UBO-QIC also appeared to inhibit G16. Further studies are required to establish its profile with respect to the different Gq-family proteins.
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31
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Hiebel C, Behl C. The complex modulation of lysosomal degradation pathways by cannabinoid receptors 1 and 2. Life Sci 2015; 138:3-7. [DOI: 10.1016/j.lfs.2015.03.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/26/2015] [Accepted: 03/04/2015] [Indexed: 01/05/2023]
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32
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Kashiwazaki A, Fujiwara Y, Tsuchiya H, Sakai N, Shibata K, Koshimizu TA. Subcellular localization and internalization of the vasopressin V1B receptor. Eur J Pharmacol 2015; 765:291-9. [PMID: 26318147 DOI: 10.1016/j.ejphar.2015.08.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 08/20/2015] [Accepted: 08/25/2015] [Indexed: 01/14/2023]
Abstract
Only limited information is available on agonist-dependent changes in the subcellular localization of vasopressin V1B receptors. Our radioligand binding study of membrane preparations and intact cells revealed that a large fraction of the V1B receptor is located in the cytoplasm in unstimulated CHO cells, which is in contrast to the plasma membrane localization of the V1A and V2 receptors. Moreover, when the affinity of radiolabeled arginine-vasopressin ([3H]AVP) was compared between membrane preparations and intact cells, the affinity of [3H]AVP to the cell surface V1B receptors, but not the V1A receptors, was significantly reduced. Although the number and affinity of cell surface V1B receptors decreased, they became extensively internalized upon binding with [3H]AVP. Approximately 87% of cell surface-bound [3H]AVP was internalized and became resistant to acid wash during incubation with 1 nM [3H]AVP. By contrast, less ligand (35%) was internalized in the cells expressing the V1A receptor. Extensive internalization of the V1B receptors was partially attenuated by inhibitors of cytoskeletal proteins, siRNA against β-arrestin 2, or the removal of sodium chloride from the extracellular buffer, indicating that this internalization involves clathrin-coated pits. Together, these results indicate that the mechanism that regulates the number and affinity of V1B receptors in the plasma membrane is markedly distinct from the corresponding mechanisms for the V1A and V2 receptors and plays a critical role under stress conditions, when vasopressin release is augmented.
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Affiliation(s)
- Aki Kashiwazaki
- Division of Molecular Pharmacology, Department of Pharmacology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Yoko Fujiwara
- Division of Molecular Pharmacology, Department of Pharmacology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Hiroyoshi Tsuchiya
- Division of Molecular Pharmacology, Department of Pharmacology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Nobuya Sakai
- Department of Functional Genomics, Graduate School of Pharmaceutical Sciences, Himeji Dokkyo University, Hyogo 670-8524, Japan
| | - Katsushi Shibata
- Department of Functional Genomics, Graduate School of Pharmaceutical Sciences, Himeji Dokkyo University, Hyogo 670-8524, Japan
| | - Taka-aki Koshimizu
- Division of Molecular Pharmacology, Department of Pharmacology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
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Banister SD, Stuart J, Kevin RC, Edington A, Longworth M, Wilkinson SM, Beinat C, Buchanan AS, Hibbs DE, Glass M, Connor M, McGregor IS, Kassiou M. Effects of bioisosteric fluorine in synthetic cannabinoid designer drugs JWH-018, AM-2201, UR-144, XLR-11, PB-22, 5F-PB-22, APICA, and STS-135. ACS Chem Neurosci 2015; 6:1445-58. [PMID: 25921407 DOI: 10.1021/acschemneuro.5b00107] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Synthetic cannabinoid (SC) designer drugs featuring bioisosteric fluorine substitution are identified by forensic chemists and toxicologists with increasing frequency. Although terminal fluorination of N-pentyl indole SCs is sometimes known to improve cannabinoid type 1 (CB1) receptor binding affinity, little is known of the effects of fluorination on functional activity of SCs. This study explores the in vitro functional activities of SC designer drugs JWH-018, UR-144, PB-22, and APICA, and their respective terminally fluorinated analogues AM-2201, XLR-11, 5F-PB-22, and STS-135 at human CB1 and CB2 receptors using a FLIPR membrane potential assay. All compounds demonstrated agonist activity at CB1 (EC50 = 2.8-1959 nM) and CB2 (EC50 = 6.5-206 nM) receptors, with the fluorinated analogues generally showing increased CB1 receptor potency (∼2-5 times). Additionally, the cannabimimetic activities and relative potencies of JWH-018, AM-2201, UR-144, XLR-11, PB-22, 5F-PB-22, APICA, and STS-135 in vivo were evaluated in rats using biotelemetry. All SCs dose-dependently induced hypothermia and reduced heart rate at doses of 0.3-10 mg/kg. There was no consistent trend for increased potency of fluorinated SCs over the corresponding des-fluoro SCs in vivo. Based on magnitude and duration of hypothermia, the SCs were ranked for potency (PB-22 > 5F-PB-22 = JWH-018 > AM-2201 > APICA = STS-135 = XLR-11 > UR-144).
