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Duan W, Cao D, Wang S, Cheng J. Serotonin 2A Receptor (5-HT 2AR) Agonists: Psychedelics and Non-Hallucinogenic Analogues as Emerging Antidepressants. Chem Rev 2024; 124:124-163. [PMID: 38033123 DOI: 10.1021/acs.chemrev.3c00375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Psychedelics make up a group of psychoactive compounds that induce hallucinogenic effects by activating the serotonin 2A receptor (5-HT2AR). Clinical trials have demonstrated the traditional psychedelic substances like psilocybin as a class of rapid-acting and long-lasting antidepressants. However, there is a pressing need for rationally designed 5-HT2AR agonists that possess optimal pharmacological profiles in order to fully reveal the therapeutic potential of these agonists and identify safer drug candidates devoid of hallucinogenic effects. This Perspective provides an overview of the structure-activity relationships of existing 5-HT2AR agonists based on their chemical classifications and discusses recent advancements in understanding their molecular pharmacology at a structural level. The encouraging clinical outcomes of psychedelics in depression treatment have sparked drug discovery endeavors aimed at developing novel 5-HT2AR agonists with improved subtype selectivity and signaling bias properties, which could serve as safer and potentially nonhallucinogenic antidepressants. These efforts can be significantly expedited through the utilization of structure-based methods and functional selectivity-directed screening.
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Affiliation(s)
- Wenwen Duan
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Dongmei Cao
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Sheng Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Jianjun Cheng
- iHuman Institute, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
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2
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Hakami Zanjani AA, Nguyen TQT, Jacobsen L, Khandelia H. The molecular basis of the antidepressant action of the magic mushroom extract, psilocin. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2023; 1871:140914. [PMID: 37019325 DOI: 10.1016/j.bbapap.2023.140914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 03/27/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023]
Abstract
Magic mushrooms, and their extract psilocybin, are well-known for their psychedelic properties and recreational use. Psilocin, the bio-active form of psilocybin, can potentially treat various psychiatric diseases. Psilocin putatively exerts its psychedelic effect as an agonist to the serotonin 2A receptor (5-HT2AR), which is also the receptor for the neurological hormone serotonin. The two key chemical differences between the two molecules are first, that the primary amine in serotonin is replaced with a tertiary amine in psilocin, and second, the hydroxyl group is substituted differently on the aromatic ring. Here, we find that psilocin can bind to 5-HT2AR with an affinity higher than serotonin, and provide the molecular logic behind the higher binding affinity of psilocin using extensive molecular dynamics simulations and free energy calculations. The binding free energy of psilocin is dependent upon the protonation states of the ligands, as well as that of the key residue in the binding site: Aspartate 155. We find that the tertiary amine of psilocin, and not the altered substitution of the hydroxyl group in the ring is responsible for the increased affinity of psilocin. We propose design rules for effective antidepressants based on molecular insights from our simulations.
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Affiliation(s)
- Ali Asghar Hakami Zanjani
- PHYLIFE, Physical Life Science, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense 5230, Denmark.
| | - Teresa Quynh Tram Nguyen
- PHYLIFE, Physical Life Science, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense 5230, Denmark
| | - Luise Jacobsen
- PHYLIFE, Physical Life Science, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense 5230, Denmark
| | - Himanshu Khandelia
- PHYLIFE, Physical Life Science, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense 5230, Denmark.
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3
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Sessa L, Concilio S, Fominaya J, Eletto D, Piotto S, Busquets X. A new serotonin 2A receptor antagonist with potential benefits in Non-Alcoholic Fatty Liver Disease. Life Sci 2023; 314:121315. [PMID: 36581095 DOI: 10.1016/j.lfs.2022.121315] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 12/28/2022]
Abstract
Peripheral 5-hydroxytryptamine 2A receptor (5-HT2AR) could be a new pharmacological target for NASH, an evolution of NAFLD characterized by hepatic steatosis, cytoskeletal alterations, and hepatic inflammation that can arise with or without fibrosis. SJT4a is a synthetic β-carboline antagonist for 5-HT2AR developed by SJT molecular research to treat NASH. We performed a combined in silico/in vivo study on this potential drug to elucidate its activity and possible mechanism of action. The in silico protocol compares SJT4a with four known 5-HT2AR ligands with different activities (LSD, methiothepin, zotepine, risperidone). We performed molecular docking calculations, evaluation of binding energy by AI-based methods and Molecular Dynamics simulations of the five ligand-target complexes. Moreover, we used a pseudo-semantic analysis to evaluate the potential mechanism of action of SJT4a. In silico predictions and pseudo-semantic analysis suggested antagonistic activity for SJT4a. The in silico prediction was confirmed by [3H]-5HT radioligand binding together with SJT4a competition analysis in CHO-K1 cell cultures expressing 5-HT2AR. SJT4a was then tested in vivo. We investigated the effect of 8 weeks of treatment with SJT4A on metabolic parameters, liver pathology, NAFLD activity score, and fibrosis stage in male DIO-NASH C57BL/6 J mice diet-induced obesity fed with an obesogenic diet compared with DIO-NASH and LEAN-CHOW vehicles. In our tests, SJT4a showed intense activity in diminishing the most relevant hallmarks of NASH in the DIO-NASH mice model. We proposed a possible mode of action for SJT4a based on its 5-HT2AR antagonist activity.
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Affiliation(s)
- Lucia Sessa
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, Fisciano 84084, SA, Italy; Bionam Center for Biomaterials, University of Salerno, Via Giovanni Paolo II, 132, Fisciano 84084, SA, Italy
| | - Simona Concilio
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, Fisciano 84084, SA, Italy; Bionam Center for Biomaterials, University of Salerno, Via Giovanni Paolo II, 132, Fisciano 84084, SA, Italy
| | - Jesús Fominaya
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, 07122 Palma, Spain
| | - Daniela Eletto
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, Fisciano 84084, SA, Italy
| | - Stefano Piotto
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, Fisciano 84084, SA, Italy; Bionam Center for Biomaterials, University of Salerno, Via Giovanni Paolo II, 132, Fisciano 84084, SA, Italy.
| | - Xavier Busquets
- Laboratory of Molecular Cell Biomedicine, Department of Biology, University of the Balearic Islands, 07122 Palma, Spain.
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Halberstadt AL, Luethi D, Hoener MC, Trachsel D, Brandt SD, Liechti ME. Use of the head-twitch response to investigate the structure-activity relationships of 4-thio-substituted 2,5-dimethoxyphenylalkylamines. Psychopharmacology (Berl) 2023; 240:115-126. [PMID: 36477925 PMCID: PMC9816194 DOI: 10.1007/s00213-022-06279-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022]
Abstract
RATIONALE 4-Thio-substituted phenylalkylamines such as 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2) and 2,5-dimethoxy-4-n-propylthiophenethylamine (2C-T-7) produce psychedelic effects in humans and have been distributed as recreational drugs. OBJECTIVES The present studies were conducted to examine the structure-activity relationships (SAR) of a series of 4-thio-substituted phenylalkylamines using the head twitch response (HTR), a 5-HT2A receptor-mediated behavior induced by psychedelic drugs in mice. The HTR is commonly used as a behavioral proxy in rodents for human psychedelic effects and can be used to discriminate hallucinogenic and non-hallucinogenic 5-HT2A agonists. METHODS HTR dose-response studies with twelve different 4-thio-substituted phenylalkylamines were conducted in male C57BL/6 J mice. To detect the HTR, head movement was recorded electronically using a magnetometer coil and then head twitches were identified in the recordings using a validated method based on artificial intelligence. RESULTS 2C-T, the parent compound of this series, had relatively low potency in the HTR paradigm, but adding an α-methyl group increased potency fivefold. Potency was also increased when the 4-methylthio group was extended by one to three methylene units. Fluorination of the 4-position alkylthio chain, however, was detrimental for activity, as was the presence of a 4-allylthio substituent versus a propylthio group. 2C-T analogs containing a 4-benzylthio group showed little or no effect in the HTR paradigm, which is consistent with evidence that bulky 4-substituents can dampen agonist efficacy at the 5-HT2A receptor. Binding and functional studies confirmed that the compounds have nanomolar affinity for 5-HT2 receptor subtypes and act as partial agonists at 5-HT2A. CONCLUSIONS In general, there were close parallels between the HTR data and the known SAR governing activity of phenylalkylamines at the 5-HT2A receptor. These findings further support the classification of 2C-T compounds as psychedelic drugs.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093-0804, USA.
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
| | - Dino Luethi
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Department of Pharmaceutical Sciences, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Marius C Hoener
- pRED, Roche Innovation Center Basel, Neuroscience Research, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | | | - Simon D Brandt
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK
| | - Matthias E Liechti
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine and Department of Pharmaceutical Sciences, University Hospital Basel and University of Basel, Basel, Switzerland
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5
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Kirchweger B, Klein-Junior LC, Pretsch D, Chen Y, Cretton S, Gasper AL, Heyden YV, Christen P, Kirchmair J, Henriques AT, Rollinger JM. Azepine-Indole Alkaloids From Psychotria nemorosa Modulate 5-HT 2A Receptors and Prevent in vivo Protein Toxicity in Transgenic Caenorhabditis elegans. Front Neurosci 2022; 16:826289. [PMID: 35360162 PMCID: PMC8963987 DOI: 10.3389/fnins.2022.826289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/18/2022] [Indexed: 11/26/2022] Open
Abstract
Nemorosine A (1) and fargesine (2), the main azepine-indole alkaloids of Psychotria nemorosa, were explored for their pharmacological profile on neurodegenerative disorders (NDs) applying a combined in silico–in vitro–in vivo approach. By using 1 and 2 as queries for similarity-based searches of the ChEMBL database, structurally related compounds were identified to modulate the 5-HT2A receptor; in vitro experiments confirmed an agonistic effect for 1 and 2 (24 and 36% at 10 μM, respectively), which might be linked to cognition-enhancing properties. This and the previously reported target profile of 1 and 2, which also includes BuChE and MAO-A inhibition, prompted the evaluation of these compounds in several Caenorhabditis elegans models linked to 5-HT modulation and proteotoxicity. On C. elegans transgenic strain CL4659, which expresses amyloid beta (Aβ) in muscle cells leading to a phenotypic paralysis, 1 and 2 reduced Aβ proteotoxicity by reducing the percentage of paralyzed worms to 51%. Treatment of the NL5901 strain, in which α-synuclein is yellow fluorescent protein (YFP)-tagged, with 1 and 2 (10 μM) significantly reduced the α-synuclein expression. Both alkaloids were further able to significantly extend the time of metallothionein induction, which is associated with reduced neurodegeneration of aged brain tissue. These results add to the multitarget profiles of 1 and 2 and corroborate their potential in the treatment of NDs.
