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Liddle I, Glass M, Tyndall JDA, Vernall AJ. Covalent cannabinoid receptor ligands - structural insight and selectivity challenges. RSC Med Chem 2022; 13:497-510. [PMID: 35694688 PMCID: PMC9132230 DOI: 10.1039/d2md00006g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 03/31/2022] [Indexed: 11/21/2022] Open
Abstract
X-ray crystallography and cryogenic electronic microscopy have provided significant advancement in the knowledge of GPCR structure and have allowed the rational design of GPCR ligands. The class A GPCRs cannabinoid receptor type 1 and type 2 are implicated in many pathophysiological processes and thus rational design of drug and tool compounds is of great interest. Recent structural insight into cannabinoid receptors has already led to a greater understanding of ligand binding sites and receptor residues that likely contribute to ligand selectivity. Herein, classes of heterocyclic covalent cannabinoid receptor ligands are reviewed in light of the recent advances in structural knowledge of cannabinoid receptors, with particular discussion regarding covalent ligand selectivity and rationale design.
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Affiliation(s)
- Ian Liddle
- Department of Chemistry, University of Otago Dunedin New Zealand +64 3 479 5214
| | - Michelle Glass
- Department of Pharmacology and Toxicology, University of Otago Dunedin New Zealand
| | | | - Andrea J Vernall
- Department of Chemistry, University of Otago Dunedin New Zealand +64 3 479 5214
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2
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Mielnik CA, Lam VM, Ross RA. CB 1 allosteric modulators and their therapeutic potential in CNS disorders. Prog Neuropsychopharmacol Biol Psychiatry 2021; 106:110163. [PMID: 33152384 DOI: 10.1016/j.pnpbp.2020.110163] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/30/2020] [Accepted: 10/29/2020] [Indexed: 01/05/2023]
Abstract
CB1 is the most abundant GPCR found in the mammalian brain. It has garnered considerable attention as a potential therapeutic drug target. CB1 is involved in a wide range of physiological and psychiatric processes and has the potential to be targeted in a wide range of disease states. However, most of the selective and non-selective synthetic CB1 agonists and antagonists/inverse agonists developed to date are primarily used as research tools. No novel synthetic cannabinoids are currently in the clinic for use in psychiatric illness; synthetic analogues of the phytocannabinoid THC are on the market to treat nausea and vomiting caused by cancer chemotherapy, along with off-label use for pain. Novel strategies are being explored to target CB1, but with emphasis on the elimination or mitigation of the potential psychiatric adverse effects that are observed by central agonism/antagonism of CB1. New pharmacological options are being pursued that may avoid these adverse effects while preserving the potential therapeutic benefits of CB1 modulation. Allosteric modulation of CB1 is one such approach. In this review, we will summarize and critically analyze both the in vitro characterization and in vivo validation of CB1 allosteric modulators developed to date, with a focus on CNS therapeutic effects.
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Affiliation(s)
- Catharine A Mielnik
- Department of Pharmacology & Toxicology, University of Toronto, ON M5S 1A8, Canada
| | - Vincent M Lam
- Department of Pharmacology & Toxicology, University of Toronto, ON M5S 1A8, Canada
| | - Ruth A Ross
- Department of Pharmacology & Toxicology, University of Toronto, ON M5S 1A8, Canada.
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Saldaña-Shumaker SL, Grenning AJ, Cunningham CW. Modern approaches to the development of synthetic cannabinoid receptor probes. Pharmacol Biochem Behav 2021; 203:173119. [PMID: 33508249 DOI: 10.1016/j.pbb.2021.173119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 10/13/2020] [Accepted: 01/18/2021] [Indexed: 10/22/2022]
Abstract
The endocannabinoid system, which spans the central and peripheral nervous systems and regulates many biologic processes, is an important target for probe discovery and medications development. Whereas the earliest endocannabinoid receptor probes were derivatives of the non-selective phytocannabinoids isolated from Cannabis species, modern drug discovery techniques have expanded the definitions of what constitutes a CB1R or CB2R cannabinoid receptor ligand. This review highlights recent advances in synthetic cannabinoid receptor chemistry and pharmacology. We provide examples of new CB1R- and CB2R-selective probes, and discuss rational approaches to the design of peripherally-restricted agents. We also describe structural classes of positive- and negative allosteric modulators (PAMs and NAMs) of CB1R and CB2R. Finally, we introduce new opportunities for cannabinoid receptor probe development that have emerged in recent years, including biased agonists that may lead to medications lacking adverse effects.