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Affiliation(s)
- Samuel D. Banister
- Department
of Radiology, Stanford University School of Medicine, Stanford, California 94305, United States
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jordyn Stuart
- Faculty
of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Richard C. Kevin
- School
of Psychology, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Amelia Edington
- Faculty
of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Mitchell Longworth
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Shane M. Wilkinson
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Corinne Beinat
- Department
of Radiology, Stanford University School of Medicine, Stanford, California 94305, United States
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Alexandra S. Buchanan
- Center
for Immersive and Simulation-based Learning, Stanford University School of Medicine, Stanford, California 94305, United States
- Department
of Anaesthesia, Prince of Wales Hospital, Randwick, New South Wales 2031, Australia
| | - David E. Hibbs
- Faculty
of Pharmacy, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Michelle Glass
- School
of Medical Sciences, The University of Auckland, Auckland 1142, New Zealand
| | - Mark Connor
- Faculty
of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Iain S. McGregor
- School
of Psychology, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Michael Kassiou
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
- Discipline
of Medical Radiation Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
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Structure–activity relationships of synthetic cannabinoid designer drug RCS-4 and its regioisomers and C4 homologues. Forensic Toxicol 2015. [DOI: 10.1007/s11419-015-0282-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Application of xCELLigence RTCA Biosensor Technology for Revealing the Profile and Window of Drug Responsiveness in Real Time. BIOSENSORS-BASEL 2015; 5:199-222. [PMID: 25893878 PMCID: PMC4493546 DOI: 10.3390/bios5020199] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 03/27/2015] [Accepted: 04/02/2015] [Indexed: 12/12/2022]
Abstract
The xCELLigence technology is a real-time cellular biosensor, which measures the net adhesion of cells to high-density gold electrode arrays printed on custom-designed E-plates. The strength of cellular adhesion is influenced by a myriad of factors that include cell type, cell viability, growth, migration, spreading and proliferation. We therefore hypothesised that xCELLigence biosensor technology would provide a valuable platform for the measurement of drug responses in a multitude of different experimental, clinical or pharmacological contexts. In this manuscript, we demonstrate how xCELLigence technology has been invaluable in the identification of (1) not only if cells respond to a particular drug, but (2) the window of drug responsiveness. The latter aspect is often left to educated guess work in classical end-point assays, whereas biosensor technology reveals the temporal profile of the response in real time, which enables both acute responses and longer term responses to be profiled within the same assay. In our experience, the xCELLigence biosensor technology is suitable for highly targeted drug assessment and also low to medium throughput drug screening, which produces high content temporal data in real time.
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Cawston EE, Redmond WJ, Breen CM, Grimsey NL, Connor M, Glass M. Real-time characterization of cannabinoid receptor 1 (CB1 ) allosteric modulators reveals novel mechanism of action. Br J Pharmacol 2014; 170:893-907. [PMID: 23937487 DOI: 10.1111/bph.12329] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 08/01/2013] [Accepted: 08/05/2013] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE The cannabinoid receptor type 1 (CB1 ) has an allosteric binding site. The drugs ORG27569 {5-chloro-3-ethyl-N-[2-[4-(1-piperidinyl)phenyl]ethyl]-1H-indole-2-carboxamide} and PSNCBAM-1 {1-(4-chlorophenyl)-3-[3-(6-pyrrolidin-1-ylpyridin-2-yl)phenyl]urea} have been extensively characterized with regard to their effects on signalling of the orthosteric ligand CP55,940 {(-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)cyclohexanol}, and studies have suggested that these allosteric modulators increase binding affinity but act as non-competitive antagonists in functional assays. To gain a deeper understanding of allosteric modulation of CB1 , we examined real-time signalling and trafficking responses of the receptor in the presence of allosteric modulators. EXPERIMENTAL APPROACH Studies of CB1 signalling were carried out in HEK 293 and AtT20 cells expressing haemagglutinin-tagged human and rat CB1 . We measured real-time accumulation of cAMP, activation and desensitization of potassium channel-mediated cellular hyperpolarization and CB1 internalization. KEY RESULTS ORG27569 and PSNCBAM-1 produce a complex, concentration and time-dependent modulation of agonist-mediated regulation of cAMP levels, as well as an increased rate of desensitization of CB1 -mediated cellular hyperpolarization and a decrease in agonist-induced receptor internalization. CONCLUSIONS AND IMPLICATIONS Contrary to previous studies characterizing allosteric modulators at CB1, this study suggests that the mechanism of action is not non-competitive antagonism of signalling, but rather that enhanced binding results in an increased rate of receptor desensitization and reduced internalization, which results in time-dependent modulation of cAMP signalling. The observed effect of the allosteric modulators is therefore dependent on the time frame over which the signalling response occurs. This finding may have important consequences for the potential therapeutic application of these compounds.
