title: Adenine nucleotides inhibit cytokine generation by human mast cells through a Gs-coupled receptor.
abstract: ATP and ADP activate functionally distinct G protein-coupled purinergic (P2Y) receptors. We determined the expression and function of adenine nucleotide-specific P2Y receptors on cord blood-derived human mast cells (hMCs). Human MCs expressed mRNA encoding the ADP-specific P2Y1, P2Y12, and P2Y13 receptors; the ATP/UTP-specific P2Y2 receptor; and the ATP-selective P2Y11 receptor. ADP (0.05-50 muM) induced calcium flux that was completely blocked by a P2Y1 receptor-selective antagonist and was not cross-desensitized by ATP. Low doses of ADP induced strong phosphorylation of ERK and p38 MAPKs; higher doses stimulated eicosanoid production and exocytosis. Although MAPK phosphorylation was blocked by a combination of P2Y1- and P2Y12-selective antagonists, neither interfered with secretion responses. Unexpectedly, both ADP and ATP inhibited the generation of TNF-alpha in response to the TLR2 ligand, peptidoglycan, and blocked the production of TNF-alpha, IL-8, and MIP-1beta in response to leukotriene D(4). These effects were mimicked by two ATP analogues, adenosine 5'-O-(3-thiotriphosphate) and 2',3'-O-(4-benzoyl-benzoyl) adenosine 5'-triphosphate (BzATP), but not by adenosine. ADP, ATP, adenosine 5'-O-(3-thiotriphosphate), and 2',3'-O-(4-benzoyl-benzoyl) adenosine 5'-triphosphate each induced cAMP accumulation, stimulated the phosphorylation of CREB, and up-regulated the expression of inducible cAMP early repressor, a CREB-dependent inhibitor of cytokine transcription. Human MCs thus express several ADP-selective P2Y receptors and at least one G(s)-coupled ADP/ATP receptor. Nucleotides could therefore contribute to MC-dependent microvascular leakage in atherosclerosis, tissue injury, and innate immunity while simultaneously limiting the extent of subsequent inflammation by attenuating the generation of inducible cytokines by MCs.
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA.
authors.forename: Chunli
authors.initials: C
authors.lastname: Feng
authors.forename: Amin G
authors.initials: AG
authors.lastname: Mery
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Beller
authors.forename: Christa
authors.initials: C
authors.lastname: Favot
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Boyce
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism / Q000502:physiology*; D000244:Adenosine Diphosphate / Q000378:metabolism / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000502:physiology; D002478:Cells, Cultured; D003545:Cysteine / Q000378:metabolism; D016207:Cytokines / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D015536:Down-Regulation / Q000276:immunology; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000502:physiology*; D006801:Humans; D015289:Leukotrienes / Q000378:metabolism; D008407:Mast Cells / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D058472:Receptors, Purinergic P2Y1; D058925:Receptors, Purinergic P2Y12; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism
chemical_list: D000227:Adenine Nucleotides; D016207:Cytokines; D015289:Leukotrienes; D008565:Membrane Proteins; C546382:P2RY1 protein, human; C548576:P2RY12 protein, human; C440036:P2RY13 protein, human; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D058925:Receptors, Purinergic P2Y12; C112381:cysteinyl-leukotriene; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D001619:beta-N-Acetylhexosaminidases; D019205:GTP-Binding Protein alpha Subunits, Gs; D000262:Adenylyl Cyclases; D003545:Cysteine