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Affiliation(s)
- Savanah L Saldaña-Shumaker
- Department of Pharmaceutical Sciences, Concordia University Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA
| | - Alexander J Grenning
- Department of Chemistry, University of Florida, PO Box 117200, Gainesville, FL 32611, USA
| | - Christopher W Cunningham
- Department of Pharmaceutical Sciences, Concordia University Wisconsin, 12800 N. Lake Shore Drive, Mequon, WI 53097, USA.
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Haspula D, Clark MA. Cannabinoid Receptors: An Update on Cell Signaling, Pathophysiological Roles and Therapeutic Opportunities in Neurological, Cardiovascular, and Inflammatory Diseases. Int J Mol Sci 2020; 21:E7693. [PMID: 33080916 PMCID: PMC7590033 DOI: 10.3390/ijms21207693] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 12/16/2022] Open
Abstract
The identification of the human cannabinoid receptors and their roles in health and disease, has been one of the most significant biochemical and pharmacological advancements to have occurred in the past few decades. In spite of the major strides made in furthering endocannabinoid research, therapeutic exploitation of the endocannabinoid system has often been a challenging task. An impaired endocannabinoid tone often manifests as changes in expression and/or functions of type 1 and/or type 2 cannabinoid receptors. It becomes important to understand how alterations in cannabinoid receptor cellular signaling can lead to disruptions in major physiological and biological functions, as they are often associated with the pathogenesis of several neurological, cardiovascular, metabolic, and inflammatory diseases. This review focusses mostly on the pathophysiological roles of type 1 and type 2 cannabinoid receptors, and it attempts to integrate both cellular and physiological functions of the cannabinoid receptors. Apart from an updated review of pre-clinical and clinical studies, the adequacy/inadequacy of cannabinoid-based therapeutics in various pathological conditions is also highlighted. Finally, alternative strategies to modulate endocannabinoid tone, and future directions are also emphasized.
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Affiliation(s)
- Dhanush Haspula
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA;
| | - Michelle A. Clark
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL 33314, USA
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Zhang Z, Gu Y, Wang Z, Wang H, Zhao Y, Chu X, Zhang C, Yan M. Synthesis and biological evaluation of novel indoleamide derivatives as antioxidative and antitumor agents. J Heterocycl Chem 2020. [DOI: 10.1002/jhet.3853] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Zhen Zhang
- School of PharmacyJining Medical University Shandong China
| | - Ying‐Lin Gu
- School of PharmacyJining Medical University Shandong China
| | | | - Huan‐Nan Wang
- School of PharmacyJining Medical University Shandong China
| | - Yan Zhao
- Oncology Department, Rizhao Central Hospital Shandong China
| | - Xue‐Mei Chu
- School of PharmacyJining Medical University Shandong China
| | - Chun‐Yan Zhang
- School of PharmacyJining Medical University Shandong China
| | - Mao‐Cai Yan
- School of PharmacyJining Medical University Shandong China
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Dopart R, Immadi SS, Lu D, Kendall DA. Structural Optimization of the Diarylurea PSNCBAM-1, an Allosteric Modulator of Cannabinoid Receptor 1. Curr Ther Res Clin Exp 2019; 92:100574. [PMID: 32021660 PMCID: PMC6994307 DOI: 10.1016/j.curtheres.2019.100574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 12/15/2019] [Indexed: 11/05/2022] Open
Abstract
PSNCBAM-1 is an allosteric modulator of the cannabinoid receptor 1. Derivatives of PSNCBAM-1 were made, to reduce the total rings in the structure. Several derivatives maintained allosteric activity, as shown by binding experiments. Some calculated physicochemical properties for these derivatives are provided.
