title: GPR119 Agonist AS1269574 Activates TRPA1 Cation Channels to Stimulate GLP-1 Secretion.
abstract: GPR119 is a G protein-coupled receptor expressed on intestinal L cells that synthesize and secrete the blood glucose-lowering hormone glucagon-like peptide-1 (GLP-1). GPR119 agonists stimulate the release of GLP-1 from L cells, and for this reason there is interest in their potential use as a new treatment for type 2 diabetes mellitus. AS1269574 is one such GPR119 agonist, and it is the prototype of a series of 2,4,6 trisubstituted pyrimidines that exert positive glucoregulatory actions in mice. Here we report the unexpected finding that AS1269574 stimulates GLP-1 release from the STC-1 intestinal cell line by directly promoting Ca(2+) influx through transient receptor potential ankyrin 1 (TRPA1) cation channels. These GPR119-independent actions of AS1269574 are inhibited by TRPA1 channel blockers (AP-18, A967079, HC030031) and are not secondary to intracellular Ca(2+) release or cAMP production. Patch clamp studies reveal that AS1269574 activates an outwardly rectifying membrane current with properties expected of TRPA1 channels. However, the TRPA1 channel-mediated action of AS1269574 to increase intracellular free calcium concentration is not replicated by GPR119 agonists (AR231453, oleoylethanolamide) unrelated in structure to AS1269574. Using human embryonic kidney-293 cells expressing recombinant rat TRPA1 channels but not GPR119, direct TRPA1 channel activating properties of AS1269574 are validated. Because we find that AS1269574 also acts in a conventional GPR119-mediated manner to stimulate proglucagon gene promoter activity in the GLUTag intestinal L cell line, new findings reported here reveal the surprising capacity of AS1269574 to act as a dual agonist at two molecular targets (GPR119/TRPA1) important to the control of L-cell function and type 2 diabetes mellitus drug discovery research.
authors.affiliation: Departments of Medicine (O.G.C., G.G.H., M.W.R., C.A.L.), Pharmacology (G.G.H.), and Cell and Developmental Biology (M.W.R.), State University of New York, and Upstate Medical University, Syracuse, New York 13210.
authors.forename: Oleg G
authors.initials: OG
authors.lastname: Chepurny
authors.affiliation: Departments of Medicine (O.G.C., G.G.H., M.W.R., C.A.L.), Pharmacology (G.G.H.), and Cell and Developmental Biology (M.W.R.), State University of New York, and Upstate Medical University, Syracuse, New York 13210.
authors.forename: George G
authors.initials: GG
authors.lastname: Holz
authors.affiliation: Departments of Medicine (O.G.C., G.G.H., M.W.R., C.A.L.), Pharmacology (G.G.H.), and Cell and Developmental Biology (M.W.R.), State University of New York, and Upstate Medical University, Syracuse, New York 13210.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Roe
authors.affiliation: Departments of Medicine (O.G.C., G.G.H., M.W.R., C.A.L.), Pharmacology (G.G.H.), and Cell and Developmental Biology (M.W.R.), State University of New York, and Upstate Medical University, Syracuse, New York 13210.
authors.forename: Colin A
authors.initials: CA
authors.lastname: Leech
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D000081007:Cymenes; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D004983:Ethanolamines / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D005934:Glucagon / Q000378:metabolism; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects*; D017879:Isothiocyanates / Q000494:pharmacology; D008156:Luciferases / Q000378:metabolism; D039821:Monoterpenes / Q000494:pharmacology; D050505:Mutant Proteins / Q000378:metabolism; D052336:Proglucagon / Q000235:genetics / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology*; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors*; D011994:Recombinant Proteins / Q000494:pharmacology; D000074025:TRPA1 Cation Channel / Q000378:metabolism*; D014162:Transfection
chemical_list: C552740:2-(2-(4-bromophenyl)-6-methylpyrimidin-4-yl)aminoethanol; D000081007:Cymenes; D004983:Ethanolamines; D017879:Isothiocyanates; D039821:Monoterpenes; D050505:Mutant Proteins; D011743:Pyrimidines; D043562:Receptors, G-Protein-Coupled; D011994:Recombinant Proteins; D000074025:TRPA1 Cation Channel; D052336:Proglucagon; C041942:2,3,4-tri-O-acetylarabinopyranosyl isothiocyanate; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; C073316:carvacrol; D000242:Cyclic AMP; D008156:Luciferases; D017868:Cyclic AMP-Dependent Protein Kinases; D002118:Calcium