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Affiliation(s)
- Erin E Cawston
- Centre for Brain Research and Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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Jäntti MH, Putula J, Turunen PM, Näsman J, Reijonen S, Lindqvist C, Kukkonen JP. Autocrine endocannabinoid signaling through CB1 receptors potentiates OX1 orexin receptor signaling. Mol Pharmacol 2012; 83:621-32. [PMID: 23233488 DOI: 10.1124/mol.112.080523] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has been proposed that OX(1) orexin receptors and CB(1) cannabinoid receptors can form heteromeric complexes, which affect the trafficking of OX(1) receptors and potentiate OX(1) receptor signaling to extracellular signal-regulated kinase (ERK). We have recently shown that OX(1) receptor activity releases high levels of the endocannabinoid 2-arachidonoyl glycerol (2-AG), suggesting an alternative route for OX(1)-CB(1) receptor interaction in signaling, for instance, in retrograde synaptic transmission. In the current study, we set out to investigate this possibility utilizing recombinant Chinese hamster ovary K1 cells. 2-AG released from OX(1) receptor-expressing cells acted as a potent paracrine messenger stimulating ERK activity in neighboring CB(1) receptor-expressing cells. When OX(1) and CB(1) receptors were expressed in the same cells, OX(1) stimulation-induced ERK phosphorylation and activity were strongly potentiated. The potentiation but not the OX(1) response as such was fully abolished by specific inhibition of CB(1) receptors or the enzyme responsible for 2-AG generation, diacylglycerol lipase (DAGL). Although the results do not exclude the previously proposed OX(1)-CB(1) heteromerization, they nevertheless unequivocally identify DAGL-dependent 2-AG generation as the pivotal determinant of the OX(1)-CB(1) synergism and thus suggest a functional rather than a molecular interaction of OX(1) and CB(1) receptors.
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Affiliation(s)
- Maria H Jäntti
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
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Gaffuri AL, Ladarre D, Lenkei Z. Type-1 cannabinoid receptor signaling in neuronal development. Pharmacology 2012; 90:19-39. [PMID: 22776780 DOI: 10.1159/000339075] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 04/13/2012] [Indexed: 01/21/2023]
Abstract
The type-1 cannabinoid receptor (CB1R) was initially identified as the neuronal target of Δ(9)-tetrahydrocannabinol (THC), the major psychoactive substance of marijuana. This receptor is one of the most abundant G-protein-coupled receptors in the adult brain, the target of endocannabinoid ligands and a well-characterized retrograde synaptic regulator. However, CB1Rs are also highly and often transiently expressed in neuronal populations in the embryonic and early postnatal brain, even before the formation of synapses. This suggests important physiological roles for CB1Rs during neuronal development. Several recent reviews have summarized our knowledge about the role of the endocannabinoid (eCB) system in neurodevelopment and neurotransmission by focusing on the metabolism of endocannabinoid molecules. Here, we review current knowledge about the effects of the modulation of CB1R signaling during the different phases of brain development. More precisely, we focus on reports that directly implicate CB1Rs during progenitor cell migration and differentiation, neurite outgrowth, axonal pathfinding and synaptogenesis. Based on theoretical considerations and on the reviewed experimental data, we propose a new model to explain the diversity of experimental findings on eCB signaling on neurite growth and axonal pathfinding. In our model, cell-autonomus and paracrine eCBs acting on CB1Rs are part of a global inhibitory network of cytoskeletal effectors, which act in concert with positive-feedback local-excitation loops, to ultimately yield highly polarized neurons.
