title: Identification of small-molecule agonists of human relaxin family receptor 1 (RXFP1) by using a homogenous cell-based cAMP assay.
abstract: The relaxin hormone is involved in a variety of biological functions, including female reproduction and parturition, as well as regulation of cardiovascular, renal, pulmonary, and hepatic functions. It regulates extracellular matrix remodeling, cell invasiveness, proliferation, differentiation, and overall tissue homeostasis. The G protein-coupled receptor (GPCR) relaxin family receptor 1 (RXFP1) is a cognate relaxin receptor that mainly signals through cyclic AMP second messenger. Although agonists of the receptor could have a wide range of pharmacologic utility, until now there have been no reported small-molecule agonists for relaxin receptors. Here, we report the development of a quantitative high-throughput platform for an RXFP1 agonist screen based on homogenous cell-based HTRF cyclic AMP (cAMP) assay technology. Two small molecules of similar structure were independently identified from a screen of more than 365 677 compounds. Neither compound showed activity in a counterscreen with HEK293T cells transfected with an unrelated GPCR vasopressin 1b receptor. These small-molecule agonists also demonstrated selectivity against the RXFP2 receptor, providing a basis for future medicinal chemistry optimization of selective relaxin receptor agonists.
authors.affiliation: National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA.
authors.forename: Catherine Z
authors.initials: CZ
authors.lastname: Chen
authors.forename: Noel
authors.initials: N
authors.lastname: Southall
authors.forename: Jingbo
authors.initials: J
authors.lastname: Xiao
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Marugan
authors.forename: Marc
authors.initials: M
authors.lastname: Ferrer
authors.forename: Xin
authors.initials: X
authors.lastname: Hu
authors.forename: Raisa E
authors.initials: RE
authors.lastname: Jones
authors.forename: Shu
authors.initials: S
authors.lastname: Feng
authors.forename: Irina U
authors.initials: IU
authors.lastname: Agoulnik
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Agoulnik
mesh_terms: D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism*; D057809:HEK293 Cells; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D043562:Receptors, G-Protein-Coupled / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018000:Receptors, Peptide / Q000819:agonists* / Q000378:metabolism*; D054852:Small Molecule Libraries / Q000494:pharmacology*
chemical_list: C417543:RXFP1 protein, human; C472867:RXFP2 protein, human; D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide; D054852:Small Molecule Libraries; D000242:Cyclic AMP