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Affiliation(s)
- Benjamin Kirchweger
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Luiz C Klein-Junior
- School of Health Sciences, Universidade do Vale do Itajaí (UNIVALI), Itajaí, Brazil.,Laboratory of Pharmacognosy and Quality Control of Phytomedicines, Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Dagmar Pretsch
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Ya Chen
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Sylvian Cretton
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - André L Gasper
- Herbarium Dr. Roberto Miguel Klein, Department of Natural Sciences, Universidade Regional de Blumenau (FURB), Blumenau, Brazil
| | - Yvan Vander Heyden
- Department of Analytical Chemistry, Applied Chemometrics and Molecular Modeling, Center for Pharmaceutical Research (CePhaR), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Philippe Christen
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Johannes Kirchmair
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Amélia T Henriques
- Laboratory of Pharmacognosy and Quality Control of Phytomedicines, Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Judith M Rollinger
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Vienna, Austria
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6
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Casey AB, Cui M, Booth RG, Canal CE. "Selective" serotonin 5-HT 2A receptor antagonists. Biochem Pharmacol 2022; 200:115028. [PMID: 35381208 DOI: 10.1016/j.bcp.2022.115028] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/25/2022] [Accepted: 03/29/2022] [Indexed: 01/29/2023]
Abstract
Blockade of the serotonin 5-HT2A G protein-coupled receptor (5-HT2AR) is a fundamental pharmacological characteristic of numerous antipsychotic medications, which are FDA-approved to treat schizophrenia, bipolar disorder, and as adjunctive therapies in major depressive disorder. Meanwhile, activation of the 5-HT2AR by serotonergic psychedelics may be useful in treating neuropsychiatric indications, including major depressive and substance use disorders. Serotonergic psychedelics and other 5-HT2AR agonists, however, often bind other receptors, and standard 5-HT2AR antagonists lack sufficient selectivity to make well-founded mechanistic conclusions about the 5-HT2AR-dependent effects of these compounds and the general neurobiological function of 5-HT2ARs. This review discusses the limitations and strengths of currently available "selective" 5-HT2AR antagonists, the molecular determinants of antagonist selectivity at 5-HT2ARs, and the utility of molecular pharmacological and computational methods in guiding the discovery of novel unambiguously selective 5-HT2AR antagonists.
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Affiliation(s)
- Austen B Casey
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Meng Cui
- Department of Pharmaceutical Sciences, Boston, Massachusetts 02115, USA; Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115, USA
| | - Raymond G Booth
- Department of Pharmaceutical Sciences, Boston, Massachusetts 02115, USA; Department of Chemistry and Chemical Biology, Boston, Massachusetts 02115, USA; Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115, USA
| | - Clinton E Canal
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, 3001 Mercer University Drive, Atlanta, Georgia 30341, USA
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7
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Pottie E, Stove CP. In vitro assays for the functional characterization of (psychedelic) substances at the serotonin receptor 5-HT 2A R. J Neurochem 2022; 162:39-59. [PMID: 34978711 DOI: 10.1111/jnc.15570] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/24/2021] [Accepted: 12/29/2021] [Indexed: 12/20/2022]
Abstract
Serotonergic psychedelics are substances that induce alterations in mood, perception, and thought, and have the activation of serotonin (5-HT) 2A receptors (5-HT2A Rs) as a main pharmacological mechanism. Besides their appearance on the (illicit) drug market, e.g. as new psychoactive substances, their potential therapeutic application is increasingly explored. This group of substances demonstrates a broad structural variety, leading to insufficiently described structure-activity relationships, hence illustrating the need for better functional characterization. This review therefore elaborates on the in vitro molecular techniques that have been used the most abundantly for the characterization of (psychedelic) 5-HT2A R agonists. More specifically, this review covers assays to monitor the canonical G protein signaling pathway (e.g. measuring G protein recruitment/activation, inositol phosphate accumulation, or Ca2+ mobilization), assays to monitor non-canonical G protein signaling (such as arachidonic acid release), assays to monitor β-arrestin recruitment or signaling, and assays to monitor receptor conformational changes. In particular, focus lies on the mechanism behind the techniques, and the specific advantages and challenges that are associated with these. Additionally, several variables are discussed that one should consider when attempting to compare functional outcomes from different studies, both linked to the specific assay mechanism and linked to its specific execution, as these may heavily impact the assay outcome.
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Affiliation(s)
- Eline Pottie
- Laboratory of Toxicology, Faculty of Pharmaceutical Sciences, Department of Bioanalysis, Ghent University, Ghent, Belgium
| | - Christophe P Stove
- Laboratory of Toxicology, Faculty of Pharmaceutical Sciences, Department of Bioanalysis, Ghent University, Ghent, Belgium
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8
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Fierro A, Matthies DJ, Cassels BK, Jaque P, Zapata-Torres G. 5-HT 2 Receptor Subfamily and the Halogen Bond Promise. J Chem Inf Model 2021; 61:5001-5012. [PMID: 34617740 DOI: 10.1021/acs.jcim.1c00466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The binding of C-4-halogenated 1-(4-X-2,5-dimethoxyphenyl)-2-aminopropane (DOX) serotonin agonist psychedelics at all three 5-HT2 receptor subtypes is up to two orders of magnitude stronger for X = Cl, Br, or I (but not F) than when C-4 bears a hydrogen atom and more than expected from their hydrophobicities. Our docking and molecular dynamics simulations agree with the fact that increasing the polarizability of halogens results in halogen-oxygen distances to specific backbone C═O groups, and C-X···O angles, in ranges expected for halogen bonds (XBs), which could contribute to the high affinities observed. Good linear correlations are found for each receptor type, indicating that the binding pocket-ligand affinity is enhanced as the XB interaction becomes stronger (i.e., I ≈ Br > Cl > F). It is also striking to note how the linear equations unveil that the receptor's response on the strength of the XB interaction is quite similar among 5-HT2A and 5-HT2C, whereas the 5-HT2B's sensitivity is less. The calculated dipole polarizabilities in the binding pocket of the receptors reflect the experimental affinity values, indicating that less-polarizable and harder binding sites are more prone to XB formation.
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Affiliation(s)
- Angélica Fierro
- Departamento de Química Orgánica, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile
| | - Douglas J Matthies
- Unidad de Gráfica Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Sergio Livingstone 1007, Independencia, Santiago 8380494, Chile
| | - Bruce K Cassels
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile
| | - Pablo Jaque
- Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Sergio Livingstone 1007, Independencia, Santiago 8380492, Chile
| | - Gerald Zapata-Torres
- Unidad de Gráfica Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Sergio Livingstone 1007, Independencia, Santiago 8380494, Chile
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Tropmann K, Bresinsky M, Forster L, Mönnich D, Buschauer A, Wittmann HJ, Hübner H, Gmeiner P, Pockes S, Strasser A. Abolishing Dopamine D 2long/D 3 Receptor Affinity of Subtype-Selective Carbamoylguanidine-Type Histamine H 2 Receptor Agonists. J Med Chem 2021; 64:8684-8709. [PMID: 34110814 DOI: 10.1021/acs.jmedchem.1c00692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
3-(2-Amino-4-methylthiazol-5-yl)propyl-substituted carbamoylguanidines are potent, subtype-selective histamine H2 receptor (H2R) agonists, but their applicability as pharmacological tools to elucidate the largely unknown H2R functions in the central nervous system (CNS) is compromised by their concomitant high affinity toward dopamine D2-like receptors (especially to the D3R). To improve the selectivity, a series of novel carbamoylguanidine-type ligands containing various heterocycles, spacers, and side residues were rationally designed, synthesized, and tested in binding and/or functional assays at H1-4 and D2long/3 receptors. This study revealed a couple of selective candidates (among others 31 and 47), and the most promising ones were screened at several off-target receptors, showing good selectivities. Docking studies suggest that the amino acid residues (3.28, 3.32, E2.49, E2.51, 5.42, and 7.35) are responsible for the different affinities at the H2- and D2long/3-receptors. These results provide a solid base for the exploration of the H2R functions in the brain in further studies.
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Affiliation(s)
- Katharina Tropmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Merlin Bresinsky
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Lisa Forster
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Denise Mönnich
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Armin Buschauer
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Hans-Joachim Wittmann
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Harald Hübner
- Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-University of Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander-University of Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Steffen Pockes
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany.,Department of Neurology, University of Minnesota, Minneapolis, Minnesota 55455, United States.,Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Andrea Strasser
- Institute of Pharmacy, University of Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
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10
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Kim K, Che T, Panova O, DiBerto JF, Lyu J, Krumm BE, Wacker D, Robertson MJ, Seven AB, Nichols DE, Shoichet BK, Skiniotis G, Roth BL. Structure of a Hallucinogen-Activated Gq-Coupled 5-HT 2A Serotonin Receptor. Cell 2021; 182:1574-1588.e19. [PMID: 32946782 DOI: 10.1016/j.cell.2020.08.024] [Citation(s) in RCA: 249] [Impact Index Per Article: 83.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/17/2020] [Accepted: 08/14/2020] [Indexed: 02/07/2023]
Abstract
Hallucinogens like lysergic acid diethylamide (LSD), psilocybin, and substituted N-benzyl phenylalkylamines are widely used recreationally with psilocybin being considered as a therapeutic for many neuropsychiatric disorders including depression, anxiety, and substance abuse. How psychedelics mediate their actions-both therapeutic and hallucinogenic-are not understood, although activation of the 5-HT2A serotonin receptor (HTR2A) is key. To gain molecular insights into psychedelic actions, we determined the active-state structure of HTR2A bound to 25-CN-NBOH-a prototypical hallucinogen-in complex with an engineered Gαq heterotrimer by cryoelectron microscopy (cryo-EM). We also obtained the X-ray crystal structures of HTR2A complexed with the arrestin-biased ligand LSD or the inverse agonist methiothepin. Comparisons of these structures reveal determinants responsible for HTR2A-Gαq protein interactions as well as the conformational rearrangements involved in active-state transitions. Given the potential therapeutic actions of hallucinogens, these findings could accelerate the discovery of more selective drugs for the treatment of a variety of neuropsychiatric disorders.
