title: Strategy for the identification of GPR23/LPA4 receptor agonists and inverse agonists.
abstract: Lysophosphatidic acid (LPA) is a bioactive phospholipid that signals through G-protein-coupled receptors to produce a range of biological responses. A recently reported LPA receptor GPR23 (LPA4 receptor) has a low homology to the LPA(1-3) receptors identified previously. In Chinese hamster ovary cells expressing the human GPR23, LPA induced an increase in cellular cyclic adenosine monophosphate (cAMP) and calcium levels. GPR23-selective agonists or antagonists have not been reported previously. Such ligands, if available, would be valuable tools for studying the functions of this receptor. Here we report the identification of novel GPR23 agonists, inverse agonists, and a negative modulator from 2 high-throughput screens, a beta-lactamase reporter screen, and a [3H]LPA-binding screen. Several screening hits were selected for mechanism of action studies using the beta-lactamase reporter assay and a cAMP assay. An evaluation of their selectivity at the other LPA receptors was also conducted. This study demonstrates a strategy for the identification of GPR23 agonists and inverse agonists. We believe the strategy employed here is applicable to other constitutively active GPCRs.
authors.affiliation: Lead Discovery, Amgen Inc., Thousand Oaks, California 91320, USA.
authors.forename: Soo Hang
authors.initials: SH
authors.lastname: Wong
authors.forename: Rommel
authors.initials: R
authors.lastname: Mallari
authors.forename: Melissa
authors.initials: M
authors.lastname: Graham
authors.forename: Larissa
authors.initials: L
authors.lastname: Atangan
authors.forename: Shu-Chen
authors.initials: SC
authors.lastname: Lu
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Zhao
authors.forename: Wei
authors.initials: W
authors.lastname: Gu
authors.forename: Paul H
authors.initials: PH
authors.lastname: Lee
mesh_terms: D000818:Animals; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D000242:Cyclic AMP / Q000378:metabolism; D054313:Drug Agonism; D054314:Drug Inverse Agonism; D057166:High-Throughput Screening Assays; D006801:Humans; D008024:Ligands; D008246:Lysophospholipids / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D049368:Receptors, Lysophosphatidic Acid / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: C082320:LPAR4 protein, human; D008024:Ligands; D008246:Lysophospholipids; D010743:Phospholipids; D049368:Receptors, Lysophosphatidic Acid; D018048:Receptors, Purinergic P2; D000242:Cyclic AMP; D001618:beta-Lactamases; C032881:lysophosphatidic acid; D002118:Calcium