Background Structure–activity relationship studies improve the pharmacological and pharmacokinetic properties of a lead compound such as PSNCBAM-1, an allosteric modulator of the cannabinoid receptor 1. Objectives Here, several derivatives of PSNCBAM-1 were synthesized with the aim of reducing the number of rings within its structure and enhancing the solubility of the compounds. The derivatives studied contain substituents previously shown to enhance binding of agonists (ie, a cyano group and a pyrimidine ring), with a reduced number of rings compared with the parent compound, PSNCBAM-1. Methods The synthesized compounds were tested for the enhancement of the binding of orthosteric cannabinoid receptor 1 agonist CP55,940 in the presence of varying concentrations of each test compound. Select compounds were also tested for their effects on cannabinoid receptor 1 inverse agonist SR141716A binding. The compounds were also subjected to computational analysis of drug-like properties and solubility. Results Consistent with a positive allosteric modulator for orthosteric ligand binding, compounds LDK1317 (12a), LDK1320 (12b), LDK1321 (6a), LDK1323 (8a), and LDK1324 (6b) all enhanced the binding of agonist CP55,940 to some degree. Reduction in the number of rings did not abolish the activity. The new lead compounds LDK1317 (12a) and LDK1321 (6a) showed improved drug-like properties and enhanced solubility in silico. Conclusions In contrast to PSNCBAM-1, the synthesized compounds are analogs with fewer rings. The compounds LDK1317 (12a) and LDK1321 (6a) contained only 2 or 3 rings, respectively, and showed the binding parameters (KB = 110 nM, α = 2.3, and KB = 85 nM, α = 5.9). Further, the computationally predicted drug-like properties and solubility suggest these compounds are acceptable new lead compounds for further development of cannabinoid receptor 1 allosteric modulators. (Curr Ther Res Clin Exp. 2020; 81:XXX–XXX)
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Affiliation(s)
- Rachel Dopart
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut
| | - Sri Sujana Immadi
- Rangel College of Pharmacy, Health Science Center, Texas A&M University, Kingsville, Texas
| | - Dai Lu
- Rangel College of Pharmacy, Health Science Center, Texas A&M University, Kingsville, Texas
| | - Debra A Kendall
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut
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Dopart R, Kendall DA. Allosteric modulators restore orthosteric agonist binding to mutated CB 1 receptors. J Pharm Pharmacol 2019; 72:84-91. [PMID: 31722122 DOI: 10.1111/jphp.13193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/21/2019] [Indexed: 01/23/2023]
Abstract
OBJECTIVES To determine if diminished orthosteric agonist binding due to mutations in extracellular loops 1 or 2 of the cannabinoid receptor 1 (CB1 ) can be overcome by an allosteric modulator and restore agonist binding. METHODS Binding assays were performed using a range of concentrations of orthosteric compound, in the presence or absence of a set concentration of the allosteric modulator PSNCBAM-1 to determine the EC50 in its absence or presence. KEY FINDINGS Single mutations in extracellular loop 1 or 2 of CB1 showed weak or no binding of agonist CP55940 to the receptor. Interestingly, upon addition of the allosteric modulator PSNCBAM-1, this binding was restored typically to wild-type CB1 levels. In a few cases, the allosteric modulator ORG27569 was compared with PSNCBAM-1 for CP55940 binding and it also restored binding. Further, wild-type levels of inverse agonist bound the CB1 mutants in the absence of modulator, suggesting the mutants were originally folded like the wild type. CONCLUSIONS Based on our findings, we provide evidence of a therapeutic application for allosteric modulators in situations where a mutation in the receptor may hinder its function. By utilizing allosteric modulators, restoration of orthosteric binding may be possible.
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Affiliation(s)
- Rachel Dopart
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, USA
| | - Debra A Kendall
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, USA
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Banister SD, Krishna Kumar K, Kumar V, Kobilka BK, Malhotra SV. Selective modulation of the cannabinoid type 1 (CB 1) receptor as an emerging platform for the treatment of neuropathic pain. MEDCHEMCOMM 2019; 10:647-659. [PMID: 31191856 PMCID: PMC6533890 DOI: 10.1039/c8md00595h] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/12/2019] [Indexed: 12/27/2022]
Abstract
Neuropathic pain is caused by a lesion or dysfunction in the nervous system, and it may arise from illness, be drug-induced or caused by toxin exposure. Since the discovery of two G-protein-coupled cannabinoid receptors (CB1 and CB2) nearly three decades ago, there has been a rapid expansion in our understanding of cannabinoid pharmacology. This is currently one of the most active fields of neuropharmacology, and interest has emerged in developing cannabinoids and other small molecule modulators of CB1 and CB2 as therapeutics for neuropathic pain. This short review article provides an overview of the chemotypes currently under investigation for the development of novel neuropathic pain treatments targeting CB1 receptors.
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Affiliation(s)
- Samuel D Banister
- Department of Radiation Oncology , Stanford University School of Medicine , Stanford , CA 94305 , USA .
| | - Kaavya Krishna Kumar
- Department of Molecular and Cellular Physiology , Stanford University School of Medicine , Stanford , CA 94305 , USA
| | - Vineet Kumar
- Department of Radiation Oncology , Stanford University School of Medicine , Stanford , CA 94305 , USA .
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology , Stanford University School of Medicine , Stanford , CA 94305 , USA
| | - Sanjay V Malhotra
- Department of Radiation Oncology , Stanford University School of Medicine , Stanford , CA 94305 , USA .
