title: Predictability of peripheral lymphocyte reduction of novel S1P1 agonists by in vitro GPCR signaling profile.
abstract: Surrogate readouts of G-protein-coupled receptor signaling pathways using highly engineered systems are often employed in the drug discovery process. However, accumulating data have demonstrated the importance of selecting relevant biological activity rather than technically facile assays to support high-throughout screening and subsequent structure-activity relationship studies. Here we report a case study using sphingosine-1-phosphate receptor 1 (S1P(1)) as the model system to compare compound activity in six different in vitro assays with their ability to predict in vivo efficacy. S1P(1) has long been validated as a therapeutic target for autoimmune diseases. In this article, in vivo and in vitro studies on 19 S1P1 agonists are reported. In vitro activities of these S1P(1) agonists, together with S1P and FTY720p, on Ca(2+) mobilization, adenylyl cyclase inhibition, extracellular signal-related kinase (ERK) phosphorylation, β-arrestin recruitment, and receptor internalization, were determined. The in vitro potency of these compounds was correlated with their ability to induce peripheral lymphocyte reduction. The results revealed that inhibition of adenylyl cyclase and induction of β-arrestin recruitment and receptor internalization are good indicators to predict in vivo efficacy, whereas induction of Ca(2+) mobilization through G(qi/5) coupling and ERK phosphorylation is irrelevant. This study demonstrated the importance of identifying an appropriate in vitro assay to predict in vivo activity based on the biological relevance in the drug discovery setting.
authors.affiliation: 1Department of Molecular Structure and Characterization, Amgen, Inc., Thousand Oaks, CA, USA.
authors.forename: Han
authors.initials: H
authors.lastname: Xu
authors.forename: Michele
authors.initials: M
authors.lastname: McElvain
authors.forename: Mike
authors.initials: M
authors.lastname: Fiorino
authors.forename: Brad
authors.initials: B
authors.lastname: Henkle
authors.forename: Lisa
authors.initials: L
authors.lastname: Sherman
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Tominey
authors.forename: Keith
authors.initials: K
authors.lastname: Kelley
authors.forename: Matt
authors.initials: M
authors.lastname: Adlam
authors.forename: Roland
authors.initials: R
authors.lastname: Bürli
authors.forename: Jerry
authors.initials: J
authors.lastname: Siu
authors.forename: Min
authors.initials: M
authors.lastname: Wong
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Cee
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism; D019390:Arrestins / Q000235:genetics / Q000378:metabolism; D001681:Biological Assay; D002118:Calcium / Q000378:metabolism; D055808:Drug Discovery; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007700:Kinetics; D008212:Lymphocyte Depletion / Q000379:methods*; D010755:Organophosphates / Q000494:pharmacology; D010766:Phosphorylation; D011237:Predictive Value of Tests; D011487:Protein Conformation; D049349:Receptors, Lysosphingolipid / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology*; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000071557:beta-Arrestins
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D019390:Arrestins; C525008:FTY 720P; D010755:Organophosphates; D049349:Receptors, Lysosphingolipid; D054852:Small Molecule Libraries; D000071557:beta-Arrestins; D048049:Extracellular Signal-Regulated MAP Kinases; D000262:Adenylyl Cyclases; D013110:Sphingosine; D002118:Calcium
keywords: G-protein coupling; S1P1; β-arrestin