Discovery of (3-Phenylcarbamoyl-3,4-dihydro-2-pyrrol-2-yl)phosphonates as Imidazoline Receptor Ligands with Anti-Alzheimer and Analgesic Properties.

Imidazoline receptors (I-IRs) are altered in Alzheimer's disease (AD) patients and are associated with analgesia. I-IRs are not structurally described, and their pharmacological characterization relies on their modulation by highly affine ligands. Herein, we describe the synthesis of (3-phenylcarbamoyl-3,4-dihydro-2-pyrrol-2-yl)phosphonates endowed with relevant affinities for I-IRs in human brain tissues.

Conformation- and activation-based BRET sensors differentially report on GPCR-G protein coupling.

G protein-coupled receptors (GPCRs) regulate cellular signaling processes by coupling to diverse combinations of heterotrimeric G proteins composed of Gα, Gβ, and Gγ subunits. Biosensors based on bioluminescence resonance energy transfer (BRET) have advanced our understanding of GPCR functional selectivity. Some BRET biosensors monitor ligand-induced conformational changes in the receptor or G proteins, whereas others monitor the recruitment of downstream effectors to sites of G protein activation.

G protein-specific mechanisms in the serotonin 5-HT receptor regulate psychosis-related effects and memory deficits.

G protein-coupled receptors (GPCRs) are sophisticated signaling machines able to simultaneously elicit multiple intracellular signaling pathways upon activation. Complete (in)activation of all pathways can be counterproductive for specific therapeutic applications. This is the case for the serotonin 2 A receptor (5-HTR), a prominent target for the treatment of schizophrenia.

Ligand bias and inverse agonism on 5-HT receptor-mediated modulation of G protein activity in post-mortem human brain.

Background And Purpose: Whereas biased agonism on the 5-HT receptor has been ascribed to hallucinogenic properties of psychedelics, no information about biased inverse agonism on this receptor is available. In schizophrenia, increased 5-HT receptor constitutive activity has been suggested, highlighting the therapeutic relevance of inverse agonism. This study characterized the modulation of G protein activity promoted by different drugs, commonly considered as 5-HT receptor antagonists, in post-mortem human brain cortex.