TAAR1 dependent and independent actions of the potential antipsychotic and dual TAAR1/5-HT

Saarinen, M., Mantas, I., Flais, I., Ågren, R., Sahlholm, K., Millan, M. J. and Svenningsson, P. (2022) TAAR1 dependent and independent actions of the potential antipsychotic and dual TAAR1/5-HT. Neuropsychopharmacology, 47(13), pp. 2319-2329. (doi: 10.1038/s41386-022-01421-2) (PMID:36100653)

[img] Text
281126.pdf - Published Version
Available under License Creative Commons Attribution.



SEP-383856 (SEP-856) is a novel antipsychotic under clinical development. It displays a unique pattern of receptor interaction, with only weak (partial agonist) activity at dopamine D2 receptors, yet more potent agonist activity at the trace amine associated receptor (TAAR1) and 5-hydroxytryptamine 1 A receptor (5-HT1A). Nonetheless, these observations await independent confirmation and more detailed characterization of the in vitro and in vivo actions of SEP-856 at TAAR1 and 5-HT1A receptors would be instructive. Herein, we employed luminescence complementation technology in heterologous live cell systems, confocal microscopy, voltage clamp electrophysiology, behavioral readouts and TAAR1 knockout (KO) mice to study SEP-856 in further detail. We provide evidence for the ability of SEP-856 to activate TAAR1 at the surface plasma membrane, and show that this interaction results in Gαs recruitment (pEC50: 6.08 ± 0.22 EMAX: 96.41% ± 15.26) and by extension, to G-protein inwardly rectifying potassium (GIRK) channel activation. Using TAAR1-KO mice, we find TAAR1 to be indispensable for SEP-856 control of body temperature, baseline locomotion reduction and for “antipsychotic-like” efficacy as characterized by a reversal of dizocilipine (MK-801) mediated disruption of pre-pulse inhibition. Conversely, the inhibition by SEP-856 of MK-801 induced locomotion was unaffected in TAAR1 KO mice. SEP-856 behaved as a low-potency, partial agonist at the 5-HT1A receptor, while it partially inhibited recruitment of D2 receptor-coupled Gα and GIRK by DA and acted as a weak partial agonist with low potency at the same receptor when applied alone. Our findings corroborate and extend previous observations on the molecular substrates engaged by this unique, dual TAAR1/5-HT1A receptor agonist and potential antipsychotic that could prove to have major advantages in the treatment of schizophrenia and other psychotic disorders.

Item Type:Articles
Additional Information:Open access funding provided by Karolinska Institute.
Glasgow Author(s) Enlighten ID:Millan, Dr Mark
Authors: Saarinen, M., Mantas, I., Flais, I., Ågren, R., Sahlholm, K., Millan, M. J., and Svenningsson, P.
College/School:College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
Journal Name:Neuropsychopharmacology
Publisher:Springer Nature
ISSN (Online):1740-634X
Published Online:13 September 2022
Copyright Holders:Copyright © 2022 The Authors
First Published:First published in Neuropsychopharmacology 47(13): 2319-2329
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record