title: Structure-activity relationship studies toward the discovery of selective apelin receptor agonists.
abstract: Apelin is the endogenous ligand for the previously orphaned G protein-coupled receptor APJ. Apelin and its receptor are widely distributed in the brain, heart, and vasculature, and are emerging as an important regulator of body fluid homeostasis and cardiovascular functions. To further progress in the pharmacology and the physiological role of the apelin receptor, the development of small, bioavailable agonists and antagonists of the apelin receptor, is crucial. In this context, E339-3D6 (1) was described as the first nonpeptidic apelin receptor agonist. We show here that 1 is actually a mixture of polymethylated species, and we describe an alternative and versatile solid-phase approach that allows access to highly pure 27, the major component of 1. This approach was also applied to prepare a series of derivatives in order to identify the crucial structural determinants required for the ligand to maintain its affinity for the apelin receptor as well as its capacity to promote apelin receptor signaling and internalization. The study of the structure-activity relationships led to the identification of ligands 19, 21, and 38, which display an increased affinity compared to that of 27. The latter and 19 behave as full agonists with regard to cAMP production and apelin receptor internalization, whereas 21 is a biased agonist toward cAMP production. Interestingly, the three ligands display a much higher stability in mouse plasma (T1/2 > 10 h) than the endogenous apelin-17 peptide 2 (T1/2 < 4 min).
authors.affiliation: Laboratoire d'Innovation Thérapeutique, UMR7200 CNRS/Université de Strasbourg, Labex Medalis, Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Margathe
authors.forename: Xavier
authors.initials: X
authors.lastname: Iturrioz
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Alvear-Perez
authors.forename: Claire
authors.initials: C
authors.lastname: Marsol
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Riché
authors.forename: Hadjila
authors.initials: H
authors.lastname: Chabane
authors.forename: Nassera
authors.initials: N
authors.lastname: Tounsi
authors.forename: Maxime
authors.initials: M
authors.lastname: Kuhry
authors.forename: Denis
authors.initials: D
authors.lastname: Heissler
authors.forename: Marcel
authors.initials: M
authors.lastname: Hibert
authors.forename: Catherine
authors.initials: C
authors.lastname: Llorens-Cortes
authors.forename: Dominique
authors.initials: D
authors.lastname: Bonnet
mesh_terms: D000818:Animals; D000075244:Apelin Receptors; D016466:CHO Cells; D003412:Cricetulus; D000242:Cyclic AMP / Q000378:metabolism; D004151:Dipeptides / Q000737:chemistry* / Q000494:pharmacology*; D055808:Drug Discovery; D005452:Fluoresceins / Q000737:chemistry* / Q000494:pharmacology*; D008024:Ligands; D051379:Mice; D015394:Molecular Structure; D010949:Plasma / Q000737:chemistry; D051381:Rats; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000819:agonists* / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013329:Structure-Activity Relationship
chemical_list: D000075244:Apelin Receptors; C491284:Aplnr protein, rat; D004151:Dipeptides; C549403:E339-3D6 compound; D005452:Fluoresceins; D008024:Ligands; D044140:Receptor, Angiotensin, Type 1; D043562:Receptors, G-Protein-Coupled; D000242:Cyclic AMP