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Affiliation(s)
- Anne-Lise Gaffuri
- Neurobiology Laboratory, ESPCI-ParisTech, ESPCI-CNRS UMR 7637, Paris, France
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Turunen PM, Jäntti MH, Kukkonen JP. OX1 orexin/hypocretin receptor signaling through arachidonic acid and endocannabinoid release. Mol Pharmacol 2012; 82:156-67. [PMID: 22550093 DOI: 10.1124/mol.112.078063] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We showed previously that OX(1) orexin receptor stimulation produced a strong (3)H overflow response from [(3)H]arachidonic acid (AA)-labeled cells. Here we addressed this issue with a novel set of tools and methods, to distinguish the enzyme pathways responsible for this response. CHO-K1 cells heterologously expressing human OX(1) receptors were used as a model system. By using selective pharmacological inhibitors, we showed that, in orexin-A-stimulated cells, the AA-derived radioactivity was released as two distinct components, i.e., free AA and the endocannabinoid 2-arachidonoyl glycerol (2-AG). Two orexin-activated enzymatic cascades are responsible for this response: cytosolic phospholipase A(2) (cPLA(2)) and diacylglycerol lipase; the former cascade is responsible for part of the AA release, whereas the latter is responsible for all of the 2-AG release and part of the AA release. Essentially only diacylglycerol released by phospholipase C but not by phospholipase D was implicated as a substrate for 2-AG production, although both phospholipases were strongly activated. The 2-AG released acted as a potent paracrine messenger through cannabinoid CB(1) receptors in an artificial cell-cell communication assay that was developed. The cPLA(2) cascade, in contrast, was involved in the activation of orexin receptor-operated Ca(2+) influx. 2-AG was also released upon OX(1) receptor stimulation in recombinant HEK-293 and neuro-2a cells. The results directly show, for the first time, that orexin receptors are able to generate potent endocannabinoid signals in addition to arachidonic acid signals, which may explain the proposed orexin-cannabinoid interactions (e.g., in neurons).
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Affiliation(s)
- Pauli M Turunen
- Biochemistry and Cell Biology, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
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Nguyen PT, Schmid CL, Raehal KM, Selley DE, Bohn LM, Sim-Selley LJ. β-arrestin2 regulates cannabinoid CB1 receptor signaling and adaptation in a central nervous system region-dependent manner. Biol Psychiatry 2012; 71:714-24. [PMID: 22264443 PMCID: PMC3319102 DOI: 10.1016/j.biopsych.2011.11.027] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 10/25/2011] [Accepted: 11/30/2011] [Indexed: 01/14/2023]
Abstract
BACKGROUND Cannabinoid CB(1) receptors (CB(1)Rs) mediate the effects of ▵(9)-tetrahydrocannabinol (THC), the psychoactive component in marijuana. Repeated THC administration produces tolerance and dependence, which limit therapeutic development. Moreover, THC produces motor and psychoactive side effects. β-arrestin2 mediates receptor desensitization, internalization, and signaling, but its role in these CB(1)R effects and receptor regulation is unclear. METHODS CB(1)R signaling and behaviors (antinociception, hypothermia, catalepsy) were assessed in β-arrestin2-knockout (βarr2-KO) and wild-type mice after THC administration. Cannabinoid-stimulated [(35)S]GTPγS and [(3)H]ligand autoradiography were assessed by statistical parametric mapping and region-of-interest analysis. RESULTS β-arrestin2 deletion increased CB(1)R-mediated G-protein activity in subregions of the cortex but did not affect CB(1)R binding, in vehicle-treated mice. βarr2-KO mice exhibited enhanced acute THC-mediated antinociception and hypothermia, with no difference in catalepsy. After repeated THC administration, βarr2-KO mice showed reduced CB(1)R desensitization and/or downregulation in cerebellum, caudal periaqueductal gray, and spinal cord and attenuated tolerance to THC-mediated antinociception. In contrast, greater desensitization was found in hypothalamus, cortex, globus pallidus, and substantia nigra of βarr2-KO compared with wild-type mice. Enhanced tolerance to THC-induced catalepsy was observed in βarr2-KO mice. CONCLUSIONS β-arrestin2 regulation of CB(1)R signaling following acute and repeated THC administration was region-specific, and results suggest that multiple, overlapping mechanisms regulate CB(1)Rs. The observations that βarr2-KO mice display enhanced antinociceptive responses to acute THC and decreased tolerance to the antinociceptive effects of the drug, yet enhanced tolerance to catalepsy, suggest that development of cannabinoid drugs that minimize CB(1)R interactions with β-arrestin2 might produce improved cannabinoid analgesics with reduced motor suppression.
