title: Activity of 2-substituted lysophosphatidic acid (LPA) analogs at LPA receptors: discovery of a LPA1/LPA3 receptor antagonist.
abstract: The physiological implications of lysophosphatidic acid occupancy of individual receptors are largely unknown because selective agonists/antagonists are unavailable currently. The molecular cloning of three high-affinity lysophosphatidic acid receptors, LPA1, LPA2, and LPA3, provides a platform for developing receptor type-selective ligands. Starting with an N-acyl ethanolamide phosphate LPA analog, we made a series of substitutions at the second carbon to generate compounds with varying spatial, stereochemical, and electronic characteristics. Analysis of this series at each recombinant LPA receptor using a guanosine 5'-O-(3-[35S]thio)triphosphate (GTP[gamma35S]) binding assay revealed sharp differences in activity. Our results suggest that these receptors have one spatially restrictive binding pocket that interacts with the 2-substituted moieties and prefers small hydrophobic groups and hydrogen bonding functionalities. The agonist activity predicted by the GTP[gamma35S] binding assay was reflected in the activity of a subset of compounds in increasing arterial pressure in anesthetized rats. One compound with a bulky hydrophobic group (VPC12249) was a dual LPA1/LPA3 competitive antagonist. Several compounds that had smaller side chains were found to be LPA1-selective agonists.
authors.affiliation: Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Heise
authors.forename: W L
authors.initials: WL
authors.lastname: Santos
authors.forename: A M
authors.initials: AM
authors.lastname: Schreihofer
authors.forename: B H
authors.initials: BH
authors.lastname: Heasley
authors.forename: Y V
authors.initials: YV
authors.lastname: Mukhin
authors.forename: T L
authors.initials: TL
authors.lastname: Macdonald
authors.forename: K R
authors.initials: KR
authors.lastname: Lynch
mesh_terms: D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects* / Q000503:physiopathology; D002478:Cells, Cultured; D006801:Humans; D008246:Lysophospholipids / Q000737:chemistry / Q000494:pharmacology*; D008297:Male; D008968:Molecular Conformation; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors* / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid; D013329:Structure-Activity Relationship
chemical_list: D008246:Lysophospholipids; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D049368:Receptors, Lysophosphatidic Acid