title: Biased signaling of lipids and allosteric actions of synthetic molecules for GPR119.
abstract: GPR119 is a Gαs-coupled lipid-sensor in the gut, where it mediates release of incretin hormones from the enteroendocrine cells and in pancreatic α-cells, where it releases insulin. Naturally occurring lipids such as monoacylglycerols (MAGs) and N-acylethanolamines (NAEs), like oleoylethanolamide (OEA), activate GPR119, and multiple synthetic ligands have been described. Here, we extend the GPR119 signaling profile to Gαq and Gαi in addition to β-arrestin recruitment and the downstream transcription factors CRE (cAMP response element), SRE (serum response element) and NFAT (nuclear factor of activated T cells). The endogenous OEA and the synthetic AR231453 were full agonists in all pathways except for NFAT, where no ligand-modulation was observed. The potency of AR231453 varied <16-fold (EC50from 6 to 95nM) across the different signaling pathways, whereas that of OEA varied >175-fold (from 85nM to 15μM) indicating a biased signaling for OEA. The degree of constitutive activity was 1-10%, 10-30% and 30-70% of OEA-induced Emaxin Gαi, Gαq and Gαs-driven pathways, respectively. This coincided with the lowest and highest OEA potency observed in Gαi and Gαs-driven pathways, respectively. Incubation for 2h with the 2-MAG-lipase inhibitor JZL84 doubled the constitutive activity, indicating that endogenous lipids contribute to the apparent constitutive activity. Finally, besides being an agonist, AR231453 acted as a positive allosteric modulator of OEA and increased its potency by 54-fold at 100nM AR231453. Our studies uncovering broad and biased signaling, masked constitutive activity by endogenous MAGs, and ago-allosteric properties of synthetic ligands may explain why many GPR119 drug-discovery programs have failed so far.
authors: Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
authors: Helle A
authors: HA
authors: Hassing
authors: Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
authors: Suzan
authors: S
authors: Fares
authors: Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
authors: Olav
authors: O
authors: Larsen
authors: Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
authors: Hamideh
authors: H
authors: Pad
authors: Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark; Section for Metabolic Receptology and Enteroendocrinology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
authors: Maria
authors: M
authors: Hauge
authors: Department of Medicinal Chemistry, Arena Pharmaceutical, San Diego, USA.
authors: Robert M
authors: RM
authors: Jones
authors: Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark; Section for Metabolic Receptology and Enteroendocrinology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
authors: Thue W
authors: TW
authors: Schwartz
authors: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark. Electronic address: hsh@sund.ku.dk.
authors: Harald S
authors: HS
authors: Hansen
authors: Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark. Electronic address: rosenkilde@sund.ku.dk.
authors: Mette M
authors: MM
authors: Rosenkilde
mesh_terms: D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D050356:Lipid Metabolism / Q000187:drug effects; D015394:Molecular Structure; D009829:Oleic Acids / Q000737:chemistry / Q000494:pharmacology; D010069:Oxadiazoles / Q000737:chemistry / Q000494:pharmacology; D011743:Pyrimidines / Q000737:chemistry / Q000494:pharmacology; D043562:Receptors, G-Protein-Coupled / Q000819:agonists* / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: C521085:AR 231453; C519854:GPR119 protein, human; D009829:Oleic Acids; C440229:Oleylethanolamide; D010069:Oxadiazoles; D011743:Pyrimidines; D043562:Receptors, G-Protein-Coupled
keywords: AR231453; AR231453 (PubChem CID: 24939268); Allosteric action; Biased signaling; Diabetes/obesity treatment; GPR119; Insulinotropic effects; JZL184 (PubChem CID: 25021165); N-oleylethanolamine (PubChem CID: 5283454); Oleoylethanolamide; URB597 (PubChem CID: 1383884)