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MESH Headings
- Animals
- Cryoelectron Microscopy
- Crystallography, X-Ray
- GTP-Binding Protein alpha Subunits, Gq-G11/chemistry
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Gene Expression
- HEK293 Cells
- Hallucinogens/chemistry
- Hallucinogens/pharmacology
- Hallucinogens/therapeutic use
- Humans
- Ligands
- Lysergic Acid Diethylamide/chemistry
- Lysergic Acid Diethylamide/pharmacology
- Methiothepin/chemistry
- Methiothepin/metabolism
- Models, Chemical
- Mutation
- Protein Conformation, alpha-Helical
- Receptor, Serotonin, 5-HT2A/chemistry
- Receptor, Serotonin, 5-HT2A/genetics
- Receptor, Serotonin, 5-HT2A/metabolism
- Recombinant Proteins
- Serotonin/metabolism
- Spodoptera
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Affiliation(s)
- Kuglae Kim
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA
| | - Tao Che
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA
| | - Ouliana Panova
- Department of Molecular and Cellular Physiology, Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jeffrey F DiBerto
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA
| | - Jiankun Lyu
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Brian E Krumm
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA
| | - Daniel Wacker
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA
| | - Michael J Robertson
- Department of Molecular and Cellular Physiology, Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alpay B Seven
- Department of Molecular and Cellular Physiology, Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - David E Nichols
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599-7365, USA
| | - Brian K Shoichet
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Georgios Skiniotis
- Department of Molecular and Cellular Physiology, Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Bryan L Roth
- Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA; Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599-7365, USA.
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11
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Pottie E, Kupriyanova OV, Brandt AL, Laprairie RB, Shevyrin VA, Stove CP. Serotonin 2A Receptor (5-HT 2AR) Activation by 25H-NBOMe Positional Isomers: In Vitro Functional Evaluation and Molecular Docking. ACS Pharmacol Transl Sci 2021; 4:479-487. [PMID: 33860178 DOI: 10.1021/acsptsci.0c00189] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Indexed: 01/12/2023]
Abstract
Serotonergic psychedelics are defined as compounds having serotonin 2A receptor (5-HT2AR) activation as an important pharmacological mechanism. These compounds include the phenylalkylamine class, containing substances with e.g. 2C-X structures (phenethylamines) or their N-methoxybenzyl analogues (NBOMes). Besides their abuse potential, psychedelics are increasingly recognized for having therapeutic benefits. However, many psychedelics remain incompletely characterized, even concerning their structure-activity relationships. Here, five positional isomers of 25H-NBOMe, with two methoxy groups on the different positions of the phenyl ring of the phenethylamine moiety, were subjected to split-nanoluciferase assays assessing the in vitro recruitment of cytosolic proteins to the 5-HT2AR. Furthermore, molecular docking at the 5-HT2AR allowed estimation of which residues interact with the specific isomers' methoxy groups. Although the optimal substitution pattern of N-unsubstituted phenylalkylamines has been extensively studied, this is the first comparative evaluation of the functional effects of the positioning of the methoxy groups in the phenethylamine moiety of NBOMes.
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Affiliation(s)
- Eline Pottie
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Olga V Kupriyanova
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan 420008, Russian Federation.,Kazan State Medical University, Kazan 420012, Russian Federation
| | - Asher L Brandt
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Robert B Laprairie
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.,Department of Pharmacology, College of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Vadim A Shevyrin
- Institute of Chemistry and Technology, Ural Federal University, Ekaterinburg 620002, Russian Federation
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
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12
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Marcher-Rørsted E, Halberstadt AL, Klein AK, Chatha M, Jademyr S, Jensen AA, Kristensen JL. Investigation of the 2,5-Dimethoxy Motif in Phenethylamine Serotonin 2A Receptor Agonists. ACS Chem Neurosci 2020; 11:1238-1244. [PMID: 32212672 DOI: 10.1021/acschemneuro.0c00129] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The 2,5-dimethoxyphenethylamine (2,5-PEA) scaffold is recognized as a motif conferring potent agonist activity at the serotonin 2A receptor (5-HT2AR). The 2,5-dimethoxy motif is present in several classical phenethylamine psychedelics such as 2,4,5- trimethoxyamphetamine (TMA-2), 2,5-dimethoxy-4-methylamphetamine (DOM), 2,5-dimethoxy-4-iodoamphetamine (DOI), 2,5- dimethoxy-4-bromoamphetamine (DOB), 2,5-dimethoxy-4-bromophenethylamine (2C-B), and 2,5-dimethoxy-4-iodophenethylamine (2C-I), and it has previously been suggested that this structural motif is essential for 5-HT2AR activation. In the present study, we present data that challenges this assumption. The 2- and 5-desmethoxy derivatives of 2C-B and DOB were synthesized, and their pharmacological profiles were evaluated in vitro at 5-HT2AR and 5-HT2CR in binding and functional assays and in vivo by assessing their induction of the head-twitch response in mice. Elimination of either the 2- or 5-methoxy group leads to a modest drop in binding affinity and functional potency at 5-HT2AR and 5-HT2CR, which was more pronounced upon removal of the 2-methoxy group. However, this trend was not mirrored in vivo, as removal of either methoxy group resulted in significant reduction in the ability of the compounds to induce the head-twitch response in mice. Thus, the 2,5-dimethoxyphenethylamine motif appears to be important for in vivo potency of phenethylamine 5-HT2AR agonists, but this does not correlate to the relative affinity and potency of the ligands at the recombinant 5-HT2AR.
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Affiliation(s)
- Emil Marcher-Rørsted
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Adam L. Halberstadt
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr., La Jolla 92093, California
| | - Adam K. Klein
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr., La Jolla 92093, California
| | - Muhammad Chatha
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr., La Jolla 92093, California
| | - Simon Jademyr
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Anders A. Jensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Jesper L. Kristensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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13
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Canal CE. Serotonergic Psychedelics: Experimental Approaches for Assessing Mechanisms of Action. Handb Exp Pharmacol 2019; 252:227-260. [PMID: 29532180 PMCID: PMC6136989 DOI: 10.1007/164_2018_107] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Recent, well-controlled - albeit small-scale - clinical trials show that serotonergic psychedelics, including psilocybin and lysergic acid diethylamide, possess great promise for treating psychiatric disorders, including treatment-resistant depression. Additionally, fresh results from a deluge of clinical neuroimaging studies are unveiling the dynamic effects of serotonergic psychedelics on functional activity within, and connectivity across, discrete neural systems. These observations have led to testable hypotheses regarding neural processing mechanisms that contribute to psychedelic effects and therapeutic benefits. Despite these advances and a plethora of preclinical and clinical observations supporting a central role for brain serotonin 5-HT2A receptors in producing serotonergic psychedelic effects, lingering and new questions about mechanisms abound. These chiefly pertain to molecular neuropharmacology. This chapter is devoted to illuminating and discussing such questions in the context of preclinical experimental approaches for studying mechanisms of action of serotonergic psychedelics, classic and new.
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Affiliation(s)
- Clinton E Canal
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA, USA.
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14
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Spasov AA, Yakovlev DS, Brigadirova AA, Maltsev DV, Agatsarskaya YV. Novel Approaches to the Development of Antimigraine Drugs: A Focus on 5-HT2A Receptor Antagonists. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2019. [DOI: 10.1134/s1068162019020146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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15
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Shah UH, Gaitonde SA, Moreno JL, Glennon RA, Dukat M, González-Maeso J. Revised Pharmacophore Model for 5-HT 2A Receptor Antagonists Derived from the Atypical Antipsychotic Agent Risperidone. ACS Chem Neurosci 2019; 10:2318-2331. [PMID: 30609893 DOI: 10.1021/acschemneuro.8b00637] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Pharmacophore models for 5-HT2A receptor antagonists consist of two aromatic/hydrophobic regions at a given distance from a basic amine. We have previously shown that both aromatic/hydrophobic moieties are unnecessary for binding or antagonist action. Here, we deconstructed the 5-HT2A receptor antagonist/serotonin-dopamine antipsychotic agent risperidone into smaller structural segments that were tested for 5-HT2A receptor affinity and function. We show, again, that the entire risperidone structure is unnecessary for retention of affinity or antagonist action. Replacement of the 6-fluoro-3-(4-piperidinyl)-1,2-benz[ d]isoxazole moiety by isosteric tryptamines resulted in retention of affinity and antagonist action. Additionally, 3-(4-piperidinyl)-1,2-benz[ d]isoxazole (10), which represents less than half the structural features of risperidone, retains both affinity and antagonist actions. 5-HT2A receptor homology modeling/docking studies suggest that 10 binds in a manner similar to risperidone and that there is a large cavity to accept various N4-substituted analogues of 10 such as risperidone and related agents. Alterations of this "extended" moiety improve receptor binding and functional potency. We propose a new risperidone-based pharmacophore for 5-HT2A receptor antagonist action.
