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Soares BA, Yempala T, Martínez-Afani D, Acevedo-Fuentes W, Brea J, Loza MI, Cimadevila M, Cassels BK. Effect of Bulky N-Dibenzofuranylmethyl Substitution on the 5-HT 2 Receptor Affinity and Efficacy of a Psychedelic Phenethylamine. ACS Chem Neurosci 2024; 15:608-616. [PMID: 38241462 DOI: 10.1021/acschemneuro.3c00639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024] Open
Abstract
The introduction of arylmethyl substituents on the amine nitrogen atom of phenethylamines and tryptamines often results in profound increases in their affinity and functional activity at 5-HT2 serotonin receptors. To probe the sensitivity of this effect to substantially larger N-substituents, ten derivatives of the well-characterized psychedelic phenethylamine 2C-B were prepared by appending different dibenzo[b,d]furylmethyl (DBFM) moieties to the basic nitrogen. The DBFM group attached to the amino group through its 1-, -2-, or 3-position decreased affinity and agonist activity at the 5-HT2A/2C receptors. Substitution through the 4-position usually favored affinity for all three 5-HT2 receptor subtypes with compound 5 exhibiting 10- and 40-fold higher affinities at the 5-HT2A and 5-HT2C receptors, respectively, but less than fourfold selectivity among the three receptor subtypes. Nevertheless, all were relatively weak partial 5-HT2AR agonists, mostly in the low micromolar range, but full or nearly full agonists at the 5-HT2C subtype as determined in a calcium mobilization assay. Molecular docking simulations suggested that the dibenzofuryl portion dives more deeply into the orthosteric binding site of the 5-HT2A than the 5-HT2C receptor, interacting with the Trp3366.48 toggle switch associated with its activation, while the phenylamine moiety lies close to the extracellular side of the receptor. In conclusion, a very bulky N-substituent on a phenethylamine 5-HT2 receptor agonist is tolerated and may increase affinity if its orientation is appropriate. However, the Gq protein-mediated potencies are generally low, with low efficacy (relative to 5-HT) at the 5-HT2A receptor, somewhat higher efficacy at the 5-HT2B subtype, and full or nearly full efficacy at the 5-HT2C subtype.
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Affiliation(s)
- Breno A Soares
- Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 780003, Chile
- Institute of Exact and Technological Sciences, Federal University of Jataí, Jataí 75804 Goiás, Brazil
| | - Thirumal Yempala
- Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 780003, Chile
| | - Darío Martínez-Afani
- Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 780003, Chile
| | | | - José Brea
- Biofarma Research Group, CiMUS, Departamento de Farmacología, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago 15705, Spain
| | - María Isabel Loza
- Biofarma Research Group, CiMUS, Departamento de Farmacología, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago 15705, Spain
| | - Marta Cimadevila
- Biofarma Research Group, CiMUS, Departamento de Farmacología, Facultad de Farmacia, Universidade de Santiago de Compostela, Santiago 15705, Spain
| | - Bruce K Cassels
- Department of Chemistry, Faculty of Sciences, University of Chile, Santiago 780003, Chile
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Benhadda A, Delhaye C, Moutkine I, Marques X, Russeau M, Le Magueresse C, Roumier A, Lévi S, Maroteaux L. 5-HT 1A and 5-HT 2B receptor interaction and co-clustering regulate serotonergic neuron excitability. iScience 2023; 26:107401. [PMID: 37575185 PMCID: PMC10415917 DOI: 10.1016/j.isci.2023.107401] [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: 04/03/2023] [Revised: 05/26/2023] [Accepted: 07/12/2023] [Indexed: 08/15/2023] Open
Abstract
Many psychiatric diseases have been associated with serotonin (5-HT) neuron dysfunction. The firing of 5-HT neurons is known to be under 5-HT1A receptor-mediated autoinhibition, but functional consequences of coexpressed receptors are unknown. Using co-immunoprecipitation, BRET, confocal, and super-resolution microscopy in hippocampal and 5-HT neurons, we present evidence that 5-HT1A and 5-HT2B receptors can form heterodimers and co-cluster at the plasma membrane of dendrites. Selective agonist stimulation of coexpressed 5-HT1A and 5-HT2B receptors prevents 5-HT1A receptor internalization and increases 5-HT2B receptor membrane clustering. Current clamp recordings of 5-HT neurons revealed that 5-HT1A receptor stimulation of acute slices from mice lacking 5-HT2B receptors in 5-HT neurons increased their firing activity trough Ca2+-activated potassium channel inhibition compared to 5-HT neurons from control mice. This work supports the hypothesis that the relative expression of 5-HT1A and 5-HT2B receptors tunes the neuronal excitability of serotonergic neurons through potassium channel regulation.
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Affiliation(s)
- Amina Benhadda
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
| | - Célia Delhaye
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
| | - Imane Moutkine
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
| | - Xavier Marques
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
| | - Marion Russeau
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
| | - Corentin Le Magueresse
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
| | - Anne Roumier
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
| | - Sabine Lévi
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
| | - Luc Maroteaux
- Institut du Fer à Moulin, U1270 INSERM, Sorbonne Université, 17 rue du Fer à Moulin, 75005 Paris, France
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