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Wold EA, Chen J, Cunningham KA, Zhou J. Allosteric Modulation of Class A GPCRs: Targets, Agents, and Emerging Concepts. J Med Chem 2019; 62:88-127. [PMID: 30106578 PMCID: PMC6556150 DOI: 10.1021/acs.jmedchem.8b00875] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
G-protein-coupled receptors (GPCRs) have been tractable drug targets for decades with over one-third of currently marketed drugs targeting GPCRs. Of these, the class A GPCR superfamily is highly represented, and continued drug discovery for this family of receptors may provide novel therapeutics for a vast range of diseases. GPCR allosteric modulation is an innovative targeting approach that broadens the available small molecule toolbox and is proving to be a viable drug discovery strategy, as evidenced by recent FDA approvals and clinical trials. Numerous class A GPCR allosteric modulators have been discovered recently, and emerging trends such as the availability of GPCR crystal structures, diverse functional assays, and structure-based computational approaches are improving optimization and development. This Perspective provides an update on allosterically targeted class A GPCRs and their disease indications and the medicinal chemistry approaches toward novel allosteric modulators and highlights emerging trends and opportunities in the field.
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Affiliation(s)
- Eric A. Wold
- Department of Pharmacology and Toxicology, Chemical Biology Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, Center for Addiction Research, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jianping Chen
- Department of Pharmacology and Toxicology, Chemical Biology Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, Center for Addiction Research, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Kathryn A. Cunningham
- Department of Pharmacology and Toxicology, Chemical Biology Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, Center for Addiction Research, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Jia Zhou
- Department of Pharmacology and Toxicology, Chemical Biology Program, University of Texas Medical Branch, Galveston, Texas 77555, United States
- Department of Pharmacology and Toxicology, Center for Addiction Research, University of Texas Medical Branch, Galveston, Texas 77555, United States
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Immadi SS, Dopart R, Wu Z, Fu B, Kendall DA, Lu D. Exploring 6-Azaindole and 7-Azaindole Rings for Developing Cannabinoid Receptor 1 Allosteric Modulators. Cannabis Cannabinoid Res 2018; 3:252-258. [PMID: 30547095 PMCID: PMC6290480 DOI: 10.1089/can.2018.0046] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Introduction and Objective: Org27569 is a prototypical allosteric modulator of the cannabinoid receptor 1 (CB1). It belongs to the indole-2-carboxamide scaffold and has been intensively investigated in pharmacology and in structure-activity relationship (SAR) studies. Although azaindoles are rare in natural products and differ only by the presence of an extra ring nitrogen, they were demonstrated as valuable bioisosteres in many pharmacologically important molecules. To extend the SAR investigation of the indole-2-carboxamide class of CB1 allosteric modulators, azaindole (pyrrolopyridine) rings were used to replace the indole ring of Org27569 analogs to explore the potential of azaindole-2-carboxamides as CB1 allosteric modulators. Using 6- and 7-azaindole in lieu of the indole moiety within this class of CB1 allosteric modulators indeed improved the aqueous solubility. Materials and Methods: We synthesized 6- and 7-azaindole-2-carboxamides and their indole-2-carboxamide counterparts. The molecules were evaluated by [3H]CP55,940 binding and [35S]GTPγS binding assays for their allosteric modulation of the CB1 receptor. Results: The 7-azaindole-2-carboxamides lost the ability to bind to the CB1 receptor. The 6-azaindole-2-carboxamides (e.g., 3c and 3d) showed markedly reduced binding affinities to the CB1 receptor in comparison with their indole-2-carboxamide counterparts. However, they behaved similarly as indole-2-carboxamides in potentiating the orthosteric agonist binding and inhibiting the orthosteric agonist-induced G-protein coupling. The results indicated that some azaindole scaffolds (e.g., 6-azaindole) are worth further exploration, whereas the 7-azaindole ring is not a viable bioisostere of the indole ring in the Org27569 class of CB1 allosteric modulators.
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Affiliation(s)
- Sri Sujana Immadi
- Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Health Science Center, Texas A&M University, Kingsville, Texas
| | - Rachel Dopart
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut
| | - Zhixing Wu
- Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Health Science Center, Texas A&M University, Kingsville, Texas
| | - Boqiao Fu
- Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Health Science Center, Texas A&M University, Kingsville, Texas
| | - Debra A. Kendall
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut
| | - Dai Lu
- Department of Pharmaceutical Sciences, Rangel College of Pharmacy, Health Science Center, Texas A&M University, Kingsville, Texas
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Dopart R, Lu D, Lichtman AH, Kendall DA. Allosteric modulators of cannabinoid receptor 1: developing compounds for improved specificity. Drug Metab Rev 2018; 50:3-13. [PMID: 29355030 PMCID: PMC6134837 DOI: 10.1080/03602532.2018.1428342] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The cannabinoid receptor 1 (CB1) is a G protein-coupled receptor (GPCR) that is located primarily in the central nervous system. CB1 is a therapeutic target which may impact pathways to mediate pain, neurodegenerative disorders, hunger, and drug-seeking behavior. Despite these benefits, development of orthosteric therapeutic compounds, which target the endogenous ligand-binding site of CB1, has been challenging due to detrimental side effects including psychoactivity, depression, and suicidal thoughts. However, CB1 also has an allosteric binding site(s), which is topographically distinct from the orthosteric site. Allosteric modulation of CB1 has a number of potential advantages including providing a mechanism for more precise control of downstream pathways and circumventing these side effects. In this review, we summarize the concept of allosteric modulation and focus on the structure-activity relationship studies of the well-characterized allosteric modulators, ORG27569 and PSNCBAM-1 and their derivatives, and a few other recent modulators. We review studies on the properties of these modulators on CB1 signaling in cells and their effects in vivo. While many current allosteric modulators also produce complex outcomes, they provide new advances for the design of CB1 centered therapeutics.