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Affiliation(s)
- Urjita H. Shah
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, United States
- Department of Medicinal Chemistry, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia 23298, United States
| | - Supriya A. Gaitonde
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, United States
- Department of Medicinal Chemistry, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia 23298, United States
| | - José L. Moreno
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, United States
| | - Richard A. Glennon
- Department of Medicinal Chemistry, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia 23298, United States
| | - Małgorzata Dukat
- Department of Medicinal Chemistry, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia 23298, United States
| | - Javier González-Maeso
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, United States
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16
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Halberstadt AL, Chatha M, Stratford A, Grill M, Brandt SD. Comparison of the behavioral responses induced by phenylalkylamine hallucinogens and their tetrahydrobenzodifuran ("FLY") and benzodifuran ("DragonFLY") analogs. Neuropharmacology 2019; 144:368-376. [PMID: 30385253 PMCID: PMC6863604 DOI: 10.1016/j.neuropharm.2018.10.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/24/2018] [Accepted: 10/27/2018] [Indexed: 01/05/2023]
Abstract
In recent years, rigid analogs of phenylalkylamine hallucinogens have appeared as recreational drugs. Examples include 2-(8-bromo-2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran-4-yl)ethan-1-amine (2C-B-FLY) and 1-(8-bromobenzo[1,2-b;4,5-b']difuran-4-yl)-2-aminopropane (Bromo-DragonFLY, DOB-DFLY). Although some rigid compounds such as DOB-DFLY reportedly have higher potency than their non-rigid counterparts, it is not clear whether the same is true for 2C-B-FLY and other tetrahydrobenzodifurans. In the present study, the head twitch response (HTR), a 5-HT2A receptor-mediated behavior induced by serotonergic hallucinogens, was used to assess the effects of 2,5-dimethoxy-4-bromoamphetamine (DOB) and its α-desmethyl homologue 2,5-dimethoxy-4-bromophenethylamine (2C-B), as well as their benzodifuranyl and tetrahydrobenzodifuranyl analogs, in C57BL/6J mice. DOB (ED50 = 0.75 μmol/kg) and 2C-B (ED50 = 2.43 μmol/kg) induced the HTR. The benzodifurans DOB-DFLY (ED50 = 0.20 μmol/kg) and 2C-B-DFLY (ED50 = 1.07 μmol/kg) had significantly higher potency than DOB and 2C-B, respectively. The tetrahydrobenzodifurans DOB-FLY (ED50 = 0.67 μmol/kg) and 2C-B-FLY (ED50 = 1.79 μmol/kg), by contrast, were approximately equipotent with their non-rigid counterparts. Three novel tetrahydrobenzodifurans (2C-I-FLY, 2C-E-FLY and 2C-EF-FLY) were also active in the HTR assay but had relatively low potency. In summary, the in vivo potency of 2,5-dimethoxyphenylalkylamines is enhanced when the 2- and 5-methoxy groups are incorporated into aromatic furan rings, whereas potency is not altered if the methoxy groups are incorporated into dihydrofuran rings. The potency relationships for these compounds in mice closely parallel the human hallucinogenic data. The high potency of DOB-DFLY is probably linked to the presence of two structural features (a benzodifuran nucleus and an α-methyl group) known to enhance the potency of phenylalkylamine hallucinogens.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA; Research Service, VA San Diego Healthcare System, 3350 La Jolla Village Dr., San Diego, CA, 92161, USA.
| | - Muhammad Chatha
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA
| | | | - Matthias Grill
- Lipomed AG, Fabrikmattenweg 4, CH-4144, Arlesheim, Switzerland
| | - Simon D Brandt
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK
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17
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Dopamine D3 receptor antagonist reveals a cryptic pocket in aminergic GPCRs. Sci Rep 2018; 8:897. [PMID: 29343833 PMCID: PMC5772633 DOI: 10.1038/s41598-018-19345-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/27/2017] [Indexed: 12/20/2022] Open
Abstract
The recent increase in the number of X-ray crystal structures of G-protein coupled receptors (GPCRs) has been enabling for structure-based drug design (SBDD) efforts. These structures have revealed that GPCRs are highly dynamic macromolecules whose function is dependent on their intrinsic flexibility. Unfortunately, the use of static structures to understand ligand binding can potentially be misleading, especially in systems with an inherently high degree of conformational flexibility. Here, we show that docking a set of dopamine D3 receptor compounds into the existing eticlopride-bound dopamine D3 receptor (D3R) X-ray crystal structure resulted in poses that were not consistent with results obtained from site-directed mutagenesis experiments. We overcame the limitations of static docking by using large-scale high-throughput molecular dynamics (MD) simulations and Markov state models (MSMs) to determine an alternative pose consistent with the mutation data. The new pose maintains critical interactions observed in the D3R/eticlopride X-ray crystal structure and suggests that a cryptic pocket forms due to the shift of a highly conserved residue, F6.52. Our study highlights the importance of GPCR dynamics to understand ligand binding and provides new opportunities for drug discovery.
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18
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Abstract
This chapter will summarize structure-activity relationships (SAR) that are known for the classic serotonergic hallucinogens (aka psychedelics), focusing on the three chemical types: tryptamines, ergolines, and phenethylamines. In the brain, the serotonin 5-HT2A receptor plays a key role in regulation of cortical function and cognition, and also appears to be the principal target for hallucinogenic/psychedelic drugs such as LSD. It is one of the most extensively studied of the 14 known types of serotonin receptors. Important structural features will be identified for activity and, where possible, those that the psychedelics have in common will be discussed. Because activation of the 5-HT2A receptor is the principal mechanism of action for psychedelics, compounds with 5-HT2A agonist activity generally are quickly discarded by the pharmaceutical industry. Thus, most of the research on psychedelics can be related to activation of 5-HT2A receptors. Therefore, much of the discussion will include not only clinical or anecdotal studies, but also will consider data from animal models as well as a certain amount of molecular pharmacology where it is known.
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Affiliation(s)
- David E Nichols
- Division of Chemical Biology and Medicinal Chemistry, University of North Carolina, Chapel Hill, NC, 27514, USA.
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19
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Alkozi HA, Sánchez Montero JM, Doadrio AL, Pintor J. Docking studies for melatonin receptors. Expert Opin Drug Discov 2017; 13:241-248. [PMID: 29271261 DOI: 10.1080/17460441.2018.1419184] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Melatonin is a neurohormone that controls many relevant physiological processes beyond the control of circadian rhythms. Melatonin's actions are carried out by two main types of melatonin receptors; MT1 and MT2. These receptors are important, and not just because of the biological actions of its natural agonist; but also, because melatonin analogues can improve or antagonize their biological effect. Area covered: The following article describes the importance of melatonin as a biologically relevant molecule. It also defines the receptors for this substance, as well as the second messengers coupled to these receptors. Lastly, the article describes the amino acid residues involved in the docking process in both MT1 and MT2 melatonin receptors. Expert opinion: The biological actions of melatonin and their interpretations are becoming more relevant and therefore require the development of new pharmacological tools. Understanding the second messenger mechanisms involved in melatonin actions, as well as the characteristics of the docking of this molecule to MT1 and MT2 melatonin receptors, will permit the development of more selective agonists and antagonists which will help us to better understand this molecule as well to develop new therapeutic compounds.
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Affiliation(s)
- Hanan Awad Alkozi
- a Department of Biochemistry and Molecular Biology IV, Faculty of Optometry , Universidad Complutense de Madrid , Madrid , Spain
| | - José Maria Sánchez Montero
- b Department of Organic Chemistry and Pharmaceutical, Faculty of Pharmacy , Ciudad Universitaria , Madrid , Spain
| | - Antonio Luis Doadrio
- c Department of Inorganic Chemistry and Bioorganic, Faculty of Pharmacy , University Complutense of Madrid , Ciudad Universitaria, Madrid , Spain
| | - Jesus Pintor
- a Department of Biochemistry and Molecular Biology IV, Faculty of Optometry , Universidad Complutense de Madrid , Madrid , Spain
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20
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Halberstadt AL. Pharmacology and Toxicology of N-Benzylphenethylamine ("NBOMe") Hallucinogens. Curr Top Behav Neurosci 2017; 32:283-311. [PMID: 28097528 DOI: 10.1007/7854_2016_64] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Serotonergic hallucinogens induce profound changes in perception and cognition. The characteristic effects of hallucinogens are mediated by 5-HT2A receptor activation. One class of hallucinogens are 2,5-dimethoxy-substituted phenethylamines, such as the so-called 2C-X compounds 2,5-dimethoxy-4-bromophenethylamine (2C-B) and 2,5-dimethoxy-4-iodophenethylamine (2C-I). Addition of an N-benzyl group to phenethylamine hallucinogens produces a marked increase in 5-HT2A-binding affinity and hallucinogenic potency. N-benzylphenethylamines ("NBOMes") such as N-(2-methoxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBOMe) show subnanomolar affinity for the 5-HT2A receptor and are reportedly highly potent in humans. Several NBOMEs have been available from online vendors since 2010, resulting in numerous cases of toxicity and multiple fatalities. This chapter reviews the structure-activity relationships, behavioral pharmacology, metabolism, and toxicity of members of the NBOMe hallucinogen class. Based on a review of 51 cases of NBOMe toxicity reported in the literature, it appears that rhabdomyolysis is a relatively common complication of severe NBOMe toxicity, an effect that may be linked to NBOMe-induced seizures, hyperthermia, and vasoconstriction.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0804, USA.
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
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21
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Leth-Petersen S, Petersen IN, Jensen AA, Bundgaard C, Bæk M, Kehler J, Kristensen JL. 5-HT 2A/5-HT 2C Receptor Pharmacology and Intrinsic Clearance of N-Benzylphenethylamines Modified at the Primary Site of Metabolism. ACS Chem Neurosci 2016; 7:1614-1619. [PMID: 27564969 DOI: 10.1021/acschemneuro.6b00265] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The toxic hallucinogen 25B-NBOMe is very rapidly degraded by human liver microsomes and has low oral bioavailability. Herein we report on the synthesis, microsomal stability, and 5-HT2A/5-HT2C receptor profile of novel analogues of 25B-NBOMe modified at the primary site of metabolism. Although microsomal stability could be increased while maintaining potent 5-HT2 receptor agonist properties, all analogues had an intrinsic clearance above 1.3 L/kg/h predictive of high first-pass metabolism.
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Affiliation(s)
- Sebastian Leth-Petersen
- Department of Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 København Ø, Denmark
| | - Ida N. Petersen
- Department of Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 København Ø, Denmark
| | - Anders A. Jensen
- Department of Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 København Ø, Denmark
| | - Christoffer Bundgaard
- Department
of Discovery Chemistry and DMPK, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark
| | - Mathias Bæk
- Department of Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 København Ø, Denmark
| | - Jan Kehler
- Department
of Discovery Chemistry and DMPK, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark
| | - Jesper L. Kristensen
- Department of Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 København Ø, Denmark
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22
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Spasov AA, Yakovlev DS, Maltsev DV, Zhukovskaya ON, Anisimova VA, Kovalev GI, Zimin IA, Morkovina YV. The derivatives of imidazo[1,2-a]benzimidazole as 5-HT2A receptor antagonists. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2016. [DOI: 10.1134/s1068162016040178] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Abstract
Psychedelics (serotonergic hallucinogens) are powerful psychoactive substances that alter perception and mood and affect numerous cognitive processes. They are generally considered physiologically safe and do not lead to dependence or addiction. Their origin predates written history, and they were employed by early cultures in many sociocultural and ritual contexts. After the virtually contemporaneous discovery of (5R,8R)-(+)-lysergic acid-N,N-diethylamide (LSD)-25 and the identification of serotonin in the brain, early research focused intensively on the possibility that LSD and other psychedelics had a serotonergic basis for their action. Today there is a consensus that psychedelics are agonists or partial agonists at brain serotonin 5-hydroxytryptamine 2A receptors, with particular importance on those expressed on apical dendrites of neocortical pyramidal cells in layer V. Several useful rodent models have been developed over the years to help unravel the neurochemical correlates of serotonin 5-hydroxytryptamine 2A receptor activation in the brain, and a variety of imaging techniques have been employed to identify key brain areas that are directly affected by psychedelics. Recent and exciting developments in the field have occurred in clinical research, where several double-blind placebo-controlled phase 2 studies of psilocybin-assisted psychotherapy in patients with cancer-related psychosocial distress have demonstrated unprecedented positive relief of anxiety and depression. Two small pilot studies of psilocybin-assisted psychotherapy also have shown positive benefit in treating both alcohol and nicotine addiction. Recently, blood oxygen level-dependent functional magnetic resonance imaging and magnetoencephalography have been employed for in vivo brain imaging in humans after administration of a psychedelic, and results indicate that intravenously administered psilocybin and LSD produce decreases in oscillatory power in areas of the brain's default mode network.