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Affiliation(s)
- Peter T Nguyen
- Department of Pharmacology and Toxicology and Institute for Drug and Alcohol Studies, Virginia Commonwealth University, Richmond, VA 23298, USA
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Kleyer J, Nicolussi S, Taylor P, Simonelli D, Furger E, Anderle P, Gertsch J. Cannabinoid receptor trafficking in peripheral cells is dynamically regulated by a binary biochemical switch. Biochem Pharmacol 2012; 83:1393-412. [PMID: 22387618 DOI: 10.1016/j.bcp.2012.02.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 02/16/2012] [Accepted: 02/17/2012] [Indexed: 12/20/2022]
Abstract
The cannabinoid G protein-coupled receptors (GPCRs) CB₁ and CB₂ are expressed in different peripheral cells. Localization of GPCRs in the cell membrane determines signaling via G protein pathways. Here we show that unlike in transfected cells, CB receptors in cell lines and primary human cells are not internalized upon agonist interaction, but move between cytoplasm and cell membranes by ligand-independent trafficking mechanisms. Even though CB receptors are expressed in many cells of peripheral origin they are not always localized in the cell membrane and in most cancer cell lines the ratios between CB₁ and CB₂ receptor gene and surface expression vary significantly. In contrast, CB receptor cell surface expression in HL60 cells is subject to significant oscillations and CB₂ receptors form oligomers and heterodimers with CB₁ receptors, showing synchronized surface expression, localization and trafficking. We show that hydrogen peroxide and other nonspecific protein tyrosine phosphatase inhibitors (TPIs) such as phenylarsine oxide trigger both CB₂ receptor internalization and externalization, depending on receptor localization. Phorbol ester-mediated internalization of CB receptors can be inhibited via this switch. In primary human immune cells hydrogen peroxide and other TPIs lead to a robust internalization of CB receptors in monocytes and an externalization in T cells. This study describes, for the first time, the dynamic nature of CB receptor trafficking in the context of a biochemical switch, which may have implications for studies on the cell-type specific effects of cannabinoids and our understanding of the regulation of CB receptor cell surface expression.
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Affiliation(s)
- Jonas Kleyer
- Institute of Biochemistry and Molecular Medicine, Swiss National Centre of Competence in Research NCCR TransCure, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland
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Ahn KH, Mahmoud MM, Kendall DA. Allosteric modulator ORG27569 induces CB1 cannabinoid receptor high affinity agonist binding state, receptor internalization, and Gi protein-independent ERK1/2 kinase activation. J Biol Chem 2012; 287:12070-82. [PMID: 22343625 DOI: 10.1074/jbc.m111.316463] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The cannabinoid receptor 1 (CB1), a member of the class A G protein-coupled receptor family, is expressed in brain tissue where agonist stimulation primarily activates the pertussis toxin-sensitive inhibitory G protein (G(i)). Ligands such as CP55940 ((1R,3R,4R)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4-(3- hydroxypropyl)cyclohexan-1-ol) and Δ(9)-tetrahydrocannabinol are orthosteric agonists for the receptor, bind the conventional binding pocket, and trigger G(i)-mediated effects including inhibition of adenylate cyclase. ORG27569 (5-chloro-3-ethyl-1H-indole-2-carboxylic acid [2-(4-piperidin-1-yl-phenyl)ethyl]amide) has been identified as an allosteric modulator that displays positive cooperativity for CP55940 binding to CB1 yet acts as an antagonist of G protein coupling. To examine this apparent conundrum, we used the wild-type CB1 and two mutants, T210A and T210I (D'Antona, A. M., Ahn, K. H., and Kendall, D. A. (2006) Biochemistry 45, 5606-5617), which collectively cover a spectrum of receptor states from inactive to partially active to more fully constitutively active. Using these receptors, we demonstrated that ORG27569 induces a CB1 receptor state that is characterized by enhanced agonist affinity and decreased inverse agonist affinity consistent with an active conformation. Also consistent with this conformation, the impact of ORG27569 binding was most dramatic on the inactive T210A receptor and less pronounced on the already active T210I receptor. Although ORG27569 antagonized CP55940-induced guanosine 5'-3-O-(thio)triphosphate binding, which is indicative of G protein coupling inhibition in a concentration-dependent manner, the ORG27569-induced conformational change of the CB1 receptor led to cellular internalization and downstream activation of ERK signaling, providing the first case of allosteric ligand-biased signaling via CB1. ORG27569-induced ERK phosphorylation persisted even after pertussis toxin treatment to abrogate G(i) and occurs in HEK293 and neuronal cells.