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Affiliation(s)
- Rachel Dopart
- a Department of Pharmaceutical Sciences , University of Connecticut , Storrs , CT , USA
| | - Dai Lu
- b Rangel College of Pharmacy , Health Science Center, Texas A&M University , Kingsville , TX , USA
| | - Aron H Lichtman
- c Department of Pharmacology and Toxicology , Virginia Commonwealth University , Richmond , VA , USA
| | - Debra A Kendall
- a Department of Pharmaceutical Sciences , University of Connecticut , Storrs , CT , USA
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Abstract
Allosteric modulation of the type 1 cannabinoid receptor (CB1R) holds great therapeutic potential. This is because allosteric modulators do not possess intrinsic efficacy, but instead augment (positive allosteric modulation) or diminish (negative allosteric modulation) the receptor's response to endogenous ligand. Consequently, CB1R allosteric modulators have an effect ceiling which allows for the tempering of CB1R signaling without the desensitization, tolerance, dependence, and psychoactivity associated with orthosteric compounds. Pain, movement disorders, epilepsy, obesity are all potential therapeutic targets for CB1R allosteric modulation. Several challenges exist for the development of CB1R allosteric modulators, such as receptor subtype specificity, translation to in vivo systems, and mixed allosteric/agonist/inverse agonist activity. Despite these challenges, elucidation of crystal structures of CB1R and compound design based on structure-activity relationships will advance the field. In this review, we will cover recent progress for CB1R allosteric modulators and discuss the future promise of this research.
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Affiliation(s)
- Mariam Alaverdashvili
- a College of Pharmacy and Nutrition , University of Saskatchewan , Saskatoon , Canada
| | - Robert B Laprairie
- a College of Pharmacy and Nutrition , University of Saskatchewan , Saskatoon , Canada
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Panlilio LV, Justinova Z. Preclinical Studies of Cannabinoid Reward, Treatments for Cannabis Use Disorder, and Addiction-Related Effects of Cannabinoid Exposure. Neuropsychopharmacology 2018; 43:116-141. [PMID: 28845848 PMCID: PMC5719102 DOI: 10.1038/npp.2017.193] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/17/2017] [Accepted: 08/22/2017] [Indexed: 12/21/2022]
Abstract
Cannabis use has become increasingly accepted socially and legally, for both recreational and medicinal purposes. Without reliable information about the effects of cannabis, people cannot make informed decisions regarding its use. Like alcohol and tobacco, cannabis can have serious adverse effects on health, and some people have difficulty discontinuing their use of the drug. Many cannabis users progress to using and becoming addicted to other drugs, but the reasons for this progression are unclear. The natural cannabinoid system of the brain is complex and involved in many functions, including brain development, reward, emotion, and cognition. Animal research provides an objective and controlled means of obtaining information about: (1) how cannabis affects the brain and behavior, (2) whether medications can be developed to treat cannabis use disorder, and (3) whether cannabis might produce lasting changes in the brain that increase the likelihood of becoming addicted to other drugs. This review explains the tactics used to address these issues, evaluates the progress that has been made, and offers some directions for future research.
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Affiliation(s)
- Leigh V Panlilio
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA
| | - Zuzana Justinova
- Preclinical Pharmacology Section, Behavioral Neuroscience Research Branch, Intramural Research Program, National Institute on Drug Abuse, NIH, DHHS, Baltimore, MD, USA
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Ogawa LM, Burford NT, Liao YH, Scott CE, Hine AM, Dowling C, Chin J, Power M, Hunnicutt EJ, Emerick VL, Banks M, Zhang L, Gerritz SW, Alt A, Kendall DA. Discovery of Selective Cannabinoid CB 2 Receptor Agonists by High-Throughput Screening. SLAS DISCOVERY 2017; 23:375-383. [PMID: 29257918 DOI: 10.1177/2472555217748403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The endocannabinoid system (ECS) plays a diverse role in human physiology ranging from the regulation of mood and appetite to immune modulation and the response to pain. Drug development that targets the cannabinoid receptors (CB1 and CB2) has been explored; however, success in the clinic has been limited by the psychoactive side effects associated with modulation of the neuronally expressed CB1 that are enriched in the CNS. CB2, however, are expressed in peripheral tissues, primarily in immune cells, and thus development of CB2-selective drugs holds the potential to modulate pain among other indications without eliciting anxiety and other undesirable side effects associated with CB1 activation. As part of a collaborative effort among industry and academic laboratories, we performed a high-throughput screen designed to discover selective agonists or positive allosteric modulators (PAMs) of CB2. Although no CB2 PAMs were identified, 167 CB2 agonists were discovered here, and further characterization of four select compounds revealed two with high selectivity for CB2 versus CB1. These results broaden drug discovery efforts aimed at the ECS and may lead to the development of novel therapies for immune modulation and pain management with improved side effect profiles.