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Affiliation(s)
- David E Nichols
- Eschelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina
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24
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Nichols DE, Sassano MF, Halberstadt AL, Klein LM, Brandt SD, Elliott SP, Fiedler WJ. N-Benzyl-5-methoxytryptamines as Potent Serotonin 5-HT2 Receptor Family Agonists and Comparison with a Series of Phenethylamine Analogues. ACS Chem Neurosci 2015; 6:1165-75. [PMID: 25547199 PMCID: PMC4505863 DOI: 10.1021/cn500292d] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Indexed: 11/28/2022] Open
Abstract
A series of N-benzylated-5-methoxytryptamine analogues was prepared and investigated, with special emphasis on substituents in the meta position of the benzyl group. A parallel series of several N-benzylated analogues of 2,5-dimethoxy-4-iodophenethylamine (2C-I) also was included for comparison of the two major templates (i.e., tryptamine and phenethylamine). A broad affinity screen at serotonin receptors showed that most of the compounds had the highest affinity at the 5-HT2 family receptors. Substitution at the para position of the benzyl group resulted in reduced affinity, whereas substitution in either the ortho or the meta position enhanced affinity. In general, introduction of a large lipophilic group improved affinity, whereas functional activity often followed the opposite trend. Tests of the compounds for functional activity utilized intracellular Ca(2+) mobilization. Function was measured at the human 5-HT2A, 5-HT2B, and 5-HT2C receptors, as well as at the rat 5-HT2A and 5-HT2C receptors. There was no general correlation between affinity and function. Several of the tryptamine congeners were very potent functionally (EC50 values from 7.6 to 63 nM), but most were partial agonists. Tests in the mouse head twitch assay revealed that many of the compounds induced the head twitch and that there was a significant correlation between this behavior and functional potency at the rat 5-HT2A receptor.
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Affiliation(s)
- David E. Nichols
- Division
of Chemical Biology and Medicinal Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - M. Flori Sassano
- Division
of Chemical Biology and Medicinal Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Adam L. Halberstadt
- Department of Psychiatry, and Department of Neurosciences, University of California San Diego, La Jolla, California 92093, United States
| | - Landon M. Klein
- Department of Psychiatry, and Department of Neurosciences, University of California San Diego, La Jolla, California 92093, United States
| | - Simon D. Brandt
- School
of Pharmacy and Biomolecular Sciences, Liverpool
John Moores University, Byrom Street, Liverpool L3 3AF, U.K.
| | - Simon P. Elliott
- ROAR Forensics, Malvern Hills Science Park, Geraldine Road, Malvern, Worcestershire WR14 3SZ, U.K.
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Ramasamy S, Chin SP, Sukumaran SD, Buckle MJC, Kiew LV, Chung LY. In Silico and In Vitro Analysis of Bacoside A Aglycones and Its Derivatives as the Constituents Responsible for the Cognitive Effects of Bacopa monnieri. PLoS One 2015; 10:e0126565. [PMID: 25965066 PMCID: PMC4428790 DOI: 10.1371/journal.pone.0126565] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 04/03/2015] [Indexed: 12/20/2022] Open
Abstract
Bacopa monnieri has been used in Ayurvedic medicine to improve memory and cognition. The active constituent responsible for its pharmacological effects is bacoside A, a mixture of dammarane-type triterpenoid saponins containing sugar chains linked to a steroid aglycone skeleton. Triterpenoid saponins have been reported to be transformed in vivo to metabolites that give better biological activity and pharmacokinetic characteristics. Thus, the activities of the parent compounds (bacosides), aglycones (jujubogenin and pseudojujubogenin) and their derivatives (ebelin lactone and bacogenin A1) were compared using a combination of in silico and in vitro screening methods. The compounds were docked into 5-HT1A, 5-HT2A, D1, D2, M1 receptors and acetylcholinesterase (AChE) using AutoDock and their central nervous system (CNS) drug-like properties were determined using Discovery Studio molecular properties and ADMET descriptors. The compounds were screened in vitro using radioligand receptor binding and AChE inhibition assays. In silico studies showed that the parent bacosides were not able to dock into the chosen CNS targets and had poor molecular properties as a CNS drug. In contrast, the aglycones and their derivatives showed better binding affinity and good CNS drug-like properties, were well absorbed through the intestines and had good blood brain barrier (BBB) penetration. Among the compounds tested in vitro, ebelin lactone showed binding affinity towards M1 (Ki = 0.45 μM) and 5-HT2A (4.21 μM) receptors. Bacoside A and bacopaside X (9.06 μM) showed binding affinity towards the D1 receptor. None of the compounds showed any inhibitory activity against AChE. Since the stimulation of M1 and 5-HT2A receptors has been implicated in memory and cognition and ebelin lactone was shown to have the strongest binding energy, highest BBB penetration and binding affinity towards M1 and 5-HT2A receptors, we suggest that B. monnieri constituents may be transformed in vivo to the active form before exerting their pharmacological activity.
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Affiliation(s)
- Seetha Ramasamy
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sek Peng Chin
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sri Devi Sukumaran
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | | | - Lik Voon Kiew
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Lip Yong Chung
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- Center for Natural Products and Drug Research (CENAR), University of Malaya, Kuala Lumpur, Malaysia
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Martí-Solano M, Iglesias A, de Fabritiis G, Sanz F, Brea J, Loza MI, Pastor M, Selent J. Detection of New Biased Agonists for the Serotonin 5-HT2A Receptor: Modeling and Experimental Validation. Mol Pharmacol 2015; 87:740-6. [DOI: 10.1124/mol.114.097022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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McCorvy JD, Roth BL. Structure and function of serotonin G protein-coupled receptors. Pharmacol Ther 2015; 150:129-42. [PMID: 25601315 DOI: 10.1016/j.pharmthera.2015.01.009] [Citation(s) in RCA: 224] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 12/12/2014] [Indexed: 12/18/2022]
Abstract
Serotonin receptors are prevalent throughout the nervous system and the periphery, and remain one of the most lucrative and promising drug discovery targets for disorders ranging from migraine headaches to neuropsychiatric disorders such as schizophrenia and depression. There are 14 distinct serotonin receptors, of which 13 are G protein-coupled receptors (GPCRs), which are targets for approximately 40% of the approved medicines. Recent crystallographic and biochemical evidence has provided a converging understanding of the basic structure and functional mechanics of GPCR activation. Currently, two GPCR crystal structures exist for the serotonin family, the 5-HT1B and 5-HT2B receptor, with the antimigraine and valvulopathic drug ergotamine bound. The first serotonin crystal structures not only provide the first evidence of serotonin receptor topography but also provide mechanistic explanations into functional selectivity or biased agonism. This review will detail the findings of these crystal structures from a molecular and mutagenesis perspective for driving rational drug design for novel therapeutics incorporating biased signaling.
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MESH Headings
- Allosteric Site
- Animals
- Ergotamine/pharmacology
- Ergotamine/therapeutic use
- GTP-Binding Proteins/physiology
- Heart Valve Diseases/drug therapy
- Heart Valve Diseases/metabolism
- Humans
- Migraine Disorders/drug therapy
- Migraine Disorders/metabolism
- Models, Molecular
- Protein Conformation
- Receptor, Serotonin, 5-HT1B/chemistry
- Receptor, Serotonin, 5-HT1B/metabolism
- Receptor, Serotonin, 5-HT2B/chemistry
- Receptor, Serotonin, 5-HT2B/metabolism
- Receptors, Serotonin/chemistry
- Receptors, Serotonin/metabolism
- Serotonin Receptor Agonists/pharmacology
- Serotonin Receptor Agonists/therapeutic use
- Signal Transduction
- Vasoconstrictor Agents/pharmacology
- Vasoconstrictor Agents/therapeutic use
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Affiliation(s)
- John D McCorvy
- Department of Pharmacology and Division of Chemical Biology and Medicinal Chemistry, University of North Carolina Chapel Hill Medical School, Chapel Hill, NC 27514, USA
| | - Bryan L Roth
- Department of Pharmacology and Division of Chemical Biology and Medicinal Chemistry, University of North Carolina Chapel Hill Medical School, Chapel Hill, NC 27514, USA
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Isberg V, Paine J, Leth-Petersen S, Kristensen JL, Gloriam DE. Structure-activity relationships of constrained phenylethylamine ligands for the serotonin 5-HT2 receptors. PLoS One 2013; 8:e78515. [PMID: 24244317 PMCID: PMC3820707 DOI: 10.1371/journal.pone.0078515] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 09/18/2013] [Indexed: 11/25/2022] Open
Abstract
Serotonergic ligands have proven effective drugs in the treatment of migraine, pain, obesity, and a wide range of psychiatric and neurological disorders. There is a clinical need for more highly 5-HT2 receptor subtype-selective ligands and the most attention has been given to the phenethylamine class. Conformationally constrained phenethylamine analogs have demonstrated that for optimal activity the free lone pair electrons of the 2-oxygen must be oriented syn and the 5-oxygen lone pairs anti relative to the ethylamine moiety. Also the ethyl linker has been constrained providing information about the bioactive conformation of the amine functionality. However, combined 1,2-constriction by cyclization has only been tested with one compound. Here, we present three new 1,2-cyclized phenylethylamines, 9–11, and describe their synthetic routes. Ligand docking in the 5-HT2B crystal structure showed that the 1,2-heterocyclized compounds can be accommodated in the binding site. Conformational analysis showed that 11 can only bind in a higher-energy conformation, which would explain its absent or low affinity. The amine and 2-oxygen interactions with D3.32 and S3.36, respectively, can form but shift the placement of the core scaffold. The constraints in 9–11 resulted in docking poses with the 4-bromine in closer vicinity to 5.46, which is polar only in the human 5-HT2A subtype, for which 9–11 have the lowest affinity. The new ligands, conformational analysis and docking expand the structure-activity relationships of constrained phenethylamines and contributes towards the development of 5-HT2 receptor subtype-selective ligands.
