ABSTRACT
G protein-coupled receptors (GPCRs) exist as collections of conformations in equilibrium, and the efficacy of drugs has been proposed to be associated with their absolute and relative affinities for these different conformations. The serotonin 2A (5-HT2A) receptor regulates multiple physiological functions, is involved in the pathophysiology of schizophrenia, and serves as an important target of atypical antipsychotic drugs. This receptor was one of the first GPCRs for which the functional selectivity phenomenon was observed, with its various ligands exerting differential effects on the phospholipase A2 (PLA2) and phospholipase C (PLC) signaling pathways. We aimed to develop a multiplex functional assay in 96-well plates for the simultaneous measurement of the PLA2 and PLC pathways coupled to 5-HT2A receptors; this approach enables the detection of either functional selectivity or cooperativity phenomena in early drug screening stages. The suitability of the method for running screening campaigns was tested using the Prestwick Chemical Library, and 22 confirmed hits with activities of more than 90% were identified; 11 of these hits produced statistically significant differences between the two effector pathways. Thus, we have developed a miniaturized multiplex assay in 96-well plates to measure functional selectivity for 5-HT2A receptors in the early stages of the drug discovery process.
Subject(s)
Antipsychotic Agents/isolation & purification , High-Throughput Screening Assays/methods , Receptors, Serotonin, 5-HT2/metabolism , Schizophrenia/drug therapy , Serotonin 5-HT2 Receptor Antagonists/isolation & purification , Antipsychotic Agents/therapeutic use , Binding Sites , Drug Evaluation, Preclinical , Humans , Ligands , Phospholipases A2/metabolism , Schizophrenia/metabolism , Serotonin 5-HT2 Receptor Antagonists/metabolism , Signal Transduction , Type C Phospholipases/metabolismABSTRACT
A forward chemical genetic approach was followed to discover new targets and lead compounds for Parkinson's disease (PD) treatment. By analysis of the cell protection produced by some small molecules, a diphenyl sulfide compound was revealed to be a new phosphodiesterase 7 (PDE7) inhibitor and identified as a new hit. This result allows us to confirm the utility of PDE7 inhibitors as a potential pharmacological treatment of PD. On the basis of these data, a diverse family of diphenyl sulfides has been developed and pharmacologically evaluated in the present work. Moreover, to gain insight into the safety of PDE7 inhibitors for human chronic treatment, we evaluated the new compounds in a surrogate emesis model, showing nonemetic effects.