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Affiliation(s)
- Lisa M Ogawa
- 1 Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
| | - Neil T Burford
- 2 Bristol-Myers Squibb, Research and Development, Wallingford, CT, USA
| | - Yu-Hsien Liao
- 3 Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, USA
| | - Caitlin E Scott
- 3 Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, USA
| | - Ashley M Hine
- 3 Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, USA
| | - Craig Dowling
- 2 Bristol-Myers Squibb, Research and Development, Wallingford, CT, USA
| | - Jefferson Chin
- 2 Bristol-Myers Squibb, Research and Development, Wallingford, CT, USA
| | - Mike Power
- 2 Bristol-Myers Squibb, Research and Development, Wallingford, CT, USA
| | | | | | - Martyn Banks
- 2 Bristol-Myers Squibb, Research and Development, Wallingford, CT, USA
| | - Litao Zhang
- 2 Bristol-Myers Squibb, Research and Development, Wallingford, CT, USA
| | - Samuel W Gerritz
- 2 Bristol-Myers Squibb, Research and Development, Wallingford, CT, USA
| | - Andrew Alt
- 2 Bristol-Myers Squibb, Research and Development, Wallingford, CT, USA
| | - Debra A Kendall
- 3 Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, USA
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Khurana L, Mackie K, Piomelli D, Kendall DA. Modulation of CB1 cannabinoid receptor by allosteric ligands: Pharmacology and therapeutic opportunities. Neuropharmacology 2017; 124:3-12. [PMID: 28527758 PMCID: PMC5540789 DOI: 10.1016/j.neuropharm.2017.05.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/12/2017] [Accepted: 05/16/2017] [Indexed: 02/03/2023]
Abstract
Cannabinoid pharmacology has been intensely studied because of cannabis' pervasive medicinal and non-medicinal uses as well as for the therapeutic potential of cannabinoid-based drugs for the treatment of pain, anxiety, substance abuse, obesity, cancer and neurodegenerative disorders. The identification of allosteric modulators of the cannabinoid receptor 1 (CB1) has given a new direction to the development of cannabinoid-based therapeutics due to the many advantages offered by targeting allosteric site(s). Allosteric receptor modulators hold potential to develop subtype-specific and pathway-specific therapeutics. Here we briefly discuss the first-generation of allosteric modulators of CB1 receptor, their structure-activity relationships, signaling pathways and the allosteric binding site(s) on the CB1 receptor. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Affiliation(s)
- Leepakshi Khurana
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, United States
| | - Ken Mackie
- Gill Center and Departmental of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, United States
| | - Daniele Piomelli
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697, United States; Department of Biological Chemistry, University of California, Irvine, CA 92697, United States
| | - Debra A Kendall
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, United States.
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Kulkarni AR, Garai S, Janero DR, Thakur GA. Design and Synthesis of Cannabinoid 1 Receptor (CB1R) Allosteric Modulators: Drug Discovery Applications. Methods Enzymol 2017; 593:281-315. [PMID: 28750808 DOI: 10.1016/bs.mie.2017.06.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Also expressed in various peripheral tissues, the type-1 cannabinoid receptor (CB1R) is the predominant G protein-coupled receptor (GPCR) in brain, where it is responsible for retrograde control of neurotransmitter release. Cellular signaling mediated by CB1R is involved in numerous physiological processes, and pharmacological CB1R modulation is considered a tenable therapeutic approach for diseases ranging from substance-use disorders and glaucoma to metabolic syndrome. Despite the design and synthesis of a variety of bioactive small molecules targeted to the CB1R orthosteric ligand-binding site, the potential of CB1R as a therapeutic GPCR has been largely unrealized due to adverse events associated with typical orthosteric CB1R agonists and antagonists/inverse agonists. Modulation of CB1R-mediated signal transmission by targeting alternative allosteric ligand-binding site(s) on the receptor has garnered interest as a potentially safer and more effective therapeutic modality. This chapter highlights the design and synthesis of novel, pharmacologically active CB1R allosteric modulators and emphasizes how their molecular properties and the positive and negative allosteric control they exert can lead to improved CB1R-targeted pharmacotherapeutics, as well as designer covalent probes that can be used to map CB1R allosteric binding domains and inform structure-based drug design.