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Affiliation(s)
- Kwang H Ahn
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269, USA
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Grimsey NL, Moodley KS, Glass M, Graham ES. Sensitive and accurate quantification of human leukocyte migration using high-content Discovery-1 imaging system and ATPlite assay. ACTA ACUST UNITED AC 2011; 17:386-93. [PMID: 22140120 DOI: 10.1177/1087057111428985] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Migration is a fundamental aspect of leukocyte behavior and represents a significant therapeutic target clinically. However, most migration assays used in research are relatively low throughput and not easily compatible with rapid analysis or high-throughput screening (HTS) protocols required for drug screening assays. We therefore investigated the quantification of the migration of human leukocytes using the Molecular Devices high-content Discovery-1 platform or PerkinElmer ATPlite assay compared to manual counting. We have conducted extensive assay validation, investigating the detection limits, sensitivity, and precision of each method to count human leukocytes. Leukocyte migration assays were conducted using 96-well HTS-Transwell plates and the potent chemokine stromal cell-derived factor-1 (SDF-1). We reveal that the Discovery-1 and ATPlite methods developed here provide useful approaches to quantify leukocyte migration in an HTS manner with high levels of detection, sensitivity, and precision.
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Affiliation(s)
- Natasha L Grimsey
- Centre for Brain Research and Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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Grant MP, Stepanchick A, Cavanaugh A, Breitwieser GE. Agonist-Driven Maturation and Plasma Membrane Insertion of Calcium-Sensing Receptors Dynamically Control Signal Amplitude. Sci Signal 2011; 4:ra78. [DOI: 10.1126/scisignal.2002208] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Wasik AM, Christensson B, Sander B. The role of cannabinoid receptors and the endocannabinoid system in mantle cell lymphoma and other non-Hodgkin lymphomas. Semin Cancer Biol 2011; 21:313-21. [PMID: 22024769 DOI: 10.1016/j.semcancer.2011.10.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The initiating oncogenic event in mantle cell lymphoma (MCL) is the translocation of cyclin D1, t(11;14)(q13;q32). However, other genetic aberrations are necessary for an overt lymphoma to arise. Like other B cell lymphomas, MCL at some points during the oncogenesis is dependent on interactions with other cells and factors in the microenvironment. The G protein coupled receptors cannabinoid receptors 1 and 2 (CB1 and CB2) are expressed at low levels on non-malignant lymphocytes and at higher levels in MCL and other lymphoma subtypes. In this review we give an overview of what is known on the role of the cannabinoid receptors and their ligands in lymphoma as compared to non-malignant T and B lymphocytes. In MCL cannabinoids mainly reduce cell proliferation and induce cell death. Importantly, our recent findings demonstrate that cannabinoids may induce either apoptosis or another type of programmed cell death, cytoplasmic vacuolation/paraptosis in MCL. The signalling to death has been partly characterized. Even though cannabinoid receptors seem to be expressed in many other types of B cell lymphoma, the functional role of cannabinoid receptor targeting is yet largely unknown. In non-malignant B and T lymphocytes, cannabinoid receptors are up-regulated in response to antigen receptor signalling or CD40. For T lymphocytes IL-4 has also a crucial role in transcriptional regulation of CB1. In lymphocytes, cannabinoid act in several ways - by affecting cell migration, cytokine response, at high doses inhibit cell proliferation and inducing cell death. The possible role for the endocannabinoid system in the immune microenvironment of lymphoma is discussed.
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Affiliation(s)
- Agata M Wasik
- Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet and Karolinska University Hospital Huddinge, SE 141 86 Stockholm, Sweden.