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Affiliation(s)
- Vignir Isberg
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - James Paine
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sebastian Leth-Petersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jesper L. Kristensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - David E. Gloriam
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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Canal CE, Cordova-Sintjago T, Liu Y, Kim MS, Morgan D, Booth RG. Molecular pharmacology and ligand docking studies reveal a single amino acid difference between mouse and human serotonin 5-HT2A receptors that impacts behavioral translation of novel 4-phenyl-2-dimethylaminotetralin ligands. J Pharmacol Exp Ther 2013; 347:705-16. [PMID: 24080681 DOI: 10.1124/jpet.113.208637] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
During translational studies to develop 4-phenyl-2-dimethylaminotetralin (PAT) compounds for neuropsychiatric disorders, the (2R,4S)-trans-(+)- and (2S,4R)-trans-(-)-enantiomers of the analog 6-hydroxy-7-chloro-PAT (6-OH-7-Cl-PAT) demonstrated unusual pharmacology at serotonin (5-HT) 5-HT2 G protein-coupled receptors (GPCRs). The enantiomers had similar affinities (Ki) at human (h) 5-HT2A receptors (≈ 70 nM). In an in vivo mouse model of 5-HT2A receptor activation [(±)-(2,5)-dimethoxy-4-iodoamphetamine (DOI)-elicited head twitch], however, (-)-6-OH-7-Cl-PAT was about 5-fold more potent than the (+)-enantiomer at attenuating the DOI-elicited response. It was discovered that (+)-6-OH-7-Cl-PAT (only) had ≈ 40-fold-lower affinity at mouse (m) compared with h5-HT2A receptors. Molecular modeling and computational ligand docking studies indicated that the 6-OH moiety of (+)- but not (-)-6-OH-7-Cl-PAT could form a hydrogen bond with serine residue 5.46 of the h5-HT2A receptor. The m5-HT2A as well as m5-HT2B, h5-HT2B, m5-HT2C, and h5-HT2C receptors have alanine at position 5.46, obviating this interaction; (+)-6-OH-7-Cl-PAT also showed ≈ 50-fold lower affinity than (-)-6-OH-7-Cl-PAT at m5-HT2C and h5-HT2C receptors. Mutagenesis studies confirmed that 5-HT2A S5.46 is critical for (+)- but not (-)-6-OH-7-Cl-PAT binding, as well as function. The (+)-6-OH-7-Cl-PAT enantiomer showed partial agonist effects at h5-HT2A wild-type (WT) and m5-HT2A A5.46S point-mutated receptors but did not activate m5-HT2A WT and h5-HT2A S5.46A point-mutated receptors, or h5-HT2B, h5-HT2C, and m5-HT2C receptors; (-)-6-OH-7-Cl-PAT did not activate any of the 5-HT2 receptors. Experiments also included the (2R,4S)-trans-(+)- and (2S,4R)-trans-(-)-enantiomers of 6-methoxy-7-chloro-PAT to validate hydrogen bonding interactions proposed for the corresponding 6-OH analogs. Results indicate that PAT ligand three-dimensional structure impacts target receptor binding and translational outcomes, supporting the hypothesis that GPCR ligand structure governs orthosteric binding pocket molecular determinants and resulting pharmacology.
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Affiliation(s)
- Clinton E Canal
- Center for Drug Discovery (C.E.C., T.C.-S., Y.L., R.G.B.), Department of Pharmaceutical Sciences (C.E.C., T.C.-S., Y.L., R.G.B.), and Department of Chemistry and Chemical Biology (R.G.B.), Northeastern University, Boston, Massachusetts; and Department of Medicinal Chemistry (M.S.K., T.C.-S.) and Department of Psychiatry (D.M.), University of Florida, Gainesville, Florida
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30
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Homology models of melatonin receptors: challenges and recent advances. Int J Mol Sci 2013; 14:8093-121. [PMID: 23584026 PMCID: PMC3645733 DOI: 10.3390/ijms14048093] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 03/28/2013] [Accepted: 03/28/2013] [Indexed: 12/15/2022] Open
Abstract
Melatonin exerts many of its actions through the activation of two G protein-coupled receptors (GPCRs), named MT1 and MT2. So far, a number of different MT1 and MT2 receptor homology models, built either from the prototypic structure of rhodopsin or from recently solved X-ray structures of druggable GPCRs, have been proposed. These receptor models differ in the binding modes hypothesized for melatonin and melatonergic ligands, with distinct patterns of ligand-receptor interactions and putative bioactive conformations of ligands. The receptor models will be described, and they will be discussed in light of the available information from mutagenesis experiments and ligand-based pharmacophore models. The ability of these ligand-receptor complexes to rationalize structure-activity relationships of known series of melatonergic compounds will be commented upon.
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31
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Wang C, Jiang Y, Ma J, Wu H, Wacker D, Katritch V, Han GW, Liu W, Huang XP, Vardy E, McCorvy JD, Gao X, Zhou XE, Melcher K, Zhang C, Bai F, Yang H, Yang L, Jiang H, Roth BL, Cherezov V, Stevens RC, Xu HE. Structural basis for molecular recognition at serotonin receptors. Science 2013; 340:610-4. [PMID: 23519210 DOI: 10.1126/science.1232807] [Citation(s) in RCA: 385] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Serotonin or 5-hydroxytryptamine (5-HT) regulates a wide spectrum of human physiology through the 5-HT receptor family. We report the crystal structures of the human 5-HT1B G protein-coupled receptor bound to the agonist antimigraine medications ergotamine and dihydroergotamine. The structures reveal similar binding modes for these ligands, which occupy the orthosteric pocket and an extended binding pocket close to the extracellular loops. The orthosteric pocket is formed by residues conserved in the 5-HT receptor family, clarifying the family-wide agonist activity of 5-HT. Compared with the structure of the 5-HT2B receptor, the 5-HT1B receptor displays a 3 angstrom outward shift at the extracellular end of helix V, resulting in a more open extended pocket that explains subtype selectivity. Together with docking and mutagenesis studies, these structures provide a comprehensive structural basis for understanding receptor-ligand interactions and designing subtype-selective serotonergic drugs.
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Affiliation(s)
- Chong Wang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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32
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Munusamy V, Yap BK, Buckle MJC, Doughty SW, Chung LY. Structure-Based Identification of Aporphines with Selective 5-HT2AReceptor-Binding Activity. Chem Biol Drug Des 2012; 81:250-6. [DOI: 10.1111/cbdd.12069] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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33
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Canal CE, Morgan D. Head-twitch response in rodents induced by the hallucinogen 2,5-dimethoxy-4-iodoamphetamine: a comprehensive history, a re-evaluation of mechanisms, and its utility as a model. Drug Test Anal 2012; 4:556-76. [PMID: 22517680 DOI: 10.1002/dta.1333] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 01/09/2012] [Accepted: 01/10/2012] [Indexed: 11/06/2022]
Abstract
Two primary animal models persist for assessing hallucinogenic potential of novel compounds and for examining the pharmacological and neurobiological substrates underlying the actions of classical hallucinogens, the two-lever drug discrimination procedure and the drug-induced head-twitch response (HTR) in rodents. The substituted amphetamine hallucinogen, serotonin 2 (5-HT(2) ) receptor agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI) has emerged as the most popular pharmacological tool used in HTR studies of hallucinogens. Synthesizing classic, recent, and relatively overlooked findings, addressing ostensibly conflicting observations, and considering contemporary theories in receptor and behavioural pharmacology, this review provides an up-to-date and comprehensive synopsis of DOI and the HTR model, from neural mechanisms to utility for understanding psychiatric diseases. Also presented is support for the argument that, although both the two-lever drug discrimination and the HTR models in rodents are useful for uncovering receptors, interacting proteins, intracellular signalling pathways, and neurochemical processes affected by DOI and related classical hallucinogens, results from both models suggest they are not reporting hallucinogenic experiences in animals.
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Affiliation(s)
- Clint E Canal
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA.
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Ligand-dependent conformations and dynamics of the serotonin 5-HT(2A) receptor determine its activation and membrane-driven oligomerization properties. PLoS Comput Biol 2012; 8:e1002473. [PMID: 22532793 PMCID: PMC3330085 DOI: 10.1371/journal.pcbi.1002473] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 02/26/2012] [Indexed: 11/19/2022] Open
Abstract
From computational simulations of a serotonin 2A receptor (5-HT2AR) model complexed with pharmacologically and structurally diverse ligands we identify different conformational states and dynamics adopted by the receptor bound to the full agonist 5-HT, the partial agonist LSD, and the inverse agonist Ketanserin. The results from the unbiased all-atom molecular dynamics (MD) simulations show that the three ligands affect differently the known GPCR activation elements including the toggle switch at W6.48, the changes in the ionic lock between E6.30 and R3.50 of the DRY motif in TM3, and the dynamics of the NPxxY motif in TM7. The computational results uncover a sequence of steps connecting these experimentally-identified elements of GPCR activation. The differences among the properties of the receptor molecule interacting with the ligands correlate with their distinct pharmacological properties. Combining these results with quantitative analysis of membrane deformation obtained with our new method (Mondal et al, Biophysical Journal 2011), we show that distinct conformational rearrangements produced by the three ligands also elicit different responses in the surrounding membrane. The differential reorganization of the receptor environment is reflected in (i)-the involvement of cholesterol in the activation of the 5-HT2AR, and (ii)-different extents and patterns of membrane deformations. These findings are discussed in the context of their likely functional consequences and a predicted mechanism of ligand-specific GPCR oligomerization. The 5-HT2A receptor for the neurotransmitter serotonin (5-HT) belongs to family A (rhodopsin-like) G-protein coupled receptors (GPCRs), one of the most important classes of membrane proteins that are targeted by an extensive and diverse collection of external stimuli. Recently we learned that different ligands targeting the same GPCR can elicit different biological responses, but the mechanisms remain unknown. We address this fundamental question for the serotonin 5-HT2A receptor, because it is known to respond to the binding of structurally diverse ligands by producing similar stimuli in the cell, and to the binding of quite similar ligands with dramatically different responses. Molecular dynamics simulations of molecular models of the serotonin 5-HT2A receptor in complex with pharmacologically distinct ligands show the dynamic rearrangements of the receptor molecule to be different for these ligands, and the nature and extents of the rearrangements reflect the known pharmacological properties of the ligands as full, partial or inverse activators of the receptor. The different rearrangements of the receptor molecule are shown to produce different rearrangements of the surrounding membrane, a remodeling of the environment that can have differential ligand-determined effects on receptor function and association in the cell's membrane.