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Affiliation(s)
- Abhijit R Kulkarni
- School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, MA, United States
| | - Sumanta Garai
- School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, MA, United States
| | - David R Janero
- School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, MA, United States; Center for Drug Discovery, Northeastern University, Boston, MA, United States; College of Science, Northeastern University, Boston, MA, United States; Health Sciences Entrepreneurs, Northeastern University, Boston, MA, United States
| | - Ganesh A Thakur
- School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, MA, United States.
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Abstract
The cannabinoid CB1 receptor is abundant in the central nervous system and regulates neuronal transmission and other key physiological processes including those leading to pain, inflammation, memory, and feeding behavior. CB1 is activated by the endogenous ligands, arachidonoyl ethanolamine and 2-arachidonoyl glycerol, by various synthetic ligands (e.g., CP55940), and by Δ9-tetrahydrocannabinol, the psychoactive component of Cannabis sativa. These CB1 ligands are orthosteric and transduce downstream signals by binding CB1 and primarily inducing Gi coupling, but Gs and β-arrestin coupling are also possible. Recently, allosteric modulators for CB1 were discovered that bind to topographically distinct sites and can noncompetitively impact the potency and efficacy of orthosteric compounds. These offer the exciting potential for mechanistic analyses and for developing therapeutics. Yet, it is critical to elucidate whether a compound is a positive allosteric modulator or a negative allosteric modulator of orthosteric ligand-induced CB1 profiles to understand pathway specificity and ameliorate diseases. In this chapter, we present equilibrium and kinetic binding analysis to reveal the impact of allosteric modulators on CB1. Also described are activities consistent with CB1 activation (or inactivation) and include cellular internalization of CB1 and downstream signaling patterns. Since many CB1 allosteric modulators do not enhance G protein coupling, it is critical to distinguish CB1 activation and biased signaling patterns via β-arrestin from CB1 inactivation. These strategies can illuminate pathway specificity and are valuable for the fine-tuning of CB1 function.
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Badal S, Smith KN, Rajnarayanan R. Analysis of natural product regulation of cannabinoid receptors in the treatment of human disease. Pharmacol Ther 2017; 180:24-48. [PMID: 28583800 DOI: 10.1016/j.pharmthera.2017.06.003] [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] [Indexed: 12/25/2022]
Abstract
The organized, tightly regulated signaling relays engaged by the cannabinoid receptors (CBs) and their ligands, G proteins and other effectors, together constitute the endocannabinoid system (ECS). This system governs many biological functions including cell proliferation, regulation of ion transport and neuronal messaging. This review will firstly examine the physiology of the ECS, briefly discussing some anomalies in the relay of the ECS signaling as these are consequently linked to maladies of global concern including neurological disorders, cardiovascular disease and cancer. While endogenous ligands are crucial for dispatching messages through the ECS, there are also commonalities in binding affinities with copious exogenous ligands, both natural and synthetic. Therefore, this review provides a comparative analysis of both types of exogenous ligands with emphasis on natural products given their putative safer efficacy and the role of Δ9-tetrahydrocannabinol (Δ9-THC) in uncovering the ECS. Efficacy is congruent to both types of compounds but noteworthy is the effect of a combination therapy to achieve efficacy without unideal side-effects. An example is Sativex that displayed promise in treating Huntington's disease (HD) in preclinical models allowing for its transition to current clinical investigation. Despite the in vitro and preclinical efficacy of Δ9-THC to treat neurodegenerative ailments, its psychotropic effects limit its clinical applicability to treating feeding disorders. We therefore propose further investigation of other compounds and their combinations such as the triterpene, α,β-amyrin that exhibited greater binding affinity to CB1 than CB2 and was more potent than Δ9-THC and the N-alkylamides that exhibited CB2 selective affinity; the latter can be explored towards peripherally exclusive ECS modulation. The synthetic CB1 antagonist, Rimonabant was pulled from commercial markets for the treatment of diabetes, however its analogue SR144528 maybe an ideal lead molecule towards this end and HU-210 and Org27569 are also promising synthetic small molecules.