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Gustafsson SB, Palmqvist R, Henriksson ML, Dahlin AM, Edin S, Jacobsson SOP, Öberg Å, Fowler CJ. High tumour cannabinoid CB1 receptor immunoreactivity negatively impacts disease-specific survival in stage II microsatellite stable colorectal cancer. PLoS One 2011; 6:e23003. [PMID: 21901119 PMCID: PMC3161987 DOI: 10.1371/journal.pone.0023003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 07/11/2011] [Indexed: 12/22/2022] Open
Abstract
Background There is good evidence in the literature that the cannabinoid system is disturbed in colorectal cancer. In the present study, we have investigated whether CB1 receptor immunoreactive intensity (CB1IR intensity) is associated with disease severity and outcome. Methodology/Principal Findings CB1IR was assessed in formalin-fixed, paraffin-embedded specimens collected with a consecutive intent during primary tumour surgical resection from a series of cases diagnosed with colorectal cancer. Tumour centre (n = 483) and invasive front (n = 486) CB1IR was scored from 0 (absent) to 3 (intense staining) and the data was analysed as a median split i.e. CB1IR <2 and ≥2. In microsatellite stable, but not microsatellite instable tumours (as adjudged on the basis of immunohistochemical determination of four mismatch repair proteins), there was a significant positive association of the tumour grade with the CB1IR intensity. The difference between the microsatellite stable and instable tumours for this association of CB1IR was related to the CpG island methylation status of the cases. Cox proportional hazards regression analyses indicated a significant contribution of CB1IR to disease-specific survival in the microsatellite stable tumours when adjusting for tumour stage. For the cases with stage II microsatellite stable tumours, there was a significant effect of both tumour centre and front CB1IR upon disease specific survival. The 5 year probabilities of event-free survival were: 85±5 and 66±8%; tumour interior, 86±4% and 63±8% for the CB1IR<2 and CB1IR≥2 groups, respectively. Conclusions/Significance The level of CB1 receptor expression in colorectal cancer is associated with the tumour grade in a manner dependent upon the degree of CpG hypermethylation. A high CB1IR is indicative of a poorer prognosis in stage II microsatellite stable tumour patients.
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Affiliation(s)
- Sofia B. Gustafsson
- Department of Pharmacology and Clinical Neuroscience, Pharmacology, Umeå University, Umeå, Sweden
| | - Richard Palmqvist
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | | | - Anna M. Dahlin
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | - Sofia Edin
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | - Stig O. P. Jacobsson
- Department of Pharmacology and Clinical Neuroscience, Pharmacology, Umeå University, Umeå, Sweden
| | - Åke Öberg
- Department of Surgical and Perioperative Sciences, Surgery, Umeå University, Umeå, Sweden
| | - Christopher J. Fowler
- Department of Pharmacology and Clinical Neuroscience, Pharmacology, Umeå University, Umeå, Sweden
- * E-mail:
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Brailoiu GC, Oprea TI, Zhao P, Abood ME, Brailoiu E. Intracellular cannabinoid type 1 (CB1) receptors are activated by anandamide. J Biol Chem 2011; 286:29166-29174. [PMID: 21719698 DOI: 10.1074/jbc.m110.217463] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent studies have demonstrated that the majority of endogenous cannabinoid type 1 (CB(1)) receptors do not reach the cell surface but are instead associated with endosomal and lysosomal compartments. Using calcium imaging and intracellular microinjection in CB(1) receptor-transfected HEK293 cells and NG108-15 neuroblastoma × glioma cells, we provide evidence that anandamide acting on CB(1) receptors increases intracellular calcium concentration when administered intracellularly but not extracellularly. The calcium-mobilizing effect of intracellular anandamide was dose-dependent and abolished by pretreatment with SR141716A, a CB(1) receptor antagonist. The anandamide-induced calcium increase was reduced by blocking nicotinic acid-adenine dinucleotide phosphate- or inositol 1,4,5-trisphosphate-dependent calcium release and abolished when both lysosomal and endoplasmic reticulum calcium release pathways were blocked. Taken together, our results indicate that, in CB(1) receptor-transfected HEK293 cells, intracellular CB(1) receptors are functional; they are located in acid-filled calcium stores (endolysosomes). Activation of intracellular CB(1) receptors releases calcium from endoplasmic reticulum and lysosomal calcium stores. In addition, our results support a novel role for nicotinic acid-adenine dinucleotide phosphate in cannabinoid-induced calcium signaling.