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35
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36
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Trachsel D. Fluorine in psychedelic phenethylamines. Drug Test Anal 2012; 4:577-90. [DOI: 10.1002/dta.413] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 12/13/2011] [Accepted: 12/13/2011] [Indexed: 12/15/2022]
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Homology modeling of the human 5-HT1A, 5-HT2A, D1, and D2 receptors: model refinement with molecular dynamics simulations and docking evaluation. J Mol Model 2012; 18:3639-55. [DOI: 10.1007/s00894-012-1368-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 01/23/2012] [Indexed: 12/22/2022]
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Canal CE, Cordova-Sintjago TC, Villa NY, Fang LJ, Booth RG. Drug discovery targeting human 5-HT(2C) receptors: residues S3.36 and Y7.43 impact ligand-binding pocket structure via hydrogen bond formation. Eur J Pharmacol 2011; 673:1-12. [PMID: 22020288 DOI: 10.1016/j.ejphar.2011.10.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 09/27/2011] [Accepted: 10/02/2011] [Indexed: 11/28/2022]
Abstract
Specific activation of serotonin (5-HT) 5-HT(2C) G protein-coupled receptors may be therapeutic for obesity and neuropsychiatric disorders. Mutagenesis coupled with computational and molecular modeling experiments based on the human β₂ adrenergic receptor structure was employed to delineate the interactions of different ligands at human 5-HT(2C) residues D3.32, S3.36 and Y7.43. No binding of the tertiary amine radioligand ([³H]-mesulergine) could be detected when the 5-HT(2C) D3.32 residue was mutated to alanine (D3.32A). The S3.36A point-mutation greatly reduced affinity of primary amine ligands, modestly reduced affinity of a secondary amine, and except for the 5-HT(2C)-specific agonist N(CH₃)₂-PAT, affinity of tertiary amines was unaffected. Molecular modeling results indicated that the primary amines form hydrogen bonds with the S3.36 residue, whereas, with the exception of N(CH₃)₂-PAT, tertiary amines do not interact considerably with this residue. The Y7.43A point-mutation greatly reduced affinity of 5-HT, yet reduced to a lesser extent the affinity of tryptamine that lacks the 5-hydroxy moiety present in 5-HT; modeling results indicated that the 5-HT 5-hydroxy moiety hydrogen bonds with Y7.43 at the 5-HT(2C) receptor. Additional modeling results showed that 5-HT induced a hydrogen bond between Y7.43 and D3.32. Finally, modeling results revealed two low-energy binding modes for 5-HT in the 5-HT(2C) binding pocket, supporting the concept that multiple agonist binding modes may stabilize different receptor active conformations to influence signaling. Ligand potencies for modulating WT and point-mutated 5-HT(2C) receptor-mediated phospholipase C activity were in accordance with the affinity data. Ligand efficacies, however, were altered considerably by the S3.36A mutation only.
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Affiliation(s)
- Clinton E Canal
- Department of Medicinal Chemistry, University of Florida, P.O. Box 100485, 1600 SW Archer Road, Gainesville, FL 32610-0485, USA
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Dougherty JP, Aloyo VJ. Pharmacological and behavioral characterization of the 5-HT2A receptor in C57BL/6N mice. Psychopharmacology (Berl) 2011; 215:581-93. [PMID: 21340474 DOI: 10.1007/s00213-011-2207-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 01/27/2011] [Indexed: 11/30/2022]
Abstract
RATIONALE The serotonin (5-HT) 2A receptor is implicated in numerous psychiatric disorders, making it an important, clinically relevant target. Despite the availability of transgenic mouse lines, the native mouse 5-HT(2A) receptor is not well-characterized. OBJECTIVES The goals of the current study were to determine 5-HT(2A) and 5-HT(2C) receptor densities in mouse cortex, establish a pharmacological profile of the mouse 5-HT(2A) receptor, and determine the effects of chronic drug treatment on 5-HT(2A) receptor density and 5-HT(2A) receptor-mediated behavior. METHODS Receptor densities were determined in cortex and frontal cortex via saturation binding assays using [(3)H]ketanserin or [(3)H]mesulergine. A pharmacological profile was established by displacing [(3)H]ketanserin binding with several ligands. Chronic treatment with 5-HT(2A/2C) receptor agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI), 5-HT(2A) receptor antagonist, MDL 11939, or vehicle was followed by 5-HT(2A) receptor density determination. Head twitch responses (HTRs) were counted on select days. RESULTS Mice had high 5-HT(2A), but low 5-HT(2C) receptor densities. Ligand binding affinities for mouse 5-HT(2A) receptors correlated with rat, but not rabbit or human, affinities. Chronically DOI-treated mice displayed reduced HTRs and 5-HT(2A) receptor density compared to saline-treated mice. Receptor density was unchanged following chronic treatment with MDL 11939. CONCLUSIONS The current study provides some basic information about mouse 5-HT(2A) and 5-HT(2C) receptors and provides comparisons to rats, rabbits, and humans. The current chronic agonist treatment study demonstrated an important similarity between the 5-HT(2A) receptor in mice, rats, and rabbits, while antagonist treatment revealed an interesting difference from previous studies in rabbits.
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Affiliation(s)
- John P Dougherty
- Drexel University College of Medicine, Philadelphia, PA 19102, USA.
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40
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Molecular dynamics simulations and docking studies on 3D models of the heterodimeric and homodimeric 5-HT2A receptor subtype. Future Med Chem 2011; 3:665-81. [DOI: 10.4155/fmc.11.27] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: G-protein coupled receptors may exist as functional homodimers, heterodimers and even as higher aggregates. In this work, we investigate the 5-HT2A receptor, which is a known target for antipsychotic drugs. Recently, 5-HT2A has been shown to form functional homodimers and heterodimers with the mGluR2 receptor. The objective of this study is to build up 3D models of the 5-HT2A/mGluR2 heterodimer and of the 5-HT2A-5-HT2A homodimer, and to evaluate the impact of the dimerization interface on the shape of the 5-HT2A binding pocket by using molecular dynamics simulations and docking studies. Results and discussion: The heterodimer, homodimer and monomeric 5-HT2A receptors were simulated by molecular dynamics for 40 ns each. The trajectories were clustered and representative structures of six clusters for each system were generated. Inspection of the these representative structures clearly indicate an effect of the dimerization interface on the topology of the binding pocket. Docking studies allowed to generate receiver operating characteristic curves for a set of 5-HT2A ligands, indicating that different complexes prefer different classes of 5-HT2A ligands. Conclusion: This study clearly indicates that the presence of a dimerization interface must explicitly be considered when studying G-protein coupled receptors known to exist as dimers. Molecular dynamics simulation and cluster analysis are appropriate tools to study the phenomenon.
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Ísberg V, Balle T, Sander T, Jørgensen FS, Gloriam DE. G Protein- and Agonist-Bound Serotonin 5-HT2A Receptor Model Activated by Steered Molecular Dynamics Simulations. J Chem Inf Model 2011; 51:315-25. [DOI: 10.1021/ci100402f] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Vignir Ísberg
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Thomas Balle
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Tommy Sander
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Flemming Steen Jørgensen
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - David E. Gloriam
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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Varin T, Gutiérrez-de-Terán H, Castro M, Brea J, Fabis F, Dauphin F, Åqvist J, Lepailleur A, Perez P, Burgueño J, Vela JM, Loza MI, Rodrigo J. Phe369(7.38) at human 5-HT(7) receptors confers interspecies selectivity to antagonists and partial agonists. Br J Pharmacol 2010; 159:1069-81. [PMID: 19922537 PMCID: PMC2839265 DOI: 10.1111/j.1476-5381.2009.00481.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Revised: 07/22/2009] [Accepted: 07/31/2009] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Human and rat 5-HT(7) receptors were studied with a particular emphasis on the molecular interactions involved in ligand binding, searching for an explanation to the interspecies selectivity observed for a set of compounds. We performed affinity studies, molecular modelling and site-directed mutagenesis, with special focus on residue Phe(7.38) of the human 5-HT(7) receptor [Cys(7.38) in rat]. EXPERIMENTAL APPROACH Competition binding studies were performed for seven 5-HT(7) receptor ligands at three different 5-HT(7) receptors. The functional behaviour was evaluated by measuring 5-carboxytryptamine-stimulated cAMP production. Computational simulations were carried out to explore the structural bases in ligand binding observed for these compounds. KEY RESULTS Competition experiments showed a remarkable selectivity for the human receptor when compared with the rat receptor. These results indicate that mutating Cys to Phe at position 7.38 profoundly affects the binding affinities at the 5-HT(7) receptor. Computational simulations provide a structural interpretation for this key finding. Pharmacological characterization of compounds mr25020, mr25040 and mr25053 revealed a competitive antagonistic behaviour. Compounds mr22423, mr22433, mr23284 and mr25052 behaved as partial agonists. CONCLUSIONS AND IMPLICATIONS We propose that the interspecies difference in binding affinities observed for the compounds at human and rat 5-HT(7) receptors is due to the nature of the residue at position 7.38. Our molecular modelling simulations suggest that Phe(7.38) in the human receptor is integrated in the hydrophobic pocket in the central part of the binding site [Phe(6.51)-Phe(6.52)] and allows a tighter binding of the ligands when compared with the rat receptor.