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Affiliation(s)
- S Badal
- Department of Basic Medical Sciences, Faculty of Medical Sciences, University of the West Indies, Mona, Jamaica.
| | - K N Smith
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - R Rajnarayanan
- Jacobs School of Medicine and Biomedical Sciences, Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, NY 14228, USA
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Nguyen T, Li JX, Thomas BF, Wiley JL, Kenakin TP, Zhang Y. Allosteric Modulation: An Alternate Approach Targeting the Cannabinoid CB1 Receptor. Med Res Rev 2016; 37:441-474. [PMID: 27879006 PMCID: PMC5397374 DOI: 10.1002/med.21418] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/21/2016] [Accepted: 08/23/2016] [Indexed: 12/21/2022]
Abstract
The cannabinoid CB1 receptor is a G protein coupled receptor and plays an important role in many biological processes and physiological functions. A variety of CB1 receptor agonists and antagonists, including endocannabinoids, phytocannabinoids, and synthetic cannabinoids, have been discovered or developed over the past 20 years. In 2005, it was discovered that the CB1 receptor contains allosteric site(s) that can be recognized by small molecules or allosteric modulators. A number of CB1 receptor allosteric modulators, both positive and negative, have since been reported and importantly, they display pharmacological characteristics that are distinct from those of orthosteric agonists and antagonists. Given the psychoactive effects commonly associated with CB1 receptor agonists and antagonists/inverse agonists, allosteric modulation may offer an alternate approach to attain potential therapeutic benefits while avoiding inherent side effects of orthosteric ligands. This review details the complex pharmacological profiles of these allosteric modulators, their structure-activity relationships, and efforts in elucidating binding modes and mechanisms of actions of reported CB1 allosteric modulators. The ultimate development of CB1 receptor allosteric ligands could potentially lead to improved therapies for CB1-mediated neurological disorders.
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Affiliation(s)
- Thuy Nguyen
- Research Triangle Institute, Research Triangle Park, North Carolina
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, University at Buffalo, Buffalo, New York
| | - Brian F Thomas
- Research Triangle Institute, Research Triangle Park, North Carolina
| | - Jenny L Wiley
- Research Triangle Institute, Research Triangle Park, North Carolina
| | - Terry P Kenakin
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina
| | - Yanan Zhang
- Research Triangle Institute, Research Triangle Park, North Carolina
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Janero DR, Thakur GA. Leveraging allostery to improve G protein-coupled receptor (GPCR)-directed therapeutics: cannabinoid receptor 1 as discovery target. Expert Opin Drug Discov 2016; 11:1223-1237. [PMID: 27712124 DOI: 10.1080/17460441.2016.1245289] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Allosteric modulators of G-protein coupled receptors (GPCRs) hold the promise of improved pharmacology and safety over typical orthosteric GPCR ligands. These features are particularly relevant to the cannabinoid receptor 1 (CB1R) GPCR, since typical orthosteric CB1R ligands are associated with adverse events that limit their translational potential. Areas covered: The contextual basis for applying allostery to CB1R is considered from pharmacological, drug-discovery, and medicinal standpoints. Rational design of small-molecule CB1R allosteric modulators as potential pharmacotherapeutics would be greatly facilitated by direct experimental characterization of structure-function correlates underlying the biological activity of chemically-diverse CB1R allosteric modulators, CB1R allosteric ligand-binding binding pockets, and amino acid contact residues critical to allosteric ligand engagement and activity. In these regards, designer covalent probes exhibiting well-characterized molecular pharmacology as CB1R allosteric modulators are emerging as valuable molecular reporters enabling experimental interrogation of CB1R allosteric site(s) and informing the design of new CB1R agents as drugs. Expert opinion: Synthesis and pharmacological profiling of CB1R allosteric ligands will continue to provide valuable insights into CB1R structure-function correlates. The resulting data should expand the repertoire of novel agents capable of exerting therapeutic benefit by modulating CB1R-dependent signaling.
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Affiliation(s)
- David R Janero
- a Center for Drug Discovery; Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences; Department of Chemistry and Chemical Biology, College of Science; and Health Sciences Entrepreneurs , Northeastern University , Boston , MA , USA
| | - Ganesh A Thakur
- b Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences , Northeastern University , Boston , MA , USA
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Greig IR, Baillie GL, Abdelrahman M, Trembleau L, Ross RA. Development of indole sulfonamides as cannabinoid receptor negative allosteric modulators. Bioorg Med Chem Lett 2016; 26:4403-4407. [DOI: 10.1016/j.bmcl.2016.08.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/05/2016] [Accepted: 08/06/2016] [Indexed: 01/28/2023]
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Mane YD, Sarnikar YP, Surwase SM, Biradar DO, Gorepatil PB, Shinde VS, Khade BC. Design, synthesis, and antimicrobial activity of novel 5-substituted indole-2-carboxamide derivatives. RESEARCH ON CHEMICAL INTERMEDIATES 2016. [DOI: 10.1007/s11164-016-2696-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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