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Affiliation(s)
- G Cristina Brailoiu
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Tudor I Oprea
- Division of Biocomputing, Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131
| | - Pingwei Zhao
- Department of Anatomy and Cell Biology and Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 and
| | - Mary E Abood
- Department of Anatomy and Cell Biology and Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 and.
| | - Eugen Brailoiu
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
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Goodfellow CE, Graham SE, Dragunow M, Glass M. Characterization of NTera2/D1 cells as a model system for the investigation of cannabinoid function in human neurons and astrocytes. J Neurosci Res 2011; 89:1685-97. [PMID: 21674570 DOI: 10.1002/jnr.22692] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Revised: 04/03/2011] [Accepted: 04/17/2011] [Indexed: 12/12/2022]
Abstract
The limited availability and potential to culture primary human brain cells means that there is still a need for cell lines that reliably model human neurons and glial cells. The human-derived NTera2/D1 (NT2) cell line is a promising tool from which both neuronal (NT2N) and astrocytic (NT2A) cells can be derived in vitro. Here we have investigated the potential to use this cell model to investigate the endocannabinoid system in the CNS. Through immunocytochemical characterization with a range of neuronal and glial markers, we found that these cell lines differentiate into cells with immature neuronal and astrocytic phenotypes, respectively. By real-time PCR, immunocytochemistry, and functional inhibition of cAMP accumulation, the cannabinoid 1 receptors were identified only on NT2N cells, consistent with high levels of expression of this receptor in neuronal cells of the CNS. No evidence of cannabinoid 2 receptor expression was found on any of the NT2 cell types. Both the precursors and the differentiated NT2N and NT2A cells demonstrated mRNA expression for the key enzymes involved in endocannabinoid synthesis and degradation. This work establishes a cannabinergic phenotype in NT2N and NT2A cells, providing an alternative human derived renewable cell model for investigation of cannabinoid receptor function and endocannabinoid synthesis and metabolism in the CNS.
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Affiliation(s)
- Catherine E Goodfellow
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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Cannabinoid receptor 2 undergoes Rab5-mediated internalization and recycles via a Rab11-dependent pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1554-60. [PMID: 21640764 DOI: 10.1016/j.bbamcr.2011.05.010] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 05/17/2011] [Accepted: 05/17/2011] [Indexed: 11/20/2022]
Abstract
Cannabinoid receptor 2 (CB2) is a GPCR highly expressed on the surface of cells of the immune system, supporting its role in immunomodulation. This study has investigated the trafficking properties of this receptor when stably expressed by HEK-293 cells. As previously reported, cell surface CB2 rapidly internalized upon exposure to agonist. Direct evidence of CB2 recycling was observed upon competitive removal of the stimulating agonist by inverse agonist. CB2 also underwent slow constitutive internalization when agonist was absent and was up-regulated in the presence of inverse agonist. Co-expression of CB2 and dominant negative Rab5 resulted in a significantly reduced capacity for receptors to internalize with no effect on recycling of the internalized receptors. Conversely, co-expression with dominant negative Rab11 did not alter the ability of CB2 to internalize but did impair their ability to return to the cell surface. Co-expression of wild-type, dominant negative or constitutively active Rab4 with CB2 did not alter basal surface expression, extent of internalization, or extent of recycling. These results suggest that Rab5 is involved in CB2 endocytosis and that internalized receptors are recycled via a Rab11 associated pathway rather than the rapid Rab4 associated pathway. This report provides the first comprehensive description of CB2 internalization and recycling to date.
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Abstract
The majority of G-protein-coupled receptors (GPCRs) function at the cell surface, where they are activated by their ligands present in the extracellular milieu. Interestingly, type I cannabinoid receptor (CB(1) R), one of the most abundant GPCRs in the central nervous system, is predominantly intracellular. The important physiological roles of CB(1) R have sparked interest in the elucidation of the molecular mechanisms underlying the trafficking of this receptor and the role of intracellular CB(1) Rs. Thus far, results from different groups have been, at least in part, contradictory and the basis of CB(1) R intracellular localization remains controversial. In this commentary, by comparing the studies examining CB(1) R trafficking and localization, we identify technical or experimental ground responsible for the conflicting results. Finally, we propose a possible mechanism of CB(1) R trafficking that may reconcile the different models.
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Affiliation(s)
- Raphael Rozenfeld
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY 10029, USA.
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