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Affiliation(s)
- Thibault Varin
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
| | - Hugo Gutiérrez-de-Terán
- Fundación Pública Galega de Medicina Xenómica, Hospital Clínico Universitario de SantiagoSantiago de Compostela, Spain
| | - Marián Castro
- BioFarma Research Group, Departamento de Farmacoloxia, Facultade de Farmacia, Instituto de Farmacia Industrial, Universidade de Santiago de CompostelaSantiago de Compostela, Spain
| | - José Brea
- BioFarma Research Group, Departamento de Farmacoloxia, Facultade de Farmacia, Instituto de Farmacia Industrial, Universidade de Santiago de CompostelaSantiago de Compostela, Spain
| | - Frederic Fabis
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
| | - François Dauphin
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
| | - Johan Åqvist
- Department of Cell and Molecular Biology, Uppsala UniversityUppsala, Sweden
| | - Alban Lepailleur
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
| | - Pilar Perez
- Department of Pharmacology, Laboratorios EsteveBarcelona, Spain
| | - Javier Burgueño
- Department of Pharmacology, Laboratorios EsteveBarcelona, Spain
| | | | - Maria Isabel Loza
- BioFarma Research Group, Departamento de Farmacoloxia, Facultade de Farmacia, Instituto de Farmacia Industrial, Universidade de Santiago de CompostelaSantiago de Compostela, Spain
| | - Jordi Rodrigo
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), UFR des Sciences Pharmaceutiques, Université de Caen Basse-NormandieCaen, France
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McRobb FM, Capuano B, Crosby IT, Chalmers DK, Yuriev E. Homology Modeling and Docking Evaluation of Aminergic G Protein-Coupled Receptors. J Chem Inf Model 2010; 50:626-37. [DOI: 10.1021/ci900444q] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Fiona M. McRobb
- Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052 Australia
| | - Ben Capuano
- Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052 Australia
| | - Ian T. Crosby
- Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052 Australia
| | - David K. Chalmers
- Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052 Australia
| | - Elizabeth Yuriev
- Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052 Australia
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Halberstadt AL, Nichols DE. Serotonin and Serotonin Receptors in Hallucinogen Action. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2010. [DOI: 10.1016/s1569-7339(10)70103-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Miller KJ, Wu GY, Varnes JG, Levesque P, Li J, Li D, Robl JA, Rossi KA, Wacker DA. Position 5.46 of the serotonin 5-HT2A receptor contributes to a species-dependent variation for the 5-HT2C agonist (R)-9-ethyl-1,3,4,10b-tetrahydro-7-trifluoromethylpyrazino[2,1-a]isoindol-6(2H)-one: impact on selectivity and toxicological evaluation. Mol Pharmacol 2009; 76:1211-9. [PMID: 19767451 DOI: 10.1124/mol.109.059204] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Successful development of 5-HT(2C) agonists requires selectivity versus the highly homologous 5-HT(2A) receptor, because agonism at this receptor can result in significant adverse events. (R)-9-Ethyl-1,3,4,10b-tetrahydro-7-trifluoromethylpyrazino[2,1-a]isoindol-6(2H)-one (compound 1) is a potent 5-HT(2C) agonist exhibiting selectivity over the human 5-HT(2A) receptor. Evaluation of the compound at the rat 5-HT(2A) receptor, however, revealed potent binding and agonist functional activity. The physiological consequence of this higher potency was the observation of a significant increase in blood pressure in conscious telemeterized rats that could be prevented by ketanserin. Docking of compound 1 in a homology model of the 5-HT(2A) receptor indicated a possible binding mode in which the ethyl group at the 9-position of the molecule was oriented toward position 5.46 of the 5-HT(2A) receptor. Within the human 5-HT(2A) receptor, position 5.46 is Ser242; however, in the rat 5-HT(2A) receptor, it is Ala242, suggesting that the potent functional activity in this species resulted from the absence of the steric bulk provided by the -OH moiety of the Ser in the human isoform. We confirmed this hypothesis using site-directed mutagenesis through the mutation of both the human receptor Ser242 to Ala and the rat receptor Ala242 to Ser, followed by radioligand binding and second messenger studies. In addition, we attempted to define the space allowed by the alanine by evaluating compounds with larger substitutions at the 9-position. The data indicate that position 5.46 contributed to the species difference in 5-HT(2A) receptor potency observed for a pyrazinoisoindolone compound, resulting in the observation of a significant cardiovascular safety signal.
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Affiliation(s)
- Keith J Miller
- Obesity Department, HPW 2.03, Bristol-Myers Squibb, P.O. Box 5400, Princeton, NJ 08543-5400, USA.
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Kanagarajadurai K, Malini M, Bhattacharya A, Panicker MM, Sowdhamini R. Molecular modeling and docking studies of human 5-hydroxytryptamine 2A (5-HT2A) receptor for the identification of hotspots for ligand binding. MOLECULAR BIOSYSTEMS 2009; 5:1877-88. [PMID: 19763327 DOI: 10.1039/b906391a] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The serotonergic system has been implicated in emotional and cognitive function. In particular, 5-HT(2A) (5-hydroxytrytamine receptor 2A) is attributed to a number of disorders like schizophrenia, depression, eating disorders and anxiety. 5-HT(2A), being a GPCR (G-protein coupled receptor), is important in the pharmaceutical industry as a proven target for these disorders. Despite their extensive clinical importance, the structural studies of this protein is lacking due to difficulties in determining its crystal structure. We have performed sequence analysis and molecular modeling of 5-HT(2A) that has revealed a set of conserved residues and motifs considered to play an important role in maintaining structural integrity and function of the receptor. The analysis also revealed a set of residues specific to the receptor which distinguishes them from other members of the subclass and their orthologs. Further, starting from the model structure of human 5-HT(2A) receptor, docking studies were attempted to envisage how it might interact with eight of its ligands (such as serotonin, dopamine, DOI, LSD, haloperidol, ketanserin, risperidone and clozapine). The binding studies of dopamine to 5-HT(2A) receptor can bring up better understanding in the etiology of a number of neurological disorders involving both these two receptors. Our sequence analysis and study of interactions of this receptor with other ligands reveal additional residue hotspots such as Asn 363 and Tyr 370. The function of these residues can be further analyzed by rational design of site-directed mutagenesis. Two distinct binding sites are identified which could play important roles in ligand binding and signaling.
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Bruno A, Guadix AE, Costantino G. Molecular dynamics simulation of the heterodimeric mGluR2/5HT(2A) complex. An atomistic resolution study of a potential new target in psychiatric conditions. J Chem Inf Model 2009; 49:1602-16. [PMID: 19422244 DOI: 10.1021/ci900067g] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Homo- and heterodimerization is becoming an assessed concept in G-protein coupled receptor (GPCR) pharmacology, and the notion that GPCRs may dimerize or oligomerize is allowing for a reinterpretation of some inconsistencies or anomalies and is providing medicinal chemists with potentially relevant novel molecular targets for a variety of therapeutic conditions. Recently, it has been reported that two unrelated GPCRs, namely class C metabotropic glutamate receptor type-2 (mGluR2) and class A 5HT(2A) serotoninergic receptor, can heterodimerize at the transmembrane domain level. We performed a 40 ns molecular dynamics simulation of the mGluR2/5HT(2A) heterocomplex constructed around a TM4/TM5 interface and embedded in an explicit phospholipidic bilayer surrounded by water molecules. In a separate experiment, the monomeric 5HT(2A) receptor was simulated for additional 40 ns under the same conditions. The analysis and the comparison of the two simulations allowed us to clearly identify a cross-talk between the two protomers and to put forward an effect of the heterodimerization on the shape of the binding pocket of 5HT(2A). This result provides the first molecular explanation for the reported allosteric effect of mGluR2 on 5HT(2A)-mediated response and suggests that the heterocomplex can be a more suitable target for in silico screening than the monomeric protomers.
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Affiliation(s)
- Agostino Bruno
- Dipartimento Farmaceutico, Via G. P. Usberti 27/A- Campus Universitario, Universita degli Studi di Parma, 43124 Parma, Italy
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Blaazer A, Smid P, Kruse C. Structure-Activity Relationships of Phenylalkylamines as Agonist Ligands for 5-HT2AReceptors. ChemMedChem 2008; 3:1299-309. [DOI: 10.1002/cmdc.200800133] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Schultz DM, Prescher JA, Kidd S, Marona-Lewicka D, Nichols DE, Monte A. 'Hybrid' benzofuran-benzopyran congeners as rigid analogs of hallucinogenic phenethylamines. Bioorg Med Chem 2008; 16:6242-51. [PMID: 18467103 PMCID: PMC2601679 DOI: 10.1016/j.bmc.2008.04.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Accepted: 04/14/2008] [Indexed: 10/22/2022]
Abstract
Phenylalkylamines that possess conformationally rigidified furanyl moieties in place of alkoxy arene ring substituents have been shown previously to possess the highest affinities and agonist functional potencies at the serotonin 5-HT(2A) receptor among this chemical class. Further, affinity declines when both furanyl rings are expanded to the larger dipyranyl ring system. The present paper reports the synthesis and pharmacological evaluation of a series of 'hybrid' benzofuranyl-benzopyranyl phenylalkylamines to probe further the sizes of the binding pockets within the serotonin 5-HT(2A) agonist binding site. Thus, 4(a-b), 5(a-b), and 6 were prepared as homologs of the parent compound, 8-bromo-1-(2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran-4-yl)-2-aminopropane 2, and their affinity, functional potency, and intrinsic activity were assessed using cells stably expressing the rat 5-HT(2A) receptor. The behavioral pharmacology of these new analogs was also evaluated in the two-lever drug discrimination paradigm. Although all of the hybrid isomers had similar, nanomolar range receptor affinities, those with the smaller furanyl ring at the arene 2-position (4a-b) displayed a 4- to 15-fold greater functional potency than those with the larger pyranyl ring at that position (5a-b). When the furan ring of the more potent agonist 4b was aromatized to give 6, a receptor affinity similar to the parent difuranyl compound 2 was attained, along with a functional potency equivalent to 2, 4a, and 4b. In drug discrimination experiments using rats trained to discriminate LSD from saline, 4b was more than two times more potent than 5b, with the latter having a potency similar to the classic hallucinogenic amphetamine 1 (DOB).
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Affiliation(s)
- Danielle M. Schultz
- Department of Chemistry, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, Wisconsin 54601
| | - Jennifer A. Prescher
- Department of Chemistry, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, Wisconsin 54601
| | - Stephanie Kidd
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907
| | - Danuta Marona-Lewicka
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907
| | - David E. Nichols
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47907
| | - Aaron Monte
- Department of Chemistry, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, Wisconsin 54601
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Affiliation(s)
- David E Nichols
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Purdue University, West Lafayette, Indiana 47906-2091, USA.
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